WorldWideScience

Sample records for luminosity performance studies

  1. LHC Luminosity Performance

    CERN Document Server

    AUTHOR|(CDS)2091107; Fuchsberger, Kajetan; Papotti, Giulia

    This thesis adresses several approaches with the common goal of assessing, understanding and improving the luminosity of the Large Hadron Collider (LHC). To better exploit existing margins for maximum luminosity while fulfilling the requirements of the LHC experiments, new techniques for luminosity levelling are studied and developed to an operational state, such as changing the crossing angle or $\\beta^*$ (beam size) at the interaction points with the beams in collisions. In 2017 LHC operation, the crossing angle reduction in collisions improved the integrated luminosity by $\\mathrm{\\sim} 2\\,\\mathrm{fb^{-1}}$ ($\\mathrm{\\sim} 4\\,\\mathrm{\\%}$ of the yearly production). For additional diagnostics, a new method for measuring beam sizes and orbits for each circulating bunch using the luminosity measurement during beam separation scans is shown. The results of these Emittance Scans improved the understanding of the LHC luminosity reach and of the orbit offsets introduced by beam-beam long-range effects.

  2. Multi-Bunch Simulations of the ILC for Luminosity Performance Studies

    CERN Document Server

    White, Glen; Walker, Nicholas J

    2005-01-01

    To study the luminosity performance of the International Linear Collider (ILC) with different design parameters, a simulation was constructed that tracks a multi-bunch representation of the beam from the Damping Ring extraction through to the Interaction Point. The simulation code PLACET is used to simulate the LINAC, MatMerlin is used to track through the Beam Delivery System and GUINEA-PIG for the beam-beam interaction. Included in the simulation are ground motion and wakefield effects, intra-train fast feedback and luminosity-based feedback systems. To efficiently study multiple parameters/multiple seeds, the simulation is deployed on the Queen Mary High-Throughput computing cluster at Queen Mary, University of London, where 100 simultaneous simulation seeds can be run.

  3. The performance of the CDF luminosity monitor

    CERN Document Server

    Acosta, D; Konigsberg, J; Korytov, A; Mitselmakher, G; Necula, V; Nomerotski, A; Pronko, A; Sukhanov, A; Safonov, A; Tsybychev, D; Wang, S M; Wong, M

    2002-01-01

    We describe the initial performance of the detector used for the luminosity measurement in the CDF experiment in Run II at the Tevatron. The detector consists of low-mass gaseous Cherenkov counters with high light yield (approx 100 photoelectrons) and monitors the process of inelastic pp-bar scattering. It allows for several methods of precise luminosity measurements at peak instantaneous luminosities of 2x10 sup 3 sup 2 cm sup - sup 2 s sup - sup 1 , corresponding to an average of six pp-bar interactions per bunch crossing.

  4. Parametric study on the thermal performance of beam screen samples of the High-Luminosity LHC upgrade

    Science.gov (United States)

    Borges de Sousa, P.; Morrone, M.; Hovenga, N.; Garion, C.; van Weelderen, R.; Koettig, T.; Bremer, J.

    2017-12-01

    The High-Luminosity upgrade of the Large Hadron Collider (HL-LHC) will increase the accelerator’s luminosity by a factor 10 beyond its original design value, giving rise to more collisions and generating an intense flow of debris. A new beam screen has been designed for the inner triplets that incorporates tungsten alloy blocks to shield the superconducting magnets and the 1.9 K superfluid helium bath from incoming radiation. These screens will operate between 60 K and 80 K and are designed to sustain a nominal head load of 15 Wm-1, over 10 times the nominal heat load for the original LHC design. Their overall new and more complex design requires them and their constituent parts to be characterised from a thermal performance standpoint. In this paper we describe the experimental parametric study carried out on two principal thermal components: a representative sample of the beam screen with a tungsten-based alloy block and thermal link and the supporting structure composed of an assembly of ceramic spheres and titanium springs. Results from both studies are shown and discussed regarding their impact on the baseline considerations for the thermal design of the beam screens.

  5. High Luminosity LHC Studies with ATLAS

    CERN Document Server

    Duncan, Anna Kathryn; The ATLAS collaboration

    2017-01-01

    The High-Luminosity LHC aims to provide a total integrated luminosity of 3000fb$^{-1}$ from proton-proton collisions at $\\sqrt{s}$ = 14 TeV over the course of $\\sim$ 10 years, reaching instantaneous luminosities of up to L = 7.5 $\\times$ 1034cm$^{-2}s$^{-1}$, corresponding to an average of 200 inelastic p-p collisions per bunch crossing ($\\mu$ = 200). Fast simulation studies have been carried out to evaluate the prospects of various benchmark physics analyses to be performed using the upgraded ATLAS detector with the full HL-LHC dataset. The performance of the upgrade has been estimated in full simulation studies, assuming expected HL-LHC conditions. This talk will focus on the results of physics prospects studies for benchmark analyses involving in particular boosted hadronic objects (e.g. ttbar resonances, HH resonances), and on results of Jet/EtMiss studies of jet performance and pileup mitigation techniques that will be critical in HL-LHC analyses.

  6. Notes on LEP luminosity performance in July and August

    CERN Document Server

    Assmann, R W

    1998-01-01

    The LEP luminosity performance at 94.5 GeV is examined for two periods of the 1998 run. The analysis is meant to complement other ongoing studies. The studies presented here analyze the performance in terms of specific luminosity. The large amount of available data is filtered through quality cuts and appropriate averaging and binning algorithms. The results show that the beam-beam limit is being a pproached in high current LEP operation. This is seen in an increase of vertical beam size and a reduction of specific luminosity with current. Though the effect is clear for both analyzed periods of time, it is also shown that the full beam-beam limit is not yet reached. Over a fill the reduction of specific luminosity with beam current is less than half of the one expected in the fully beam-beam limited regime. It is shown that the measured positron lifetime can be fully explained from the beam-beam interaction. It turns out that the beam lifetime is indeed an excellent way to measure the ab solute luminosity in ...

  7. LHCb: LHCb Muon System Performance at High Luminosity

    CERN Multimedia

    Pinci, D

    2013-01-01

    The LHCb detector was conceived to operate with an average Luminosity of $2 \\times 10^{32}$ cm$^{-2}$ s$^{-1}$. During the last year of LHC run, the whole apparatus has shown to be able to perfectly acquire and manage data produced at a Luminosity as high as $4 \\times 10^{32}$ cm$^{-2}$ s$^{-1}$. In these conditions, all sub-detectors operated at average particle rates higher than the design ones and in particular the Multi-Wire Proportional Chambers equipping the Muon System had to sustain a particle rate as high as 250 kHz/cm$^{2}$. In order to study the possibility of increasing the Luminosity of operation of the whole experiment several tests were performed. The effective beam Luminosity at the interaction point of LHCb was increased in several steps up to $10^{33}$ cm$^{-2}$ s$^{-1}$ and in each step the behavior of all the detectors in the Muon System was recorded. The data analysis has allowed to study the performance of the Muon System as a function of the LHC Luminosity and the results are r...

  8. Luminosity performance reach after LS1

    International Nuclear Information System (INIS)

    Herr, W.

    2012-01-01

    Based on past experience (2010/2011), in particular expected limitations from beam-beam effects, and taking into account the expected beam quality from the LHC injectors, the peak and integrated luminosity at top energy is discussed for different scenarios (e.g. bunch spacing, beta*). In particular it will be shown which are the key parameters to reach the nominal luminosity and it is also shown that peak luminosities two times larger than nominal (or higher) are possible. Possible test in 2012 are discussed

  9. Evolution of the CMS ECAL Performance and R&D Studies for Calorimetry Options at High Luminosity LHC

    CERN Document Server

    Lucchini, Marco Toliman; Auffray, Etiennette

    During the past years the Large Hadron Collider (LHC) at CERN operated with a maximum center-of-mass energy of $\\sqrt{s} = 8$~TeV, a peak luminosity of around $7\\times 10^{33}$~cm$^{-2}$s$^{-1}$ and collected about $23$~fb$^{-1}$ of data which lead to the discovery of a Higgs Boson in July 2012. To further constrain the properties of the newly discovered Higgs boson, the decision to extend the LHC program has recently been made. In this framework, a major upgrade of the beam optics in the interaction region will take place around 2022 to achieve a leveled peak luminosity of $\\mathcal{L} = 5\\times10^{34}$~cm$^{-2}$s$^{-1}$. These will be the operating conditions during the High Luminosity LHC (HL-LHC) which is expected to deliver an integrated luminosity of 3000~fb$^{-1}$ by 2035. During HL-LHC phase the radiation levels will become much higher with respect to the nominal values for which the CMS detector was designed. Therefore it is of crucial importance to identify and quantify the effects ofradiation damag...

  10. Performance of the new high precision luminosity monitor of DELPHI

    International Nuclear Information System (INIS)

    Alvsvaag, S.J.; Maeland, O.A.; Klovning, A.; Benvenuti, A.C.; Giordano, V.; Guerzoni, M.; Navarria, F.L.; Perrotta, A.; Camporesi, T.; Obraztsov, V.; Paganoni, M.; Vallazza, E.; Bozzo, M.; Cereseto, R.; Barreira, G.; Espirito Santo, M.C.; Maio, A.; Onofre, A.; Peralta, L.; Pimenta, M.; Tome, B.; Carling, H.; Falk, E.; Hedberg, V.; Jarlskog, G.; Kronkvist, I.; Bonesini, M.; Chignoli, F.; Ferrari, P.; Gumenyuk, S.; Leoni, R.; Mazza, R.; Negri, P.; Petrovykh, L.; Terranova, F.; Dharmasiri, D.R.; Nossum, B.; Read, A.L.; Skaali, B.; Rohne, O.; Castellani, L.; Pegoraro, M.; Fenyuk, A.; Ivanyushenkov, I.; Karyukhin, A.; Konopliannikov, A.; Shalanda, N.; Sen'ko, V.; Vlasov, E.; Zaitsev, A.; Bigi, M.; Cassio, V.; Gamba, D.; Gouz, I.; Migliore, E.; Romero, A.; Simonetti, L.; Trapani, P.P.; Bari, M.; Della Ricca, G.; Lanceri, L.; Poropat, P.; Prest, M.

    1997-01-01

    The STIC calorimeter was installed in the DELPHI detector in 1994. The main goal is to measure the luminosity with an accuracy better than 0.1%. The calorimeter was built using the ''Shashlik'' technique. The light is collected by wavelength shifting fibers and readout by phototetrodes that can operate inside the magnetic field. The detector performance during the 1994-1995 data taking is presented. The different contributions to the systematic error on the luminosity measurement are discussed. (orig.)

  11. Detector Performance and Upgrade Plans of the Pixel Luminosity Telescope for Online per-Bunch Luminosity Measurement at CMS

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The Pixel Luminosity Telescope (PLT) is a dedicated system for luminosity measurement at the CMS experiment using silicon pixel sensors. It was installed during LS1 and has been providing luminosity measurements throughout Run 2. The online bunch-by-bunch luminosity measurement employs the "fast-or" capability of the pixel readout chip (PSI46) to quickly identify likely tracks at the full 40MHz interaction rate. In addition, the full pixel information is read out at a lower rate, allowing for more detailed offline analysis. In this talk, we will present details of the commissioning, performance and operational history of the currently installed hardware and upgrade plans for LS2.

  12. Performance of the Pixel Luminosity Telescope for Luminosity Measurement at CMS during Run 2

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The Pixel Luminosity Telescope (PLT) is a dedicated system for luminosity measurement at the CMS experiment using silicon pixel sensors arranged into "telescopes", each consisting of three planes. It was installed during LS1 at the beginning of 2015 and has been providing online and offline luminosity measurements throughout Run 2. The online bunch-by-bunch luminosity measurement employs the "fast-or" capability of the pixel readout chip (PSI46) to identify events where a hit is registered in all three sensors in a telescope corresponding primarily to tracks originating from the interaction point. In addition, the full pixel information is read out at a lower rate, allowing for the calculation of corrections to the online luminosity from effects such as the miscounting of tracks not originating from the interaction point and detector efficiency. In this talk, we will present results from 2016 running and preliminary 2017 results, including commissioning and operational history, luminosity calibration using Va...

  13. Performance of the Pixel Luminosity Telescope for Luminosity Measurement at CMS during Run2

    CERN Document Server

    Lujan, Paul Joseph

    2017-01-01

    The Pixel Luminosity Telescope (PLT) is a dedicated system for luminosity measurement at the CMS experiment using silicon pixel sensors arranged into telescopes, each consisting of three sensor planes. It was installed in CMS at the beginning of 2015 and has been providing online and offline luminosity measurements throughout Run 2 of the LHC. The online bunch-by-bunch luminosity measurement employs the fast-or capability of the pixel readout chip to identify events where a hit is registered in all three sensors in a telescope, corresponding primarily to tracks originating from the interaction point. In addition, the full pixel information is read out at a lower rate, allowing for the calculation of corrections to the online luminosity from effects such as the miscounting of tracks not originating from the interaction point and detector efficiency. This paper presents results from the 2016 running of the PLT, including commissioning and operational history, luminosity calibration using Van der Meer scans, and...

  14. LHC abort gap cleaning studies during luminosity operation

    CERN Document Server

    Bartmann, W; Bracco, C; Bravin, E; Goddard, B; Höfle, W; Jacquet, D; Jeff, A; Kain, V; Meddahi, M; Roncarolo, F; Uythoven, J; Valuch, D; Gianfelice-Wendt, E

    2012-01-01

    The presence of significant intensities of un-bunched beam is a potentially serious issue in the LHC. Procedures using damper kickers for cleaning both the Abort Gap (AG) and the buckets targeted for injection, are currently in operation at flat bottom. Recent observations of relatively high population of the AG during physics runs brought up the need for AG cleaning during luminosity operation. In this paper the results of experimental studies performed in October 2011 are presented.

  15. Precision Crystal Calorimetry at High Energy and High Luminosity CMS ECAL Performance at 13 TeV and Upgrade Test Beam studies

    CERN Document Server

    Micheli, Francesco

    2016-01-01

    The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid Experiment (CMS) is operating at the Large Hadron Collider (LHC) in 2016 with proton-proton collisions at 13 TeV center-of-mass energy and at a bunch spacing of 25 ns. The instantaneous luminosity during this LHC Run II is expected to exceed 10^34 cm-2s-1 in routine operation. In this talk we present detailed performance results from the 2016 data taking period. At the higher center of mass energy and with the rapidly growing data set the performance at higher electron and photon energies becomes crucial. The CMS ECAL design ensures that its superb performance extends over a very wide range of energies up to electron and photon energies of 1 TeV and beyond. This is of crucial importance for physics searches beyond the standard model. We discuss how the triggering, event reconstruction and calibration of the ECAL detector is performing in this new regime. The impact of the ECAL performance on resonance searches in the mass range up to 1 TeV wi...

  16. LHCb Upgrades and operation at 1034 cm-2 s-1 luminosity –A first study

    CERN Document Server

    Efthymiopoulos, Ilias; Baglin, Vincent; Burkhardt, Helmut; Cerutti, Francesco; Claudet, Serge; Di Girolamo, Beniamino; De Maria, Riccardo; Esposito, Luigi Salvatore; Karastathis, Nikos; Lindner, Rolf; Papaphilippou, Yannis; Pellegrini, Dario; Redaelli, Stefano; Roesler, Stefan; Sanchez Galan, Francisco; Thomas, Eric; Tsinganis, Andrea; Wollmann, Daniel; Wilkinson, Guy; Schwarz, Philip; CERN. Geneva. ATS Department

    2018-01-01

    Presently, the LHCb experiment at IP8 operates at reduced luminosity (~4.0 1032 cm-2 s-1) compared to ATLAS and CMS experiments. The LHCb collaboration is proposing an Upgrade II during HL-LHC operation, where the beams at IP8 will collide at high-luminosity (~1-2 1034 cm-2 s-1), comparable to the present high-luminosity regions IP1&IP5. The LHCb experiment aims to collect more than 300 fb-1 by the end of the HL-LHC operation. A feasibility study of operating IP8 at high-luminosity whilst preserving the performance at IP1 and IP5 and on the impact to the LHC machine and experimental cavern was done. Optics studies shows that solutions allowing to reach an integrated luminosity of 40 to 50 fb-1 per year to LHCb/IP8 at the cost of a reduction of about 5% in the integrated luminosity of the main experiments ATLAS and CMS, under the assumption that there are no lifetime limitations besides burn-off, are feasible. Energy deposition in the machine elements of the IR straight section 8 and LHC infrastructure and...

  17. Study of the mass-luminosity in binary stars

    International Nuclear Information System (INIS)

    Gimenez, A.; Zamorano, J.

    1986-01-01

    The results of a study of the mass-luminosity relation for main-sequence stars are presented as obtained from the latest data provided by the analysis of eclipsing and visual binary systems. The derived numerical values are discussed in light of their practical use and possible parametrizations indicated by internal structure homologous models. Finally, the astrophysical significance of our results is evaluated and they are compared to available theoretical models. (author)

  18. Dynamic Aperture Studies for the LHC High Luminosity Lattice

    CERN Document Server

    De Maria, R; Giovannozzi, Massimo; Mcintosh, Eric; Cai, Y; Nosochkov, Y; Wang, M H

    2015-01-01

    Since quite some time, dynamic aperture studies have been undertaken with the aim of specifying the required field quality of the new magnets that will be installed in the LHC ring in the framework of the high-luminosity upgrade. In this paper the latest results concerning the specification work will be presented, taking into account both injection and collision energies and the field quality contribution from all the magnets in the newly designed interaction regions.

  19. Beam dynamics studies to develop LHC luminosity model

    CERN Document Server

    Campogiani, Giovanna; Papaphilippou, Ioannis

    The thesis project aims at studying the different physical processes that are impacting luminosity, one of the key figures of merit of a collider operation. In particular the project focuses on extracting the most relevant parameters for the high-energy part of the model, which is mostly dominated by the beam-beam effect. LHC luminosity is degraded by parasitic collisions that reduce the beam lifetime and the particles stability in the collider. This instability is due to the non-linear effects of one beam electromagnetic field on another in the interaction region. Such parasitic encounters can be as many as 16 per interaction region, piling up to around 180 000 per second. Our goal is to study the evolution of charge density distribution in the beam, by tracking particles through a symplectic integrator that includes the beam-beam effect. In particular we want to obtain data on the halo particles, which are more sensible to instability, to better characterise the beam lifetime and monitor the luminosity evol...

  20. Run II performance of luminosity and beam condition monitors at CMS

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Jessica Lynn [DESY, Hamburg (Germany)

    2016-07-01

    The BRIL (Beam Radiation Instrumentation and Luminosity) system of CMS consists of instrumentation to measure the luminosity online and offline, and to monitor the LHC beam conditions inside CMS. An accurate luminosity measurement is essential to the CMS physics program, and measurement of the beam background is necessary to ensure safe operation of CMS. Many of the BRIL subsystems have been upgraded and others have been added for LHC Run II to complement the existing measurements. The beam condition monitor (BCM) consists of several sets of diamond sensors used to measure online luminosity and beam background with a single-bunch-crossing resolution. The BCM also detects when beam conditions become unfavorable for CMS running and may trigger a beam abort to protect the detector. The beam halo monitor (BHM) uses quartz bars to measure the background of the incoming beams at larger radii. The pixel luminosity telescope (PLT) consists of telescopes of silicon sensors designed to provide a CMS online and offline luminosity measurement. In addition, the forward hadronic calorimeter (HF) delivers an independent luminosity measurement, making the whole system robust and allowing for cross-checks of the systematics. An overview of the performance during 2015 LHC running for the new/updated BRIL subsystems will be given, including the uncertainties of the luminosity measurements.

  1. Abort Gap Cleaning tests performed on 13 October 2011 during luminosity operation

    CERN Document Server

    Boccardi, A; Jeff, A; Roncarolo, F; Höfle, W; Valuch, D; Kain, V; Goddard, B; Meddahi, M; Uythoven, J; Gianfelice-Wendt, E

    2012-01-01

    Following the abort gap cleaning tests performed on 7 October 2011 [1] additional tests were carried out on 13 October 2011 to further investigate the effects of the cleaning on the luminosity production. The abort gap cleaning parameters (strength and duration of the beam excitation kick) were varied and the cleaning effectiveness measured together with the change in luminosity. The outcome is summarised in this note.

  2. Upgrade of ATLAS and CMS for High Luminosity LHC: Detector performance and Physics potential

    International Nuclear Information System (INIS)

    Testa, M.

    2017-01-01

    The High Luminosity Large Hadron Collider (HL-LHC) is expected to start providing proton-proton collisions by 2026. In the following 10 years it will deliver about 3000 fb −1 of integrated luminosity, more than a factor 10 of the data that will be collected by the end of Run3 at LHC in 2023. For such amount of data, an instantaneous luminosity of ∼ 7.5 × 10 34 cm −2 s −1 is needed. At this luminosity an unprecedented average number of pile-up collision per bunch crossing of 200 is expected. The ATLAS and CMS detectors will be upgraded to fully exploit the HL-LHC potential in this harsh environment. In this document the performances of the ATLAS and CMS upgraded detectors will be described. Their impact on crucial measurements of the Higgs boson sector, of the vector boson fusion process and on new physics searches, will be reported as well.

  3. High luminosity μ+ μ- collider: Report of a feasibility study

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.; Tollestrup, A.; Sessler, A.

    1996-12-01

    Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity μ + μ - colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are analyzed. Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. We briefly mention the luminosity requirements of hadrons and lepton machines and their high-energy-physics advantages and disadvantages in reference to their effective center of mass energy. Finally, we present an R ampersand D plan to determine whether such machines are practical

  4. Impact of detector solenoid on the Compact Linear Collider luminosity performance

    CERN Document Server

    Inntjore Levinsen, Y.; Tomás, Rogelio; Schulte, Daniel

    2014-05-27

    In order to obtain the necessary luminosity with a reasonable amount of beam power, the Compact Linear Collider (CLIC) design includes an unprecedented collision beam size of {\\sigma} = 1 nm vertically and {\\sigma} = 45 nm horizontally. Given the small and very flat beams, the luminosity can be significantly degraded from the impact of the experimental solenoid field in combination with a large crossing angle. Main effects include y-x'-coupling and increase of vertical dispersion. Additionally, Incoherent Synchrotron Radiation (ISR) from the orbit deflection created by the solenoid field, increases the beam emittance. A detailed study of the impact from a realistic solenoid field and the associated correction techniques for the CLIC Final Focus is presented. In particular, the impact of techniques to compensate the beam optics distortions due to the detector solenoid main field and its overlap with the final focus magnets are shown. The unrecoverable luminosity loss due to ISR has been evaluated, and found to...

  5. EU supports the LHC high-luminosity study

    CERN Document Server

    CERN Bulletin

    2011-01-01

    The design collision energy and luminosity of the LHC are already at record numbers, making the machine one of the most complex scientific instruments ever built. However, to extend its discovery potential even further, a major upgrade of the LHC will be required around 2020. This will increase its average luminosity by a factor of 5 to 10 beyond its design value. Fifteen worldwide institutions and the European Union are supporting the initial design phase of the project through the HiLumi LHC programme, whose kick-off meeting will take place on 16-18 November.   The CERN team that has successfully built and tested the Short Magnet Coil – a small 40 cm long magnet capable of producing a 12.5 T magnetic field. The upgrade of the LHC will require about 10 years of design, construction and implementation. The new machine configuration will be called “High Luminosity LHC” (HL-LHC). The similarly named “HiLumi LHC” is the EU programme that supports...

  6. Performance of the first short model 150 mm aperture Nb$_3$Sn Quadrupole MQXFS for the High- Luminosity LHC upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Chlachidze, G.; et al.

    2016-08-30

    The US LHC Accelerator Research Program (LARP) and CERN combined their efforts in developing Nb3Sn magnets for the High-Luminosity LHC upgrade. The ultimate goal of this collaboration is to fabricate large aperture Nb3Sn quadrupoles for the LHC interaction regions (IR). These magnets will replace the present 70 mm aperture NbTi quadrupole triplets for expected increase of the LHC peak luminosity by a factor of 5. Over the past decade LARP successfully fabricated and tested short and long models of 90 mm and 120 mm aperture Nb3Sn quadrupoles. Recently the first short model of 150 mm diameter quadrupole MQXFS was built with coils fabricated both by the LARP and CERN. The magnet performance was tested at Fermilab’s vertical magnet test facility. This paper reports the test results, including the quench training at 1.9 K, ramp rate and temperature dependence studies.

  7. Radio and optical studies of high luminosity Iras galaxies

    International Nuclear Information System (INIS)

    Wolstencroft, R.D.; Parker, Q.A.; Savage, A.; MacGillivray, H.T.; Leggett, S.K.; Clowes, R.G.; Unger, S.W.; Pedlar, A.; Heasley, J.N.; Menzies, J.W.

    1987-01-01

    Follow-up observations of a complete sample of 154 IRAS galaxies, optically identified down to B=21, indicate that between 3 and 9% of the sample are ultraluminous depending on the choice of H 0 . VLA observations at 20 cm of the complete sample indicate that 85% are detected above 1mJy and for the most part the radio emission is centrally concentrated. The tight linear relation between radio and infrared luminosities is valid at the highest luminosities. Of the 11 most luminous objects one is a quasar: it fits the radio infrared relation very well which suggests that the infrared and radio emission has the same origin as in the other IRAS galaxies, ie. it probably originates primarily in regions of star formation in the host galaxy. The other 10 very luminous galaxies are either close but resolved mergers or double galaxies, presumably interacting. Radio observations of the 10 original empty field sources in our sample with no optical counterpart (B ≤ 21) allow us to conclude that 4 of these are fainter galaxies just outside the IRAS error ellipse with high values of L IR /L B . One other object, with a radio source at the edge of the error ellipse but no optical counterpart brighter than B = 23, may prove to be a highly luminous galaxy with L IR /L B > ∼ 1250

  8. Performance of Drift-Tube Detectors at High Counting Rates for High-Luminosity LHC Upgrades

    CERN Document Server

    Bittner, Bernhard; Kortner, Oliver; Kroha, Hubert; Manfredini, Alessandro; Nowak, Sebastian; Ott, Sebastian; Richter, Robert; Schwegler, Philipp; Zanzi, Daniele; Biebel, Otmar; Hertenberger, Ralf; Ruschke, Alexander; Zibell, Andre

    2016-01-01

    The performance of pressurized drift-tube detectors at very high background rates has been studied at the Gamma Irradiation Facility (GIF) at CERN and in an intense 20 MeV proton beam at the Munich Van-der-Graaf tandem accelerator for applications in large-area precision muon tracking at high-luminosity upgrades of the Large Hadron Collider (LHC). The ATLAS muon drifttube (MDT) chambers with 30 mm tube diameter have been designed to cope with and neutron background hit rates of up to 500 Hz/square cm. Background rates of up to 14 kHz/square cm are expected at LHC upgrades. The test results with standard MDT readout electronics show that the reduction of the drift-tube diameter to 15 mm, while leaving the operating parameters unchanged, vastly increases the rate capability well beyond the requirements. The development of new small-diameter muon drift-tube (sMDT) chambers for LHC upgrades is completed. Further improvements of tracking e?ciency and spatial resolution at high counting rates will be achieved with ...

  9. Luminosity excesses in low-mass young stellar objects - a statistical study

    International Nuclear Information System (INIS)

    Strom, K.M.; Strom, S.E.; Kenyon, S.J.; Hartmann, L.

    1988-01-01

    This paper presents a statistical study in which the observed total luminosity is compared quantitatively with an estimate of the stellar luminosity for a sample of 59 low-mass young stellar objects (YSOs) in the Taurus-Auriga complex. In 13 of the analyzed YSOs, luminosity excesses greater than 0.20 are observed together with greater than 0.6 IR excesses, which typically contribute the bulk of the observed excess luminosity and are characterized by spectral energy distributions which are flat or rise toward long wavelengths. The analysis suggests that YSOs showing the largest luminosity excesses typically power optical jets and/or molecular outflows or have strong winds, as evidenced by the presence of O I emission, indicating a possible correlation between accretion and mass-outflow properties. 38 references

  10. Galaxy luminosity function and Tully-Fisher relation: reconciled through rotation-curve studies

    International Nuclear Information System (INIS)

    Cattaneo, Andrea; Salucci, Paolo; Papastergis, Emmanouil

    2014-01-01

    The relation between galaxy luminosity L and halo virial velocity v vir required to fit the galaxy luminosity function differs from the observed Tully-Fisher relation between L and disk speed v rot . Because of this, the problem of reproducing the galaxy luminosity function and the Tully-Fisher relation simultaneously has plagued semianalytic models since their inception. Here we study the relation between v rot and v vir by fitting observational average rotation curves of disk galaxies binned in luminosity. We show that the v rot -v vir relation that we obtain in this way can fully account for this seeming inconsistency. Therefore, the reconciliation of the luminosity function with the Tully-Fisher relation rests on the complex dependence of v rot on v vir , which arises because the ratio of stellar mass to dark matter mass is a strong function of halo mass.

  11. Design and performance of a lead fluoride detector as a luminosity monitor

    International Nuclear Information System (INIS)

    Pérez Benito, R.; Khaneft, D.; O'Connor, C.; Capozza, L.; Diefenbach, J.; Gläser, B.; Ma, Y.; Maas, F.E.; Rodríguez Piñeiro, D.

    2016-01-01

    Precise luminosity measurements for the OLYMPUS two-photon exchange experiment at DESY were performed by counting scattering events with alternating beams of electrons and positrons incident on atomic electrons in a gaseous hydrogen target. Final products of Møller, Bhabha, and pair annihilation interactions were observed using a pair of lead fluoride Cherenkov calorimeters with custom housings and electronics, adapted from a system used by the A4 parity violation experiment at MAMI. This paper describes the design, calibration, and operation of these detectors. An explanation of the Monte Carlo methods used to simulate the physical processes involved both at the scattering vertices and in the detector apparatus is also included.

  12. Design and performance of a lead fluoride detector as a luminosity monitor

    Energy Technology Data Exchange (ETDEWEB)

    Pérez Benito, R.; Khaneft, D. [Johannes Gutenberg-Universität, Mainz (Germany); O' Connor, C., E-mail: colton@mit.edu [Massachusetts Institute of Technology, Cambridge, MA (United States); Capozza, L. [Johannes Gutenberg-Universität, Mainz (Germany); Diefenbach, J. [Hampton University, Hampton, VA (United States); Gläser, B.; Ma, Y.; Maas, F.E.; Rodríguez Piñeiro, D. [Johannes Gutenberg-Universität, Mainz (Germany)

    2016-08-01

    Precise luminosity measurements for the OLYMPUS two-photon exchange experiment at DESY were performed by counting scattering events with alternating beams of electrons and positrons incident on atomic electrons in a gaseous hydrogen target. Final products of Møller, Bhabha, and pair annihilation interactions were observed using a pair of lead fluoride Cherenkov calorimeters with custom housings and electronics, adapted from a system used by the A4 parity violation experiment at MAMI. This paper describes the design, calibration, and operation of these detectors. An explanation of the Monte Carlo methods used to simulate the physical processes involved both at the scattering vertices and in the detector apparatus is also included.

  13. FLUKA studies of hadron-irradiated scintillating crystals for calorimetry at the High-Luminosity LHC

    CERN Document Server

    Quittnat, Milena Eleonore

    2015-01-01

    Calorimetry at the High-Luminosity LHC (HL-LHC) will be performed in a harsh radiation environment with high hadron fluences. The upgraded CMS electromagnetic calorimeter design and suitable scintillating materials are a focus of current research. In this paper, first results using the Monte Carlo simulation program FLUKA are compared to measurements performed with proton-irradiated LYSO, YSO and cerium fluoride crystals. Based on these results, an extrapolation to the behavior of an electromagnetic sampling calorimeter, using one of the inorganic scintillators above as an active medium, is performed for the upgraded CMS experiment at the HL-LHC. Characteristic parameters such as the induced ambient dose, fluence spectra for different particle types and the residual nuclei are studied, and the suitability of these materials for a future calorimeter is surveyed. Particular attention is given to the creation of isotopes in an LYSO-tungsten calorimeter that might contribute a prohibitive background to the measu...

  14. Performance Evaluation of the SPS Scraping System in View of the High Luminosity LHC

    CERN Document Server

    AUTHOR|(SzGeCERN)659273; Cerutti, Francesco

    Injection in the LHC is a delicate moment, since the LHC collimation system cannot offer adequate protection during beam transfer. For this reason, a complex chain of injection protection devices has been put in place. Among them, the SPS scrapers are the multi-turn cleaning system installed in the SPS aimed at halo removal immediately before injection in the LHC. The upgrade in luminosity of the LHC foresees beams brighter than those currently available in machine, posing serious problems to the performance of the existing injection protection systems. In particular, the integrity of beam-intercepting devices is challenged by unprecedented beam parameters, leading to interactions potentially destructive. In this context, a new design of scrapers has been proposed, aimed at improved robustness and performance. This thesis compares the two scraping systems, i.e. the existing one and the one proposed for upgrade. Unlike any other collimation system for regular halo cleaning, both are "fast" systems, characteris...

  15. The performance of the DELPHI SAT tracker during 1991 and its contribution to the absolute luminosity measurement

    International Nuclear Information System (INIS)

    Bugge, L.; Buran, T.; Read, A.L.; Wilhelmsen, E.

    1994-01-01

    The performance of the DELPHI Small Angle Tagger (SAT) tracker in 1991 is presented. A method to use the SAT tracker for monitoring the internal geometry of the SAT calorimeter and thereby improving the luminosity measurement for DELPHI is described. A reduction from 0.35% to 0.05% in the relevant contribution to the systematic error on the luminosity is reported. 15 refs., 23 figs., 6 tabs

  16. Performance of New and Upgraded Detectors for Luminosity and Beam Condition Measurement at CMS

    CERN Document Server

    Leonard, Jessica Lynn

    2015-01-01

    The beam monitoring and luminosity systems of the CMS experiment are enhanced by several new and upgraded sub-detectors to match the challenges of the LHC operation and physics program at increased energy and higher luminosity. A dedicated pixelated luminosity telescope is installed for a fast and precise luminosity measurement. This detector measures coincidences between several three-layer telescopes of silicon pixel detectors to arrive at luminosity for each colliding LHC bunch pair. An upgraded fast beam conditions monitor measures the particle flux using single crystalline diamond sensors. It is equipped with a dedicated front-end ASIC produced in 130 nm CMOS technology. The excellent time resolution is used to separate collision products from machine induced background, thus serving as online luminosity measurement. A new beam-halo monitor at larger radius exploits Cerenkov light from fused silica to provide direction sensitivity and excellent time resolution to separate incoming and outgoing particles....

  17. Study of systematic errors in the luminosity measurement

    International Nuclear Information System (INIS)

    Arima, Tatsumi

    1993-01-01

    The experimental systematic error in the barrel region was estimated to be 0.44 %. This value is derived considering the systematic uncertainties from the dominant sources but does not include uncertainties which are being studied. In the end cap region, the study of shower behavior and clustering effect is under way in order to determine the angular resolution at the low angle edge of the Liquid Argon Calorimeter. We also expect that the systematic error in this region will be less than 1 %. The technical precision of theoretical uncertainty is better than 0.1 % comparing the Tobimatsu-Shimizu program and BABAMC modified by ALEPH. To estimate the physical uncertainty we will use the ALIBABA [9] which includes O(α 2 ) QED correction in leading-log approximation. (J.P.N.)

  18. Study of systematic errors in the luminosity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Arima, Tatsumi [Tsukuba Univ., Ibaraki (Japan). Inst. of Applied Physics

    1993-04-01

    The experimental systematic error in the barrel region was estimated to be 0.44 %. This value is derived considering the systematic uncertainties from the dominant sources but does not include uncertainties which are being studied. In the end cap region, the study of shower behavior and clustering effect is under way in order to determine the angular resolution at the low angle edge of the Liquid Argon Calorimeter. We also expect that the systematic error in this region will be less than 1 %. The technical precision of theoretical uncertainty is better than 0.1 % comparing the Tobimatsu-Shimizu program and BABAMC modified by ALEPH. To estimate the physical uncertainty we will use the ALIBABA [9] which includes O({alpha}{sup 2}) QED correction in leading-log approximation. (J.P.N.).

  19. Performance of the CMS precision electromagnetic calorimeter at LHC Run II and prospects for High-Luminosity LHC

    Science.gov (United States)

    Zhang, Zhicai

    2018-04-01

    Many physics analyses using the Compact Muon Solenoid (CMS) detector at the LHC require accurate, high-resolution electron and photon energy measurements. Following the excellent performance achieved during LHC Run I at center-of-mass energies of 7 and 8 TeV, the CMS electromagnetic calorimeter (ECAL) is operating at the LHC with proton-proton collisions at 13 TeV center-of-mass energy. The instantaneous luminosity delivered by the LHC during Run II has achieved unprecedented levels. The average number of concurrent proton-proton collisions per bunch-crossing (pileup) has reached up to 40 interactions in 2016 and may increase further in 2017. These high pileup levels necessitate a retuning of the ECAL readout and trigger thresholds and reconstruction algorithms. In addition, the energy response of the detector must be precisely calibrated and monitored. We present new reconstruction algorithms and calibration strategies that were implemented to maintain the excellent performance of the CMS ECAL throughout Run II. We will show performance results from the 2015-2016 data taking periods and provide an outlook on the expected Run II performance in the years to come. Beyond the LHC, challenging running conditions for CMS are expected after the High-Luminosity upgrade of the LHC (HL-LHC) . We review the design and R&D studies for the CMS ECAL and present first test beam studies. Particular challenges at HL-LHC are the harsh radiation environment, the increasing data rates, and the extreme level of pile-up events, with up to 200 simultaneous proton-proton collisions. We present test beam results of hadron irradiated PbWO crystals up to fluences expected at the HL-LHC . We also report on the R&D for the new readout and trigger electronics, which must be upgraded due to the increased trigger and latency requirements at the HL-LHC.

  20. Expected Performance of the ATLAS Inner Tracker at the High Luminosity LHC

    CERN Document Server

    Mansour, Jason Dhia; The ATLAS collaboration

    2017-01-01

    The large data samples at the High-Luminosity LHC will enable precise measurements of the Higgs boson and other Standard Model particles, as well as searches for new phenomena such as supersymmetry and extra dimensions. To cope with the experimental challenges presented by the HL-LHC such as large radiation doses and high pileup, the current Inner Detector will be replaced with a new all-silicon Inner Tracker for the Phase II upgrade of the ATLAS detector. The current tracking performance of two candidate Inner Tracker layouts with an increased tracking acceptance (compared to the current Inner Detector) of |η|<4.0, employing either an ‘Extended’ or ‘Inclined’ Pixel barrel, is evaluated. New pattern recognition approaches facilitated by the detector designs are discussed, and ongoing work in optimising the track reconstruction for the new layouts and experimental conditions are outlined. Finally, future approaches that may improve the physics and/or technical performance of the ATLAS track reconst...

  1. The design and simulated performance of a fast Level 1 track trigger for the ATLAS High Luminosity Upgrade

    CERN Document Server

    Martensson, Mikael; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment at the High Luminosity LHC will face a fivefold increase in the number of interactions per bunch crossing relative to the ongoing Run 2. This will require a proportional improvement in rejection power at the earliest levels of the detector trigger system, while preserving good signal efficiency. One critical aspect of this improvement will be the implementation of precise track reconstruction, through which sharper trigger turn-on curves can be achieved, and b-tagging and tau-tagging techniques can in principle be implemented. The challenge of such a project comes in the development of a fast, custom electronic device integrated in the hardware based first trigger level of the experiment. This article will discuss the requirements, architecture and projected performance of the system in terms of tracking, timing and physics, based on detailed simulations. Studies are carried out using data from the strip subsystem only or both strip and pixel subsystems.

  2. Luminosity monitor

    International Nuclear Information System (INIS)

    Underwood, D. G.

    1998-01-01

    Luminosity monitors are needed in each experiment doing spin physics at RHIC. They concentrate on the luminosity aspects here because, for example, with a 10 -3 raw asymmetry in an experiment, an error of 10 -4 in the luminosity is as significant as a 10% polarization error. Because luminosity is a property of how two beams overlap, the luminosity at an interaction region must be measured at that interaction region in order to be relevant to the experiment at that interaction region. The authors will have to do the physics and the luminosity measurements by using labels on the event sums according to the polarization labels on the colliding bunches. Most likely they will not have independent polarization measurement on each bunch, but only on all the filled bunches in a ring, or perhaps all the bunches that are actually used in an experiment. Most analyses can then be handled by using the nine combinations gotten from three kinds of bunches in each ring, +, - and empty bunches. The empty bunches are needed to measure beam-gas background, (and some, like six in a row, are needed for the beam abort). Much of the difficulty comes from the fact that they must use a physics process to represent the luminosity. This process must have kinematic and geometric cuts both to reduce systematics such as beam-gas backgrounds, and to make it representative of the part of the interaction diamond from which the physics events come

  3. LEP3: A High Luminosity e+e- Collider to Study the Higgs Boson

    CERN Document Server

    Blondel, A U; Assmann, R W; Butterworth, A; Janot, P; Jimenez, J M; Grojean, C; Milanese, A; Modena, M; Osborne, J A; Zimmermann, F; Piekarz, H; Oide, K; Yokoya, K; Ellis, J; Klute, M; Zanetti, M; Velasco, M; Telnov, V; Rivkin, L; Cai, Y

    2012-01-01

    The LHC experiments have discovered a new particle with a mass around 125 GeV that is a strong candidate for the scalar Higgs boson expected in the Standard Model. An e+e− collider operating close to the ZH threshold (at a centre-of-mass energy of 240 GeV) could be the tool of choice for studying this unique particle in detail. We present here the concept of a storage ring collider, which we call LEP3. Preliminary studies show that at a centre-of-mass energy of 240 GeV, near-constant luminosities of 1034 cm-2s-1 are possible in up to four collision points, while respecting a number of constraints including beamstrahlung limits. With an integrated luminosity of 100fb-1 per year and per interaction point, 20,000 e+e- - ZH events would be produced per year and per experiment. LEP3 could also operate in multi-bunch mode at the Z resonance, with luminosities of several×1035cm-2s-1, yielding O(1011) Z decays per year, as well as just above the WW threshold, potentially improving our knowledge of W and Z propert...

  4. Performance Limits and IR Design Challenges of a Possible LHC Luminosity Upgrade Based on Nb-Ti SC Magnet Technology

    CERN Document Server

    Brüning, Oliver Sim; Ostojic, R; Rossi, L; Ruggiero, F; Scandale, Walter; Taylor, T

    2004-01-01

    We investigate the maximum LHC performance for a standard IR design based on classical NbTi insertion magnets. We include in our analysis a ternary Nb-based ductile allow such as NbTi(Ta), a less developed but relatively cheap superconducting material which may allow to gain about 1 T in the peak field in the coils, and discuss the corresponding luminosity reach for a possible LHC upgrade compared to that based on Nb$_{3}$Sn magnets.

  5. Performance of the CMS precision electromagnetic calorimeter at the LHC Run II and prospects for high-luminosity LHC

    CERN Document Server

    Negro, Giulia

    2017-01-01

    The Compact Muon Solenoid (CMS) electromagnetic calorimeter (ECAL) is a high-performance calorimeter wich will operate also at the High Luminosity Large Hadron Collider (HL-LHC). This talk will describe the strategies that have been employed to maintain the excellent performance of the CMS ECAL throughout Run 2. Performance results from the 2015-2016 data taking periods will be shown and an outlook on the expected Run 2 performance in the years to come will be provided. The status and plans for the upgraded ECAL barrel electronics for the HL-LHC will be presented, based on recent results from simulations, laboratory tests, and test beam measurements of prototype devices.

  6. Luminosity measurement at CMS

    Energy Technology Data Exchange (ETDEWEB)

    Karacheban, Olena

    2017-10-15

    van der Meer (VdM) scans. The proton beams are scanned against each other separately in the x and y directions. The effective width of the beams is measured and the visible cross section, the key quantity for the luminosity measurement, is determined. The imi pact of detector instability, beam-beam effects, correlations of the particle density distributions in the x and y planes, and satellite and ghost bunches are studied in detail and systematic uncertainties are derived. The systematic error on the visible cross section was estimated to be 3.1% in the 50 ns operation period. A comparison of the VdM scans of 2015 and 2016 completes the second part of the thesis, as well as a comparison of the results delivered by other luminometers. As a contribution to the upgrade of the beam instrumentation for the high luminosity LHC, a novel single crystal sapphire detector was designed, built and studied in a test-beam. The detector comprises a stack of sapphire plates. The response depends on the direction of the incident particles. The performance of the detector is described in the third part of the thesis. It is demonstrated that this sapphire detector can be used for the detection of single relativistic particles. The results point to the dominant contribution of the electrons to the signal generation in sapphire.

  7. Luminosity measurement at CMS

    International Nuclear Information System (INIS)

    Karacheban, Olena

    2017-10-01

    M) scans. The proton beams are scanned against each other separately in the x and y directions. The effective width of the beams is measured and the visible cross section, the key quantity for the luminosity measurement, is determined. The imi pact of detector instability, beam-beam effects, correlations of the particle density distributions in the x and y planes, and satellite and ghost bunches are studied in detail and systematic uncertainties are derived. The systematic error on the visible cross section was estimated to be 3.1% in the 50 ns operation period. A comparison of the VdM scans of 2015 and 2016 completes the second part of the thesis, as well as a comparison of the results delivered by other luminometers. As a contribution to the upgrade of the beam instrumentation for the high luminosity LHC, a novel single crystal sapphire detector was designed, built and studied in a test-beam. The detector comprises a stack of sapphire plates. The response depends on the direction of the incident particles. The performance of the detector is described in the third part of the thesis. It is demonstrated that this sapphire detector can be used for the detection of single relativistic particles. The results point to the dominant contribution of the electrons to the signal generation in sapphire.

  8. Studies of Read-Out Electronics and Trigger for Muon Drift Tube Detectors at High Luminosities

    CERN Document Server

    Nowak, Sebastian

    The Large Hadron Collider (LHC) at the European Centre for Particle Physics, CERN, collides protons with an unprecedentedly high centre-of-mass energy and luminosity. The collision products are recorded and analysed by four big experiments, one of which is the ATLAS detector. For precise measurements of the properties of the Higgs-Boson and searches for new phenomena beyond the Standard Model, the LHC luminosity of $L=10^{34}cm^{-2}s^{-1}$ is planned to be increased by a factor of ten leading to the High Luminosity LHC (HL-LHC). In order to cope with the higher background and data rates, the LHC experiments need to be upgraded. In this thesis, studies for the upgrade of the ATLAS Muon Spectrometer are presented with respect to the read-out electronics of the Monitored Drift Tube (MDT) and the small-diameter Muon Drift Tube (sMDT) chambers and the Level-1 muon trigger. Due to the reduced tube diameter of sMDT chambers, background occupancy and space charge effects are suppressed by an order of magnitude compar...

  9. Performance of the first short model 150 mm aperture Nb$_3$Sn Quadrupole MQXFS for the High-Luminosity LHC upgrade

    CERN Document Server

    Chlachidze, G; Anerella, M; Bossert, R; Cavanna, E; Cheng, D; Dietderich, D; DiMarco, J; Felice, H; Ferracin, P; Ghosh, A; Grosclaude, P; Guinchard, M; Hafalia, A R; Holik, E; Izquierdo Bermudez, S; Krave, S; Marchevsky, M; Nobrega, F; Orris, D; Pan, H; Perez, J C; Prestemon, S; Ravaioli, E; Sabbi, G L; Salmi, T; Schmalzle, J; Stoynev, S; Strauss, T; Sylvester, C; Tartaglia, M; Todesco, E; Vallone, G; Velev, G; Wanderer, P; Wang, X; Yu, M

    2017-01-01

    The US LHC Accelerator Research Program (LARP) and CERN combined their efforts in developing Nb$_{3}$Sn magnets for the High-Luminosity LHC upgrade. The ultimate goal of this collaboration is to fabricate large aperture Nb$_{3}$Sn quadrupoles for the LHC interaction regions (IR). These magnets will replace the present 70 mm aperture NbTi quadrupole triplets for expected increase of the LHC peak luminosity by a factor of 5. Over the past decade LARP successfully fabricated and tested short and long models of 90 mm and 120 mm aperture Nb$_{3}$Sn quadrupoles. Recently the first short model of 150 mm diameter quadrupole MQXFS was built with coils fabricated both by the LARP and CERN. The magnet performance was tested at Fermilab’s vertical magnet test facility. This paper reports the test results, including the quench training at 1.9 K, ramp rate and temperature dependence studies.

  10. The design and simulated performance of a fast Level 1 track trigger for the ATLAS High Luminosity Upgrade

    CERN Document Server

    Martensson, Mikael; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment at the high-luminosity LHC will face a five-fold increase in the number of interactions per collision relative to the ongoing Run 2. This will require a proportional improvement in rejection power at the earliest levels of the detector trigger system, while preserving good signal efficiency. One critical aspect of this improvement will be the implementation of precise track reconstruction, through which sharper trigger turn-on curves can be achieved, and b-tagging and tau-tagging techniques can in principle be implemented. The challenge of such a project comes in the development of a fast, custom electronic device integrated in the hardware-based first trigger level of the experiment, with repercussions propagating as far as the detector read-out philosophy. This talk will discuss the requirements, architecture and projected performance of the system in terms of tracking, timing and physics, based on detailed simulations. Studies are carried out comparing two detector geometries and using...

  11. Luminosity measurement at AMY

    International Nuclear Information System (INIS)

    Kurihara, Y.

    1995-01-01

    A precise measurement of a luminosity is required by experiments with high statistics. The largest sources of a systematic error of a luminosity measurement are an alignment of the tube chambers which measure a polar angle of Bhabha events and a higher order correction for the Bhabha cross section calculation. We describe a resent study for these uncertainties and how to reduce the systematic errors from these sources. The total systematic error of the luminosity measurement of 1.8% can be reduced to 1.0% by this study. (author)

  12. Updates on Performance of Physics Objects with the Upgraded CMS detector for High Luminosity LHC.

    CERN Document Server

    CMS Collaboration

    2016-01-01

    This document contains a collection of performance plots obtained with the simulation of the upgrade Phase2 CMS detector for HL-LHC at the centre of mass energy of 14 TeV. Two pileup scenarios with and average = 140 and 200 collisions per event have been considered. We present updated results compared to the Technical Proposal (CMS-TDR-15-02) and Scope Document (CERN-LHCC-2015-019) for: track, muon, jet reconstruction and btagging performance. In addition, a set of plots containing studies of performance as a function of the linear pile up density along the beam axis are presented for tracking, vertexing, b-tagging, tau identification, muon isolation and missing $E_T$ resolution.

  13. The ATLAS Run-2 Trigger Menu for higher luminosities: Design, Performance and Operational Aspects

    CERN Document Server

    Ruiz-Martinez, Aranzazu; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment aims at recording about 1 kHz of physics collisions, starting with an LHC design bunch crossing rate of 40 MHz. To reduce the massive background rate while maintaining a high selection efficiency for rare physics events (such as beyond the Standard Model physics), a two-level trigger system is used. Events are selected based on physics signatures such as presence of energetic leptons, photons, jets or large missing energy. The trigger system exploits topological information, as well as multi-variate methods to carry out the necessary physics filtering. In total, the ATLAS online selection consists of thousands of different individual triggers. A trigger menu is a compilation of these triggers which specifies the physics algorithms to be used during data taking and the bandwidth a given trigger is allocated. Trigger menus reflect not only the physics goals of the collaboration for a given run, but also take into consideration the instantaneous luminosity of the LHC and limitations from the...

  14. The ATLAS Run-2 Trigger Menu for higher luminosities: Design, Performance and Operational Aspects

    CERN Document Server

    Torro Pastor, Emma; The ATLAS collaboration

    2018-01-01

    The ATLAS experiment aims at recording about 1 kHz of physics collisions, starting with an LHC design bunch crossing rate of 40 MHz. To reduce the massive background rate while maintaining a high selection efficiency for rare physics events (such as beyond the Standard Model physics), a two-level trigger system is used. Events are selected based on physics signatures such as presence of energetic leptons, photons, jets or large missing energy. The trigger system exploits topological information, as well as multi-variate methods to carry out the necessary physics filtering. In total, the ATLAS online selection consists of thousands of different individual triggers. A trigger menu is a compilation of these triggers which specifies the physics algorithms to be used during data taking and the bandwidth a given trigger is allocated. Trigger menus reflect not only the physics goals of the collaboration for a given run, but also take into consideration the instantaneous luminosity of the LHC and limitations from the...

  15. The ATLAS Run-2 Trigger Menu for higher luminosities: Design, Performance and Operational Aspects

    CERN Document Server

    Montejo Berlingen, Javier; The ATLAS collaboration

    2017-01-01

    The LHC, at design capacity, has a bunch-crossing rate of 40 MHz whereas the ATLAS experiment has an average recording rate of about 1 kHz. To reduce the rate of events, but maintain high selection efficiency for rare events such as physics signals beyond the Standard Model, a two-level trigger system is used. Events are selected based on physics signatures such as presence of energetic leptons, photons, jets or large missing energy. Despite the limited time available for processing collision events the trigger system is able to exploit topological information, as well as using multi-variate methods. In total, the ATLAS trigger systems consists of thousands of different individual triggers. The ATLAS trigger menu specifies which triggers are used during data taking and how much rate a given trigger is allocated. This menu reflects not only the physics goals of the collaboration but also takes into consideration the instantaneous luminosity of the LHC and the design limits of the ATLAS detector and offline pro...

  16. Progress with Long-Range Beam-Beam Compensation Studies for High Luminosity LHC

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Adriana; et al.

    2017-05-01

    Long-range beam-beam (LRBB) interactions can be a source of emittance growth and beam losses in the LHC during physics and will become even more relevant with the smaller '* and higher bunch intensities foreseen for the High Luminosity LHC upgrade (HL-LHC), in particular if operated without crab cavities. Both beam losses and emittance growth could be mitigated by compensat-ing the non-linear LRBB kick with a correctly placed current carrying wire. Such a compensation scheme is currently being studied in the LHC through a demonstration test using current-bearing wires embedded into col-limator jaws, installed either side of the high luminosity interaction regions. For HL-LHC two options are considered, a current-bearing wire as for the demonstrator, or electron lenses, as the ideal distance between the particle beam and compensating current may be too small to allow the use of solid materials. This paper reports on the ongoing activities for both options, covering the progress of the wire-in-jaw collimators, the foreseen LRBB experiments at the LHC, and first considerations for the design of the electron lenses to ultimately replace material wires for HL-LHC.

  17. Theoretical studies of hadronic calorimetry for high luminosity, high energy colliders

    Energy Technology Data Exchange (ETDEWEB)

    Brau, J.E.; Gabriel, T.A.

    1989-01-01

    Experiments at the high luminosity, high energy colliders of the future are going to demand optimization of the state of the art of calorimetry design and construction. During the past few years, the understanding of the basic phenomenology of hadron calorimeters has advanced through paralleled theoretical and experimental investigations. The important underlying processes are reviewed to set the framework for the presentation of recent calculations of the expected performance of silicon detector based hadron calorimeters. Such devices employing uranium are expected to achieve the compensation condition (that is, e/h approx. 1.0) based on the understanding that has been derived from the uranium-liquid argon and uranium-plastic scintillator systems. In fact, even lead-silicon calorimeters are found to achieve the attractive value for the e/h ratio of 1.16 at 10 GeV. 62 refs., 22 figs., 3 tabs.

  18. Theoretical studies of hadronic calorimetry for high luminosity, high energy colliders

    International Nuclear Information System (INIS)

    Brau, J.E.; Gabriel, T.A.

    1989-01-01

    Experiments at the high luminosity, high energy colliders of the future are going to demand optimization of the state of the art of calorimetry design and construction. During the past few years, the understanding of the basic phenomenology of hadron calorimeters has advanced through paralleled theoretical and experimental investigations. The important underlying processes are reviewed to set the framework for the presentation of recent calculations of the expected performance of silicon detector based hadron calorimeters. Such devices employing uranium are expected to achieve the compensation condition (that is, e/h ∼ 1.0) based on the understanding that has been derived from the uranium-liquid argon and uranium-plastic scintillator systems. In fact, even lead-silicon calorimeters are found to achieve the attractive value for the e/h ratio of 1.16 at 10 GeV. 62 refs., 22 figs., 3 tabs

  19. Electron-electron luminosity in the Next Linear Collider -- a preliminary study

    International Nuclear Information System (INIS)

    Zimmermann, F.; Thompson, K.A.; Helm, R.H.

    1997-11-01

    In this paper, the authors discuss some operational aspects of electron-electron collisions at the Next Linear Collider (NLC) and estimate the luminosity attainable in such a machine. They also consider the use of two future technologies which could simplify the operation and improve the luminosity in an e - e - collider: polarized rf guns and plasma lenses

  20. Study relating to an e+e- storage ring of very high luminosity, with and without monochromatization of the beams (for the Tau-Charm Factory)

    International Nuclear Information System (INIS)

    Faus-Golfe, A.

    1994-01-01

    When two e + e - beams collide the effective luminosity is reduced due to the finite energy spread of each beam. If a scheme is used to separate the particle orbits, at the interaction point, with respect to their energy deviation, and with opposite polarities for the two beams, then a positron with energy (E+ΔE) will collide an electron with energy (E-ΔE). This allows an increase of the effective luminosity following a reduction of the energy spread in the CM. This original idea, though it was known since a long time, has never been experienced on existing machines. Since more recently, new e + e - circular colliders are being envisaged at energies already covered, but with design luminosities 2 or 3 orders of magnitude above past performances. These projects are called ''Factories'', and namely ''Tau-Charm Factory'' with 2.0 GeV beam energy and a luminosity of 10 33 cm -2 s -1 is being considered in Europe. Its performances can be enhanced using a monochromatization scheme, as described above. However the lack of past experience suggests to design the machine in such a way that a back up standard mode of operation is included from the beginning. The present study deals with optics developments which allow the two modes of operation within the same geometrical machine configuration. The corresponding lattices are called ''versatile''. (orig.)

  1. Performance of Edgeless Silicon Pixel Sensors on p-type substrate for the ATLAS High-Luminosity Upgrade

    CERN Document Server

    INSPIRE-00052711; Boscardin, Maurizio; Bosisio, Luciano; Calderini, Giovanni; Chauveau, Jacques; Ducourthial, Audrey; Giacomini, Gabriele; Marchiori, Giovanni; Zorzi, Nicola

    2016-01-01

    In view of the LHC upgrade phases towards the High Luminosity LHC (HL-LHC), the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising candidate to achieve a large area instrumented with pixel sensors, since it is radiation hard and cost effective. The paper reports on the performance of novel n-on-p edgeless planar pixel sensors produced by FBK-CMM, making use of the active trench for the reduction of the dead area at the periphery of the device. After discussing the sensor technology an overview of the first beam test results will be given.

  2. Studies on the measurement of differential luminosity using Bhabha events at the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Sailer, Andre Philippe

    2009-04-15

    The International Linear Collider (ILC) is an electron-positron-collider with a variable center-of-mass energy {radical}(2) between 200 and 500 GeV. The small bunch sizes needed to reach the design luminosity of L{sub Peak}=2.10{sup 34} cm{sup -2}s{sup -1} necessary for the physics goals of the ILC, cause the particles to radiate beamstrahlung during the bunch crossings. Beamstrahlung reduces the center-of-mass energy from its nominal value to the effective center-of-mass energy {radical}(2'). The spectrum of the effective center-of-mass energy {radical}(2') is the differential luminosity dL/d{radical}(2'), which has to be known to precisely measure particle masses through threshold scans. The differential luminosity can be measured by using Bhabha events. The real differential luminosity is simulated by the GuineaPig software. The energy spectrum of the Bhabha events is measured by the detector and compared to the energy spectrum of Monte Carlo (MC) Bhabha events with a known differential luminosity given by an approximate parameterization. The parameterization is used to assign each MC event a weight. By re-weighting the events, until the energy spectra from the real and the MC Bhabha events match, the differential luminosity can be measured. The approximate parameterization of the differential luminosity is given by the Circe parameterization introduced by T. Ohl (1997), which does not include the correlation between the particle energies due to beamstrahlung. The Circe parameterization is extended to include the correlation and better describe the differential luminosity. With this new parameterization of the differential luminosity it is possible to predict the observed production cross section of a MC toy particle with a mass of 250 GeV/c{sup 2} to a precision better than 0.2%. Using the re-weighting fit with the extended parameterization also allows the measurement of the beam energy spreads of {sigma}{sub E}=0.0014 for electrons and {sigma

  3. Studies on the measurement of differential luminosity using Bhabha events at the International Linear Collider

    International Nuclear Information System (INIS)

    Sailer, Andre Philippe

    2009-04-01

    The International Linear Collider (ILC) is an electron-positron-collider with a variable center-of-mass energy √(2) between 200 and 500 GeV. The small bunch sizes needed to reach the design luminosity of L Peak =2.10 34 cm -2 s -1 necessary for the physics goals of the ILC, cause the particles to radiate beamstrahlung during the bunch crossings. Beamstrahlung reduces the center-of-mass energy from its nominal value to the effective center-of-mass energy √(2'). The spectrum of the effective center-of-mass energy √(2') is the differential luminosity dL/d√(2'), which has to be known to precisely measure particle masses through threshold scans. The differential luminosity can be measured by using Bhabha events. The real differential luminosity is simulated by the GuineaPig software. The energy spectrum of the Bhabha events is measured by the detector and compared to the energy spectrum of Monte Carlo (MC) Bhabha events with a known differential luminosity given by an approximate parameterization. The parameterization is used to assign each MC event a weight. By re-weighting the events, until the energy spectra from the real and the MC Bhabha events match, the differential luminosity can be measured. The approximate parameterization of the differential luminosity is given by the Circe parameterization introduced by T. Ohl (1997), which does not include the correlation between the particle energies due to beamstrahlung. The Circe parameterization is extended to include the correlation and better describe the differential luminosity. With this new parameterization of the differential luminosity it is possible to predict the observed production cross section of a MC toy particle with a mass of 250 GeV/c 2 to a precision better than 0.2%. Using the re-weighting fit with the extended parameterization also allows the measurement of the beam energy spreads of σ E =0.0014 for electrons and σ E = 0.0010 for positrons with a precision of a few percent. The total error

  4. CLIC Luminosity Monitoring

    CERN Document Server

    Apyan, Armen; Gschwendtner, Edda; Lefevre, Thibault; Tygier, Sam; Appleby, Robert B

    2012-01-01

    The CLIC post-collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14 MW to the main beam dump. Luminosity monitoring for CLIC is based on high energy muons produced by beamstrahlung photons in the main dump. Threshold Cherenkov counters are proposed for the detection of these muons. The expected rates and layout for these detectors is presented. Another method for luminosity monitoring is to directly detect the beamstrahlung photons in the post-collision line. Full Monte Carlo simulation has been performed to address its feasibility.

  5. Performance of the CMS precision electromagnetic calorimeter at LHC Run II and prospects for High-Luminosity LHC

    CERN Document Server

    Zhang, Zhicai

    2017-01-01

    Many physics analyses using the Compact Muon Solenoid (CMS) detector at the LHC require accurate, high-resolution electron and photon energy measurements. Following the excellent performance achieved during LHC Run I at center-of-mass energies of 7 and 8 TeV, the CMS electromagnetic calorimeter (ECAL) is operating at the LHC with proton-proton collisions at 13 TeV center-of-mass energy. The instantaneous luminosity delivered by the LHC during Run II has achieved unprecedented levels. The average number of concurrent proton-proton collisions per bunch-crossing (pileup) has reached up to 40 interactions in 2016 and may increase further in 2017. These high pileup levels necessitate a retuning of the ECAL readout and trigger thresholds and reconstruction algorithms. In addition, the energy response of the detector must be precisely calibrated and monitored. We present new reconstruction algorithms and calibration strategies that were implemented to maintain the excellent performance of the CMS ECAL throughout Run...

  6. properties and luminosity functions

    Directory of Open Access Journals (Sweden)

    Hektor Monteiro

    2007-01-01

    Full Text Available In this article, we present an investigation of a sample of 1072 stars extracted from the Villanova Catalog of Spectroscopically Identified White Dwarfs (2005 on-line version, studying their distribution in the Galaxy, their physical properties and their luminosity functions. The distances and physical properties of the white dwarfs are determined through interpolation of their (B-V or (b-y colors in model grids. The solar position relative to the Galactic plane, luminosity function, as well as separate functions for each white dwarf spectral type are derived and discussed. We show that the binary fraction does not vary significantly as a function of distance from the Galactic disk out to 100 pc. We propose that the formation rates of DA and non-DAs have changed over time and/or that DAs evolve into non-DA types. The luminosity functions for DAs and DBs have peaks possibly related to a star burst event.

  7. Luminosity enhancements at SLAC

    International Nuclear Information System (INIS)

    Coward, D.H.

    1984-04-01

    Several ideas are discussed that have been proposed to improve the luminosity at the SPEAR and PEP electron-positron storage rings and to insure good luminosity at the SLAC Linear Collider. There have been two proposals studied recently for SPEAR: a Microbeta insertion using Samarium Cobalt permanent magnets, and a Minibeta insertion using conventional quadrupole magnets. The notations Microbeta and minibeta used here are somewhat arbitrary since the front faces of the first quadrupole magnets for both insertions are at nearly the same distance from the interaction point

  8. Experimental Study of Natural Gas Temperature Effects on the Flame Luminosity and No Emission

    Directory of Open Access Journals (Sweden)

    S. M. Javadi

    2012-06-01

    Full Text Available The flame radiation enhancement in gas-fired furnaces significantly improves the thermal efficiency without significantly affecting the NOx emissions. In this paper, the effects of inlet natural gas preheating on the flame luminosity, overall boiler efficiency, and NO emission in a 120 kW boiler have been investigated experimentally. Flame radiation is measured by use of laboratory pyranometer with photovoltaic sensor. A Testo350XL gas analyzer is also used for measuring the temperature and combustion species. The fuel is preheated from the room temperature to 350°C. The experimental measurements show that the preheating of natural gas up to about 240°C has no considerable effect on the flame luminosity. The results show that increasing the inlet gas temperature from 240°C, abruptly increases the flame luminosity. This luminosity increase enhances the boiler efficiency and also causes significant reduction in flame temperature and NO emission. The results show that increasing the inlet gas temperature from 240°C to 300°C increases the flame luminous radiation by 60% and boiler efficiency by 20%; while the maximum flame temperature and the boiler NO emission show a 10% and 8% decrease respectively.

  9. Photometric studies of globular clusters in the Andromeda Nebula. Luminosity function for old globular clusters

    International Nuclear Information System (INIS)

    Sharov, A.S.; Lyutyj, V.M.

    1989-01-01

    The luminosity function for old globular clusters in M 31 is presented. The objects were selected according to their structural and photometric properties. At the usually accepted normal (Gaussian) distribution, the luminosity function is characterized by the following parameters: the mean magnitude, corrected for the extinction inside M 31, V-bar 0 =16 m ,38±0 m .08, and the absolute magnitude M-bar v =-8 m .29 assuming )m-M) v =23 m .67, standard deviation σ M v =1 m .16±0 m .08 and total object number N=300±17. Old globular clusters in M 31 are in the average about one magnitude more luminous then those in our Galaxy (M v ≅ -7 m .3). Intrinsic luminosity dispersions of globular clusters are nearly the same in both galaxies. Available data on globular clusters in the Local Group galaxies against the universality of globular luminosity function with identical parameters M v and σ M v

  10. Luminosity measurement at CMS

    CERN Document Server

    Karacheban, Olena

    2017-01-01

    Luminosity is a key quantity of any collider, since it allows for the determinationof the absolute cross sections from the observed rates in a detector. Since theHiggs boson discovery in 2012, the highest priority at the Large Hadron Collider(LHC) has been given to an accurate understanding of the electroweak scale anda search for new physics. Precise luminosity measurements in such conditions areof crucial importance, as they determine the precision of any physics cross sectionmeasurement.To increase the production of particles of interest, usually of low cross section,the LHC is running at the highest possible luminosity. After the first Long Shutdown (LS1) the original performance goal for the luminosity of 1 × 1034 cm−2 s−1was reached with 1011 protons per bunch and a bunch spacing of 25 ns. In suchconditions radiation hard detectors with extremely fast response time are required,especially for instrumentation near the beam.The Compact Muon Solenoid experiment is equipped with three online luminomet...

  11. An Anthropology of Luminosity

    DEFF Research Database (Denmark)

    Bille, Mikkel; Sørensen, Tim Flohr

    2007-01-01

    of luminosity in the practice of day-to-day activities. The article surveys an array of past conceptions of light within philosophy, natural science and more recent approaches to light in the fields of anthropology and material culture studies. A number of implications are discussed, and by way of three case...

  12. Electromagnetic noise studies in a silicon strip detector, used as part of a luminosity monitor at LEP

    Science.gov (United States)

    Ødegaard, Trygve; Tafjord, Harald; Buran, Torleiv

    1995-02-01

    As part of the luminosity monitor, SAT, in the DELPHI [1] experiment at CERN's Large Electron Positron collider, a tracking detector constructed from silicon strip detector elements was installed in front of an electromagnetic calorimeter. The luminosity was measured by counting the number of Bhabha events at the interaction point of the electron and the positron beans. The tracking detector reconstructs from the interaction point and the calorimeter measures the corresponding particles' energies. The SAT Tracker [2] consists of 504 silicon strip detectors. The strips are DC-coupled to CMOS VLSI-chips, baptized Balder [3,4]. The chip performs amplification, zero-suppression, digitalisation, and multiplexing. The requirements of good space resolution and high efficiency put strong requirements on noise control. A short description of the geometry and the relevant circuit layout is given. We describe the efforts made to minimise the electromagnetic noise in the detector and present some numbers of the noise level using various techniques.

  13. Operation of the ATLAS end-cap calorimeters at sLHC luminosities, an experimental study

    CERN Document Server

    Ferencei, J; The ATLAS collaboration

    2009-01-01

    The expected increase of luminosity at sLHC by a factor of ten with respect to LHC luminosities has serious consequences for the signal reconstruction, radiation hardness requirements and operations of the ATLAS liquid argon calorimeters (EMEC, HEC, FCAL) in the endcap, respectively forward region. Small modules of each type of calorimeter have been built. The layout and the components used are very close to the ones used in the construction of the ATLAS calorimeter. The goal is to simulate in the high intensity proton beam at IHEP /Protvino the particle impact as expected for ATLAS in sLHC. Depending on the position in pseudorapidity |η|, each forward calorimeter has to cope with a different particle and energy flux. Placing absorber elements in-between the various small calorimeter modules, the particle and energy flux as expected in ATLAS later - given the variation due to |η| and longitudinal position - can be simulated very well.

  14. ECFA study week on instrumentation technology for high-luminosity hadron colliders. Proceedings. Vol. 1 and 2

    International Nuclear Information System (INIS)

    Fernandez, E.; Jarlskog, G.

    1989-01-01

    The main aim of the present ECFA Study Week on 'Instrumentation Technology for High Luminosity Hadron Colliders' was to review the progress made after the La Thuile Workshop (1987) and to critically evaluate which of the detection methods and data handling structures could be suitable for luminosities in the 10 34 cm -2 s -1 range. The Study Week was sponsored by the Universitat Autonoma de Barcelona, the Comision Interministerial Ciencia y Tecnologia of Spain, CERN, and the Commission of the European Communities. It attracted 220 participants, including 35 from industry and good representation from groups planning experiments at the SSC. The various conveners gathered many excellent and original contributions, which led to intense discussions. Subjects covered include the use of scintillating fibres; silicon, gaseous, and crystal detectors, particle identification; readout and data acquisition systems. A separate session dealt with the contributions of industry to this kind of research. (orig.)

  15. OLYMPUS luminosity monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Ates, Ozgur [Hampton University, Hampton, Virginia (United States); Collaboration: OLYMPUS-Collaboration

    2013-07-01

    The OLYMPUS experiment at DESY has been measuring the ratio of positron-proton and electron-proton elastic scattering cross sections to quantify the effect of two-photon exchange, which is widely considered to be responsible for the discrepancy between measurements of the proton electric to magnetic form factor ratio with the Rosenbluth and polarization transfer methods. In order to control the systematic uncertainties to the percent level, the luminosities are monitored redundantly with high precision by measuring the rates for symmetric Moller and Bhabha scattering, and by measuring the ep-elastic count rates at forward angles and low momentum transfer with tracking telescopes based on GEM (Gas Electron Multiplier) and MWPC (Multi Wire Proportional Chamber) technology. During two data taking periods, performances of GEM and MWPC luminosity monitors are presented.

  16. Do You See What I See? Exploring the Consequences of Luminosity Limits in Black Hole–Galaxy Evolution Studies

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Mackenzie L.; Hickox, Ryan C.; DiPompeo, Michael A. [Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States); Mutch, Simon J. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Croton, Darren J. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia); Ptak, Andrew F. [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2017-07-10

    In studies of the connection between active galactic nuclei (AGNs) and their host galaxies, there is widespread disagreement on some key aspects of the connection. These disagreements largely stem from a lack of understanding of the nature of the full underlying AGN population. Recent attempts to probe this connection utilize both observations and simulations to correct for a missed population, but presently are limited by intrinsic biases and complicated models. We take a simple simulation for galaxy evolution and add a new prescription for AGN activity to connect galaxy growth to dark matter halo properties and AGN activity to star formation. We explicitly model selection effects to produce an “observed” AGN population for comparison with observations and empirically motivated models of the local universe. This allows us to bypass the difficulties inherent in models that attempt to infer the AGN population by inverting selection effects. We investigate the impact of selecting AGNs based on thresholds in luminosity or Eddington ratio on the “observed” AGN population. By limiting our model AGN sample in luminosity, we are able to recreate the observed local AGN luminosity function and specific star formation-stellar mass distribution, and show that using an Eddington ratio threshold introduces less bias into the sample by selecting the full range of growing black holes, despite the challenge of selecting low-mass black holes. We find that selecting AGNs using these various thresholds yield samples with different AGN host galaxy properties.

  17. MPX detectors as LHC luminosity monitor

    Energy Technology Data Exchange (ETDEWEB)

    Sopczak, Andre; Ali, Babar; Bergmann, Benedikt; Caforio, Davide; Heijne, Erik; Pospisil, Stanislav; Seifert, Frank; Solc, Jaroslav; Suk, Michal; Turecek, Daniel [IEAP CTU in Prague (Czech Republic); Ashba, Nedaa; Leroy, Claude; Soueid, Paul [University of Montreal (Canada); Bekhouche, Khaled [Biskra University (Algeria); Campbell, Michael; Nessi, Marzio [CERN (Switzerland); Lipniacka, Anna [Bergen University (Norway)

    2016-07-01

    A network of 16 Medipix-2 (MPX) silicon pixel devices was installed in the ATLAS detector cavern at CERN. It was designed to measure the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. This study demonstrates that the MPX network can also be used as a self-sufficient luminosity monitoring system. The MPX detectors collect data independently of the ATLAS data-recording chain, and thus they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors located close enough to the primary interaction point are used to perform van der Meer calibration scans with high precision. Results from the luminosity monitoring are presented for 2012 data taken at √(s) =8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction rate are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The systematic variations observed in the MPX luminosity measurements are below 0.3% for one minute intervals.

  18. Study on dynamics of beams of high luminosity in electron linacs

    International Nuclear Information System (INIS)

    Polyakov, V.A.; Shchedrin, I.S.

    1981-01-01

    To increase the electron beam luminosity in electron linacs (ELA), designed for electron microscopy, a numerical analysis of the electron dynamics in the ELA is carried out. Insufficiency of the available data on longitudinal beam motion in the 10 -4 -10 -5 relative energy spread on radial motion, as well as inadequacy of the data on aberrations of the second order introduced by the accelerating structure are shown. The necessary accountancy of the longitudinal Coulomb field is also shown. For the 1-10 MeV electron energies, 10 9 and 5x10 9 cm -3 bunch density, 5 deg-0.5 deg phase extension the beam current varies within the 0.2-10 mA. The bunch moves in the drift space of the 2.5 m length. The energy spread is 8x10 -8 (1 MeV) to 10 -4 (10 MeV) at the 2 mA beam current [ru

  19. Detectors and luminosity for hadron colliders

    International Nuclear Information System (INIS)

    Diebold, R.

    1983-01-01

    Three types of very high energy hadron-hadron coliders are discussed in terms of the trade-off between energy and luminosity. The usable luminosity depends both on the physics under study and the rate capabilities of the detector

  20. Fast luminosity monitor at LEP

    International Nuclear Information System (INIS)

    Bini, C.; De Pedis, D.; De Zorzi, G.; Diambrini-Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Gauzzi, P.; Zanello, D.

    1994-01-01

    In 1990 the LEP-5 experiment measured luminosity at LEP by detecting the single bremsstrahlung photons emitted in the e + e - collisions. In 1991 the experiment was upgraded to exploit the intrinsic high speed of the method which allows luminosity measurement of the single bunches of LEP. In this paper the LEP-5 upgrade is described and the results of a test performed are discussed. ((orig.))

  1. Hadron collider luminosity limitations

    CERN Document Server

    Evans, Lyndon R

    1992-01-01

    The three colliders operated to date have taught us a great deal about the behaviour of both bunched and debunched beams in storage rings. The main luminosity limitations are now well enough understood that most of them can be stronglu attenuated or eliminated by approriate design precautions. Experience with the beam-beam interaction in both the SPS and the Tevatron allow us to predict the performance of the new generation of colliders with some degree of confidence. One of the main challenges that the accelerator physicist faces is the problem of the dynamic aperture limitations due to the lower field quality expected, imposed by economic and other constraints.

  2. Electromagnetic noise studies in a silicon strip detector, used as part of a luminosity monitor at LEP

    International Nuclear Information System (INIS)

    Oedegaard, T.; Tafjord, H.; Buran, T.

    1994-12-01

    As part of the luminosity monitor SAT in the DELPHI experiment at CERN's Large Electron Positron collider, a tracking detector constructed from silicon strip detector elements was installed in front of an electromagnetic calorimeter. The luminosity was measured by counting the number of Bhabha events at the interaction point of the electron and the positron beams. The tracking detector reconstructs tracks from the interaction point and the calorimeter measures the corresponding particles' energies.The SAT Tracker consists of 504 silicon strip detectors. The strips are DC-coupled to CMOS VLSI-chips, baptized Balder. The chip performs amplification, zero-suppression, digitalisation, and multiplexing. The requirements of good space resolution and high efficiency put strong requirements on noise control. A short description of the geometry and the relevant circuit layout is given. The authors describe the efforts made to minimise the electromagnetic noise in the detector and present some numbers of the noise level using various techniques. 11 refs., 5 figs., 4 tabs

  3. High-luminosity primary vertex selection in top-quark studies using the Collider Detector at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Buzatu, Adrian; /McGill U.

    2006-08-01

    Improving our ability to identify the top quark pair (t{bar t}) primary vertex (PV) on an event-by-event basis is essential for many analyses in the lepton-plus-jets channel performed by the Collider Detector at Fermilab (CDF) Collaboration. We compare the algorithm currently used by CDF (A1) with another algorithm (A2) using Monte Carlo simulation at high instantaneous luminosities. We confirm that A1 is more efficient than A2 at selecting the t{bar t} PV at all PV multiplicities, both with efficiencies larger than 99%. Event selection rejects events with a distance larger than 5 cm along the proton beam between the t{bar t} PV and the charged lepton. We find flat distributions for the signal over background significance of this cut for all cut values larger than 1 cm, for all PV multiplicities and for both algorithms. We conclude that any cut value larger than 1 cm is acceptable for both algorithms under the Tevatron's expected instantaneous luminosity improvements.

  4. Luminosity monitor at PEP

    International Nuclear Information System (INIS)

    Fox, J.D.; Franklin, M.E.B.

    1981-02-01

    The luminosity monitor system utilized by the MKII Detector and by the PEP operators is described. This system processes information from 56 photomultipliers and calculates independent luminosities for each of the 3 colliding bunches in PEP. Design considerations, measurement techniques, and sources of error in the luminosity measurement are discussed

  5. LHC luminosity upgrade detector challenges

    CERN Multimedia

    CERN. Geneva; de Roeck, Albert; Bortoletto, Daniela; Wigmans, Richard; Riegler, Werner; Smith, Wesley H

    2006-01-01

    LHC luminosity upgrade: detector challenges The upgrade of the LHC machine towards higher luminosity (1035 cm -2s-1) has been studied over the last few years. These studies have investigated scenarios to achieve the increase in peak luminosity by an order of magnitude, as well as the physics potential of such an upgrade and the impact of a machine upgrade on the LHC DETECTORS. This series of lectures will cover the following topics: • Physics motivation and machine scenarios for an order of magnitude increase in the LHC peak luminosity (lecture 1) • Detector challenges including overview of ideas for R&D programs by the LHC experiments: tracking and calorimetry, other new detector developments (lectures 2-4) • Electronics, trigger and data acquisition challenges (lecture 5) Note: the much more ambitious LHC energy upgrade will not be covered

  6. To High Luminosity and beyond!

    CERN Multimedia

    CERN Bulletin

    2015-01-01

    This week marks a major milestone for the High Luminosity LHC (HL-LHC - see here) project, as it moves from the design study to the machine construction phase. HL-LHC will extend the LHC’s discovery potential, increasing luminosity by a factor of 10 beyond the original design value and allowing the scientific community to study new phenomena.    Composer Domenico Vicinanza (left) directs the musical performance of sonified LHC data during a special Hi-Lumi event (see box). The green light was given during the 5th Joint HiLumi LHC-LARP annual meeting that took place at CERN from 26 to 30 October 2015. The meeting saw the participation of more than 230 experts from all over the world to discuss the results and achievements of the HiLumi LHC Design Study. During the week, these experts approved the first version of the HL-LHC Technical Design Report – the document that, following the Preliminary Design Report issued in 2014, describes in detail how the LHC upgrade progra...

  7. Luminosity lifetime in the Tevatron

    International Nuclear Information System (INIS)

    Jackson, G.; Finley, D.; Johnson, R.P.; Kerns, Q.; McCarthy, J.; Siemann, R.; Zhang, P.

    1988-01-01

    Since the inauguration of colliding proton-antiproton operations in 1987, the Tevatron has exhibited luminosity lifetimes shorter than expected. During a typical colliding beam storage period, called a store, luminosity is calculated periodically by measuring the charge and emittances of each bunch. The growth of the transverse bunch emittances is the dominant cause of luminosity deterioration. Throughout, this period, the position spectrum of the bunches exhibited betatron signals larger than expected from Schottky noise. A model assuming externally driven betatron oscillations explains both the betatron signals and the emittance growth. A program is underway to improve the Tevatron luminosity lifetime. The abort kickers have been identified as sources of emittance growth, and some quadrupole power supplies are further candidates. Because the horizontal dispersion through the RF cavities is nonzero, RF phase noise has been investigated. Noise in the main dipole regulation circuit has also been studied. 13 refs., 4 figs

  8. Luminosity Measurements with the ATLAS Detector

    CERN Document Server

    Maettig, Stefan; Pauly, T

    For almost all measurements performed at the Large Hadron Collider (LHC) one crucial ingredient is the precise knowledge about the integrated luminosity. The determination and precision on the integrated luminosity has direct implications on any cross-section measurement, and its instantaneous measurement gives important feedback on the conditions at the experimental insertions and on the accelerator performance. ATLAS is one of the main experiments at the LHC. In order to provide an accurate and reliable luminosity determination, ATLAS uses a variety of different sub-detectors and algorithms that measure the luminosity simultaneously. One of these sub-detectors are the Beam Condition Monitors (BCM) that were designed to protect the ATLAS detector from potentially dangerous beam losses. Due to its fast readout and very clean signals this diamond detector is providing in addition since May 2011 the official ATLAS luminosity. This thesis describes the calibration and performance of the BCM as a luminosity detec...

  9. MPX Detectors as LHC Luminosity Monitor

    CERN Document Server

    Sopczak, Andre; Asbah, Nedaa; Bergmann, Benedikt; Bekhouche, Khaled; Caforio, Davide; Campbell, Michael; Heijne, Erik; Leroy, Claude; Lipniacka, Anna; Nessi, Marzio; Pospisil, Stanislav; Seifert, Frank; Solc, Jaroslav; Soueid, Paul; Suk, Michal; Turecek, Daniel; Vykydal, Zdenek

    2015-01-01

    A network of 16 Medipix-2 (MPX) silicon pixel devices was installed in the ATLAS detector cavern at CERN. It was designed to measure the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. This study demonstrates that the MPX network can also be used as a self-sufficient luminosity monitoring system. The MPX detectors collect data independently of the ATLAS data-recording chain, and thus they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors located close enough to the primary interaction point are used to perform van der Meer calibration scans with high precision. Results from the luminosity monitoring are presented for 2012 data taken at sqrt(s) = 8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction rate are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The systematic variations observed in the MPX lum...

  10. First study of small-cell 3D Silicon Pixel Detectors for the High Luminosity LHC

    CERN Document Server

    E. Currás (1), J. Duarte-Campderrós (1), M. Fernández (1), A. García (1), G. Gómez (1), J. González (1), R. Jaramillo (1), D. Moya (1), I. Vila (1), S. Hidalgo (2), M. Manna (2), G. Pellegrini (2), D. Quirion (2), D. Pitzl (3), A. Ebrahimi (4), T. Rohe (5), S. Wiederkehr (5); ((1) Instituto de Física de Cantabria, (2) Instituto de Microelectrónica de Barcelona - Centro Nacional de Microelectrónica, (3) Deutsches Elektronen Synchrotron, (4) University of Hamburg, (5) Paul Scherrer Institut)

    2018-01-01

    A study of 3D pixel sensors of cell size 50 {\\mu}m x 50 {\\mu}m fabricated at IMB-CNM using double-sided n-on-p 3D technology is presented. Sensors were bump-bonded to the ROC4SENS readout chip. For the first time in such a small-pitch hybrid assembly, the sensor response to ionizing radiation in a test beam of 5.6 GeV electrons was studied. Results for non-irradiated sensors are presented, including efficiency, charge sharing, signal-to-noise, and resolution for different incidence angles.

  11. Performance of the ATLAS hadronic Tile Calorimeter in Run-2 and its upgrade for the High Luminosity LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00223789; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) of the ATLAS experiment at the LHC is the central hadronic calorimeter designed for energy reconstruction of hadrons, jets, tauparticles and missing transverse energy. TileCal is a scintillator-steel sampling calorimeter and it covers the region of pseudo-rapidity up to 1.7, with almost 10000 channels measuring energies ranging from ∼30 MeV to ∼2 TeV. Each stage of the signal production, from scintillation light to the signal reconstruction, is monitored and calibrated. The performance of the Tile calorimeter has been studied in-situ employing cosmic ray muons and a large sample of proton-proton collisions, acquired during the operations of the LHC. Prompt isolated muons of high momentum from electroweak bosons decays are employed to study the energy response of the calorimeter at the electromagnetic scale. The calorimeter response to hadronic particles is evaluated with a sample of isolated hadrons. The modelling of the response by the Monte Carlo simulation is discussed. T...

  12. Performance of the ATLAS Hadronic Tile Calorimeter in Run-2 and its Upgrade for the High Luminosity LHC

    CERN Document Server

    Solovyanov, Oleg; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) of the ATLAS experiment at the LHC is the central hadronic calorimeter designed for energy reconstruction of hadrons, jets, tau-particles and missing transverse energy. TileCal is a scintillator-steel sampling calorimeter and it covers the region of pseudorapidity < 1.7. The scintillation light produced in the scintillator tiles is transmitted by wavelength shifting fibers to photomultiplier tubes (PMTs). The analog signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25 ns. The TileCal frontend electronics reads out the signals produced by about 10000 channels measuring energies ranging from ~30 MeV to ~2 TeV. Each stage of the signal production from scintillation light to the signal reconstruction is monitored and calibrated. The performance of the Tile calorimeter has been studied in-situ employing cosmic ray muons and a large sample of proton-proton collisions acquired during the operations of the LHC. Prompt isolated muons of high moment...

  13. Precision of MPX detectors as LHC luminosity monitor

    Energy Technology Data Exchange (ETDEWEB)

    Sopczak, Andre; Ali, Babar; Benes, Petr; Bergmann, Benedikt; Biskup, Bartolomej; Caforio, Davide; Heijne, Erik; Pospisil, Stanislav; Seifert, Frank; Solc, Jaroslav; Suk, Michal; Turecek, Daniel; Vykydal, Zdenek [IEAP CTU in Prague (Czech Republic); Asbah, Nedaa; Leroy, Claude; Soueid, Paul [University of Montreal (Canada); Campbell, Michael; Nessi, Marzio [CERN (Switzerland); Kladiva, Edward [IEP SAS Kosice (Slovakia)

    2015-07-01

    A network consisting of MPX detectors based on Medipix2 silicon pixel devices were originally adapted for measuring the composition and spectral characteristics of the radiation field in the ATLAS experiment and its surroundings. We demonstrate that the MPX network, which consists of 16 MPX detectors, is a self-contained luminosity monitor system. As the MPX detectors are collecting data independently of the ATLAS data-recording chain, they provide independent measurements of the bunch-integrated ATLAS/LHC luminosity. In particular, the MPX detectors close enough to the primary interaction point are used to perform van der Meer calibration scans with good precision. Results from the luminosity monitoring are presented for 2012 data taken at √(s)=8 TeV proton-proton collisions. The characteristics of the LHC luminosity reduction are studied and the effects of beam-beam (burn-off) and beam-gas (single bunch) interactions are evaluated. The variations of the MPX luminosity measurements around the fitted curve lead to a relative uncertainty on the luminosity measurement below 0.3% for one minute time intervals.

  14. Exploratory study of a novel low occupancy vertex detector architecture based on high precision timing for high luminosity particle colliders

    Energy Technology Data Exchange (ETDEWEB)

    Orel, Peter, E-mail: porel@hawaii.edu; Varner, Gary S.; Niknejadi, Pardis

    2017-06-11

    Vertex detectors provide space–time coordinates for the traversing charged particle decay products closest to the interaction point. Resolving these increasingly intense particle fluences at high luminosity particle colliders, such as SuperKEKB, is an ever growing challenge. This results in a non-negligible occupancy of the vertex detector using existing low material budget techniques. Consequently, new approaches are being studied that meet the vertexing requirements while lowering the occupancy. In this paper, we introduce a novel vertex detector architecture. Its design relies on an asynchronous digital pixel matrix in combination with a readout based on high precision time-of-flight measurement. Denoted the Timing Vertex Detector (TVD), it consists of a binary pixel array, a transmission line for signal collection, and a readout ASIC. The TVD aims to have a spatial resolution comparable to the existing Belle2 vertex detector. At the same time it offers a reduced occupancy by a factor of ten while decreasing the channel count by almost three orders of magnitude. Consequently, reducing the event size from about 1 MB/event to about 5.9 kB/event.

  15. Luminosity measurement at CMS

    CERN Document Server

    Leonard, Jessica Lynn

    2014-01-01

    The measurement of the luminosity delivered by the LHC is pivotal for several key physics analyses. During the first three years of running, tremendous steps forwards have been made in the comprehension of the subtleties related to luminosity monitoring and calibration, which led to an unprecedented accuracy at a hadron collider. The detectors and corresponding algorithms employed to estimate online and offline the luminosity in CMS are described. Details are given concerning the procedure based on the Van der Meer scan technique that allowed a very precise calibration of the luminometers from the determination of the LHC beams parameters. What is being prepared in terms of detector and online software upgrades for the next LHC run is also summarized.

  16. New gas electron-multiplier detectors for the endcap muon system of the CMS experiment at the high-luminosity LHC design and prototype performance

    CERN Document Server

    Gruchala, Marek Michal

    2016-01-01

    The high luminosity LHC will require new detectors in the CMS endcap muon system to suppress the trigger rate of background events, to maintain high trigger efficiency for low transverse momentum muons, to enhance the robustness of muon detection in the high-flux environment of the endcap, and to extend the geometrical acceptance. We report on the design and recent progress towards implementing a new system of large-area, triple-foil gas electron-multiplier (GEM) detectors that will be installed in the first three of five muon detector stations in each endcap, the first station being closest to the interaction point. The first station will extend the geometric acceptance in pseudo-rapidity to eta lt 3.0 from the current limit of eta lt 2.4. The second and third stations will enhance the performance in the range 1.6 lt eta lt 2.4. We describe the design of the chambers and readout electronics and report on the performance of prototype systems in tests with cosmic ray muons, high-energy particlebeams, a...

  17. A luminosity measurement at LEP using the L3 detector

    Energy Technology Data Exchange (ETDEWEB)

    Koffeman, E.N.

    1996-06-25

    To perform high precision measurements at particle colliders it is crucial to know the exact intensity of the colliding beams. In particle physics this quantity is generally referred to as the luminosity. The determination of the luminosity in one of the experiments (L3) is the topic of this thesis. The implementation and the use of a silicon strip detector in L3, will be described in detail. In chapter one the most important parameters measured at LEP are discussed, preceded by a short introduction to the Standard Model. The process generally used for luminosity measurements in electron positron colliders is small angle Bhabha scattering. This process is discussed at the end of chapter one. In chapter two the characteristics of the collider and the L3 experiment are given. Together with the signature of the small angle Bhabha scattering, these experimental conditions determine the specifications for the design of the luminosity monitor. The general features of silicon strip detectors for their application in high energy physics are presented in chapter three. Some special attention is given to the behaviour of the sensors used for the tracking detector in the luminosity monitor. The more specific design details of the luminosity monitor are constricted to chapter four. In chapter five the conversion from detector signals into ccordinates relevant for the analysis is explained. The selection of the small angle Bhabha scattering events and the subsequent determination of the luminosity, are presented in chapter six. Systematic uncertainties are carefully studied. Important for a good understanding of the Bhabha selection are the events where a photon is produced in the scattering process. These events are separately studied. In chapter seven a comparison is presented between the radiative events observed in the data and their modelling in the Bhlumi Monte Carlo programme. (orig.).

  18. A luminosity measurement at LEP using the L3 detector

    International Nuclear Information System (INIS)

    Koffeman, E.N.

    1996-01-01

    To perform high precision measurements at particle colliders it is crucial to know the exact intensity of the colliding beams. In particle physics this quantity is generally referred to as the luminosity. The determination of the luminosity in one of the experiments (L3) is the topic of this thesis. The implementation and the use of a silicon strip detector in L3, will be described in detail. In chapter one the most important parameters measured at LEP are discussed, preceded by a short introduction to the Standard Model. The process generally used for luminosity measurements in electron positron colliders is small angle Bhabha scattering. This process is discussed at the end of chapter one. In chapter two the characteristics of the collider and the L3 experiment are given. Together with the signature of the small angle Bhabha scattering, these experimental conditions determine the specifications for the design of the luminosity monitor. The general features of silicon strip detectors for their application in high energy physics are presented in chapter three. Some special attention is given to the behaviour of the sensors used for the tracking detector in the luminosity monitor. The more specific design details of the luminosity monitor are constricted to chapter four. In chapter five the conversion from detector signals into ccordinates relevant for the analysis is explained. The selection of the small angle Bhabha scattering events and the subsequent determination of the luminosity, are presented in chapter six. Systematic uncertainties are carefully studied. Important for a good understanding of the Bhabha selection are the events where a photon is produced in the scattering process. These events are separately studied. In chapter seven a comparison is presented between the radiative events observed in the data and their modelling in the Bhlumi Monte Carlo programme. (orig.)

  19. Luminosity Monitoring in ATLAS with MPX Detectors

    CERN Document Server

    AUTHOR|(CDS)2086061

    2013-01-01

    The ATLAS-MPX detectors are based on the Medipix2 silicon devices designed by CERN for the detection of multiple types of radiation. Sixteen such detectors were successfully operated in the ATLAS detector at the LHC and collected data independently of the ATLAS data-recording chain from 2008 to 2013. Each ATLAS-MPX detector provides separate measurements of the bunch-integrated LHC luminosity. An internal consistency for luminosity monitoring of about 2% was demonstrated. In addition, the MPX devices close to the beam are sensitive enough to provide relative-luminosity measurements during van der Meer calibration scans, in a low-luminosity regime that lies below the sensitivity of the ATLAS calorimeter-based bunch-integrating luminometers. Preliminary results from these luminosity studies are presented for 2012 data taken at $\\sqrt{s}=8$ TeV proton-proton collisions.

  20. TileCal Trigger Tower studies considering additional segmentation on the ATLAS upgrade for high luminosity at LHC

    CERN Document Server

    March, L; The ATLAS collaboration

    2013-01-01

    The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. The TileCal readout consists of about 10000 channels and provides a compact information, called trigger towers (around 2000 signals), to the ATLAS first level online event selection system. The ATLAS upgrade program is divided in three phases: Phase 0 occurs during 2013- 2014 and prepares the LHC to reach peak luminosities of 10^34 cm2s-1; Phase 1, foreseen for 2018-1019, prepares the LHC for peak luminosity up to 2-3 x 10^34 cm2s-1, corresponding to 55 to 80 interactions per bunch-crossing with 25 ns bunch interval; and Phase 2 is foreseen for 2022-2023, whereafter the peak luminosity will reach 5-7 x 1034 cm2s-1 (HL-LHC). The ATLAS experiment is operating very well since 2009 providing large amount of data for physics analysis. The online event selection system (trigger system) was designed to reject the huge amount of background noise generated at LHC and is one of the main systems re...

  1. High luminosity particle colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.

    1997-03-01

    The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p anti p), lepton (e + e - , μ + μ - ) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed

  2. Performance of new radiation tolerant thin n-in-p Silicon pixel sensors for the CMS experiment at High Luminosity LHC

    CERN Document Server

    Dalla Betta, G.F; Darbo, G; Dinardo, Mauro; Giacomini, G; Menasce, Dario; Meschini, Marco; Messineo, Alberto; Moroni, Luigi; Rivera, Ryan Allen; Ronchin, S; Uplegger, Lorenzo; Viliani, Lorenzo; Zoi, Irene; Zuolo, Davide

    2017-01-01

    The High Luminosity upgrade of the CERN-LHC (HL-LHC) demands for a new high-radiation tolerant solid-state pixel sensor capable of surviving fluencies up to a few 10$^{16}$ particles/cm$^2$ at $\\sim$3 cm from the interaction point. To this extent the INFN ATLAS-CMS joint research activity in collaboration with Fondazione Bruno Kessler-FBK, is aiming at the development of thin n-in-p type pixel sensors for the HL-LHC. The R and D covers both planar and single-sided 3D columnar pixel devices made with the Si-Si Direct Wafer Bonding technique, which allows for the production of sensors with 100~$\\mu {\\rm m}$ and 130~$\\mu {\\rm m}$ active thickness for planars, and 130~$\\mu {\\rm m}$ for 3D sensors, the thinnest ones ever produced so far. First prototypes of hybrid modules bump-bonded to the present CMS readout chip have been tested in beam tests. Preliminary results on their performance before and after irradiation are presented.

  3. An early separation scheme for the LHC luminosity upgrade

    CERN Document Server

    Sterbini, G

    2010-01-01

    The present document is organized in five chapters. In the first chapter the framework of the study is described, developing the motivations, the goals and the requirements for the LHC Luminosity Upgrade. We analyze the need for the crossing angle and its impact on the peak luminosity of the collider. After having introduced the Early Separation Scheme, we explain how it may overcome some limitations of the present machine. We compare the nominal LHC crossing scheme with the proposed one underlining its potential in terms of performance and its issues with respect to the integration in the detectors. An analysis of the integrated magnetic field required is given. In the second chapter we introduce one of the most powerful aspect of the scheme: the luminosity leveling. After the description of the physical model adopted, we compare the results of its analytical and numerical solutions. All the potential improvement due to the Early Separation Scheme are shown on the luminosity plane (peak luminosity versus int...

  4. A study of the luminosity produced by an electron beam-emitting rocket in the polar ionosphere: ECHO 7

    International Nuclear Information System (INIS)

    Franz, R.C.

    1991-01-01

    Optical observations made during the ECHO 7 experiment show for the first time the luminous manifestations of the Beam-Plasma-Interaction in a space environment. The optical observations were made using photometers and a low-light-level television camera over an altitude range of 90 to 290 km. Imagery, obtained for the first time in the ECHO series, show the luminous spatial characteristics of the BPI including the formation of diffuse luminous columns extending along the magnetic field in the same and opposite directions as beam propagation. The beam-plasma-discharge (BPD) evolved from the BPI, igniting first about 140 km, and quenching at 115 km. The BPD appeared as discrete enhancements in the intensity of portions of the diffuse columns extending 200 to 225 m along the magnetic field line. Relaxations oscillations, or non-steady BPD with frequencies between 20 and 45 Hz were observed prior to BPD initiation. At 108 km, the distinct Larmor spiral structure of the beam became visible for distance of about 300 meters along the field. Periodic attitude control system (ACS) Nitrogen gas releases producing spectacular luminosity patterns were seen during the gun operation throughout the flight. The injected gas affected the vehicle neutralization current flow pattern causing current to be concentrated in the gas plume as it flowed toward the MAIN payload. In the absence of ACS gas, the luminosity pattern surrounding the MAIN payload showed an asymmetry, being brighter at the opposite end of the MAIN away from the electron gun

  5. Conceptual study of the cryostats for the cold powering system for the triplets of the High Luminosity LHC

    Science.gov (United States)

    Ballarino, A.; Giannelli, S.; Jacquemod, A.; Leclercq, Y.; Ortiz Ferrer, C.; Parma, V.

    2017-12-01

    The High Luminosity LHC (HL-LHC) is a project aiming to upgrade the Large Hadron Collider (LHC) after 2020-2025 in order to increase the integrated luminosity by about one order of magnitude and extend the operational capabilities until 2035. The upgrade of the focusing triplet insertions for the Atlas and CMS experiments foresees using superconducting magnets operating in a pressurised superfluid helium bath at 1.9 K. The increased radiation levels from the particle debris produced by particle collisions in the experiments require that the power converters are placed in radiation shielded zones located in a service gallery adjacent to the main tunnel. The powering of the magnets from the gallery is achieved by means of MgB2 superconducting cables in a 100-m long flexible cryostat transfer line, actively cooled by 4.5 K to 20 K gaseous helium generated close to the magnets. At the highest temperature end, the helium flow cools the High Temperature Superconducting (HTS) current leads before being recovered at room temperature. At the magnet connection side, a dedicated connection box allows connection to the magnets and a controlled boil-off production of helium for the cooling needs of the powering system. This paper presents the overall concept of the cryostat system from the magnet connection boxes, through the flexible cryostat transfer line, to the connection box of the current leads.

  6. Parametric Study of Heat Deposition from Collision Debris into the Insertion Superconducting Magnets for the LHC Luminosity Upgrade

    CERN Document Server

    Hoa, C; Cerutti, F; Koutchouk, Jean-Pierre; Sterbini, G; Wildner, E

    2007-01-01

    With a new geometry in a higher luminosity environment, the power deposition in the superconducting magnets becomes a critical aspect to analyze and to integrate in the insertion design. In this paper, we quantify the power deposited in magnets insertion at variable positions from the interaction point (IP). A fine characterization of the debris due to the proton-proton collisions at 7 TeV, shows that the energetic particles in the very forward direction give rise to non intuitive dependences of the impacting energy on the magnet front face and inner surface. The power deposition does not vary significantly with the distance to the interaction point, because of counterbalancing effects of different contributions to power deposition. We have found out that peak power density in the magnet insertion does not vary significantly with or without the Target Absorber Secondaries (TAS) protection.

  7. Luminosity Optimization Feedback in the SLC

    International Nuclear Information System (INIS)

    1999-01-01

    The luminosity optimization at the SLC has been limited by the precision with which one can measure the micron size beams at the Interaction Point. Ten independent tuning parameters must be adjusted. An automated application has been used to scan each parameter over a significant range and set the minimum beam size as measured with a beam-beam deflection scan. Measurement errors limited the accuracy of this procedure and degraded the resulting luminosity. A new luminosity optimization feedback system has been developed using novel dithering techniques to maximize the luminosity with respect to the 10 parameters, which are adjusted one at a time. Control devices are perturbed around nominal setpoints, while the averaged readout of a digitized luminosity monitor measurement is accumulated for each setting. Results are averaged over many pulses to achieve high precision and then fitted to determine the optimal setting. The dithering itself causes a small loss in luminosity, but the improved optimization is expected to significantly enhance the performance of the SLC. Commissioning results are reported

  8. Selected issues for the LHC luminosity upgrade

    International Nuclear Information System (INIS)

    Laface, E.

    2008-12-01

    The Large Hadron Collider started its operations on September 10. 2008. In a realistic forecast it is supposed to demonstrate (or confute) the existence of the Higgs boson for the year 2014. After this date the physics of rare events will be explored more in details and an upgrade of the luminosity can make an important difference in the program of experiments at CERN. This thesis proposes several ideas to increase the luminosity of ATLAS and CMS experiments and the acceptance of TOTEM experiment. The main object of study is the Interaction Region, that consists in the set of magnets in charge to provide the final beam focalization for the collisions. The Interaction Region is studied with the methods of beam optics and beam dynamics to design new layouts for the upgrade. These layouts are also explored from the point of view of integrability in the existing experiments developing the analysis of energy deposition and misalignment tolerances. This study was performed with the use of analytical methods for the general considerations and numerical methods for the parameters optimization. (author)

  9. Emittance scans for CMS luminosity calibration in 2017

    CERN Document Server

    CMS Collaboration

    2018-01-01

    Emittance scans are short van der Meer type scans performed at the beginning and at the end of LHC fills. The beams are scanned against each other in X and Y planes in 7 displacement steps. These scans are used for LHC diagnostics and since 2017 for a cross check of the CMS luminosity calibration. An XY pair of scans takes around 3 minutes. The BRIL project provides to LHC three independent online luminosity measurement from the Pixel Luminosity Telescope (PLT), the Fast Beam Condition Monitor (BCM1F) and the Forward calorimeter (HF). The excellent performance of the BRIL detector front-ends, fast back-end electronics and CMS XDAQ based data processing and publication allow the use of emittance scans for linearity and stability studies of the luminometers. Emittance scans became a powerful tool and dramatically improved the understanding of the luminosity measurement during the year. Since each luminometer is independently calibrated in every scan the measurements are independent and ratios of luminometers ca...

  10. Precision luminosity measurement at LHCb with beam-gas imaging

    International Nuclear Information System (INIS)

    Barschel, Colin

    2014-01-01

    The luminosity is the physical quantity which relates the cross-section to the production rate in collider experiments. The cross-section being the particle physics observable of interest, a precise determination of the luminosity is required. This work presents the absolute luminosity calibration results performed at the Large Hadron Collider beauty (LHCb) experiment at CERN using a novel method based on beam-gas interactions with data acquired at a center of mass energy √(s)=8 TeV and √(s)=2.76 TeV. Reconstructed beam-gas interaction vertices in LHCb are used to measure the beam profiles, thus making it possible to determine the beams overlap integral. An important element of this work was to install and use a neon gas injection system to increase the beam-gas interaction rate. The precision reached with the beam-gas imaging method relies on the two-dimensional beam shape determination developed in this work. For such precision, the interaction vertex resolution is an important ingredient. Therefore, a new method has been developed using all reconstructed vertices in order to improve the understanding of the vertex resolution. In addition to the overlap integral, the knowledge of the colliding bunch populations is required to measure the luminosity. The determination of the bunch populations relies on LHC instruments to measure the bunch population fractions and the total beam intensity. Studies performed as part of this work resulted in a reduction of the bunch current normalization uncertainty from ±2.7% to ±0.2% and making it possible to achieve precision luminosity measurements at all LHC experiments. Furthermore, information on beam-gas interactions not originating from nominally filled bunches was analyzed to determine the charge fraction not participating in bunch collisions. The knowledge of this fraction is required to correct the total beam intensity. The reference cross-section of pp interactions with at least two tracks in the vertex detector

  11. CORRELATION BETWEEN GROUP LOCAL DENSITY AND GROUP LUMINOSITY

    Energy Technology Data Exchange (ETDEWEB)

    Deng Xinfa [School of Science, Nanchang University, Jiangxi 330031 (China); Yu Guisheng [Department of Natural Science, Nanchang Teachers College, Jiangxi 330103 (China)

    2012-11-10

    In this study, we investigate the correlation between group local number density and total luminosity of groups. In four volume-limited group catalogs, we can conclude that groups with high luminosity exist preferentially in high-density regions, while groups with low luminosity are located preferentially in low-density regions, and that in a volume-limited group sample with absolute magnitude limit M{sub r} = -18, the correlation between group local number density and total luminosity of groups is the weakest. These results basically are consistent with the environmental dependence of galaxy luminosity.

  12. Luminosity function of the brightest galaxies in the IRAS survey

    International Nuclear Information System (INIS)

    Soifer, B.T.; Sanders, D.B.; Madore, B.F.; Neugebauer, G.; Persson, C.J.; Persson, S.E.; Rice, W.L.

    1987-01-01

    Results from a study of the far infrared properties of the brightest galaxies in the IRAS survey are described. There is a correlation between the infrared luminosity and the infrared to optical luminosity ratio and between the infrared luminosity and the far infrared color temperature in these galaxies. The infrared bright galaxies represent a significant component of extragalactic objects in the local universe, being comparable in space density to the Seyferts, optically identified starburst galaxies, and more numerous than quasars at the same bolometric luminosity. The far infrared luminosity in the local universe is approximately 25% of the starlight output in the same volume

  13. Mechanical studies towards a silicon micro-strip super module for the ATLAS inner detector upgrade at the high luminosity LHC

    International Nuclear Information System (INIS)

    Barbier, G; Cadoux, F; Clark, A; Favre, Y; Ferrere, D; Gonzalez-Sevilla, S; Iacobucci, G; Marra, D La; Perrin, E; Seez, W; Endo, M; Hanagaki, K; Hara, K; Ikegami, Y; Nakamura, K; Takubo, Y; Terada, S; Jinnouchi, O; Nishimura, R; Takashima, R

    2014-01-01

    It is expected that after several years of data-taking, the Large Hadron Collider (LHC) physics programme will be extended to the so-called High-Luminosity LHC, where the instantaneous luminosity will be increased up to 5 × 10 34  cm −2  s −1 . For the general-purpose ATLAS experiment at the LHC, a complete replacement of its internal tracking detector will be necessary, as the existing detector will not provide the required performance due to the cumulated radiation damage and the increase in the detector occupancy. The baseline layout for the new ATLAS tracker is an all-silicon-based detector, with pixel sensors in the inner layers and silicon micro-strip detectors at intermediate and outer radii. The super-module (SM) is an integration concept proposed for the barrel strip region of the future ATLAS tracker, where double-sided stereo silicon micro-strip modules (DSM) are assembled into a low-mass local support (LS) structure. Mechanical aspects of the proposed LS structure are described

  14. LHC Report: a break from luminosity production

    CERN Multimedia

    Jan Uythoven for the LHC team

    2016-01-01

    The LHC has been in great shape over the last few months, delivering over 20 fb-1 of integrated luminosity before the ICHEP conference in Chicago at the beginning of August. This is not much below the 25 fb-1 target for the whole of 2016. With this success in mind, a break in luminosity production was taken for six days, starting on 26 July 2016, for a machine development period.   This year, 20 days of the LHC schedule are devoted to machine development with the aim of carrying out detailed studies of the accelerator. The 20 days are divided over five different periods, called MD blocks. They can be seen as an investment in the future, so the machine can produce collisions more efficiently in the months and years to come. A detailed programme is worked out for each MD block, whereby different specialist teams are assigned periods of four to twelve hours, depending on the topic, to perform their previously approved tests. The MD program continues 24 hours per day, as in normal physics operation. One...

  15. Flare colours and luminosities

    International Nuclear Information System (INIS)

    Cristaldi, S.; Rodono, M.

    1975-01-01

    Flare colours determined from simultaneous UBV observations made at Catania Observatory and from sequential UBV observations made at McDonald Observatory are presented. They fit fairly well with the theoretical colours computed according to the Gurzadian's (1970) non-thermal model. Only part of the observed flare colours are consistent with the solar type models by Gershberg (1967) and Kunkel (1970). From a B-band patrol of UV Cet-type stars carried out from 1967 to 1972, some quantitative estimates of flare frequencies and luminosities and their average contributions to the stellar radiation are given. The corresponding parameters for the Sun, which were estimated from 'white light' flare activity, are also given for comparison. The Sun and V 1216 Sgr can be regarded as low-activity flare stars of the type found by Kunkel (1973). (Auth.)

  16. Remarks on the maximum luminosity

    Science.gov (United States)

    Cardoso, Vitor; Ikeda, Taishi; Moore, Christopher J.; Yoo, Chul-Moon

    2018-04-01

    The quest for fundamental limitations on physical processes is old and venerable. Here, we investigate the maximum possible power, or luminosity, that any event can produce. We show, via full nonlinear simulations of Einstein's equations, that there exist initial conditions which give rise to arbitrarily large luminosities. However, the requirement that there is no past horizon in the spacetime seems to limit the luminosity to below the Planck value, LP=c5/G . Numerical relativity simulations of critical collapse yield the largest luminosities observed to date, ≈ 0.2 LP . We also present an analytic solution to the Einstein equations which seems to give an unboundedly large luminosity; this will guide future numerical efforts to investigate super-Planckian luminosities.

  17. Operational results from the LHC luminosity monitors

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, R.; Ratti, A.; Matis, H.S.; Stezelberger, T.; Turner, W.C.; Yaver, H.; Bravin, E.

    2011-03-28

    The luminosity monitors for the high luminosity regions in the LHC have been operating to monitor and optimize the luminosity since 2009. The device is a gas ionization chamber inside the neutral particle absorber 140 m from the interaction point and monitors showers produced by high energy neutral particles from the collisions. It has the ability to resolve the bunch-by-bunch luminosity as well as to survive the extreme level of radiation in the nominal LHC operation. We present operational results of the device during proton and lead ion operations in 2010 and make comparisons with measurements of experiments. The Large Hadron Collider (LHC) at CERN can accelerate proton and lead ion beams to 7 TeV and 547 TeV and produce collisions of these particles. Luminosity measures performance of the LHC and is particularly important for experiments in high luminosity interaction points (IPs), ATLAS (IP1) and CMS (IP5). To monitor and optimize the luminosities of these IPs, BRAN (Beam RAte Neutral) detectors [1, 2] have been installed and operating since the beginning of the 2009 operation [3]. A neutral particle absorber (TAN) protects the D2 separation dipole from high energy forward neutral particles produced in the collisions [4]. These neutral particles produce electromagnetic and hadronic showers inside the TAN and their energy flux is proportional to the collision rate and hence to the luminosity. The BRAN detector is an Argon gas ionization chamber installed inside the TANs on both sides of the IP1 and IP5 and monitors the relative changes in the luminosity by detecting the ionization due to these showers. When the number of collisions per bunch crossing (multiplicity) is small, the shower rate inside the TAN is also proportional to the luminosity. Hence, the detector is designed to operate by measuring either the shower rate (counting mode for low and intermediate luminosities) or the average shower flux (pulse height mode for high luminosities). The detector is

  18. The BRAN luminosity detectors for the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Matis, H.S.; Placidi, M.; Ratti, A.; Turner, W.C. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bravin, E. [CERN, 1211 Geneva 23 (Switzerland); Miyamoto, R. [European Spallation Source, ESS AB, P.O. Box 176, SE-221 00 Lund (Sweden)

    2017-03-11

    This paper describes the several phases which led, from the conceptual design, prototyping, construction and tests with beam, to the installation and operation of the BRAN (Beam RAte of Neutrals) relative luminosity monitors for the LHC. The detectors have been operating since 2009 to contribute, optimize and maintain the accelerator performance in the two high luminosity interaction regions (IR), the IR1 (ATLAS) and the IR5 (CMS). The devices are gas ionization chambers installed inside a neutral particle absorber 140 m away from the Interaction Points in IR1 and IR5 and monitor the energy deposited by electromagnetic showers produced by high-energy neutral particles from the collisions. The detectors have the capability to resolve the bunch-by-bunch luminosity at the 40 MHz bunch rate, as well as to survive the extreme level of radiation during the nominal LHC operation. The devices have operated since the early commissioning phase of the accelerator over a broad range of luminosities reaching 1.4×10{sup 34} cm{sup −2} s{sup −1} with a peak pileup of 45 events per bunch crossing. Even though the nominal design luminosity of the LHC has been exceeded, the BRAN is operating well. After describing how the BRAN can be used to monitor the luminosity of the collider, we discuss the technical choices that led to its construction and the different tests performed prior to the installation in two IRs of the LHC. Performance simulations are presented together with operational results obtained during p-p operations, including runs at 40 MHz bunch rate, Pb-Pb operations and p-Pb operations.

  19. KEKB B-Factory, the luminosity frontier

    International Nuclear Information System (INIS)

    Oide, Katsunobu

    2009-01-01

    The experiment at the KEKB B-Factory, as well as PEP-II, brought the final blow on the 2008 Nobel Prize in Physics for the Kobayashi-Maskawa theory. A few key issues will be described on the design and performance of KEKB to make the world's highest luminosity possible. (author)

  20. The period-luminosity relation for Cepheids

    International Nuclear Information System (INIS)

    Brodie, J.P.

    1980-01-01

    Numerical simulations of the empirical determination of the period-luminosity-colour relation for classical Cepheids are presented. In this study the quantitative effects of random errors, reddening, sample size and the presence of both colour and period cut-offs (imposed by the finite extent of the instability strip) on the observational redetermination of the original relation are evaluated. Both random errors in the photometry and correlated errors in the reddening corrections are shown to have systematic effects. Especially sensitive to these errors is the colour coefficient in the period-luminosity-colour relation, where the ratio of the error to the width of the instability strip is the determining factor. With present observations only broad confidence limits can be placed on present knowledge of the intrinsic period-luminosity-colour relation and/or its variations from galaxy to galaxy. (author)

  1. Correlation function of the luminosity distances

    Energy Technology Data Exchange (ETDEWEB)

    Biern, Sang Gyu; Yoo, Jaiyul, E-mail: sgbiern@physik.uzh.ch, E-mail: jyoo@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich (Switzerland)

    2017-09-01

    We present the correlation function of the luminosity distances in a flat ΛCDM universe. Decomposing the luminosity distance fluctuation into the velocity, the gravitational potential, and the lensing contributions in linear perturbation theory, we study their individual contributions to the correlation function. The lensing contribution is important at large redshift ( z ∼> 0.5) but only for small angular separation (θ ∼< 3°), while the velocity contribution dominates over the other contributions at low redshift or at larger separation. However, the gravitational potential contribution is always subdominant at all scale, if the correct gauge-invariant expression is used. The correlation function of the luminosity distances depends significantly on the matter content, especially for the lensing contribution, thus providing a novel tool of estimating cosmological parameters.

  2. Luminosity class of neutron reflectometers

    Energy Technology Data Exchange (ETDEWEB)

    Pleshanov, N.K., E-mail: pnk@pnpi.spb.ru

    2016-10-21

    The formulas that relate neutron fluxes at reflectometers with differing q-resolutions are derived. The reference luminosity is defined as a maximum flux for measurements with a standard resolution. The methods of assessing the reference luminosity of neutron reflectometers are presented for monochromatic and white beams, which are collimated with either double diaphragm or small angle Soller systems. The values of the reference luminosity for unified parameters define luminosity class of reflectometers. The luminosity class characterizes (each operation mode of) the instrument by one number and can be used to classify operating reflectometers and optimize designed reflectometers. As an example the luminosity class of the neutron reflectometer NR-4M (reactor WWR-M, Gatchina) is found for four operation modes: 2.1 (monochromatic non-polarized beam), 1.9 (monochromatic polarized beam), 1.5 (white non-polarized beam), 1.1 (white polarized beam); it is shown that optimization of measurements may increase the flux at the sample up to two orders of magnitude with monochromatic beams and up to one order of magnitude with white beams. A fan beam reflectometry scheme with monochromatic neutrons is suggested, and the expected increase in luminosity is evaluated. A tuned-phase chopper with a variable TOF resolution is recommended for reflectometry with white beams.

  3. Symmetric Moeller/Bhabha luminosity monitor for the OLYMPUS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Capozza, Luigi; Maas, Frank; Perez Benito, Roberto; Rodriguez Pineiro, David [Helmholtz-Institut Mainz, Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); O' Connor, Colton [Massachusetts Institute of Technology, Cambridge, MA (United States); Diefenbach, Juergen; Glaeser, Boris [Institut fuer Kernphysik, Mainz (Germany); Khaneft, Dmitry [Johannes Gutenberg-Universitaet Mainz, Mainz (Germany); Helmholtz-Institut Mainz, Mainz (Germany); Ma, Yue [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2015-07-01

    The OLYMPUS experiment is motivated by the discrepancy between the proton electric to magnetic form factor ratio measured using unpolarized and polarized electron scattering. This discrepancy can be explained by a two-photon exchange (TPE) contribution in lepton-hadron scattering. Measuring the ratio of electron-proton and positron-proton elastic scattering cross sections the contribution of the TPE can be determined. For this purpose, very precise measurements of the relative luminosity have to be performed. The symmetric Moeller/Bhabha luminosity monitor, made of calorimetric lead fluoride (PbF{sub 2}) Cherenkov detectors, provides precise data from counting coincidences Moeller and Bhabha events. High sensitivity to the geometrical acceptance and alignment requires accurate study of systematic uncertainties.

  4. High Luminosity LHC Project Description

    CERN Document Server

    Apollinari, Giorgio; Rossi, Lucio

    2014-01-01

    The High Luminosity LHC (HL-LHC) is a novel configuration of the Large Hadron Collider, aiming at increasing the luminosity by a factor five or more above the nominal LHC design, to allow increasing the integrated luminosity, in the high luminosity experiments ATLAS and CMS, from the 300 fb-1 of the LHC original design up to 3000 fb-1 or more. This paper contains a short description of the main machine parameters and of the main equipment that need to be developed and installed. The preliminary cost evaluation and the time plan are presented, too. Finally, the international collaboration that is supporting the project, the governance and the project structure are discussed, too.

  5. Luminosity Measurement at the Compact Linear Collider

    CERN Document Server

    Schwartz, Rina; Levy, Aharon

    The compact linear collider (CLIC) is a proposed high energy accelera- tor, planned to collide electrons with positrons at a maximal center-of-mass energy of 3 TeV, and a peak luminosity of 5.9·1034 cm−2s−1. Complementary to the large hadron collider, CLIC is to provide high precision measurements of both known and new physics processes. The required relative precision of luminosity measurement at the CLIC is 10−2. The measurement will be done by the luminosity calorimeter (Lumi- Cal), designed to measure the rate of low angles Bhabha scattering events, a process with well-known cross-section from electroweak theory. Beam-beam effects, which are of unprecedented intensity at the CLIC, influence the lumi- nosity spectrum shape and create a significant amount of background charge deposits in the LumiCal, thus setting a challenge on the requirement for precision. The ability of the LumiCal to provide accurate luminosity mea- surement depends on its ability to perform accurate energy reconstruction of Bhab...

  6. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  7. The High Luminosity LHC Project

    Science.gov (United States)

    Rossi, Lucio

    The High Luminosity LHC is one of the major scientific project of the next decade. It aims at increasing the luminosity reach of LHC by a factor five for peak luminosity and a factor ten in integrated luminosity. The project, now fully approved and funded, will be finished in ten years and will prolong the life of LHC until 2035-2040. It implies deep modifications of the LHC for about 1.2 km around the high luminosity insertions of ATLAS and CMS and relies on new cutting edge technologies. We are developing new advanced superconducting magnets capable of reaching 12 T field; superconducting RF crab cavities capable to rotate the beams with great accuracy; 100 kA and hundred meter long superconducting links for removing the power converter out of the tunnel; new collimator concepts, etc... Beside the important physics goals, the High Luminosity LHC project is an ideal test bed for new technologies for the next hadron collider for the post-LHC era.

  8. CMS Luminosity Calibration for the pp Reference Run at $\\sqrt{s}=5.02~\\mathrm{TeV}$

    CERN Document Server

    CMS Collaboration

    2016-01-01

    The measurement of the integrated luminosity delivered to the CMS Experiment during the very first LHC proton-proton run at $5.02~\\mathrm{TeV}$ center-of-mass energy is presented. The Pixel Cluster Counting method is used and the absolute luminosity scale calibration is derived from an analysis of Van der Meer Scans performed in November 2015. The overall uncertainty on the luminosity measurement is $2.3\\%$. The time stability of such calibrations is also studied and taken into account for the final systematic uncertainty.

  9. Academic Training - LHC luminosity upgrade: detector challenges

    CERN Multimedia

    Françoise Benz

    2006-01-01

    ACADEMIC TRAINING LECTURE SERIES 13, 14, 15, March, from 11:00 to 12:00 - 16 March from 10:00 to 12:00 Main Auditorium, bldg. 500 on 14, 15 March, Council Room on 13, 16 March LHC luminosity upgrade: detector challenges A. De Roeck / CERN-PH, D. Bortoletto / Purdue Univ. USA, R. Wigmans / Texas, Tech Univ. USA, W. Riegler / CERN-PH, W. Smith / Wisconsin Univ. USA The upgrade of the LHC machine towards higher luminosity (1035 cm-2s-1) has been studied over the last few years. These studies have investigated scenarios to achieve the increase in peak luminosity by an order of magnitude, as well as the physics potential of such an upgrade and the impact of a machine upgrade on the LHC DETECTORS. This series of lectures will cover the following topics: Physics motivation and machine scenarios for an order of magnitude increase in the LHC peak luminosity (lecture 1) Detector challenges including overview of ideas for R&D programs by the LHC experiments: tracking and calorimetry, other new detector ...

  10. Robust Tracking at the High Luminosity LHC

    CERN Document Server

    Woods, Natasha Lee; The ATLAS collaboration

    2018-01-01

    The High Luminosity LHC (HL-LHC) aims to increase the LHC data-set by an order of magnitude in order to increase its potential for discoveries. Starting from the middle of 2026, the HL-LHC is expected to reach the peak instantaneous luminosity of 7.5×10^34cm^-2s^-1 which corresponds to about 200 inelastic proton-proton collisions per beam crossing. To cope with the large radiation doses and high pileup, the current ATLAS Inner Detector will be replaced with a new all-silicon Inner Tracker. In this talk the expected performance of tracking and vertexing with the HL-LHC tracker is presented. Comparison is made to the performance with the Run2 detector. Ongoing developments of the track reconstruction for the HL-LHC are also discussed.

  11. Luminosity function of high redshift quasars

    International Nuclear Information System (INIS)

    Vaucher, B.G.

    1982-01-01

    Data from ten different emission-line surveys are included in a study of the luminosity function of high redshift quasars. Five of the surveys are analyzed through microdensitometric techniques and the data for new quasars are given. The uncertainties in magnitudes, redshifts, and line equivalent widths are assessed and found to be +-0.3 mag. +-0.04 in z and approx. 30%, respectively. Criteria for selecting the redshift range 1.8 less than or equal to z - 1 Mpc - 1 for each of two cosmologies (q 0 = 1 and q 0 = 0). For either cosmology, the function exhibits a steep increase with magnitude at high luminosities and a gentler increase at intermediate luminosities. Data from the new surveys indicate a possible turnover at the faint end of the distribution. Total volume densities of quasars are computed for each of three extrapolations of the trend of the data to low luminosities. These densities are compared to those of active galaxies and field galaxies

  12. Perils at the heart of the Milky Way: Systematic effects for studying low-luminosity accretion onto Sgr A*

    Science.gov (United States)

    Corrales, Lia; Mon, Brayden; Haggard, Daryl; Baganoff, Frederick K.; Garmire, Gordon; Degenaar, Nathalie; Reynolds, Mark

    2017-08-01

    The supermassive black hole at the center of our galaxy, Sgr A*, is surprisingly under-luminous. This problem has motivated a host of theoretical models to explain low-level radiatively inefficient accretion flows onto compact objects. We discuss how the Galactic Center sight line, which is optically thick to the scattering of soft X-rays (tau ~ 5), affects high resolution studies of the accretion flow around Sgr A*. X-ray light from compact objects in the dense GC environment is scattered by foreground dust, producing scattering echoes that are time delayed relative to the X-ray source's light curve. We discuss the scattering halo of SWIFT J174540.7-290015, which underwent the brightest X-ray outburst within 30’' of Sgr A*. Preliminary fits to the scattering halo suggest that a small amount of foreground dust, within 250 pc of the GC, affects the X-ray surface brightness profile within 10’' of any GC point source. The associated time delay is on the order of several hours, which is important for understanding the quiescent accretion flow of Sgr A*. We take advantage of the Chandra Galactic Center XVP dataset to explore the effect of the interstellar medium on the inferred characteristics of Sgr A*.

  13. Study of Quench Protection for the Nb$_3$Sn Low-β Quadrupole for the LHC Luminosity Upgrade (HiLumi-LHC)

    CERN Document Server

    Todesco, E; Bellomo, G; Sorbi, M; Ambrosio, G; Chlachidze, G; Felice, H; Marchevsky, M; Salmi, T

    2015-01-01

    The HiLumi program is aiming to develop and build new Nb$_{3}$Sn, high-field (12 T) and large aperture (150 mm) superconducting quadrupoles, which will be inserted in the LHC interaction regions and will provide the final focusing of the beam, in the program of the luminosity upgrade. The quench protection of these magnets is one of the most challenging aspects, mainly because of the large value of the magnet inductance (160 mH for the configuration with two 8 m long magnets in series), of the large value of the stored magnetic energy density in the coils (0.12 J/mm3, a factor 2 larger than in the conventional NbTi quadrupoles) and of the use of Nb$_{3}$Sn as conductor, which has never been used for large accelerator magnets. Previous works have demonstrated that a “standard” conservative analysis, assuming quench heaters only on the coils outer layer, gives high hot spot temperature, close to the design limit (350 K). In this paper, a new study of quench protection is presented. The benefic effects of la...

  14. LUCID: The ATLAS Luminosity Detector

    CERN Document Server

    Cabras, Grazia; The ATLAS collaboration

    2018-01-01

    After the long shut-down, the LHC Run2 has started with new running conditions with respect to Run1: in particular the centre of mass energy has reached 13 TeV and the bunch-spacing is now 25 ns. In order to cope with these changes, the ATLAS luminosity monitor LUCID and its electronics have been completely rebuilt. This note describes the new detector and electronics, the new luminosity algorithms and the new calibration systems, with a brief review of the first results about the stability of the measurement and evaluation of systematic uncertainties for the 2015 data-taking.

  15. LUCID: the ATLAS Luminosity Detector

    CERN Document Server

    Fabbri, Laura; The ATLAS collaboration

    2018-01-01

    A precise measurement of luminosity is a key component of the ATLAS program: its uncertainty is a systematics for all cross-section measurements, from Standard Model processes to new discoveries, and for some precise measurements it can be dominant. To be predictive a precision compatible with PDF uncertainty ( 1-2%) is desired. LUCID (LUminosity Cherenkov Integrating Detector) is sensitive to charged particles generated by the pp collisions. It is the only ATLAS dedicated detector for this purpose and the referred one during the second run of LHC data taking.

  16. Wet drift chambers for precise luminosity

    International Nuclear Information System (INIS)

    Anderson, B.E.; Kennedy, B.W.; Ahmet, K.; Attree, D.J.; Barraclough, G.A.; Cresswell, M.J.; Hayes, D.A.; Miller, D.J.; Selby, C.; Sherwood, P.

    1994-01-01

    A set of high-precision compact drift chambers has been a vital component of the OPAL luminosity monitor since the start of data-taking at LEP. They were augmented in 1992 by the addition of Small Angle Reference Chambers with a very similar design to the original chamber. The performance of the chambers is reviewed, highlighting both the importance of using polyalkylene glycol (Breox) to maintain a uniform and parallel electric field and the construction techniques used to sustain the required field strength. We describe some of the operating problems, with their solutions, and show how the chambers have been used in achieving a systematic error of 0.41% on the luminosity measurement. ((orig.))

  17. Accelerator physics and technology limitations to ultimate energy and luminosity in very large hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    P. Bauer et al.

    2002-12-05

    The following presents a study of the accelerator physics and technology limitations to ultimate energy and luminosity in very large hadron colliders (VLHCs). The main accelerator physics limitations to ultimate energy and luminosity in future energy frontier hadron colliders are synchrotron radiation (SR) power, proton-collision debris power in the interaction regions (IR), number of events-per-crossing, stored energy per beam and beam-stability [1]. Quantitative estimates of these limits were made and translated into scaling laws that could be inscribed into the particle energy versus machine size plane to delimit the boundaries for possible VLHCs. Eventually, accelerator simulations were performed to obtain the maximum achievable luminosities within these boundaries. Although this study aimed at investigating a general VLHC, it was unavoidable to refer in some instances to the recently studied, [2], 200 TeV center-of-mass energy VLHC stage-2 design (VLHC-2). A more thorough rendering of this work can be found in [3].

  18. Conceptual design of the PANDA luminosity monitor and reconstruction strategy to measure the width of the X(3872) state

    Energy Technology Data Exchange (ETDEWEB)

    Randriamalala, Tsitohaina

    2012-04-19

    The PANDA experiment has a great potential to test with high precision QCD in the low momentum transfer region using an antiproton beam of unprecedented quality. The resonance scan method will be used to determine the lineshape of specific hadronic states. It requires a precise knowledge of the luminosity. This thesis develops the conceptual design of the PANDA luminosity monitor and a scan simulation to determine the width resolution of the X(3872) state. The luminosity monitor concept is based on the reconstruction of elastically scattered antiprotons from the interaction region. Monte Carlo performance studies of the detector were carried out. The implementation test was done using a detector prototype instrumented at the COSY accelerator and testing it with proton beam. The studies show that a precision of better than 3% on the luminosity and a width resolution for the X(3872) of about 2% can be achieved.

  19. Precision luminosity measurements at LHCb

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brodzicka, Jolanta; Brook, Nicholas; Brown, Henry; Bursche, Albert; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Calvi, Marta; Calvo Gomez, Miriam; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coco, Victor; Cogan, Julien; Cogneras, Eric; Cojocariu, Lucian; Collazuol, Gianmaria; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dreimanis, Karlis; Dujany, Giulio; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farley, Nathanael; Farry, Stephen; Fay, Robert; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fol, Philip; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; García Pardiñas, Julián; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gascon, David; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Geraci, Angelo; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Gianì, Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, V.V.; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Karodia, Sarah; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Klimaszewski, Konrad; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanfranchi, Gaia; Langenbruch, Christoph; Langhans, Benedikt; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Likhomanenko, Tatiana; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Lohn, Stefan; Longstaff, Iain; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Malinin, Alexander; Manca, Giulia; Mancinelli, Giampiero; Mapelli, Alessandro; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Moggi, Niccolò; Molina Rodriguez, Josue; Monteil, Stephane; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Mussini, Manuel; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Pessina, Gianluigi; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Price, Eugenia; Price, Joseph David; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redi, Federico; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vincente; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruiz, Hugo; Ruiz Valls, Pablo; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilschut, Hans; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2014-12-05

    Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy $\\sqrt{s}$. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for $\\sqrt{s}$ = 2.76, 7 and 8 TeV (proton-proton collisions) and for $\\sqrt{s_{NN}}$ = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at $\\sqrt{s}$ = 8 TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determin...

  20. A Multiwavelength Study of a Sample of 70 μm Selected Galaxies in the COSMOS Field : I. Spectral Energy Distributions and Luminosities

    NARCIS (Netherlands)

    Kartaltepe, Jeyhan S.; Sanders, D. B.; Le Floc'h, E.; Frayer, D. T.; Aussel, H.; Arnouts, S.; Ilbert, O.; Salvato, M.; Scoville, N. Z.; Surace, J.; Yan, L.; Brusa, M.; Capak, P.; Caputi, K.; Carollo, C. M.; Civano, F.; Elvis, M.; Faure, C.; Hasinger, G.; Koekemoer, A. M.; Lee, N.; Lilly, S.; Liu, C. T.; McCracken, H. J.; Schinnerer, E.; Smolčić, V.; Taniguchi, Y.; Thompson, D. J.; Trump, J.

    We present a large robust sample of 1503 reliable and unconfused 70 μm selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, L IR (8-1000 μm), by finding the best-fit template

  1. Does nest luminosity play a role in recognition of parasitic eggs in domed nests? A case study of the red bishop

    Czech Academy of Sciences Publication Activity Database

    Honza, Marcel; Šulc, Michal; Cherry, M. I.

    2014-01-01

    Roč. 101, č. 12 (2014), s. 1009-1015 ISSN 0028-1042 Institutional support: RVO:68081766 Keywords : Brood parasitism * Domed nest * Egg discrimination * Light conditions * Nest luminosity Subject RIV: EG - Zoology Impact factor: 2.098, year: 2014

  2. Physics potential of ATLAS detector with high luminosity

    International Nuclear Information System (INIS)

    Zhou, Bing

    2004-01-01

    The ATLAS detector is designed to exploit the full physics potential in the TeV energy region opened up by the Large Hadron Collider at a center of mass energy of 14 TeV with very high luminosities. The physics performance of the ATLAS detector on Higgs, extra-dimension and strong symmetry breaking scenario is summarized in this note. ATLAS experiment has great discovery potential for these new phenomena with high luminosity. Triple gauge couplings are very sensitive for probing new physics at TeV scale. We show that ATLAS can measure these couplings very precisely with high luminosity. (orig.)

  3. THE BIVARIATE SIZE-LUMINOSITY RELATIONS FOR LYMAN BREAK GALAXIES AT z {approx} 4-5

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kuang-Han; Su, Jian [Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Ferguson, Henry C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ravindranath, Swara, E-mail: kuanghan@pha.jhu.edu [The Inter-University Center for Astronomy and Astrophysics, Pune University Campus, Pune 411007, Maharashtra (India)

    2013-03-01

    We study the bivariate size-luminosity distribution of Lyman break galaxies (LBGs) selected at redshifts around 4 and 5 in GOODS and the HUDF fields. We model the size-luminosity distribution as a combination of log-normal distribution (in size) and Schechter function (in luminosity), therefore it enables a more detailed study of the selection effects. We perform extensive simulations to quantify the dropout-selection completenesses and measurement biases and uncertainties in two-dimensional size and magnitude bins, and transform the theoretical size-luminosity distribution to the expected distribution for the observed data. Using maximum-likelihood estimator, we find that the Schechter function parameters for B {sub 435}-dropouts and are consistent with the values in the literature, but the size distributions are wider than expected from the angular momentum distribution of the underlying dark matter halos. The slope of the size-luminosity (RL) relation is similar to those found for local disk galaxies, but considerably shallower than local early-type galaxies.

  4. THE BIVARIATE SIZE-LUMINOSITY RELATIONS FOR LYMAN BREAK GALAXIES AT z ∼ 4-5

    International Nuclear Information System (INIS)

    Huang, Kuang-Han; Su, Jian; Ferguson, Henry C.; Ravindranath, Swara

    2013-01-01

    We study the bivariate size-luminosity distribution of Lyman break galaxies (LBGs) selected at redshifts around 4 and 5 in GOODS and the HUDF fields. We model the size-luminosity distribution as a combination of log-normal distribution (in size) and Schechter function (in luminosity), therefore it enables a more detailed study of the selection effects. We perform extensive simulations to quantify the dropout-selection completenesses and measurement biases and uncertainties in two-dimensional size and magnitude bins, and transform the theoretical size-luminosity distribution to the expected distribution for the observed data. Using maximum-likelihood estimator, we find that the Schechter function parameters for B 435 -dropouts and are consistent with the values in the literature, but the size distributions are wider than expected from the angular momentum distribution of the underlying dark matter halos. The slope of the size-luminosity (RL) relation is similar to those found for local disk galaxies, but considerably shallower than local early-type galaxies.

  5. The luminosity function of quasars

    Science.gov (United States)

    Pei, Yichuan C.

    1995-01-01

    We propose a new evolutionary model for the optical luminosity function of quasars. Our analytical model is derived from fits to the empirical luminosity function estimated by Hartwick and Schade and Warren, Hewett, and Osmer on the basis of more than 1200 quasars over the range of redshifts 0 approximately less than z approximately less than 4.5. We find that the evolution of quasars over this entire redshift range can be well fitted by a Gaussian distribution, while the shape of the luminosity function can be well fitted by either a double power law or an exponential L(exp 1/4) law. The predicted number counts of quasars, as a function of either apparent magnitude or redshift, are fully consistent with the observed ones. Our model indicates that the evolution of quasars reaches its maximum at z approximately = 2.8 and declines at higher redshifts. An extrapolation of the evolution to z approximately greater than 4.5 implies that quasars may have started their cosmic fireworks at z(sub f) approximately = 5.2-5.5. Forthcoming surveys of quasars at these redshifts will be critical to constrain the epoch of quasar formation. All the results we derived are based on observed quasars and are therefore subject to the bias of obscuration by dust in damped Ly alpha systems. Future surveys of these absorption systems at z approximately greater than 3 will also be important if the formation epoch of quasars is to be known unambiguously.

  6. Luminosity Optimization With Offset, Crossing Angle, and Distortion

    CERN Document Server

    Wu, Juhao

    2005-01-01

    In a linear collider, sources of beam jitter due to kicker noise, quadrupole vibration and long-range transverse wakefields will lead to beam offsets and tilts at the Intersection Point (IP). In addition, sources of emittance dilution such as short-range transverse wakefields or dispersive errors will lead to internal beam distortions. When the IP disruption parameter is large, these beam imperfections will be amplified by a single bunch kink instability which will lead to luminosity loss. In this paper, we study the luminosity loss and then the optimization required to cancel the luminosity loss first analytically and then with simulation.

  7. Performance, operation and detector studies with the ATLAS Resistive Plate Chambers

    International Nuclear Information System (INIS)

    Aielli, G; Bindi, M; Polini, A

    2013-01-01

    Resistive Plate Chambers provide the barrel region of the ATLAS detector with an independent muon trigger and a two-coordinate measurement. The chambers, arranged in three concentric double layers, are operated in a strong magnetic toroidal field and cover a surface area of about 4000 m 2 . During 2011 the LHC has provided proton-proton collisions at 7 TeV in the center-of-mass frame with a steady increase in instantaneous luminosity, summing up to about 5 fb −1 . The operational experience for this running period is presented along with studies of the detector performance as a function of luminosity, environmental conditions and working point settings. Non-event based information including in particular the large number of gas gap currents, individually monitored with nA accuracy, have been used to study the detector behavior with growing luminosity and beam currents. These data are shown to provide, when calibrated, an independent luminosity measurement and a crucial handle for understanding the ATLAS backgrounds well beyond the scope of muon triggering and detection. The measurements presented here allow to plan a strategy for the data taking in the next years and make some predictions about the detector performance at higher luminosities. They also improve the knowledge on RPC detector physics.

  8. Improvement to the D0 luminosity monitor constant

    International Nuclear Information System (INIS)

    Bantley, J.

    1996-03-01

    The D0 experiment has previously calculated its luminosity using the visible cross section (luminosity monitor constant) for its Level 0 trigger, σ L0 = 48.2 mb, based on the world average pp inelastic cross sections at √s = 1.8 TeV. The error on luminosity had been set at 12%. Recent studies using the MBR and DTUJET Monte Carlo event generators and unbiased D0 data samples have resulted in a more precise determination of the D0 luminosity monitor constant. The result, σ L0 = 46.7 ± 2.5 mb, lowers the central value by 3.1% and reduces the error to 5.4%. 12 refs., 7 figs., 9 tabs

  9. The low-luminosity stellar mass function

    International Nuclear Information System (INIS)

    Kroupa, Pavel; Tout, C.A.; Gilmore, Gerard

    1990-01-01

    The stellar mass function for low-mass stars is constrained using the stellar luminosity function and the slope of the mass-luminosity relation. We investigate the range of mass functions for stars with absolute visual magnitude fainter than M V ≅ +5 which are consistent with both the local luminosity function and the rather poorly determined mass-absolute visual magnitude relation. Points of inflexion in the mass-luminosity relation exist because of the effects of H - , H 2 and of other molecules on the opacity and equation of state. The first two of these correspond to absolute magnitudes M V ≅ +7 and M V ≅ +12, respectively, at which structure is evident in the stellar luminosity function (a flattening and a maximum, respectively). Combining the mass-luminosity relation which shows these inflexion points with a peaked luminosity function, we test smooth mass functions in the mass range 0.9-0.1 the solar mass. (author)

  10. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs). III. Star formation properties of the host galaxies at z ≳ 6 studied with ALMA

    Science.gov (United States)

    Izumi, Takuma; Onoue, Masafusa; Shirakata, Hikari; Nagao, Tohru; Kohno, Kotaro; Matsuoka, Yoshiki; Imanishi, Masatoshi; Strauss, Michael A.; Kashikawa, Nobunari; Schulze, Andreas; Silverman, John D.; Fujimoto, Seiji; Harikane, Yuichi; Toba, Yoshiki; Umehata, Hideki; Nakanishi, Kouichiro; Greene, Jenny E.; Tamura, Yoichi; Taniguchi, Akio; Yamaguchi, Yuki; Goto, Tomotsugu; Hashimoto, Yasuhiro; Ikarashi, Soh; Iono, Daisuke; Iwasawa, Kazushi; Lee, Chien-Hsiu; Makiya, Ryu; Minezaki, Takeo; Tang, Ji-Jia

    2018-04-01

    We present our ALMA Cycle 4 measurements of the [C II] emission line and the underlying far-infrared (FIR) continuum emission from four optically low-luminosity (M1450 > -25) quasars at z ≳ 6 discovered by the Subaru Hyper Suprime Cam (HSC) survey. The [C II] line and FIR continuum luminosities lie in the ranges L_[C II] = (3.8-10.2)× 108 L_{⊙} and LFIR = (1.2-2.0) × 1011 L_{⊙}, which are at least one order of magnitude smaller than those of optically-luminous quasars at z ≳ 6. We estimate the star formation rates (SFRs) of our targets as ≃ 23-40 M_{⊙} yr-1. Their line and continuum-emitting regions are marginally resolved, and found to be comparable in size to those of optically-luminous quasars, indicating that their SFR or likely gas mass surface densities (key controlling parameter of mass accretion) are accordingly different. The L_[C II]/L_FIR ratios of the hosts, ≃ (2.2-8.7) × 10-3, are fully consistent with local star-forming galaxies. Using the [C II] dynamics, we derived their dynamical masses within a radius of 1.5-2.5 kpc as ≃ (1.4-8.2) × 1010 M_{⊙}. By interpreting these masses as stellar ones, we suggest that these faint quasar hosts are on or even below the star-forming main sequence at z ˜ 6, i.e., they appear to be transforming into quiescent galaxies. This is in contrast to the optically-luminous quasars at those redshifts, which show starburst-like properties. Finally, we find that the ratios of black hole mass to host galaxy dynamical mass of most of the low-luminosity quasars, including the HSC ones, are consistent with the local value. The mass ratios of the HSC quasars can be reproduced by a semi-analytical model that assumes merger-induced black hole host galaxy evolution.

  11. Integral luminosities of radio pulsars

    Science.gov (United States)

    Malov, I.; Malov, O.

    The integral radio luminosities L for 311 normal pulsars and for 27 ones with the rotation period Pfalls for fast ones. The mean values of K are -3.73 and -4.85 for normal and fast pulsars, respectively. There are no changes of L with the kinematic age T = z/V, where z is the pulsar height over the Galactic plane and V = 300 km/s is its mean velocity. The correlation between L and the rate of the rotation energy losses E is detected for both pulsar groups under consideration. It is shown that L= A E^(1/3) for the whole sample. The total number of pulsars in the Galaxy and their birth rate are in agreement with data on the rate of supernova explosions.

  12. Upgrade plans for the Hadronic-Endcap Calorimeter of ATLAS for the high luminosity stage of the LHC

    CERN Document Server

    Ahmadov, F; The ATLAS collaboration; Cheplakov, A; Dominguez, R; Fischer, A; Habring, J; Hambarzumjan, A; Javadov, N; Kiryunin, A; Kurchaninov, L; Menke, S; Molinas Conde, I; Nagel, M; Oberlack, H; Reimann, O; Schacht, P; Strizenec, P; Vogt, S; Wichmann, G; Cadabeschi, Mircea Ioan; Langstaff, Reginald Roy; Lenckowski, Mark Stanley

    2015-01-01

    The expected increase of the instantaneous luminosity of a factor seven and of the total integrated luminosity by a factor 3-5 at the second phase of the upgraded high luminosity LHC compared to the design goals for LHC makes it necessary to re-evaluate the radiation hardness of the read-out electronics of the ATLAS Hadronic Endcap Calorimeter. The current cold electronics made of GaAs ASICs have been tested with neutron and proton beams to study their degradation under irradiation and the effect it would have on the ATLAS physics programme. New, more radiation hard technologies which could replace the current amplifiers have been studied as well: SiGe bipolar, Si CMOS FET and GaAs FET transistors have been irradiated with neutrons and protons with fluences up to ten times the total expected fluences for ten years of running of the high luminosity LHC. The performance measurements of the current read-out electronics and potential future technologies and expected performance degradations under high luminosity ...

  13. Luminosity monitoring and measurement at CDF

    International Nuclear Information System (INIS)

    Cronin-Hennessy, D.; Beretvas, A.; Derwent, P.F.

    2000-01-01

    Using two telescopes of beam-beam counters, CDF (Collider Detector at Fermilab) has measured the luminosity to an accuracy of 4.1% (3.6%) in run Ib (Ia). For run Ib (Ia) the average luminosity was 9.1(3.3)x10 30 cm -2 s -1 . For a typical data set the integrated luminosity was 86.47 (19.65) pb -1 in run Ib (Ia) resulting in a total integrated luminosity of 106.1±4.1 pb -1 . This paper shows how we have determined the accuracy of our results

  14. High luminosity polarized proton collisions at RHIC

    International Nuclear Information System (INIS)

    Roser, T.

    2001-01-01

    The Brookhaven Relativistic Heavy Ion Collider (RHIC) provides the unique opportunity to collide polarized proton beams at a center-of-mass energy of up to 500 GeV and luminosities of up to 2 x 10 32 cm -2 s -1 . Such high luminosity and high energy polarized proton collisions will open up the possibility of studying spin effects in hard processes. However, the acceleration of polarized beams in circular accelerators is complicated by the numerous depolarizing spin resonances. Using a partial Siberian snake and a rf dipole that ensure stable adiabatic spin motion during acceleration has made it possible to accelerate polarized protons to 25 GeV at the Brookhaven AGS. After successful operation of RHIC with gold beams polarized protons from the AGS have been successfully injected into RHIC and accelerated using a full Siberian snakes built from four superconducting helical dipoles. A new high energy proton polarimeter was also successfully commissioned. Operation with two snakes per RHIC ring is planned for next year

  15. The LUCID detector ATLAS luminosity monitor and its electronic system

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00378808; The ATLAS collaboration

    2016-01-01

    Starting from 2015 LHC is performing a new run, at higher center of mass energy (13 TeV) and with 25 ns bunch-spacing. The ATLAS luminosity monitor LUCID has been completely renewed, both on detector design and in the electronics, in order to cope with the new running conditions. The new detector electronics is presented, featuring a new read-out board (LUCROD), for signal acquisition and digitization, PMT-charge integration and single-side luminosity measurements, and the revisited LUMAT board for side-A-side-C combination. The contribution covers the new boards design, the firmware and software developments, the implementation of luminosity algorithms, the optical communication between boards and the integration into the ATLAS TDAQ system.

  16. Evolution of solar ultraviolet luminosity

    International Nuclear Information System (INIS)

    Zahnle, K.J.; Walker, J.C.G.

    1982-01-01

    In view of the major role of the sun in defining the properties of planetary atmospheres, their evolution cannot be fully understood outside the context of an evolving sun. The ultraviolet radiation is especially interesting because of its strong interaction with planetary atmospheres. We use astronomical observation of stars that are analogous to the sun in order to reconstruct a tentative account of the evolution of solar UV luminosity. A wealth of evidence indicates that the young sun was a much more powerful source of energetic particles and radiation than it is today. While on the main sequence, solar activity has declined as an inverse power law of age (between t -5 and t/sup -1.2/) as a consequence of angular momentum loss to the solar wind. Recent IUE satellite observations of premain sequence stars suggest that before the sun reached the main sequence (at an age of about 50 m.y.), it may have emitted as much as 10 4 times as much ultraviolet radiation (γ<2000 A) than it does today. These results could impact our understanding of the photochemistry and escape of constituents of primordial planetary atmospheres

  17. Thermomechanical study of complex structures in the aperture of superconducting magnets: Application to the design of the High-Luminosity LHC shielded beam screen

    CERN Document Server

    AUTHOR|(CDS)2086332; Aurisicchio, Marco

    In the framework of the High-Luminosity Large Hadron Collider (HL-LHC) project, a complex structure, known as the beam screen, will be installed by 2024 in the aperture of the inner triplet superconducting magnets nearby the ATLAS and CMS experiments. The beam screen is an octagonal shaped pipe that shields the 1.9 K magnet cryogenic system from the heat loads and damage to the magnet coils that would be otherwise induced by the highly penetrating collision debris. It also ensures that the vacuum conditions, required for the stability of the beam, are met. This thesis describes the design of the beam screen and proposes extensions to important components and features. The unknown physical properties of the beam screen materials have been characterised. The thermal behaviour of the beam screen during normal working conditions has been optimised by simulations and validated by measurements. The behaviour of the beam screen during a magnet quench, a resistive transition of the superconducting magnet, has been st...

  18. Prospects of a search for $t\\bar{t}$ resonances at the High Luminosity LHC with an upgraded ATLAS Detector

    CERN Document Server

    Duncan, Anna Kathryn; The ATLAS collaboration

    2017-01-01

    A study of the expected mass reach of a search for new high-mass resonances decaying to a top quark pair using a simulation of the upgraded ATLAS experiment and using an integrated luminosity of 3000 fb$^{-1}$ from the High Luminosity LHC has been made. The simulation of the upgraded ATLAS experiment under HL-LHC conditions, including pileup, was done using parameterised estimates of the performance. Expected upper limits are set on the cross section of a $t\\bar{t}$ resonance in a benchmark model for several signal masses and show that particles with masses up to 4 TeV can be seen.

  19. Missing mass from low-luminosity stars

    International Nuclear Information System (INIS)

    Hawkins, M.R.S.

    1986-01-01

    Results from a deep photometric survey for low-luminosity stars show a turnup to the luminosity function at faint magnitudes, and reopen the possibility that the missing mass in the solar neighbourhood is made up of stars after all. (author)

  20. Towards a new LHC interaction region design for a luminosity upgrade

    International Nuclear Information System (INIS)

    James Strait et al.

    2003-01-01

    After the LHC operates for several years at nominal parameters, it will be necessary to upgrade it for higher luminosity. Replacing the low-β insertions with a higher performance design based on advanced superconducting magnets is one of the most straightforward steps in this direction. Preliminary studies show that, with magnet technology that is expected to be developed by early in the next decade, a factor of 2 to 5 reduction in β* could be achieved with new insertions, as part of an upgrade aimed at a factor of 10 luminosity increase. In this paper we survey several possible second generation LHC interaction regions designs, which address the expected limitations on LHC performance imposed by the baseline insertions

  1. Towards a new LHC Interaction Region design for a luminosity upgrade

    CERN Document Server

    Strait, J; Limon, P; Mokhov, N V; Sen, T; Zlobin, A V; Brüning, Oliver Sim; Ostojic, R; Rossi, L; Ruggiero, F; Taylor, T; ten Kate, H; Devred, A; Gupta, R; Harrison, M; Peggs, S; Pilat, F; Caspi, S; Gourlay, S; Sabbi, G

    2003-01-01

    After the LHC operates for several years at nominal parameters, it will be necessary to upgrade it for higher luminosity. Replacing the low-beta insertions with a higher performance design based on advanced superconducting magnets is one of the most straightforward steps in this direction. Preliminary studies show that, with magnet technology that is expected to be developed by early in the next decade, a factor of 2 to 5 reduction in beta* could be achieved with new insertions, as part of an upgrade aimed at a factor of 10 luminosity increase. In this paper we survey several possible second generation LHC interaction regions designs, which address the expected limitations on LHC performance imposed by the baseline insertions.

  2. The feasibility of experiments at high luminosity at the large hadron collider

    International Nuclear Information System (INIS)

    Mulvey, J.H.

    1988-01-01

    The studies reported in this volume extend some of those made during Workshop on Physics at Future Accelerators held at La Thuile and CERN in January 1987 (CERN 87-07, Vol. 1 and 2). They consider the feasibility of performing experiments with a 16 TeV proton-proton collider, the Large Hadron Collider (LHC), at luminosities as high as 5.10 34 cm -2 s -1 . To illustrate the difficulties and the extent to which the potential for discovery at the LHC might be improved by such a step, three specific topics were chosen: searches for a) a massive Higgs boson, b) SUSY gluinos and squarks, and c) a new Z'. Following the Summary Report of the High Luminosity Study Group are papers discussing a possible detector system, radiation levels, and the analyses leading to estimated mass-limits for the searches. (orig.)

  3. Testing and Improving the Luminosity Relations for Gamma-Ray Bursts

    Science.gov (United States)

    Collazzi, Andrew C.

    2012-01-01

    Gamma Ray Bursts (GRBs) have several luminosity relations where a measurable property of a burst light curve or spectrum is correlated with the burst luminosity. These luminosity relations are calibrated for the fraction of bursts with spectroscopic redshifts and hence the known luminosities. GRBs have thus become known as a type of "standard candle” where standard candle is meant in the usual sense that luminosities can be derived from measurable properties of the bursts. GRBs can therefore be used for the same cosmology applications as Type Ia supernovae, including the construction of the Hubble Diagram and measuring massive star formation rate. The greatest disadvantage of using GRBs as standard candles is that their accuracy is lower than desired. With the recent advent of GRBs as a new standard candle, every effort must be made to test and improve the distance measures. Here, methods are employed to do just that. First, generalized forms of two tests are performed on the luminosity relations. All the luminosity relations pass one of these tests, and all but two pass the other. Even with this failure, redundancies in using multiple luminosity relations allows all the luminosity relations to retain value. Next, the "Firmani relation” is shown to have poorer accuracy than first advertised. It is also shown to be derivable from two other luminosity relations. For these reasons, the Firmani relation is useless for cosmology. The Amati relation is then revisited and shown to be an artifact of a combination of selection effects. Therefore, the Amati relation is also not good for cosmology. Fourthly, the systematic errors involved in measuring a luminosity indicator (Epeak) are measured. The result is an irreducible systematic error of 28%. Finally, the work concludes with a discussion about the impact of the work and the future of GRB luminosity relations.

  4. Luminosity Measurements at LHCb for Run II

    CERN Multimedia

    Coombs, George

    2018-01-01

    A precise measurement of the luminosity is a necessary component of many physics analyses, especially cross-section measurements. At LHCb two different direct measurement methods are used to determine the luminosity: the “van der Meer scan” (VDM) and the “Beam Gas Imaging” (BGI) methods. A combined result from these two methods gave a precision of less than 2% for Run I and efforts are ongoing to provide a similar result for Run II. Fixed target luminosity is determined with an indirect method based on the single electron scattering cross-section.

  5. Online luminosity measurement at BES III

    International Nuclear Information System (INIS)

    Song Wenbo; Fu Chengdong; Mo Xiaohu; He Kanglin; Zhu Kejun; Li Fei; Zhao Shujun

    2010-01-01

    As a crucial parameter of both accelerator and detector, the realization of online luminosity measurement is of great importance. Several methods of luminosity measurement are recapitulated and the emphasis is laid on the algorithm of using e + e - and γγ final states. Taking into account the status at the beginning of the joint commissioning of detector and accelerator, the information from end cap electromagnetic calorimeter is used to select the good event. With the help of online Event filter, the luminosity is calculated and the monitoring of online cross section of hadron is realized. The preliminary results indicate that the online luminosity measurement is stable and its role for machine tuning and monitoring of the overall running status is indispensable. (authors)

  6. LHC Report: Boost in bunches brings record luminosity

    CERN Multimedia

    2011-01-01

    Having hit a luminosity of around 8.4x1032 cm-2 s-1 with 768 bunches per beam, the LHC went into a 5-day machine development (MD) program on Wednesday 4 May. Operators are now working on increasing the number of particle bunches in the machine towards a 2011 maximum of around 1380 bunches. The team is already hitting major milestones, recording another record-breaking peak luminosity on Monday 23 May.   Former LHC Project Leader Lyn Evans (to the right) and Laurette Ponce, the engineer-in-charge when the recent luminosity record was achieved. The MD periods improve our understanding of the machine, with the aim of increasing its short- and long-term performance. This one also included tests of the machine’s configurations for special physics runs and a future high luminosity LHC. It was an intense program and overall it went very well, with most measurements carried out successfully. Highlights included: commissioning a dedicated machine setup for TOTEM and ALFA; succe...

  7. Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

    CERN Document Server

    Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

    2011-01-01

    We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

  8. Reverberation Mapping of High-Luminosity Quasars

    Energy Technology Data Exchange (ETDEWEB)

    Kaspi, Shai [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv (Israel); Brandt, William N. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA (United States); Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, PA (United States); Department of Physics, Pennsylvania State University, University Park, PA (United States); Maoz, Dan; Netzer, Hagai [Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv (Israel); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA (United States); Institute for Gravitation and the Cosmos, Pennsylvania State University, University Park, PA (United States); Shemmer, Ohad, E-mail: shai@wise.tau.ac.il [Department of Physics, University of North Texas, Denton, TX (United States)

    2017-10-30

    Over the past three decades reverberation mapping (RM) has been applied to about 100 AGNs. Their broad line region (BLR) sizes were measured and yielded mass estimates of the black holes in their center. However, very few attempts were carried out for high-luminosity quasars, at luminosities higher than 10{sup 46} erg/sec in the optical. Most of these attempts failed since RM of such quasars is difficult due to a number of reasons, mostly due to the long time needed to monitor these objects. During the past two decades we carried out a RM campaign on six high-luminosity quasars. This contribution presents some of the final light curves of that RM campaign in which we measured the BLR size in C iv of three of the objects (S5 0836+71, SBS 1116+603, and SBS 1425+606). We present the C iv BLR size and luminosity relation over eight orders of magnitude in luminosity, pushing the luminosity limit to its highest point so far.

  9. LOW CO LUMINOSITIES IN DWARF GALAXIES

    International Nuclear Information System (INIS)

    Schruba, Andreas; Walter, Fabian; Sandstrom, Karin; Leroy, Adam K.; Bigiel, Frank; Brinks, Elias; De Blok, W. J. G.; Kramer, Carsten; Rosolowsky, Erik; Schuster, Karl; Usero, Antonio; Weiss, Axel; Wiesemeyer, Helmut

    2012-01-01

    We present maps of 12 COJ = 2-1 emission covering the entire star-forming disks of 16 nearby dwarf galaxies observed by the IRAM HERACLES survey. The data have 13'' angular resolution, ∼250 pc at our average distance of D = 4 Mpc, and sample the galaxies by 10-1000 resolution elements. We apply stacking techniques to perform the first sensitive search for CO emission in dwarf galaxies outside the Local Group ranging from individual lines of sight, stacking over IR-bright regions of embedded star formation, and stacking over the entire galaxy. We detect five galaxies in CO with total CO luminosities of L CO2-1 = (3-28) × 10 6 K km s –1 pc 2 . The other 11 galaxies remain undetected in CO even in the stacked images and have L CO2-1 ∼ 6 K km s –1 pc 2 . We combine our sample of dwarf galaxies with a large sample of spiral galaxies from the literature to study scaling relations of L CO with M B and metallicity. We find that dwarf galaxies with metallicities of Z ≈ 1/2-1/10 Z ☉ have L CO of 2-4 orders of magnitude smaller than massive spiral galaxies and that their L CO per unit L B is 1-2 orders of magnitude smaller. A comparison with tracers of star formation (FUV and 24 μm) shows that L CO per unit star formation rate (SFR) is 1-2 orders of magnitude smaller in dwarf galaxies. One possible interpretation is that dwarf galaxies form stars much more efficiently: we argue that the low L CO /SFR ratio is due to the fact that the CO-to-H 2 conversion factor, α CO , changes significantly in low-metallicity environments. Assuming that a constant H 2 depletion time of τ dep = 1.8 Gyr holds in dwarf galaxies (as found for a large sample of nearby spirals) implies α CO values for dwarf galaxies with Z ≈ 1/2-1/10 Z ☉ that are more than one order of magnitude higher than those found in solar metallicity spiral galaxies. Such a significant increase of α CO at low metallicity is consistent with previous studies, in particular those of Local Group dwarf

  10. submitter Performance studies of CMS workflows using Big Data technologies

    CERN Document Server

    Ambroz, Luca; Grandi, Claudio

    At the Large Hadron Collider (LHC), more than 30 petabytes of data are produced from particle collisions every year of data taking. The data processing requires large volumes of simulated events through Monte Carlo techniques. Furthermore, physics analysis implies daily access to derived data formats by hundreds of users. The Worldwide LHC Computing Grid (WLCG) - an international collaboration involving personnel and computing centers worldwide - is successfully coping with these challenges, enabling the LHC physics program. With the continuation of LHC data taking and the approval of ambitious projects such as the High-Luminosity LHC, such challenges will reach the edge of current computing capacity and performance. One of the keys to success in the next decades - also under severe financial resource constraints - is to optimize the efficiency in exploiting the computing resources. This thesis focuses on performance studies of CMS workflows, namely centrallyscheduled production activities and unpredictable d...

  11. Case Study on Logistics Performance

    Directory of Open Access Journals (Sweden)

    Shahryar Sorooshian

    2013-05-01

    Full Text Available The paper presents research carried out at a medium‐size manufacturing organization in east Asia. The study tries to highlight the importance of supply chain management; specifically, our aim for this study is to understand logistics and performance measurement in the logistics and supply chain, and we include a theoretical discussion of online data collected and a case study of the logistic performance of a real organization. The study also examines the performance of the selected company, identifies the problems and provides recommendations for improvements. This study can be a guide for business advisers and those interested in analysing company performance, especially from a logistics viewpoint. We also suggest the methodology of this case study for those who want to have a better understanding of a business environment before starting their own business, or for benchmarking practice during strategic planning.

  12. On the temporal fluctuations of pulsating auroral luminosity

    International Nuclear Information System (INIS)

    Yamamoto, Tatsundo

    1988-01-01

    From a study of all-sky TV records, it is shown that the luminosity fluctuations of pulsating auroras can be understood in terms of a series of pulses with rapid on-off switchings in burstlike fashion and that the widths of successive pulses (pulsation on times) are fairly constant. This is common even when luminosity fluctuations consist of complex-irregular variations, in contrast to the pulsation off time that is significantly variable. Complex-irregular variations are ground to be due to simultaneous appearance of more pulsating patches that exhibit movements eastward and westward over the site, and each of the patches shows primarily isolated luminosity pulses. Several examples are presented and described in detail. A natural consequence of these observations is that the classical concept of period does not mean much and the luminosity fluctuations should be treated as a series of individual isolated pulses where the pulsation on time is the most essential quantity. These characteristics are briefly discussed in relation to VLF/ELF wave-particle interactions in the magnetosphere. Then a new interpretation of the nonlinear relaxation oscillation model is proposed, where the propagation effect of VLF/ELF waves in low energy plasm irregularities near the magnetospheric equatorial plane plays an essential role to produce rapid on-off switchings of precipitating energetic electron fluxes. Both electromagnetic and electrostatic waves are possibly related to the precipitation pulsations

  13. Gravitational-Wave Luminosity of Binary Neutron Stars Mergers

    Science.gov (United States)

    Zappa, Francesco; Bernuzzi, Sebastiano; Radice, David; Perego, Albino; Dietrich, Tim

    2018-03-01

    We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have the largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.

  14. Gravitational-Wave Luminosity of Binary Neutron Stars Mergers.

    Science.gov (United States)

    Zappa, Francesco; Bernuzzi, Sebastiano; Radice, David; Perego, Albino; Dietrich, Tim

    2018-03-16

    We study the gravitational-wave peak luminosity and radiated energy of quasicircular neutron star mergers using a large sample of numerical relativity simulations with different binary parameters and input physics. The peak luminosity for all the binaries can be described in terms of the mass ratio and of the leading-order post-Newtonian tidal parameter solely. The mergers resulting in a prompt collapse to black hole have the largest peak luminosities. However, the largest amount of energy per unit mass is radiated by mergers that produce a hypermassive neutron star or a massive neutron star remnant. We quantify the gravitational-wave luminosity of binary neutron star merger events, and set upper limits on the radiated energy and the remnant angular momentum from these events. We find that there is an empirical universal relation connecting the total gravitational radiation and the angular momentum of the remnant. Our results constrain the final spin of the remnant black hole and also indicate that stable neutron star remnant forms with super-Keplerian angular momentum.

  15. The luminosity function for globular clusters, 4: M3

    International Nuclear Information System (INIS)

    Simoda, Mahiro; Fukuoka, Takashi

    1976-01-01

    The subgiant-turnoff portion (V = 17.2 - 20.0 mag) of the luminosity function for the globular cluster M3 has been determined from photometry of the stars within the annuli 3'-8' and 6'-8' for V = 17.2 - 19.0 mag and 19.0 - 20.0 mag, respectively, by using plates taken with the Kitt Peak 2.1-m reflector. Our result shows that the luminosity function for M3 has a similar steep rise in the subgiant portion as other clusters so far studied (M5, M13, and M92), in direct conflict with the result by SANDAGE (1954, 1957). A probable cause of this discrepancy is given. Comparison with theoretical luminosity functions by SIMODA and IBEN (1970) suggests that theory and observation are not inconsistent if the initial helium abundance of M3 stars is taken to be about 20 percent. It is suggested that M13 has a larger helium abundance than M3 and M92 from the intercomparison of their luminosity functions and color-magnitude diagrams. (auth.)

  16. Physics potential and experimental challenges of the LHC luminosity upgrade

    CERN Document Server

    Gianotti, F.; Virdee, T.; Abdullin, S.; Azuelos, G.; Ball, A.; Barberis, D.; Belyaev, A.; Bloch, P.; Bosman, M.; Casagrande, L.; Cavalli, D.; Chumney, Pamela R.K.; Cittolin, S.; Dasu, S.; De Roeck, A.; Ellis, N.; Farthouat, P.; Fournier, D.; Hansen, J.B.; Hinchliffe, I.; Hohlfeld, M.; Huhtinen, M.; Jakobs, K.; Joram, C.; Mazzucato, F.; Mikenberg, G.; Miagkov, A.; Moretti, M.; Moretti, S.; Niinikoski, T.; Nikitenko, A.; Nisati, A.; Paige, F.; Palestini, S.; Papadopoulos, C.G.; Piccinini, F.; Pittau, R.; Polesello, G.; Richter-Was, E.; Sharp, P.; Slabospitsky, S.R.; Smith, W.H.; Stapnes, S.; Tonelli, G.; Tsesmelis, E.; Usubov, Z.; Vacavant, L.; van der Bij, J.; Watson, A.; Wielers, M.

    2005-01-01

    We discuss the physics potential and the experimental challenges of an upgraded LHC running at an instantaneous luminosity of 10**35 cm-2s-1. The detector R&D needed to operate ATLAS and CMS in a very high radiation environment and the expected detector performance are discussed. A few examples of the increased physics potential are given, ranging from precise measurements within the Standard Model (in particular in the Higgs sector) to the discovery reach for several New Physics processes

  17. DIRECT OXYGEN ABUNDANCES FOR LOW-LUMINOSITY LVL GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Danielle A.; Skillman, Evan D. [Institute for Astrophysics, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455 (United States); Marble, Andrew R.; Engelbracht, Charles W. [Steward Observatory, University of Arizona, 933 N Cherry Ave., Tucson, AZ 85721 (United States); Van Zee, Liese [Astronomy Department, Indiana University, 727 East 3rd Street, Bloomington, IN 47405 (United States); Lee, Janice C. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Kennicutt, Robert C. Jr. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Calzetti, Daniela [Department of Astronomy, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Dale, Daniel A. [Department of Physics and Astronomy, University of Wyoming, 1000 E. University, Laramie, WY 82071 (United States); Johnson, Benjamin D., E-mail: berg@astro.umn.edu, E-mail: skillman@astro.umn.edu, E-mail: cengelbracht@as.arizona.edu, E-mail: amarble@nso.edu, E-mail: vanzee@astro.indiana.edu, E-mail: jlee@stsci.edu, E-mail: calzetti@astro.umass.edu, E-mail: ddale@uwyo.edu, E-mail: johnson@iap.fr [Institut d' Astrophysique de Paris, UMR 7095, 98 bis Bvd Arago, 75014 Paris (France)

    2012-08-01

    We present MMT spectroscopic observations of H II regions in 42 low luminosity galaxies in the Spitzer Local Volume Legacy survey. For 31 of the 42 galaxies in our sample, we were able to measure the temperature sensitive [O III] {lambda}4363 line at a strength of 4{sigma} or greater, and thus determine oxygen abundances using the 'direct' method. Our results provide the first 'direct' estimates of oxygen abundance for 19 of these galaxies. 'Direct' oxygen abundances were compared to B-band luminosities, 4.5 {mu}m luminosities, and stellar masses in order to characterize the luminosity-metallicity and mass-metallicity relationships at low luminosity. We present and analyze a 'Combined Select' sample composed of 38 objects (drawn from a sub-set of our parent sample and the literature) with 'direct' oxygen abundances and reliable distance determinations (based on the tip of the red giant branch or Cepheid variables). Consistent with previous studies, the B band and 4.5 {mu}m luminosity-metallicity relationships for the 38 objects were found to be 12 + log(O/H) = (6.27 {+-} 0.21) + (- 0.11 {+-} 0.01)M{sub B} and 12 + log(O/H) = (6.10 {+-} 0.21) + (- 0.10 {+-} 0.01)M{sub [4.5]} with dispersions of {sigma} = 0.15 and 0.14, respectively. The slopes of the optical and near-IR L-Z relationships have been reported to be different for galaxies with luminosities greater than that of the LMC. However, the similarity of the slopes of the optical and near-IR L-Z relationships for our sample probably reflects little influence by dust extinction in the low luminosity galaxies. For this sample, we derive a mass-metallicity relationship of 12 + log(O/H) = (5.61 {+-} 0.24) + (0.29 {+-} 0.03)log (M{sub *}), which agrees with previous studies; however, the dispersion ({sigma} = 0.15) is not significantly lower than that of the L-Z relationships. Because of the low dispersions in these relationships, if an accurate distance is available

  18. Higher luminosities via alternative incident channels

    International Nuclear Information System (INIS)

    Spencer, J.E.

    1985-04-01

    We show that PEP provides some unique opportunities for one and two photon physics with real photons as well as for QCD studies with internal targets. Photon beams would avoid the major limitation on the luminosity of present machines and could provide PEP an ideal b-physics factory producing the full range of J/sub c//sup PC/ and J/sub b//sup PC/ states that may not be observable otherwise as well as allow a whole new class of ''missing-mass'' experiments. These latter particles are the pseudo-Goldstone bosons and their supersymmetric counterparts. These and related possibilities like a single-pass, ''free electron laser'' facility or even synchrotron radiation beam lines all favor a mini-maxi configuration for the low-beta insertions in PEP. This allows more diverse experiments without excluding any ongoing experimental programs. Such possibilities have interesting implications for a number of proposed facilities including the SSC. Some systematic machine physics studies over a range of energies are suggested. 24 refs., 6 figs

  19. Diagnostic colonoscopy: performance measurement study.

    Science.gov (United States)

    Kuznets, Naomi

    2002-07-01

    This is the fifth of a series of best practices studies undertaken by the Performance Measurement Initiative (PMI), the centerpiece of the Institute for Quality Improvement (IQI), a not-for-profit quality improvement subsidiary of the Accreditation Association for Ambulatory Health Care (AAAHC) (Performance Measurement Initiative, 1999a, 1999b, 2000a, 2000b). The IQI was created to offer clinical performance measurement and improvement opportunities to ambulatory health care organizations and others interested in quality patient care. The purpose of the study was to provide opportunities to initiate clinical performance measurement on key processes and outcomes for this procedure and use this information for clinical quality improvement. This article provides performance measurement information on how organizations that have demonstrated and validated differences in clinical practice can have similar outcomes, but at a dramatically lower cost. The intent of the article is to provide organizations with alternatives in practice to provide a better value to their patients.

  20. Performance Studies of a Micromegas Chamber in the ATLAS Environment

    CERN Document Server

    Kataoka, Y; Ntekas, K

    2014-01-01

    Five small prototype micromegas detectors were positioned in the ATLAS detector during Large Hadron Collider running at $\\sqrt{s} = 7$ and $8\\, \\mathrm{TeV}$. A $9\\times 4.5\\, \\mathrm{cm^2}$ two-gap detector was placed in front of the electromagnetic calorimeter and four $9\\times 10\\, \\mathrm{cm^2}$ detectors on the ATLAS Small Wheel, the first station of the forward muon spectrometer. The one attached to the calorimeter was exposed to interaction rates of about $70\\,\\mathrm{kHz}$ at $\\mathcal{L}=5\\times 10^{33}\\,\\mathrm{cm^{-2}s^{-1}}$ two orders of magnitude higher than the rates in the Small Wheel. We present the results from performance studies carried out using data collected with these detectors and we also compare the currents drawn by the detector installed in front of the electromagnetic calorimeter with the luminosity measurement in ATLAS.

  1. Powering the High-Luminosity Triplets

    Science.gov (United States)

    Ballarino, A.; Burnet, J. P.

    The powering of the magnets in the LHC High-Luminosity Triplets requires production and transfer of more than 150 kA of DC current. High precision power converters will be adopted, and novel High Temperature Superconducting (HTS) current leads and MgB2 based transfer lines will provide the electrical link between the power converters and the magnets. This chapter gives an overview of the systems conceived in the framework of the LHC High-Luminosity upgrade for feeding the superconducting magnet circuits. The focus is on requirements, challenges and novel developments.

  2. Calculating luminosity for a coupled Tevatron lattice

    International Nuclear Information System (INIS)

    Holt, J.A.; Martens, M.A.; Michelotti, L.; Goderre, G.

    1995-05-01

    The traditional formula for calculating luminosity assumes an uncoupled lattice and makes use of one-degree-of-freedom lattice functions, β H and β v , for relating transverse beam widths to emittances. Strong coupling requires changing this approach. It is simplest to employ directly the linear normal form coordinates of the one turn map. An equilibrium distribution in phase space is expressed as a function of the Jacobian's eigenvectors and beam size parameters or emittances. Using the equilibrium distributions an expression for the luminosity was derived and applied to the Tevatron lattice, which was coupled due to a quadrupole roll

  3. Luminosity Targets for FCC-hh

    CERN Document Server

    Zimmermann, F.; Buffat, X.; Schulte, D.

    2016-01-01

    We discuss the choice of target values for the peak and integrated luminosity of a future high-energy frontier circular hadron collider (FCC-hh). We review the arguments on the physics reach of a hadron collider. Next we show that accelerator constraints will limit the beam current and the turnaround time. Taking these limits into account, we derive an expression for the ultimate integrated luminosity per year, depending on a possible pile-up limit imposed by the physics experiments. We finally benchmark our result against the planned two phases of FCC-hh [1, 2, 3

  4. Luminosity Measurement at ATLAS with a Scintillating Fiber Tracker

    CERN Document Server

    Ask, S

    2007-01-01

    We are reporting about a scintillating fiber tracking detector which is proposed for a precise determination of the absolute luminosity of the CERN LHC at interaction point 1 where the ATLAS experiment is located. The detector needs to track protons elastically scattered under micro-radian angles in direct vicinity to the LHC beam. It is based on square shaped scintillating plastic fibers read out by multi-anode photomultiplier tubes and is housed in Roman Pots. We describe the design and construction of prototype detectors and the results of two beam test experiments carried out at DESY and at CERN. The excellent detector performance established in these tests validates the detector design and supports the feasibility of the proposed challenging method of luminosity measurement. All results from the CERN beam test should be considered as preliminary.

  5. The luminosity of galactic components and morphological segregation

    International Nuclear Information System (INIS)

    Solanes, J. M.; Salvador-Sole, E.; Sanroma, M.

    1989-01-01

    The luminosities of the bulge and disk components of disk galaxies are analyzed, and the possible correlation of these luminosities with morphological type and local density is explored. Galaxies of different types are found to be located in distinct bands in the bulge-to-disk luminosity ratio vs total luminosity diagram, allowing the determination of the typical bulge luminosity function of disk galaxies of different types from their respective total luminosity functions, along with a better characterization of morphological segregation among disk galaxies. No evidence for any bulge luminosity segregation is found, and disks appear to be less luminous with increasing local density. 33 refs

  6. Luminosity dependence in the ratio of X-ray to infrared emission of QSOs

    International Nuclear Information System (INIS)

    Worrall, D.M.

    1987-01-01

    The correlation of X-ray and near-infrared luminosity is studied for a sample of radio-quiet QSOs. The X-ray to infrared ratio is found to decrease as the infrared luminosity increases. No preference is found between the correlations of X-ray luminosity with optical or infrared luminosity. This implies that optical and infrared emission are equally good predictors of X-ray emission. Source models which directly link infrared and X-ray emission are discussed, and a preference is found for a specific synchrotron self-Compton model. This model predicts the correct luminosity dependence of the X-ray to infrared ratio if certain conditions apply. 55 references

  7. RHIC Proton Luminosity and Polarization Improvement

    International Nuclear Information System (INIS)

    Zhang, S. Y.

    2014-01-01

    The RHIC proton beam polarization can be improved by raising the Booster scraping, which also helps to reduce the RHIC transverse emittance, and therefore to improve the luminosity. By doing this, the beam-beam effect would be enhanced. Currently, the RHIC working point is constrained between 2/3 and 7/10, the 2/3 resonance would affect intensity and luminosity lifetime, and the working point close to 7/10 would enhance polarization decay in store. Run 2013 shows that average polarization decay is merely 1.8% in 8 hours, and most fills have the luminosity lifetime better than 14 hours, which is not a problem. Therefore, even without beam-beam correction, there is room to improve for RHIC polarization and luminosity. The key to push the Booster scraping is to raise the Booster input intensity; for that, two approaches can be used. The first is to extend the LINAC tank 9 pulse width, which has been successfully applied in run 2006. The second is to raise the source temperature, which has been successfully applied in run 2006 and run 2012.

  8. Recent improvements in luminosity at PEP

    International Nuclear Information System (INIS)

    Helm, R.; Allen, M.; Chao, A.

    1983-03-01

    We will describe improvements which have led to new records for peak and average luminosity at PEP. Comparison of recent results with several earlier lattice and optical modifications shows rather good correlation with the predictions of a beam-beam simulation program

  9. Luminosity Variations in Post-AGB Stars

    Science.gov (United States)

    Mesler, Robert; Henson, G.

    2007-12-01

    Although much is known about AGB stars and planetary nebulae, relatively little is known about the phase of a star's life in which it transitions between those two states. We have measured the variations in luminosity of a sample of known Post-AGB stars (as well as several candidates) relative to nearby, non-variable stars in order to compare them with theoretical models. The typical behavior of the observed variations is described and an attempt is made to discern whether any periodicity might be present. Luminosity variations were found to be on the order of a few hundredths to a few tenths of a magnitude for the stars that were surveyed, with occasional fluctuations of up to a magnitude. This agrees with current models of Post-AGB stars. Each star fell into one of three categories, which were termed groups 1, 2, and 3. Group 1 stars showed long term, non-periodic luminosity variations on the scale of weeks or longer and were most likely to display some sort of short term, coherent luminosity oscillation (each of which lasted for only a few cycles). Group 2 stars showed erratic, short-term magnitude variations occurring on scales of several days. Group 3 stars showed little or no variation in magnitude. Of the 27 Post-AGB stars that were sampled, five fell into group 1, fifteen fell into group 2, and seven fell into group 3. The luminosity variations tended to be color-independent, and occurred on timescales ranging nearly continuously from a few days to more than a year. No clear periodic behavior was found in any star in our sample. This project was funded by a partnership between the National Science Foundation (NSF AST-0552798), Research Experiences for Undergraduates (REU), and the Department of Defense (DoD) ASSURE (Awards to Stimulate and Support Undergraduate Research Experiences) programs.

  10. Precision luminosity measurement at LHCb with beam-gas imaging

    CERN Document Server

    Barschel, Colin

    The luminosity is the physical quantity which relates the cross-section to the production rate in collider experiments. The cross-section being the particle physics observable of interest, a precise determination of the luminosity is required. This work presents the absolute luminosity calibration results performed at the Large Hadron Collider beauty (LHCb) experiment at CERN using a novel method based on beam-gas interactions with data acquired at a center of mass energy $\\sqrt{s}=8$ TeV and $\\sqrt{s}=2.76$ TeV. Reconstructed beam-gas interaction vertices in LHCb are used to measure the beam profiles, thus making it possible to determine the beams overlap integral. An important element of this work was to install and use a neon gas injection system to increase the beam-gas interaction rate. The precision reached with the beam-gas imaging method relies on the two-dimensional beam shape determination developed in this work. For such precision, the interaction vertex resolution is an important ingredient. There...

  11. Electron-cloud effects in high-luminosity colliders

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, F.

    1998-01-01

    Electron-cloud instabilities are expected to be important in most high-luminosity double-ring colliders. In this report, the author describes a few parameter regimes and some critical parameter dependences of this type of instability, and illustrate these with simulation results for the PEP-II and KEK B factories, the LHC, the VLHC, and DAPHNE. In addition, the author studies the possibility and the potential impact of an electron cloud in the interaction region.

  12. An investigation of X-ray luminosity versus crystalline powder granularity

    International Nuclear Information System (INIS)

    Janecek, Martin; Borade, Ramesh; Bourret-Courchesne, Edith; Derenzo, Stephen E.

    2011-01-01

    At the High-Throughput Discovery of Scintillator Materials Facility at Lawrence Berkeley National Laboratory, scintillators are synthesized by solid-state reaction or melt mixing, forming crystalline powders. These powders are formed in various granularity and the crystal grain size affects the apparent luminosity of the scintillator. To accurately predict a “full-size” scintillator's crystal luminosity, the crystal luminosity as a function of crystal granularity size has to be known. In this study, we examine Bi 4 Ge 3 O 12 (BGO), Lu 2 SiO 5 :Ce 3+ (LSO), YAlO 3 :Ce 3+ (YAP:Ce), and CsBa 2 I 5 :Eu 2+ (CBI) luminosities as a function of crystalline grain size. The highest luminosities were measured for 600- to 1000-μm crystal grain sizes for BGO and LSO, for 310- to 600-μm crystal grain sizes for CBI, and for crystal grains larger than 165 μm for YAP:Ce. Crystal grains that were larger than 1 mm had a lower packing fraction, and smaller grains were affected by internal scattering. We measured a 34% decrease in luminosity for BGO when decreasing from the 600- to 1000-μm crystal grain size range down to the 20- to 36-μm range. The corresponding luminosity decrease for LSO was 44% for the same grain size decrease. YAP:Ce exhibited a luminosity decrease of 47% when the grain size decreased from the 165- to 310-μm crystal grains to the 20- to 36-μm range, and CBI exhibited a luminosity decrease of 98% when the grain size decreased from the 310- to 600-μm crystal grain range to the 36- to 50-μm range. We were able to very accurately estimate full-size crystal luminosities from crystalline grains that are larger than 90 μm.

  13. Luminosity determination in pp collisions at √(s) = 8 TeV using the ATLAS detector at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Aaboud, M. [Universite Mohamed Premier et LPTPM, Faculte des Sciences, Oujda (Morocco); Aad, G. [CPPM, Aix-Marseille Univ. et CNRS/IN2P3, Marseille (France); Abbott, B. [Oklahoma Univ., Norman, OK (United States). Homer L. Dodge Dept. of Physics and Astronomy; Collaboration: ATLAS Collaboration; and others

    2016-12-15

    The luminosity determination for the ATLAS detector at the LHC during pp collisions at √(s) = 8 TeV in 2012 is presented. The evaluation of the luminosity scale is performed using several luminometers, and comparisons between these luminosity detectors are made to assess the accuracy, consistency and long-term stability of the results. A luminosity uncertainty of δL/L = ± 1.9% is obtained for the 22.7 fb{sup -1} of pp collision data delivered to ATLAS at √(s) = 8 TeV in 2012. (orig.)

  14. High-Luminosity LHC moves to the next phase

    CERN Multimedia

    2015-01-01

    This week saw several meetings vital for the medium-term future of CERN.    From Monday to Wednesday, the Resource Review Board, RRB, that oversees resource allocation in the LHC experiments, had a series of meetings. Thursday then saw the close-out meeting for the Hi-Lumi LHC design study, which was partially funded by the European Commission. These meetings focused on the High Luminosity upgrade for the LHC, which responds to the top priority of the European Strategy for Particle Physics adopted by the CERN Council in 2013. This upgrade will transform the LHC into a facility for precision studies, the logical next step for the high-energy frontier of particle physics. It is a challenging upgrade, both for the LHC and the detectors. The LHC is already the highest luminosity hadron collider ever constructed, generating up to a billion collisions per second at the heart of the detectors. The High Luminosity upgrade will see that number rise by a factor of five from 2025. For the detectors...

  15. Recent luminosity improvements at the SLC

    International Nuclear Information System (INIS)

    Raimondi, P.; Usher, T.; Akre, R.

    1998-07-01

    The luminosity of the SLAC Linear Collider (SLC) has been increased by more than a factor of three during the 1997--98 run. Improved alignment and emittance tuning techniques throughout the accelerator resulted in minimal emittance growth from the damping rings to the final focus. In particular, a revised strategy for wakefield cancellation using precision beam size measurements at the entrance of the final focus proved effective for optimizing emittance. The final focus lattice was modified to provide stronger demagnification near the interaction point and to remove residual higher-order aberrations. Beam sizes as small as 1.5 by 0.65 microns were achieved at full beam intensity of 4 10 10 particles per pulse. With these parameters, the mutual focusing of the beams in collision becomes significant, resulting in a further increase in the luminosity. Recorded SLD event rates confirmed the theoretical calculations of the disruption enhancement which was typically 50 to 100%

  16. High luminosity muon scattering at FNAL

    International Nuclear Information System (INIS)

    Bazizi, K.; Conrad, J.; Fang, G.; Erdmann, M.; Geesaman, D.; Jackson, H.; Guyot, C.; Virchaux, M.; Holmgren, H.; Malensek, A.; Melanson, H.; Morfin, J.; Schellman, H.; Nickerson, R.

    1990-02-01

    The charge of this group was to evaluate the physics that can be done with a high luminosity μ scattering experiment at FNAL using the upgraded Tevatron muon beam, and consider the apparatus required. In this report, the physics that can be accomplished with a high luminosity μ scattering experiment is evaluated. The CERN and FNAL μ beams are compared in the context of such an experiment. The expected muon flux with the upgraded machine is estimated. Two possible detectors are compared: the air-core toroid experiment proposed by Guyot et al., and an upgraded version of the E665 double-diode apparatus now in place at FNAL. The relative costs of the detectors are considered. A list of detailed questions that need to be answered regarding the double-diode experiment has be compiled. 2 refs., 10 figs., 2 tabs

  17. Luminosity with more bunches in PEP

    International Nuclear Information System (INIS)

    Corbett, W.J.

    1990-12-01

    The near term accelerator physics program for PEP includes experiments in a collider mode with up to 9 bunches in each beam. In this memo, luminosity data from the 3 x 3 configuration is first used to calculate vertical beam size, emittance and tune shift as a function of current. The data is then used to extrapolate to the case with either 6 x 6 or 9 x 9 bunches colliding in PEP. Vertical emittance growth from the separated bunch optics and dispersion at the IP are included in the calculations. The conclusion is that given a 90 mA current drive limitation in PEP, operating with 6 x 6 bunches yields the maximum luminosity. 9 refs., 6 figs

  18. Classical Cepheid luminosities from binary companions

    International Nuclear Information System (INIS)

    Evans, N.R.

    1991-01-01

    Luminosities for the classical Cepheids Eta Aql, W Sgr, and SU Cas are determined from IUE spectra of their binary companions. Spectral types of the companions are determined from the spectra by comparison with the spectra of standard stars. The absolute magnitude inferred from these spectral types is used to determine the absolute magnitude of the Cepheid, either directly or from the magnitude difference between the two stars. For the temperature range of the companions (A0 V), distinctions of a quarter of a spectral subclass can be made in the comparison between the companions and standard stars. The absolute magnitudes for Eta Aql and W Sgr agree well with the period-luminosity-color relation of Feast and Walker (1987). Random errors are estimated to be 0.3 mag. SU Cas, however, is overluminous for pulsation in the fundamental mode, implying that it is pulsating in an overtone. 58 refs

  19. The infrared luminosity function of AKARI 90 μm galaxies in the local Universe

    Science.gov (United States)

    Kilerci Eser, Ece; Goto, Tomotsugu

    2018-03-01

    Local infrared (IR) luminosity functions (LFs) are necessary benchmarks for high-redshift IR galaxy evolution studies. Any accurate IR LF evolution studies require accordingly accurate local IR LFs. We present IR galaxy LFs at redshifts of z ≤ 0.3 from AKARI space telescope, which performed an all-sky survey in six IR bands (9, 18, 65, 90, 140, and 160 μm) with 10 times better sensitivity than its precursor Infrared Astronomical Satellite. Availability of 160 μm filter is critically important in accurately measuring total IR luminosity of galaxies, covering across the peak of the dust emission. By combining data from Wide-field Infrared Survey Explorer (WISE), Sloan Digital Sky Survey (SDSS) Data Release 13 (DR 13), six-degree Field Galaxy Survey and the 2MASS Redshift Survey, we created a sample of 15 638 local IR galaxies with spectroscopic redshifts, factor of 7 larger compared to previously studied AKARI-SDSS sample. After carefully correcting for volume effects in both IR and optical, the obtained IR LFs agree well with previous studies, but comes with much smaller errors. Measured local IR luminosity density is ΩIR = 1.19 ± 0.05 × 108L⊙ Mpc-3. The contributions from luminous IR galaxies and ultraluminous IR galaxies to ΩIR are very small, 9.3 per cent and 0.9 per cent, respectively. There exists no future all-sky survey in far-IR wavelengths in the foreseeable future. The IR LFs obtained in this work will therefore remain an important benchmark for high-redshift studies for decades.

  20. The AGN Luminosity Fraction in Galaxy Mergers

    Science.gov (United States)

    Dietrich, Jeremy; Weiner, Aaron; Ashby, Matthew; Martinez-Galarza, Juan Rafael; Smith, Howard Alan

    2017-01-01

    Galaxy mergers are key events in galaxy evolution, generally triggering massive starbursts and AGNs. However, in these chaotic systems, it is not yet known what fraction each of these two mechanisms contributes to the total luminosity. Here we measure and model spectral energy distributions (SEDs) using the Code for Investigating Galaxy Emission (CIGALE) in up to 33 broad bands from the UV to the far-IR for 23 IR-luminous galaxies to estimate the fraction of the bolometric IR luminosity that can be attributed to the AGN. The galaxies are split nearly evenly into two subsamples: late-stage mergers, found in the IRAS Revised Bright Galaxy Sample or Faint Source Catalog, and early-stage mergers found in the Spitzer Interacting Galaxy Sample. We find that the AGN contribution to the total IR luminosity varies greatly from system to system, from 0% up to ~90%, but is substantially greater in the later-stage and brighter mergers. This is consistent with what is known about galaxy evolution and the triggering of AGNs.The SAO REU program is funded in part by the National Science Foundation REU and Department of Defense ASSURE programs under NSF Grant no. 1262851, and by the Smithsonian Institution.

  1. K0 finding efficiencies in increasing luminosities

    International Nuclear Information System (INIS)

    Hassard, J.F.; Margetides S.

    1993-01-01

    In early LHC running it is anticipated that experiments will obtain luminosities of 10 32 cm -2 sec -1 , during which typically only one interaction per event will be obtained. But at higher luminosities, necessary for any Higgs and myriad other searches, experiments will have to deal with up to 50 distinct primary processes. Most will be minimum bias, and easily distinguished in terms of trigger. They can still, of course, confuse analysis of high P T events. When it comes to B events, the confusion even from minimum bias events becomes more acute, since B events are not open-quotes high P T close quotes in this environment. The need for vertex discrimination, particularly in z, is well understood; however, a collateral effect - the increasing difficulty in finding tracks at all - has received little attention. The authors show the distribution of the K 0 in the Pythia process B → J/ψK 0 in the space γ vs. η. Confusion in reconstructing the K 0 is acute for many reasons, not the least of which is the way their pions are boosted forward, and even out of acceptance. Extra luminosity merely increases the problems in finding K 0 's, so it must not be assumed that 10 33 cm -2 sec -1 is ten times better than 10 32 cm -2 sec -1

  2. Performance study for inlet installations

    Science.gov (United States)

    Bingaman, Donald C.

    1992-01-01

    A conceptual design trade study was conducted by McDonnell Aircraft Company (MCAIR) and NASA LARC PAB to determine the impact of inlet design features incorporated for reduced detectability on inlet performance, weight, and cost, for both fighter and attack-type aircraft. Quality Function Deployment (QFD) techniques were used to prioritize trade study issues, and select 'best' air induction system configurations for each of two notional aircraft, the Multi-Role Fighter (MRF) and the Advanced Medium Attack (AMA) bomber. Database deficiencies discovered in the trade study process were identified, and technology roadmaps were developed to address these deficiencies. Finally, two high speed inlet wind tunnel model concepts were developed for follow-on wind tunnel investigations.

  3. Effective pile-up density as a measure of the experimental data quality for High-Luminosity LHC operational scenarios.

    CERN Document Server

    Medina Medrano, Luis Eduardo; Arduini, Gianluigi; Napsuciale, Mauro

    2018-01-01

    The High-Luminosity LHC (HL-LHC) experiments will operate at unprecedented level of event pile-up from proton-proton collisions at 14TeV center-of-mass energy. In this paper we study the performance of the baseline and a series of alternative scenarios in terms of the delivered integrated luminosity and its quality (pile-up density). A new figure-of-merit is introduced, the effective pile-up density, a concept that reflects the expected detector efficiency in the reconstruction of event vertices for a given operational scenario, acting as a link between the machine and experimental slides. Alternative scenarios have been proposed either to improve the baseline performance, or tot provide operational schemes in the case of particular limitations. Simulations of the evolution of optimum fills with the latest set of parameters of the HL-LHC are performed with β* - levelling, and results are discussed in terms of both the integrated luminosity and the effective pile-up density. The crab kissing scheme, a propose...

  4. Semi-empirical model for optimising future heavy-ion luminosity of the LHC

    CERN Document Server

    Schaumann, M

    2014-01-01

    The wide spectrum of intensities and emittances imprinted on the LHC Pb bunches during the accumulation of bunch trains in the injector chain result in a significant spread in the single bunch luminosities and lifetimes in collision. Based on the data collected in the 2011 Pb-Pb run, an empirical model is derived to predict the single-bunch peak luminosity depending on the bunch’s position within the beam. In combination with this model, simulations of representative bunches are used to estimate the luminosity evolution for the complete ensemble of bunches. Several options are being considered to improve the injector performance and to increase the number of bunches in the LHC, leading to several potential injection scenarios, resulting in different peak and integrated luminosities. The most important options for after the long shutdown (LS) 1 and 2 are evaluated and compared.

  5. Cosmological perturbation effects on gravitational-wave luminosity distance estimates

    Science.gov (United States)

    Bertacca, Daniele; Raccanelli, Alvise; Bartolo, Nicola; Matarrese, Sabino

    2018-06-01

    Waveforms of gravitational waves provide information about a variety of parameters for the binary system merging. However, standard calculations have been performed assuming a FLRW universe with no perturbations. In reality this assumption should be dropped: we show that the inclusion of cosmological perturbations translates into corrections to the estimate of astrophysical parameters derived for the merging binary systems. We compute corrections to the estimate of the luminosity distance due to velocity, volume, lensing and gravitational potential effects. Our results show that the amplitude of the corrections will be negligible for current instruments, mildly important for experiments like the planned DECIGO, and very important for future ones such as the Big Bang Observer.

  6. Physics potential and experimental challenges of the LHC luminosity upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Gianotti, F.; Ball, A.; Bloch, P.; Casagrande, L.; Cittolin, S.; Roeck, A. de; Ellis, N.; Farthouat, P.; Hansen, J.-B. [CERN, Experimental Physics Division, Geneva (Switzerland); Mangano, M.L. [CERN, Theoretical Physics Division, Geneva (Switzerland); Virdee, T. [CERN, Experimental Physics Division, Geneva (Switzerland); Imperial College, London (United Kingdom); Abdullin, S. [University of Maryland (United States); Azuelos, G. [University of Montreal, Group of Particle Physics, Montreal (Canada); Barberis, D. [Universita di Genova, Dipartimento di Fisica and INFN (Italy); Belyaev, A. [Florida State University, Tallahassee, FL (United States); Bosman, M. [IFAE, Barcelona (Spain); Cavalli, D. [INFN, Milano (Italy); Chumney, P.; Dasu, S. [Univ. of Wisconsin, Madison, WI (United States); Fournier, D. [LAL, Orsay (France); Hinchliffe, I.; Hohlfeld, M.; Huhtinen, M.; Jakobs, K.; Joram, C.; Mazzucato, F.; Mikenberg, G.; Miagkov, A.; Moretti, M.; Moretti, S.; Niinikoski, T.; Nikitenko, A.; Nisati, A.; Paige, F.; Palestini, S.; Papadopoulos, C.G.; Piccinini, F.; Pittau, R.; Polesello, G.; Richter-Was, E.; Sharp, P.; Slabospitsky, S.R.; Smith, W.H.; Stapnes, S.; Tonelli, G.; Tsesmelis, E.; Usubov, Z.; Vacavant, L.; Bij, J. van der; Watson, A.; Wielers, M.

    2004-02-01

    We discuss the physics potential and the experimental challenges of an upgraded LHC running at an instantaneous luminosity of 10{sup 35} cm{sup -2}s{sup -1}. The detector R and D needed to operate ATLAS and CMS in a very high radiation environment and the expected detector performance are discussed. A few examples of the increased physics potential are given, ranging from precise measurements within the Standard Model (in particular in the Higgs sector) to the discovery reach for several New Physics processes. (orig.)

  7. The luminosity monitor of the HERMES experiment at DESY

    CERN Document Server

    Benisch, T; Devitsin, E G; Kozlov, V; Potashov, S Yu; Rith, K; Terkulov, A R; Weiskopf, C

    2001-01-01

    A detector is described which measures the luminosity of the HERMES experiment at DESY. It is based on the coincident detection of electron-positron and photon pairs, or electron pairs, originating from the interaction of the beam positrons, or electrons, with the electrons of the atomic gas target. It consists of two calorimeters with radiation hard NaBi(WO sub 4) sub 2 crystals. Properties of the monitor, investigated in an electron test beam, and its performance in the experiment are presented.

  8. IRAS bright galaxy sample. II. The sample and luminosity function

    International Nuclear Information System (INIS)

    Soifer, B.T.; Sanders, D.B.; Neugebauer, G.; Madore, B.F.; Danielson, G.E.; David Dunlap Observatory, Richmond Hill, Canada; Palomar Observatory; California Institute of Technology, Pasadena)

    1987-01-01

    A statistically complete sample of 324 of the brightest infrared galaxies discovered at 60 microns in the IRAS all-sky survey is described. The results show that far-infrared emission is a significant luminosity component in the local universe, representing 25 percent of the luminosity emitted by stars in the same volume. Above 10 to the 11th solar luminosities, the infrared luminous galaxies are the dominant population of objects in the universe, being as numerous as the Seyfert galaxies and more numerous than quasars at higher luminosities. The infrared luminosity appears to be independent of the optical luminosity of galaxies. Most infrared bright galaxies appear to require much of the interstellar matter to be contributing to the observed infrared luminosity. Approximately 60-80 percent of the far-infrared luminosity of the local universe can be attributed, directly or indirectly, to recent or ongoing star formation. 67 references

  9. Study of the performance of Micromegas detectors in magnetic field

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00222923; The ATLAS collaboration

    2015-01-01

    Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes ($10 \\times 10 \\text{cm}^2$) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the cap...

  10. Study of the performance of Micromegas detectors in magnetic field

    CERN Document Server

    Sampsonidis, Dimos; The ATLAS collaboration

    2016-01-01

    Resistive Micromegas (Micro MEsh Gaseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade due to their capability to maintain full efficiency and high spatial resolution at high rates. Operation in the Inner Muon Station of the high-rapidity region, the so called New Small Wheel (NSW) requires also these performances to be maintened in magnetic fields up to about 0.3 T. The response of Micromegas chambers is affected by the magnetic field where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10x10cm2) in magnetic fields up to 1 T using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability to operate these chambers to get unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity ...

  11. GIF++: A new CERN Irradiation Facility to test large-area particle detectors for the High-Luminosity LHC program

    CERN Document Server

    Guida, Roberto

    2016-01-01

    The high-luminosity LHC (HL-LHC) upgrade is setting a new challenge for particle detector technologies. The increase in luminosity will produce a higher particle background with respect to present conditions. To study performance and stability of detectors at LHC and future HL-LHC upgrades, a new dedicated facility has been built at CERN: the new Gamma Irradiation Facility (GIF++). The GIF++ is a unique place where high energy charged particle beams (mainly muons) are combined with gammas from a 14 TBq 137Cesium source which simulates the background radiation expected at the LHC experiments. Several centralized services and infrastructures are made available to the LHC detector community to facilitate the different R&D; programs.

  12. On the distinction between density and luminosity evolution

    International Nuclear Information System (INIS)

    Bahcall, J.N.

    1977-01-01

    It is shown that the assumptions of pure density evolution and pure luminosity evolution lead to observable differences in the distribution of sources for all convergent luminosity functions. The proof given is valid for sources with an arbitrary number of intrinisic luminosities (e.g., optical, infrared, and radio) and also holds in the special cases of mixed evolution that are considered. (author)

  13. THE LUMINOSITY PROFILES OF BRIGHTEST CLUSTER GALAXIES

    International Nuclear Information System (INIS)

    Donzelli, C. J.; Muriel, H.; Madrid, J. P.

    2011-01-01

    We have derived detailed R-band luminosity profiles and structural parameters for a total of 430 brightest cluster galaxies (BCGs), down to a limiting surface brightness of 24.5 mag arcsec -2 . Light profiles were initially fitted with a Sersic's R 1/n model, but we found that 205 (∼48%) BCGs require a double component model to accurately match their light profiles. The best fit for these 205 galaxies is an inner Sersic model, with indices n ∼ 1-7, plus an outer exponential component. Thus, we establish the existence of two categories of the BCG luminosity profiles: single and double component profiles. We found that double profile BCGs are brighter (∼0.2 mag) than single profile BCGs. In fact, the Kolmogorov-Smirnov test applied to these subsamples indicates that they have different total magnitude distributions, with mean values M R = -23.8 ± 0.6 mag for single profile BCGs and M R = -24.0 ± 0.5 mag for double profile BCGs. We find that partial luminosities for both subsamples are indistinguishable up to r = 15 kpc, while for r > 20 kpc the luminosities we obtain are on average 0.2 mag brighter for double profile BCGs. This result indicates that extra-light for double profile BCGs does not come from the inner region but from the outer regions of these galaxies. The best-fit slope of the Kormendy relation for the whole sample is a = 3.13 ± 0.04. However, when fitted separately, single and double profile BCGs show different slopes: a single = 3.29 ± 0.06 and a double = 2.79 ± 0.08. Also, the logarithmic slope of the metric luminosity α is higher in double profile BCGs (α double = 0.65 ± 0.12) than in single profile BCGs (α single = 0.59 ± 0.14). The mean isophote outer ellipticity (calculated at μ ∼ 24 mag arcsec -2 ) is higher in double profile BCGs (e double = 0.30 ± 0.10) than in single profile BCGs (e single = 0.26 ± 0.11). Similarly, the mean absolute value of inner minus outer ellipticity is also higher in double profile BCGs. From a

  14. CORNELL: Bunch trains provide higher luminosity

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The new colliding beam technique - ''bunch trains'' - at Cornell's electron-positron Storage Ring (CESR) has led to a new world record for colliding beam luminosity - 3.3 x 10 32 cm -2 s -1 . In the bid to increase reaction rate for any particular process, this luminosity is pushed as high as possible. Once all other luminosityincreasing cards have been played, the only practical way of making a large gain in luminosity is to increase the frequency of bunch-bunch collisions by increasing the number of bunches stored in the ring. However this is not without its own problems: • If the two beams travel the same orbit, the n bunches in one beam collide with the n bunches of the other at 2n points around the ring, and the resulting cumulative nonlinear beam-beam effect (tune shift) severely limits the luminosity attainable at any interaction point. • The destabilizing wakefield effects of bunches on each other increase as the number of bunches increases and the spacing between them decreases. • The synchrotron radiation emitted by the beams becomes a severe problem as the total beam current is raised: to overcome these effects means supplying radiofrequency power to maintain the beam energy, carrying away heat from the vacuum chamber walls, pumping out desorbed gases, and controlling Xray backgrounds in the experiment. In 1979, CESR was designed to run with a single bunch of electrons and a single bunch of positrons circulating on the same orbit and colliding head-on at two diametrically opposite points in the ring, where the CLEO and CUSB experiments were then located. Ideally one could store multiple bunches and solve the multiple collision point problem by using separate rings for the two beams, as in the CERN ISR proton-proton collider and in the original DORIS two-ring configuration at DESY, Hamburg, making the two beams intersect only at the experiments. A less expensive version of this two-ring scheme was accomplished at CESR in

  15. CORNELL: Bunch trains provide higher luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1995-09-15

    The new colliding beam technique - ''bunch trains'' - at Cornell's electron-positron Storage Ring (CESR) has led to a new world record for colliding beam luminosity - 3.3 x 10{sup 32} cm{sup -2}s{sup -1}. In the bid to increase reaction rate for any particular process, this luminosity is pushed as high as possible. Once all other luminosityincreasing cards have been played, the only practical way of making a large gain in luminosity is to increase the frequency of bunch-bunch collisions by increasing the number of bunches stored in the ring. However this is not without its own problems: • If the two beams travel the same orbit, the n bunches in one beam collide with the n bunches of the other at 2n points around the ring, and the resulting cumulative nonlinear beam-beam effect (tune shift) severely limits the luminosity attainable at any interaction point. • The destabilizing wakefield effects of bunches on each other increase as the number of bunches increases and the spacing between them decreases. • The synchrotron radiation emitted by the beams becomes a severe problem as the total beam current is raised: to overcome these effects means supplying radiofrequency power to maintain the beam energy, carrying away heat from the vacuum chamber walls, pumping out desorbed gases, and controlling Xray backgrounds in the experiment. In 1979, CESR was designed to run with a single bunch of electrons and a single bunch of positrons circulating on the same orbit and colliding head-on at two diametrically opposite points in the ring, where the CLEO and CUSB experiments were then located. Ideally one could store multiple bunches and solve the multiple collision point problem by using separate rings for the two beams, as in the CERN ISR proton-proton collider and in the original DORIS two-ring configuration at DESY, Hamburg, making the two beams intersect only at the experiments. A less expensive version of this two-ring scheme was accomplished at CESR in 1983, using

  16. Optical and X-ray luminosities of expanding nebulae around ultraluminous X-ray sources

    Science.gov (United States)

    Siwek, Magdalena; Sądowski, Aleksander; Narayan, Ramesh; Roberts, Timothy P.; Soria, Roberto

    2017-09-01

    We have performed a set of simulations of expanding, spherically symmetric nebulae inflated by winds from accreting black holes in ultraluminous X-ray sources (ULXs). We implemented a realistic cooling function to account for free-free and bound-free cooling. For all model parameters we considered, the forward shock in the interstellar medium becomes radiative at a radius ˜100 pc. The emission is primarily in optical and UV, and the radiative luminosity is about 50 per cent of the total kinetic luminosity of the wind. In contrast, the reverse shock in the wind is adiabatic so long as the terminal outflow velocity of the wind vw ≳ 0.003c. The shocked wind in these models radiates in X-rays, but with a luminosity of only ˜1035 erg s-1. For wind velocities vw ≲ 0.001c, the shocked wind becomes radiative, but it is no longer hot enough to produce X-rays. Instead it emits in optical and UV, and the radiative luminosity is comparable to 100 per cent of the wind kinetic luminosity. We suggest that measuring the optical luminosities and putting limits on the X-ray and radio emission from shock-ionized ULX bubbles may help in estimating the mass outflow rate of the central accretion disc and the velocity of the outflow.

  17. The Luminosity Function of Fermi-Detected Flat-Spectrum Radio Quasars

    Science.gov (United States)

    2012-05-11

    extensively studied at radio (Dunlop & Peacock 1990; Wall et al. 2005), soft X-ray (Giommi & Padovani 1994; Rector et al. 2000; Wolter & Celotti 2001...FSRQs) evolve positively (i.e., there were more blazars in the past, Dunlop & Peacock 1990) up to a redshift cutoff which depends on luminosity (e.g...luminosity of 1048 erg s−1. The LDDE model provides a good fit to the LAT data and is able to reproduce the observed distribution in Figure 2. The log

  18. Far-infrared luminosities of Markarian starburst galaxies

    International Nuclear Information System (INIS)

    Deutsch, L.K.; Willner, S.P.

    1986-01-01

    Total far-infrared luminosities have been calculated from measured IRAS fluxes for a sample of optically selected galaxies and for a comparison sample of spiral galaxies. The starburst galaxies are notably more luminous in the far-infrared and have higher dust color temperatures than the comparison galaxies. The far-infrared light dominates the total luminosity of the starburst galaxies, and a significant amount of dust must be present. The far-infrared emission correlates well with total blue luminosity, nuclear blue luminosity, and nuclear H-alpha luminosity. The dust that produces the far-infrared light is probably heated predominantly by B rather than by O stars. 30 references

  19. LHC Report: spring cleaning over, bunches of luminosity

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Scrubbing was completed on Wednesday 13 April. The run had seen over 1000 bunches per beam successfully circulating at 450 GeV. Measurements showed that electron cloud activity in the cold regions had been suppressed. A decrease of vacuum activity in the warm regions demonstrated that the cleaning had also achieved the required results there. As discussed in the last Bulletin, the scrubbing was performed with high intensity bunches with 50 nanosecond spacing. Given the potential luminosity performance with this spacing (more bunches, higher bunch intensity from the injectors) and in the light of the results of the scrubbing run, the decision was taken to continue the 2011 physics run with this bunch spacing.   A few issues with 50 nanosecond spacing had to be resolved when standard operations for luminosity production resumed. Once things had been tidied up, stable beams were provided for the experiments, firstly with 228 bunches per beam and then with 336 bunches per beam. The 336 bunch fill that w...

  20. On the average luminosity of electron positron collider and positron-producing energy

    International Nuclear Information System (INIS)

    Xie Jialin

    1985-01-01

    In this paper, the average luminosity of linac injected electron positron collider is investigated from the positron-producing energy point of view. When the energy of the linac injector is fixed to be less than the operating energy of the storage ring, it has been found that there exists a positron-producing energy to give optimum average luminosity. Two cases have been studied, one for an ideal storage ring with no single-beam instability and the other for practical storage ring with fast head-tail instability. The result indicates that there is a positron-producing energy corresponding to the minimum injection time, but this does not correspond to the optimum average luminosity for the practical storage rings. For Beijing Electron Positron Collider (BEPC), the positron-producing energy corresponding to the optimum average luminosity is about one tenth of the total injector energy

  1. Thermodynamics and luminosities of rainbow black holes

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Benrong [Physics Teaching and Research section, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, No. 1166 Liutai Avenue, Chengdu (China); Wang, Peng; Yang, Haitang, E-mail: mubenrong@uestc.edu.cn, E-mail: pengw@scu.edu.cn, E-mail: hyanga@scu.edu.cn [Center for Theoretical Physics, College of Physical Science and Technology, Sichuan University, No. 24 South Section 1 Yihuan Road, Chengdu (China)

    2015-11-01

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is ''Gravity's rainbow'', where the spacetime background felt by a test particle would depend on its energy. Focusing on the ''Amelino-Camelia dispersion relation'' which is E{sup 2} = m{sup 2}+p{sup 2}[1−η(E/m{sub p}){sup n}] with n > 0, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of η and n in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with η < 0 and n ≥ 2. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute luminosities of a 2D black hole, a Schwarzschild one and a static uncharged black string. It is found that the luminosities can be significantly suppressed or boosted depending on the values of η and n.

  2. High Luminosity LHC: challenges and plans

    Science.gov (United States)

    Arduini, G.; Barranco, J.; Bertarelli, A.; Biancacci, N.; Bruce, R.; Brüning, O.; Buffat, X.; Cai, Y.; Carver, L. R.; Fartoukh, S.; Giovannozzi, M.; Iadarola, G.; Li, K.; Lechner, A.; Medina Medrano, L.; Métral, E.; Nosochkov, Y.; Papaphilippou, Y.; Pellegrini, D.; Pieloni, T.; Qiang, J.; Redaelli, S.; Romano, A.; Rossi, L.; Rumolo, G.; Salvant, B.; Schenk, M.; Tambasco, C.; Tomás, R.; Valishev, S.; Van der Veken, F. F.

    2016-12-01

    The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will undergo a major upgrade in the 2020s. This will increase its rate of collisions by a factor of five beyond the original design value and the integrated luminosity by a factor ten. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 T superconducting magnets, including Nb3Sn-based magnets never used in accelerators before, compact superconducting cavities for longitudinal beam rotation, new technology and physical processes for beam collimation. The dynamics of the HL-LHC beams will be also particularly challenging and this aspect is the main focus of this paper.

  3. High Luminosity LHC: Challenges and plans

    International Nuclear Information System (INIS)

    Arduini, G.; Barranco, J.; Bertarelli, A.; Biancacci, N.; Bruce, R.

    2016-01-01

    The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will undergo a major upgrade in the 2020s. This will increase its rate of collisions by a factor of five beyond the original design value and the integrated luminosity by a factor ten. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11–12 T superconducting magnets, including Nb 3 Sn-based magnets never used in accelerators before, compact superconducting cavities for longitudinal beam rotation, new technology and physical processes for beam collimation. As a result, the dynamics of the HL-LHC beams will be also particularly challenging and this aspect is the main focus of this paper.

  4. LHC Report: A new luminosity record

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    After about one month of operation, the LHC has already accumulated an integrated luminosity of 28 pb-1, which corresponds to over 50% of the total delivered to the experiments in 2010. This impressive start to the LHC run in 2011 bodes well for the rest of year.   Following careful collimator set-up and validation, the first phase of beam commissioning 2011 has come to an end. The first stable beams were declared on Sunday 13 March with a moderate 3 bunches per beam and an initial luminosity of 1.6 × 1030 cm-2s-1. Machine protection tests continued during the following week as the commissioning team made absolutely sure that all critical systems (beam dumps, beam interlock system, etc.) were functioning properly. When these tests had finished, the way was opened to increased intensity and the LHC quickly moved through the first part of its planned, staged intensity increase. Fills with increasing numbers of bunches were delivered to the experiments, culminating in a fill with 200...

  5. Upper limits on the total cosmic-ray luminosity of individual sources

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, R.C.; De Souza, V. [Instituto de Física de São Carlos, Universidade de São Paulo, São Paulo (Brazil); Supanitsky, A.D., E-mail: rita@ifsc.usp.br, E-mail: vitor@ifsc.usp.br, E-mail: supanitsky@iafe.uba.ar [Instituto de Astronomía y Física del Espacio (IAFE), CONICET-UBA, Buenos Aires (Argentina)

    2014-07-01

    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) E > 10{sup 18} eV) are determined for five individual sources. The upper limit on the integral flux of GeV--TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV--TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV--TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set.

  6. Upper limits on the total cosmic-ray luminosity of individual sources

    International Nuclear Information System (INIS)

    Anjos, R.C.; De Souza, V.; Supanitsky, A.D.

    2014-01-01

    In this paper, upper limits on the total luminosity of ultra-high-energy cosmic-rays (UHECR) E > 10 18 eV) are determined for five individual sources. The upper limit on the integral flux of GeV--TeV gamma-rays is used to extract the upper limit on the total UHECR luminosity of individual sources. The correlation between upper limit on the integral GeV--TeV gamma-ray flux and upper limit on the UHECR luminosity is established through the cascading process that takes place during propagation of the cosmic rays in the background radiation fields, as explained in reference [1]. Twenty-eight sources measured by FERMI-LAT, VERITAS and MAGIC observatories have been studied. The measured upper limit on the GeV--TeV gamma-ray flux is restrictive enough to allow the calculation of an upper limit on the total UHECR cosmic-ray luminosity of five sources. The upper limit on the UHECR cosmic-ray luminosity of these sources is shown for several assumptions on the emission mechanism. For all studied sources an upper limit on the ultra-high-energy proton luminosity is also set

  7. Luminosity Determination in $pp$ Collisions at $\\sqrt{s}$ = 7 TeV using the ATLAS Detector at the LHC

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Ackers, Mario; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahmed, Hossain; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Akesson, Torsten Paul; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Aleppo, Mario; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Jose; Alviggi, Mariagrazia; Amako, Katsuya; Amaral, Pedro; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amoros, Gabriel; Amram, Nir; Anastopoulos, Christos; Andeen, Timothy; Anders, Christoph Falk; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonelli, Stefano; Antos, Jaroslav; Anulli, Fabio; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Archambault, John-Paul; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arms, Kregg; Armstrong, Stephen Randolph; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Asman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Atoian, Grigor; Aubert, Bernard; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Austin, Nicholas; Avramidou, Rachel Maria; Axen, David; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Bachy, Gerard; Backes, Moritz; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Sarah; Baltasar Dos Santos Pedrosa, Fernando; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barashkou, Andrei; Galtieri, Angela Barbaro; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barr, Alan; Barreiro, Fernando; Guimaraes da Costa, J.Barreiro; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Detlef; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Battistoni, Giuseppe; Bauer, Florian; Bawa, Harinder Singh; Beare, Brian; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Belhorma, Bouchra; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Giovanni; Bellomo, Massimiliano; Belloni, Alberto; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Benchouk, Chafik; Bendel, Markus; Benedict, Brian Hugues; Benekos, Nektarios; Benhammou, Yan; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jurg; Bernardet, Karim; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertin, Antonio; Bertinelli, Francesco; Bertolucci, Federico; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bischof, Reinhard; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Boaretto, Christian; Bobbink, Gerjan; Bobrovnikov, Victor; Bocci, Andrea; Bock, Rudolf; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boelaert, Nele; B{oser, Sebastian; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boonekamp, Maarten; Boorman, Gary; Booth, Chris; Booth, Peter; Booth, Richard; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borroni, Sara; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Botterill, David; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boulahouache, Chaouki; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozhko, Nikolay; Bozovic-Jelisavcic, Ivanka; Braccini, Saverio; Bracinik, Juraj; Braem, Andre; Brambilla, Elena; Branchini, Paolo; Brandenburg, George; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brelier, Bertrand; Bremer, Johan; Brenner, Richard; Bressler, Shikma; Breton, Dominique; Brett, Nicolas; Bright-Thomas, Paul; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brodbeck, Timothy; Brodet, Eyal; Broggi, Francesco; Bromberg, Carl; Brooijmans, Gustaaf; Brooks, William; Brown, Gareth; Brubaker, Erik; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Bucci, Francesca; Buchanan, James; Buchanan, Norman; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Buscher, Volker; Bugge, Lars; Buira-Clark, Daniel; Buis, Ernst-Jan; Bulekov, Oleg; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butin, Francois; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Byatt, Tom; Cabrera Urban, Susana; Caccia, Massimo; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camard, Arnaud; Camarri, Paolo; Cambiaghi, Mario; Cameron, David; Cammin, Jochen; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Capasso, Luciano; Garrido, Maria Del Mar Capeans; Caprini, Irinel; Caprini, Mihai; Caprio, Mario; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Caramarcu, Costin; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carpentieri, Carmen; Montoya, German D.Carrillo; Carron Montero, Sebastian; Carter, Antony; Carter, Janet; Carvalho, Joao; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Cataneo, Fernando; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavallari, Alvise; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Cazzato, Antonio; Ceradini, Filippo; Cerna, Cedric; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cervetto, Mario; Cetin, Serkant Ali; Cevenini, Francesco; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Kevin; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chen, Hucheng; Chen, Li; Chen, Shenjian; Chen, Tingyang; Chen, Xin; Cheng, Shaochen; Cheplakov, Alexander; Chepurnov, Vladimir; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chevallier, Florent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Illectra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciobotaru, Matei Dan; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Clark, Allan G.; Clark, Philip; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Clifft, Roger; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H.; Coe, Paul; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Cojocaru, Claudiu; Colas, Jacques; Colijn, Auke-Pieter; Collard, Caroline; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colon, German; Coluccia, Rita; Comune, Gianluca; Conde Muino, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Michele; Constantinescu, Serban; Conta, Claudio; Conventi, Francesco; Cook, James; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Correard, Sebastien; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, Maria Jose; Costanzo, Davide; Costin, Tudor; Cote, David; Coura Torres, Rodrigo; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Cristinziani, Markus; Crosetti, Giovanni; Crupi, Roberto; Crepe-Renaudin, Sabine; Cuenca Almenar, Cristobal; Donszelmann, Tulay Cuhadar; Cuneo, Stefano; Curatolo, Maria; Curtis, Chris; Cwetanski, Peter; Czirr, Hendrik; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Rocha Gesualdi Mello, Aline; Da Silva, Paulo Vitor; Da Via, Cinzia; Dabrowski, Wladyslaw; Dahlhoff, Andrea; Dai, Tiesheng; Dallapiccola, Carlo; Dallison, Steve; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dankers, Reinier; Dannheim, Dominik; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Daum, Cornelis; Dauvergne, Jean-Pierre; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Merlin; Davison, Adam; Dawe, Edmund; Dawson, Ian; Dawson, John; Daya, Rozmin; De, Kaushik; De Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; La Cruz-Burelo, Eduard De; de la Taille, Christophe; De Lotto, Barbara; De Mora, Lee; De Nooij, Lucie; De Oliveira Branco, Miguel; De Pedis, Daniele; de Saintignon, Paul; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; de Vivie De Regie, Jean-Baptiste; Dean, Simon; Dedes, George; Dedovich, Dmitri; Degenhardt, James; Dehchar, Mohamed; Deile, Mario; del Papa, Carlo; del Peso, Jose; del Prete, Tarcisio; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delpierre, Pierre; Delruelle, Nicolas; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; Denisov, Sergey; Dennis, Chris; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diaz Gomez, Manuel Maria; Diblen, Faruk; Diehl, Edward; Dietl, Hans; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Yagci, Kamile Dindar; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djilkibaev, Rashid; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, Andre; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobinson, Robert; Dobos, Daniel; Dobson, Ellie; Dobson, Marc; Dodd, Jeremy; Dogan, Ozgen Berkol; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donega, Mauro; Donini, Julien; Dopke, Jens; Doria, Alessandra; dos Anjos, Andre; Dosil, Mireia; Dotti, Andrea; Dova, Maria-Teresa; Dowell, John; Doxiadis, Alexander; Doyle, Tony; Drasal, Zbynek; Drees, Jurgen; Dressnandt, Nandor; Drevermann, Hans; Driouichi, Chafik; Dris, Manolis; Drohan, Janice; Dubbert, Jorg; Dubbs, Tim; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Dudarev, Alexey; Dudziak, Fanny; Duhrssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Dzahini, Daniel; Duren, Michael; Ebke, Johannes; Eckert, Simon; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Efthymiopoulos, Ilias; Ehrenfeld, Wolfgang; Ehrich, Thies; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Ely, Robert; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Facius, Katrine; Fakhrutdinov, Rinat; Falciano, Speranza; Falou, Alain; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrington, Sinead; Farthouat, Philippe; Fasching, Damon; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Ivan; Fedorko, Woiciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Felzmann, Ulrich; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferguson, Douglas; Ferland, Jonathan; Fernandes, Bruno; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Ferro, Fabrizio; Fiascaris, Maria; Fiedler, Frank; Filipcic, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fischer, Peter; Fisher, Matthew; Fisher, Steve; Flammer, Joachim; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Flores Castillo, Luis; Flowerdew, Michael; Fohlisch, Florian; Fokitis, Manolis; Fonseca Martin, Teresa; Forbush, David Alan; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Foster, Joe; Fournier, Daniel; Foussat, Arnaud; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallas, Manuel; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galyaev, Eugene; Gan, K.K.; Gao, Yongsheng; Gapienko, Vladimir; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; Garcia, Carmen; Garcia Navarro, Jose Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Garvey, John; Gatti, Claudio; Gaudio, Gabriella; Gaumer, Olivier; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gayde, Jean-Christophe; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Helene; Gentile, Simonetta; Georgatos, Fotios; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghez, Philippe; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gieraltowski, Gerry; Gilbert, Laura; Gilchriese, Murdock; Gildemeister, Otto; Gilewsky, Valentin; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giusti, Paolo; Gjelsten, Borge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Gopfert, Thomas; Goeringer, Christian; Gossling, Claus; Gottfert, Tobias; Goldfarb, Steven; Goldin, Daniel; Golling, Tobias; Gollub, Nils Peter; Golovnia, Serguei; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Goncalo, Ricardo; Gonella, Laura; Gong, Chenwei; Gonidec, Allain; Gonzalez, Saul; Gonzalez de la Hoz, Santiago; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorisek, Andrej; Gornicki, Edward; Gorokhov, Serguei; Gorski, Boguslaw Tomasz; Goryachev, Vladimir; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gouanere, Michel; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Grabowska-Bold, Iwona; Grabski, Varlen; Grafstrom, Per; Grah, Christian; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenfield, Debbie; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregor, Ingrid-Maria; Grenier, Philippe; Griesmayer, Erich; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grognuz, Joel; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Gruwe, Magali; Grybel, Kai; Guarino, Victor; Guicheney, Christophe; Guida, Angelo; Guillemin, Thibault; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Andrea; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hackenburg, Robert; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hartel, Roland; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haller, Johannes; Hamacher, Klaus; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, Christian Johan; Hansen, John Renner; Hansen, Jrgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harper, Devin; Harper, Robert; Harrington, Robert; Harris, Orin; Harrison, Karl; Hart, John; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Donovan; Hayakawa, Takashi; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heldmann, Michael; Heller, Mathieu; Hellman, Sten; Helsens, Clement; Henderson, Robert; Hendriks, Patrick John; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frederic; Hensel, Carsten; Hens, Tobias; Hernandez Jimenez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hessey, Nigel; Hidvegi, Attila; Higon-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hindson, Daniel; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Hollins, Ivan; Holmes, Alan; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Homer, Jim; Homma, Yasuhiro; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Horton, Katherine; Hostachy, Jean-Yves; Hott, Thomas; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Idzik, Marek; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Imbault, Didier; Imhaeuser, Martin; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Ionescu, Gelu; Irles Quiles, Adrian; Ishii, Koji; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Isobe, Tadaaki; Issever, Cigdem; Istin, Serhat; Itoh, Yuki; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jantsch, Andreas; Janus, Michel; Jarlskog, Goran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jez, Pavel; Jezequel, Stephane; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Mark; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joo, Kwang; Joram, Christian; Jorge, Pedro; Jorgensen, Sigrid; Joseph, John; Ju, Xiangyang; Juranek, Vojtech; Jussel, Patrick; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Kazi, Sandor Istvan; Keates, James Robert; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kelly, Marc; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kersevan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Ketterer, Christian; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kilvington, Graham; Kim, Hyeon Jin; Kim, Min Suk; Kim, Peter; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Guillaume; Kirsch, Lawrence; Kiryunin, Andrey; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kiyamura, Hironori; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimentov, Alexei; Klingenberg, Reiner; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knobloch, Juergen; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Koblitz, Birger; Kocian, Martin; Kocnar, Antonin; Kodys, Peter; Koneke, Karsten; Konig, Adriaan; Koenig, Sebastian; Konig, Stefan; Kopke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollar, Daniel; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komaragiri, Jyothsna Rani; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Kopikov, Sergey; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamaki, Miikka Juhani; Kotov, Serguei; Kotov, Vladislav; Kourkoumelis, Christine; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasel, Olaf; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Krobath, Gernot; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Kruger, Hans; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuykendall, William; Kuze, Masahiro; Kuzhir, Polina; Kvasnicka, Ondrej; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramon; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lambacher, Marion; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Landsman, Hagar; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lapin, Vladimir; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Lau, Wing; Laurelli, Paolo; Lavorato, Antonia; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Lazzaro, Alfio; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Leahu, Marius; Lebedev, Alexander; Lebel, Celine; Lechowski, Matthieu; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lehto, Mark; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lellouch, Jeremie; Leltchouk, Mikhail; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Lepidis, Johannes; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Leveque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewandowska, Marta; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhihua; Liang, Zhijun; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Lilley, Joseph; Lim, Heuijin; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Shengli; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Lockwitz, Sarah; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Losada, Marta; Loscutoff, Peter; Sterzo, Francesco Lo; Losty, Michael; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lu, Jiansen; Lu, Liang; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dorthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Bjorn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lupi, Anna; Lutz, Gerhard; Lynn, David; Lynn, James; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maasen, Michael; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Macek, Bostjan; Machado Miguens, Joana; Macina, Daniela; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mattig, Peter; Mattig, Stefan; Magalhaes Martins, Paulo Jorge; Magnoni, Luca; Magradze, Erekle; Magrath, Caroline; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amelia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandi{c, Igor; Mandrysch, Rocco; Maneira, Jose; Mangeard, Pierre-Simon; Mangin-Brinet, Mariane; Manjavidze, Ioseb; Mann, Alexander; Mann, Anthony; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchesotti, Marco; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian Thomas; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; Martin, Tim; Martin Dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Mas, Martin; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastroberardino, Anna; Masubuchi, Tatsuya; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maxfield, Stephen; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGarvie, Scott; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McMahon, Tania; McMahon, Tom; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meinhardt, Jens; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Merkl, Doris; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meuser, Stefan; Meyer, Carsten; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W.Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Miele, Paola; Migas, Sylwia; Migliaccio, Agostino; Mijovi{c, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikulec, Bettina; Mikuz, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Minano, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Miscetti, Stefano; Misiejuk, Andrzej; Mitra, Ankush; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A.; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjornmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Monig, Klaus; Moser, Nicolas; Mohapatra, Soumya; Mohn, Bjarte; Mohr, Wolfgang; Mohrdieck-Mock, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Moneta, Lorenzo; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morais, Antonio; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morii, Masahiro; Morin, Jerome; Morita, Youhei; Morley, Anthony Keith; Mornacchi, Giuseppe; Morone, Maria-Christina; Morris, John; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moye, Tamsin; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Muller, Thomas; Muenstermann, Daniel; Muijs, Sandra; Muir, Alex; Munwes, Yonathan; Murakami, Koichi; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagasaka, Yasushi; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Nash, Michael; Nasteva, Irina; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Nauyock, Farah; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Nesterov, Stanislav; Neubauer, Mark; Neukermans, Lionel; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nicholson, Caitriana; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nomoto, Hiroshi; Nordberg, Markus; Nordkvist, Bjoern; Norniella Francisco, Olga; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozicka, Miroslav; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nyman, Tommi; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Odino, Gian Andrea; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohska, Tokio Kenneth; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olcese, Marco; Olchevski, Alexander; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver, Concepcion; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, Antonio; Onyisi, Peter; Oram, Christopher; Ordonez, Gustavo; Oreglia, Mark; Orellana, Frederik; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Ortega, Eduardo; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ottewell, Brian; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Owen, Mark; Owen, Simon; Oyarzun, Alejandro; Oye, Ola; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Paganis, Efstathios; Paige, Frank; Pajchel, Katarina; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Palmer, Matt; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Paoloni, Alessandro; Papadopoulou, Theodora; Paramonov, Alexander; Park, Su-Jung; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pasztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peeters, Simon Jan Marie; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Cavalcanti, Tiago Perez; Perez Codina, Estel; Perez Garcia-Estan, Maria Teresa; Perez Reale, Valeria; Peric, Ivan; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Perus, Antoine; Peshekhonov, Vladimir; Petereit, Emil; Peters, Onne; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Alan; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Pickford, Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pina, Joao Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Plano, Will; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommes, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Bueso, Xavier Portell; Porter, Robert; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Prabhu, Robindra; Pralavorio, Pascal; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Lawrence; Price, Michael John; Prichard, Paul; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rajagopalan, Srinivasan; Rajek, Silke; Rammensee, Michael; Rammes, Marcus; Ramstedt, Magnus; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rauter, Emanuel; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Reljic, Dusan; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rensch, Bertram; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rieke, Stefan; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodier, Stephane; Rodriguez, Diego; Rodriguez Garcia, Yohany; Roe, Adam; Roe, Shaun; Rohne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romanov, Victor; Romeo, Gaston; Romero Maltrana, Diego; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosselet, Laurent; Rossetti, Valerio; 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Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schlereth, James; Schmidt, Evelyn; Schmidt, Michael; Schmieden, Kristof; Schmitt, Christian; Schmitz, Martin; Schoning, Andre; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schreiner, Alexander; Schroeder, Christian; Schroer, Nicolai; Schuh, Silvia; Schuler, Georges; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schweiger, Dietmar; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Scott, Bill; Searcy, Jacob; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, Jose; Sekhniaidze, Givi; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaver, Leif; Shaw, Christian; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siebel, Anca-Mirela; Siegert, Frank; Siegrist, James; Sijacki, Djordje; Silbert, Ohad; Silva, Jose; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sisakyan, Alexei; Sivoklokov, Serguei; Sj{olin, J{orgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skovpen, Kirill; Skubic, Patrick; Skvorodnev, Nikolai; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloan, Terrence; Sloper, John erik; Smakhtin, Vladimir; Smirnov, Sergei; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Sondericker, John; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sorbi, Massimo; Sosebee, Mark; Soukharev, Andrey; Spagnolo, Stefania; Spano, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiriti, Eleuterio; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St. Denis, Richard Dante; Stahl, Thorsten; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staude, Arnold; Stavina, Pavel; Stavropoulos, Georgios; Steele, Genevieve; Stefanidis, Efstathios; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stevenson, Kyle; Stewart, Graeme; Stockmanns, Tobias; Stockton, Mark; Stodulski, Marek; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Strohmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Soh, Dart-yin; Su, Dong; Subramania, Siva; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suita, Koichi; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Sviridov, Yuri; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Szeless, Balazs; Sanchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taga, Adrian; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanaka, Yoshito; Tani, Kazutoshi; Tannoury, Nancy; Tappern, Geoffrey; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Taylor, Christopher; Taylor, Frank; Taylor, Gary; Taylor, Geoffrey; Taylor, Wendy; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Tennenbaum-Katan, Yaniv-David; Terada, Susumu; Terashi, Koji; Terron, Juan; Terwort, Mark; Testa, Marianna; Teuscher, Richard; Tevlin, Christopher; Thadome, Jocelyn; Therhaag, Jan; Theveneaux-Pelzer, Timothee; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tic, Tomas; Tikhomirov, Vladimir; Tikhonov, Yury; Timmermans, Charles; Tipton, Paul; Viegas, Florbela De Jes Tique Aires; Tisserant, Sylvain; Tobias, Jurgen; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokar, Stanislav; Tokunaga, Kaoru; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonazzo, Alessandra; Tong, Guoliang; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torro Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Traynor, Daniel; Trefzger, Thomas; Treis, Johannes; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trivedi, Arjun; Trocme, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Typaldos, Dimitrios; Tyrvainen, Harri; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Underwood, David; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urkovsky, Evgeny; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valderanis, Chrysostomos; Valenta, Jan; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Ferrer, Juan Antonio Valls; Van der Graaf, Harry; van der Kraaij, Erik; van der Poel, Egge; van der Ster, Daniel; Van Eijk, Bob; van Eldik, Niels; Van Gemmeren, Peter; van Kesteren, Zdenko; Van Vulpen, Ivo; Vandelli, Wainer; Vandoni, Giovanna; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Varela Rodriguez, Fernando; Vari, Riccardo; Varnes, Erich; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vegni, Guido; Veillet, Jean-Jacques; Vellidis, Constantine; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Ventura, Silvia; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vertogardov, Leonid; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Viret, Sebastien; Virzi, Joseph; Vitale, Antonio; Vitells, Ofer; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vlasak, Michal; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobiev, Alexander; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vovenko, Anatoly; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Anh, Tuan Vu; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wakabayashi, Jun; Walbersloh, Jorg; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Wang, Chiho; Wang, Haichen; Wang, Jin; Wang, Joshua C.; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Jens; Weber, Marc; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wen, Mei; Wenaus, Torre; Wendler, Shanti; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; Whitaker, Scott; White, Andrew; White, Martin; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik, Liv Antje Mari; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wraight, Kenneth; Wright, Catherine; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wunstorf, Renate; Wynne, Benjamin; Xaplanteris, Leonidas; Xella, Stefania; Xie, Song; Xie, Yigang; Xu, Chao; Xu, Da; Xu, Guofa; Yabsley, Bruce; Yamada, Miho; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Stephanie; Yang, Un-Ki; Yang, Yi; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Weiming; Yao, Yushu; Yasu, Yoshiji; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Riktura; Young, Charles; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zaets, Vassilli; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zalite, Youris; Zanello, Lucia; Zarzhitsky, Pavel; Zaytsev, Alexander; Zdrazil, Marian; Zeitnitz, Christian; Zeller, Michael; Zema, Pasquale Federico; Zemla, Andrzej; Zendler, Carolin; Zenin, Anton; Zenin, Oleg; Zenis, Tibor; Zenonos, Zenonas; Zenz, Seth; Zerwas, Dirk; Zevi Della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zheng, Shuchen; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zilka, Branislav; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Zivkovi{c, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; Zolnierowski, Yves; Zsenei, Andras; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2011-01-01

    Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV are presented. The luminosity is independently determined using several detectors and multiple algorithms, each having different acceptances, systematic uncertainties and sensitivity to background. The ratios of the luminosities obtained from these methods are monitored as a function of time and of mu, the average number of inelastic interactions per bunch crossing. Residual time- and mu-dependence between the methods is less than 2% for 0luminosity calibrations, performed using beam separation scans, have a common systematic uncertainty of +/-11, dominated by the measurement of the LHC beam currents. After calibration, the luminosities obtained from the different methods differ by at most +/-2%. The visible cross sections measured using the beam scans are compared to predictions obtained with the PYTHIA and PHOJET event generators and the ATLAS detect...

  8. A Search for Water Maser Emission from Brown Dwarfs and Low-luminosity Young Stellar Objects

    Energy Technology Data Exchange (ETDEWEB)

    Gómez, José F.; Manjarrez, Guillermo [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Palau, Aina [Instituto de Radioastronomía y Astrofísica, UNAM, P.O. Box 3-72, 58090, Morelia, Michoacán, México (Mexico); Uscanga, Lucero [Departamento de Astronomía, Universidad de Guanajuato, A.P. 144, 36000 Guanajuato, Gto., México (Mexico); Barrado, David, E-mail: jfg@iaa.es [Centro de Astrobiología, INTA-CSIC, PO BOX 28692, ESAC Campus, E-208691 Villanueva de la Cañada, Madrid (Spain)

    2017-05-01

    We present a survey for water maser emission toward a sample of 44 low-luminosity young objects, comprising (proto-)brown dwarfs, first hydrostatic cores (FHCs), and other young stellar objects (YSOs) with bolometric luminosities lower than 0.4 L {sub ⊙}. Water maser emission is a good tracer of energetic processes, such as mass-loss and/or accretion, and is a useful tool to study these processes with very high angular resolution. This type of emission has been confirmed in objects with L {sub bol} ≳ 1 L {sub ⊙}. Objects with lower luminosities also undergo mass-loss and accretion, and thus, are prospective sites of maser emission. Our sensitive single-dish observations provided a single detection when pointing toward the FHC L1448 IRS 2E. However, follow-up interferometric observations showed water maser emission associated with the nearby YSO L1448 IRS 2 (a Class 0 protostar of L {sub bol} ≃ 3.6–5.3 L {sub ⊙}) and did not find any emission toward L1448 IRS 2E. The upper limits for water maser emission determined by our observations are one order of magnitude lower than expected from the correlation between water maser luminosities and bolometric luminosities found for YSOs. This suggests that this correlation does not hold at the lower end of the (sub)stellar mass spectrum. Possible reasons are that the slope of this correlation is steeper at L {sub bol} ≤ 1 L {sub ⊙} or that there is an absolute luminosity threshold below which water maser emission cannot be produced. Alternatively, if the correlation still stands at low luminosity, the detection rates of masers would be significantly lower than the values obtained in higher-luminosity Class 0 protostars.

  9. ATLAS Higgs Physics Prospects at the High Luminosity LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00218105; The ATLAS collaboration

    2016-01-01

    The High-Luminosity Large Hadron Collider will provide an unprecedented opportunity to study the properties of the Higgs boson and eventually probe for new physics beyond the Standard Model. The large anticipated data sample will allow for more precise investigations of topics already studied with earlier data samples, as well as for studies of processes that are accessible only with the much larger statistics. Rates and signal strengths will be measured for a variety of Higgs-boson production and decay modes, allowing extraction of the Higgs boson couplings. Particular final states will allow differential cross-sections to be measured for all production modes, and for studies of the Higgs width and CP properties, as well as the tensor structure of its coupling to bosons. An important part of the High-Luminosity LHC experimental program will be investigations of the Higgs self-coupling, which is accessible via studies of di-Higgs production. In this note the projections of the ATLAS physics reach in the Higgs...

  10. Absolute luminosity measurements with the LHCb detector at the LHC

    CERN Document Server

    Aaij, R; Adinolfi, M; Adrover, C; Affolder, A; Ajaltouni, Z; Albrecht, J; Alessio, F; Alexander, M; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amhis, Y; Anderson, J; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Arrabito, L; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Bachmann, S; Back, J J; Bailey, D S; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Bates, A; Bauer, C; Bauer, Th; Bay, A; Bediaga, I; Belous, K; Belyaev, I; Ben-Haim, E; Benayoun, M; Bencivenni, G; Benson, S; Benton, J; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blanks, C; Blouw, J; Blusk, S; Bobrov, A; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Bowcock, T J V; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Brisbane, S; Britsch, M; Britton, T; Brook, N H; Brown, H; Büchler-Germann, A; Burducea, I; Bursche, A; Buytaert, J; Cadeddu, S; Caicedo Carvajal, J M; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cattaneo, M; Charles, M; Charpentier, Ph; Chiapolini, N; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Collins, P; Constantin, F; Conti, G; Contu, A; Cook, A; Coombes, M; Corti, G; Cowan, G A; Currie, R; D'Almagne, B; D'Ambrosio, C; David, P; De Bonis, I; De Capua, S; De Cian, M; De Lorenzi, F; De Miranda, J M; De Paula, L; De Simone, P; Decamp, D; Deckenhoff, M; Degaudenzi, H; Deissenroth, M; Del Buono, L; Deplano, C; Deschamps, O; Dettori, F; Dickens, J; Dijkstra, H; Diniz Batista, P; Donleavy, S; Dordei, F; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dupertuis, F; Dzhelyadin, R; Eames, C; Easo, S; Egede, U; Egorychev, V; Eidelman, S; van Eijk, D; Eisele, F; Eisenhardt, S; Ekelhof, R; Eklund, L; Elsasser, Ch; d'Enterria, D G; Esperante Pereira, D; Estève, L; Falabella, A; Fanchini, E; Färber, C; Fardell, G; Farinelli, C; Farry, S; Fave, V; Fernandez Albor, V; Ferro-Luzzi, M; Filippov, S; Fitzpatrick, C; Fontana, M; Fontanelli, F; Forty, R; Frank, M; Frei, C; Frosini, M; Furcas, S; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garnier, J-C; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauvin, N; Gersabeck, M; Gershon, T; Ghez, Ph; Gibson, V; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Gregson, S; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Haefeli, G; Haen, C; Haines, S C; Hampson, T; Hansmann-Menzemer, S; Harji, R; Harnew, N; Harrison, J; Harrison, P F; He, J; Heijne, V; Hennessy, K; Henrard, P; Hernando Morata, J A; van Herwijnen, E; Hicks, E; Hofmann, W; Holubyev, K; Hopchev, P; Hulsbergen, W; Hunt, P; Huse, T; Huston, R S; Hutchcroft, D; Hynds, D; Iakovenko, V; Ilten, P; Imong, J; Jacobsson, R; Jaeger, A; Jahjah Hussein, M; Jans, E; Jansen, F; Jaton, P; Jean-Marie, B; Jing, F; John, M; Johnson, D; Jones, C R; Jost, B; Kandybei, S; Karacson, M; Karbach, T M; Keaveney, J; Kerzel, U; Ketel, T; Keune, A; Khanji, B; Kim, Y M; Knecht, M; Koblitz, S; Koppenburg, P; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kruzelecki, K; Kucharczyk, M; Kukulak, S; Kumar, R; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Li, L; Li Gioi, L; Lieng, M; Liles, M; Lindner, R; Linn, C; Liu, B; Liu, G; Lopes, J H; Lopez Asamar, E; Lopez-March, N; Luisier, J; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Magnin, J; Malde, S; Mamunur, R M D; Manca, G; Mancinelli, G; Mangiafave, N; Marconi, U; Märki, R; Marks, J; Martellotti, G; Martens, A; Martin, L; Martín Sánchez, A; Martinez Santos, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Matveev, M; Maurice, E; Maynard, B; Mazurov, A; McGregor, G; McNulty, R; Mclean, C; Meissner, M; Merk, M; Merkel, J; Messi, R; Miglioranzi, S; Milanes, D A; Minard, M-N; Monteil, S; Moran, D; Morawski, P; Mountain, R; Mous, I; Muheim, F; Müller, K; Muresan, R; Muryn, B; Musy, M; Mylroie-Smith, J; Naik, P; Nakada, T; Nandakumar, R; Nardulli, J; Nasteva, I; Nedos, M; Needham, M; Neufeld, N; Nguyen-Mau, C; Nicol, M; Nies, S; Niess, V; Nikitin, N; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Orlandea, M; Otalora Goicochea, J M; Owen, P; Pal, B; Palacios, J; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Paterson, S K; Patrick, G N; Patrignani, C; Pavel-Nicorescu, C; Pazos Alvarez, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perego, D L; Perez Trigo, E; Pérez-Calero Yzquierdo, A; Perret, P; Perrin-Terrin, M; Pessina, G; Petrella, A; Petrolini, A; Pie Valls, B; Pietrzyk, B; Pilar, T; Pinci, D; Plackett, R; Playfer, S; Plo Casasus, M; Polok, G; Poluektov, A; Polycarpo, E; Popov, D; Popovici, B; Potterat, C; Powell, A; du Pree, T; Prisciandaro, J; Pugatch, V; Puig Navarro, A; Qian, W; Rademacker, J H; Rakotomiaramanana, B; Rangel, M S; Raniuk, I; Raven, G; Redford, S; Reid, M M; dos Reis, A C; Ricciardi, S; Rinnert, K; Roa Romero, D A; Robbe, P; Rodrigues, E; Rodrigues, F; Rodriguez Perez, P; Rogers, G J; Roiser, S; Romanovsky, V; Rouvinet, J; Ruf, T; Ruiz, H; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salzmann, C; Sannino, M; Santacesaria, R; Santamarina Rios, C; Santinelli, R; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schaack, P; Schiller, M; Schleich, S; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M -H; Schwemmer, R; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Seyfert, P; Shao, B; Shapkin, M; Shapoval, I; Shatalov, P; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, O; Shevchenko, V; Shires, A; Silva Coutinho, R; Skottowe, H P; Skwarnicki, T; Smith, A C; Smith, N A; Sobczak, K; Soler, F J P; Solomin, A; Soomro, F; Souza De Paula, B; Spaan, B; Sparkes, A; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stoica, S; Stone, S; Storaci, B; Straticiuc, M; Straumann, U; Styles, N; Subbiah, V K; Swientek, S; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Topp-Joergensen, S; Tran, M T; Tsaregorodtsev, A; Tuning, N; Ubeda Garcia, M; Ukleja, A; Urquijo, P; Uwer, U; Vagnoni, V; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; Velthuis, J J; Veltri, M; Vervink, K; Viaud, B; Videau, I; Vilasis-Cardona, X; Visniakov, J; Vollhardt, A; Voong, D; Vorobyev, A; Voss, H; Wacker, K; Wandernoth, S; Wang, J; Ward, D R; Webber, A D; Websdale, D; Whitehead, M; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wishahi, J; Witek, M; Witzeling, W; Wotton, S A; Wyllie, K; Xie, Y; Xing, F; Yang, Z; Young, R; Yushchenko, O; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhong, L; Zverev, E; Zvyagin, A

    2012-01-01

    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ``van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5\\% in the absolute lumi...

  11. ATLAS Plans for the High-Luminosity LHC

    CERN Document Server

    Walkowiak, Wolfgang; The ATLAS collaboration

    2018-01-01

    Despite the excellent performance of the Large Hadron Collider (LHC) at CERN an upgrade to a High-Luminosity LHC (HL-LHC) with a peak instantaneous luminosity of up to $7.5\\times 10^{34}$ fb$^{-1}$ will be required after collecting a total dataset of approximately 300 fb$^{-1}$ by the end of Run 3 (in 2023). The upgrade will substantially increase the statistics available to the experiments for addressing the remaining open puzzles of particle physics. The HL-LHC is expected to start operating in 2026 and to deliver up to 4000 fb$^{-1}$ within twelve years. The corresponding upgrades of the ATLAS detector and the ATLAS beauty physics program at the HL-LHC are being discussed. As examples, preliminary results on the expected sensitivities for the search for CP-violation in the decay channel $B^0_s \\to J/\\psi \\,\\phi$ using the parameters $\\Delta\\Gamma_s$ and $\\phi_s$ as well as projections for the branching fractions of the rare decays $B^0_s \\to \\mu^+\\mu^-$ and $B^0\\to\\mu^+\\mu^-$ are provided.

  12. Physics as a function of energy and luminosity

    International Nuclear Information System (INIS)

    Ellis, J.

    1984-01-01

    In this paper, a new physics in the range of mass up to TeV region is discussed. Most of the discussion concern hadron-hadron (hh) colliders, and also electron-positron colliders are discussed. The cross-sections for new particle production in hh colliders have the general Drell-Yan form, in which the differential luminosity for the collision of partons is included. The formulas with the parton distribution scaled up from present energy using the Altarelli-Parisi equations may be approximately correct within a factor of 2 for the production of particles. Some typical parton-parton luminosity functions for proton-proton and proton-antiproton collisions are presented. From the consideration of luminosity, it can be said that the pp colliders are to be preferred. The case studies of some of the possible new physics discussed by Zakharov, mainly on Higgs bosons and supersymmetric particles, but also a few remarks about technicolor are presented. It seems possible to detect technicolor at a large hh collider. The physics reaches of different possible hh colliders are summarized in tables. In the tables, the observable production of Higgses up to 1 TeV in mass, the observable masses for gluinos (squarks) and the technicolor observability are shown. The cleanliness of electron-positron colliders compared to hadron-hadron colliders is pled, a guess is given as to the appropriate conversion factors between the energy in the electron-positron and hh collisions, the complementarity of electron-positron and hh colliders is urged, and it is argued that a rational mix of world accelerators would include both. (Kato, T.)

  13. Low mass hybrid pixel detectors for the high luminosity LHC upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Gonella, Laura

    2013-10-15

    Reducing material in silicon trackers is of major importance for a good overall detector performance, and poses severe challenges to the design of the tracking system. To match the low mass constraints for trackers in High Energy Physics experiments at high luminosity, dedicated technological developments are required. This dissertation presents three technologies to design low mass hybrid pixel detectors for the high luminosity upgrades of the LHC. The work targets specifically the reduction of the material from the detector services and modules, with novel powering schemes, flip chip and interconnection technologies. A serial powering scheme is prototyped, featuring a new regulator concept, a control and protection element, and AC-coupled data transmission. A modified flip chip technology is developed for thin, large area Front-End chips, and a via last Through Silicon Via process is demonstrated on existing pixel modules. These technologies, their developments, and the achievable material reduction are discussed using the upgrades of the ATLAS pixel detector as a case study.

  14. Low mass hybrid pixel detectors for the high luminosity LHC upgrade

    International Nuclear Information System (INIS)

    Gonella, Laura

    2013-10-01

    Reducing material in silicon trackers is of major importance for a good overall detector performance, and poses severe challenges to the design of the tracking system. To match the low mass constraints for trackers in High Energy Physics experiments at high luminosity, dedicated technological developments are required. This dissertation presents three technologies to design low mass hybrid pixel detectors for the high luminosity upgrades of the LHC. The work targets specifically the reduction of the material from the detector services and modules, with novel powering schemes, flip chip and interconnection technologies. A serial powering scheme is prototyped, featuring a new regulator concept, a control and protection element, and AC-coupled data transmission. A modified flip chip technology is developed for thin, large area Front-End chips, and a via last Through Silicon Via process is demonstrated on existing pixel modules. These technologies, their developments, and the achievable material reduction are discussed using the upgrades of the ATLAS pixel detector as a case study.

  15. LIGHT and LUMINOSITY, from Einstein to LHC

    CERN Multimedia

    CERN. Geneva; Prof. ROSSI, Lucio

    2015-01-01

    After an introduction on the concept of light in physics, this talk will focus on CERN’s High Luminosity LHC project, aiming at extending the discovery potential of CERN’s flagship accelerator by increasing its “luminosity” (ie the number of particles that can be squeezed inside the accelerator to maximize the number of collisions). To achieve this objective, many new technologies are being developed at CERN and many collaborating institutes worldwide, especially in the field of superconductivity. Lucio Rossi, the main speaker, is the head of the HL-LHC project, based at CERN. Giorgio Apollinari, Director for the LHC Accelerator Research Program (LARP) will speak through a videoconference from Fermilab (USA). The event is webcast live and will be followed by Fermilab and other institutes in the USA.

  16. Tracking with CVD diamond radiation sensors at high luminosity colliders (1999-3.1507)

    CERN Document Server

    Schnetzer, S R; Bauer, C; Berdermann, E; Bergonzo, P; Bogani, F; Borchi, E; Brambilla, A; Bruzzi, Mara; Colledani, C; Conway, J; Dabrowski, W; Da Graca, J; Delpierre, P A; Deneuville, A; Dulinski, W; van Eijk, B; Fallou, A; Fizzotti, F; Foulon, F; Friedl, M; Gan, K K; Gheeraert, E; Grigoriev, E; Hallewell, G D; Hall-Wilton, R; Han, S; Hartjes, F G; Hrubec, Josef; Husson, D; Jamieson, D; Kagan, H; Kania, D R; Kaplon, J; Karl, C; Kass, R; Knöpfle, K T; Krammer, Manfred; Lo Giudice, A; Lü, R; Manfredi, P F; Manfredotti, C; Marshall, R D; Meier, D; Mishina, M; Oh, A; Pan, L S; Palmieri, V G; Pernicka, Manfred; Peitz, A; Pirollo, S; Plano, R J; Polesello, P; Prawer, S; Pretzl, Klaus P; Procario, M; Re, V; Riester, J L; Roe, S; Roff, D G; Rudge, A; Runólfsson, O; Russ, J; Sciortino, S; Somalwar, S V; Speziali, V; Stelzer, H; Stone, R; Suter, B; Tapper, R J; Tesarek, R J; Thomson, G B; Trawick, M L; Trischuk, W; Vittone, E; Walsh, A M; Wedenig, R; Weilhammer, Peter; White, C; Ziock, H J; Zöller, M

    1999-01-01

    Recent progress on developing diamond-based sensors for vertex detection at high luminosity hadron colliders is described. Measurements of the performance of diamond sensors after irradiation to fluences of up to 5*10/sup 15/ hadrons/cm/sup 2/ are shown. These indicate that diamond sensors will operate at distances as close as 5 cm from the interaction point at the Large Hadron Collider (LHC) for many years at full luminosity without significant degradation in performance. Measurements of the quality of the signals from diamond sensors as well as spatial uniformity are presented. Test beam results on measurements of diamond-based microstrip and pixels devices are described.

  17. Discovery of 1-5 Hz flaring at high luminosity in SAX J1808.4-3658

    Energy Technology Data Exchange (ETDEWEB)

    Bult, Peter; Van der Klis, Michiel, E-mail: p.m.bult@uva.nl [Anton Pannekoek Institute, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands)

    2014-07-10

    We report the discovery of a 1-5 Hz X-ray flaring phenomenon observed at >30 mCrab near peak luminosity in the 2008 and 2011 outbursts of the accreting millisecond X-ray pulsar SAX J1808.4-3658 in observations with the Rossi X-ray Timing Explorer. In each of the two outbursts this high luminosity flaring is seen for ∼3 continuous days and switches on and off on a timescale of 1-2 hr. The flaring can be seen directly in the light curve, where it shows sharp spikes of emission at quasi-regular separation. In the power spectrum it produces a broad noise component, which peaks at 1-5 Hz. The total 0.05-10 Hz variability has a fractional rms amplitude of 20%-45%, well in excess of the 8%-12% rms broadband noise usually seen in power spectra of SAX J1808.4-3658. We perform a detailed timing analysis of the flaring and study its relation to the 401 Hz pulsations. We find that the pulse amplitude varies proportionally with source flux through all phases of the flaring, indicating that the flaring is likely due to mass density variations created at or outside the magnetospheric boundary. We suggest that this 1-5 Hz flaring is a high mass accretion rate version of the 0.5-2 Hz flaring which is known to occur at low luminosity (<13 mCrab), late in the tail of outbursts of SAX J1808.4-3658. We propose the dead-disk instability, previously suggested as the mechanism for the 0.5-2 Hz flaring, as a likely mechanism for the high luminosity flaring reported here.

  18. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    CERN Document Server

    AUTHOR|(CDS)2070952; Valishev, Aleksander; Shatilov, Dmitry

    2015-01-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical β∗ values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  19. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    Energy Technology Data Exchange (ETDEWEB)

    Fartoukh, Stephane [CERN; Valishev, Alexander [Fermilab; Shatilov, Dmitry [BINP, Novosibirsk

    2015-06-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical $\\beta^{\\ast}$values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  20. Detector development for the High Luminosity Large Hadron Collider

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00367854; Gößling, Claus

    To maximise the discovery potential of the Large Hadron Collider, it will be upgraded to the High Luminosity Large Hadron Collider in 2024. New detector challenges arise from the higher instantaneous luminosity and the higher particle flux. The new ATLAS Inner Tracker will replace the current tracking detector to be able to cope with these challenges. Many pixel detector technologies exist for particle tracking, but their suitability for the ATLAS Inner Tracker needs to be studied. Active high-voltage CMOS sensors, which are produced in industrialised processes, offer a fast readout and radiation tolerance. In this thesis the HV2FEI4v2 sensor, which is capacitively coupled to the ATLAS Pixel FE-I4 readout chip, is characterised for the usage in the outer layers of the ATLAS Inner Tracker. Key quantities of this prototype module are studied, such as the hit efficiency and the subpixel encoding. The early HV2FEI4v2 prototype shows promising results as a starting point for further module developments. Active CMO...

  1. ATLAS Physics Prospects at the High-Luminosity LHC

    CERN Document Server

    Bindi, Marcello; The ATLAS collaboration

    2017-01-01

    The physics prospects at the luminosity upgrade of LHC, HL-LHC, with a data set equivalent to 3000 fb-1 simulated in the ATLAS detector, are presented and discussed. The ultimate precision attainable on measurements of 125 GeV Higgs boson couplings to elementary fermions and bosons is discussed, as well as the searches for partners associated with this new particle. The electroweak sector is further studied with the analysis of the vector boson scattering, testing the SM predictions at the LHC energy scale. Supersymmetry is still one of the best motivated extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks. The sensitivity to electro-weakinos has reached the hundreds of GeV mass range. Benchmark studies are presented to show how the sensitivity improves at the future high-luminosity LHC runs. Prospects for searches for new heavy bosons and dark matter candidates at 14 TeV pp col...

  2. A luminosity monitor for LHC [notes of a thesis

    CERN Document Server

    Perrot, Anne Laure

    2000-01-01

    LHC luminosity will reach 10/sup 34/ cm/sup -2/ s/sup -1/ but special runs at 10/sup 28/ cm/sup -2/ s/sup -1/ are foreseen. Thus a luminosity monitor must have a dynamic range of six orders of magnitude. A good tolerance to radiation is also required. A detector using both ionisation and secondary emission techniques has been studied in this context. Its design is based on monitors used previously at the CERN PS and SPS. Special attention was devoted to minimise leakage currents. Linearity in both Secondary Emission Counter (SEC) and Ionisation Chamber (IC) modes has been tested from ~10/sup 4/ incident particles to ~10/sup 8/ incident particles. SEC is linear above ~5.10/sup 6/ incident particles while IC is linear over the full studied range. However, because of the radiation environment at LHC, the SEC mode is much preferred at high intensity. A solution actually foreseen is to switch from IC to SEC mode when the intensity is around 5.10/sup 6/ incident particles per second corresponding to an LHC luminosi...

  3. Physics prospects at the high luminosity LHC with ATLAS

    CERN Document Server

    Simioni, Eduard; The ATLAS collaboration

    2016-01-01

    The physics prospects at the luminosity upgrade of LHC, HL-LHC, with a data set equivalent to 3000 fb-1 simulated in the ATLAS detector, are presented and discussed. The ultimate precision attainable on measurements of 125 GeV Higgs boson couplings to elementary fermions and bosons is discussed, as well as the searches for partners associated with this new particle. The electroweak sector is further studied with the analysis of the vector boson scattering, testing the SM predictions at the LHC energy scale. Supersymmetry is still one of the best motivated extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks. The sensitivity to electro-weakinos has reached the hundreds of GeV mass range. Benchmark studies are presented to show how the sensitivity improves at the future high-luminosity LHC runs. Prospects for searches for new heavy bosons and dark matter candidates at 14 TeV pp col...

  4. High-luminosity LHC prospects with the upgraded ATLAS detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00379172; The ATLAS collaboration

    2016-01-01

    Run 1 at the LHC was very successful with the discovery of a new boson. The boson’s properties are found to be compatible with those of the Standard Model Higgs boson. It is now revealing the mechanism of electroweak symmetry breaking and (possibly) the discovery of physics beyond the Standard Model that are the primary goals of the just restarted LHC. The ultimate precision will be reached at the high-luminosity LHC run with a proton-proton centre-of-mass energy of 14 TeV. In this contribution physics prospects are presented for ATLAS for the integrated luminosities 300 and 3000 fb−1: the ultimate precision attainable on measurements of the Higgs boson couplings to elementary fermions and bosons, its trilinear self-coulping, as well as perspectives on the searches for partners associated with it. Benchmark studies are presented to show how the sensitivity improves at the future LHC runs. For all these studies, a parameterised simulation of the upgraded ATLAS detector is used and expected pileup condition...

  5. Study of the performance of Micromegas detectors in magnetic field

    Science.gov (United States)

    Dimitrios, Sampsonidis

    2018-02-01

    Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

  6. Study of the performance of Micromegas detectors in magnetic field

    Directory of Open Access Journals (Sweden)

    Dimitrios Sampsonidis

    2018-01-01

    Full Text Available Resistive Micromegas (MICRO MEsh GAseous Structure detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW, will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2 in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

  7. Studies on the impact of an extended Inner Detector tracker and a forward muon tagger on $W^{\\pm}W^{\\pm}$ scattering in $pp$ collisions at the High-Luminosity LHC with the ATLAS experiment

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    The impact of an extended silicon tracker and a forward muon tagger on the measurement of the \\ssWW vector boson scattering process is evaluated in proton-proton collisions at $\\sqrt{s}$ = 14 TeV at the High-Luminosity Large Hadron Collider. Simulated events with two leptons of the same electric charge, missing transverse momentum, and at least two jets are analysed. The gain in significance and precision obtained with tracking, electron, and muon reconstruction extended up to $|\\eta|$ $\\le$ 4 is reported, with respect to the current coverage of $|\\eta|$ $\\le$ 2.7.

  8. Impact of an Extended ATLAS Tracker on $W^{\\pm}W^{\\pm}$ Scattering at a High-Luminosity LHC

    CERN Document Server

    Milic, Adriana; The ATLAS collaboration

    2016-01-01

    The ATLAS detector will undergo a major upgrade in Phase-II in order to maintain the high performance in the challenging environmental conditions that will be imposed by the High-Luminosity (HL) LHC. Several inner detector scenarios are under consideration including an extension of the nominal tracker from $|\\eta| = 200$. The study shows a significant improvement for the tracker layouts with a larger $\\eta$ coverage than the nominal one. Hence, the physics process studied provides a strong argument for the extension of the $\\eta$ coverage of the ITk.

  9. L1Track: A fast Level 1 track trigger for the ATLAS high luminosity upgrade

    International Nuclear Information System (INIS)

    Cerri, Alessandro

    2016-01-01

    With the planned high-luminosity upgrade of the LHC (HL-LHC), the ATLAS detector will see its collision rate increase by approximately a factor of 5 with respect to the current LHC operation. The earliest hardware-based ATLAS trigger stage (“Level 1”) will have to provide a higher rejection factor in a more difficult environment: a new improved Level 1 trigger architecture is under study, which includes the possibility of extracting with low latency and high accuracy tracking information in time for the decision taking process. In this context, the feasibility of potential approaches aimed at providing low-latency high-quality tracking at Level 1 is discussed. - Highlights: • HL-LH requires highly performing event selection. • ATLAS is studying the implementation of tracking at the very first trigger level. • Low latency and high-quality seem to be achievable with dedicated hardware and adequate detector readout architecture.

  10. Luminosity on development and flowering of Dendrobium nobile Lindl.

    Directory of Open Access Journals (Sweden)

    Yara Brito Chaim Jardim Rosa

    2014-09-01

    Full Text Available This study, conducted at Jardinocultura area of Faculdade de Ciências Agrárias of UFGD during the period from September of 2010 to August of 2011, had as aim evaluate the cultivation and flowering of Dendrobium nobile Lindl., under five levels of luminosity (83, 104, 115, 154 e 237 μmol m-2 s-1 . During 12 months the plants were irrigated and fertilized with NPK 10-10-10 and after this period they were evaluated for the number, length and diameter of pseudobulbs, being calculated the increments in relation to initial data. At flowering time it was counted the total buds, reproductive buds, vegetative buds and undifferentiated buds and registered the anthesis at each light intensity. The experimental was arranged at completely randomized design with five treatments and seven replicates with two plants and the averages were compared by Tukey test at 5% probability. All the lighting conditions were favorable to the D. nobile cultivation, being registered increases of 36,7%, 16,0% e 16,2% in the number, diameter and length of pseudobulbs, respectively. The largest number of reproductive buds was observed at 104 μmol m-2 s-1. D. nobile can be cultivated in the light conditions varying between 83 and 237 μmol m-2 s-1, recommending the luminosity of 104 μmol m-2 s-1 to promote their flowering.

  11. THE LOW-LUMINOSITY END OF THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Bentz, Misty C.; Denney, Kelly D.; Vestergaard, Marianne; Grier, Catherine J.; Peterson, Bradley M.; De Rosa, Gisella; Pogge, Richard W.; Barth, Aaron J.; Bennert, Vardha N.; Canalizo, Gabriela; Filippenko, Alexei V.; Li Weidong; Gates, Elinor L.; Greene, Jenny E.; Malkan, Matthew A.; Stern, Daniel; Treu, Tommaso; Woo, Jong-Hak

    2013-01-01

    We present an updated and revised analysis of the relationship between the Hβ broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions of the host galaxies of nine new AGNs imaged with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create ''AGN-free'' images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new reverberation-mapping measurements of the Hβ time lag, which is assumed to yield the average Hβ BLR radius. The final sample includes 41 AGNs covering four orders of magnitude in luminosity. The additions and updates incorporated here primarily affect the low-luminosity end of the R BLR -L relationship. The best fit to the relationship using a Bayesian analysis finds a slope of α= 0.533 +0.035 -0.033 , consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy of their reported time lags. The scatter around the relationship is found to be 0.19 ± 0.02 dex, but would be decreased to 0.13 dex by the removal of these two suspect measurements. A large fraction of the remaining scatter in the relationship is likely due to the inaccurate distances to the AGN host galaxies. Our results help support the possibility that the R BLR -L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts.

  12. THE LOW-LUMINOSITY END OF THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, Misty C. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Denney, Kelly D.; Vestergaard, Marianne [Dark Cosmology Center, Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Grier, Catherine J.; Peterson, Bradley M.; De Rosa, Gisella; Pogge, Richard W. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Barth, Aaron J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Bennert, Vardha N. [Physics Department, California Polytechnic State University, San Luis Obispo, CA 93407 (United States); Canalizo, Gabriela [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Filippenko, Alexei V.; Li Weidong [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Gates, Elinor L. [University of California Observatories/Lick Observatory, P.O. Box 85, Mount Hamilton, CA 95140 (United States); Greene, Jenny E. [Department of Astrophysical Sciences, Princeton University, Peyton Hall - Ivy Lane, Princeton, NJ 08544 (United States); Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Treu, Tommaso [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Woo, Jong-Hak, E-mail: bentz@chara.gsu.edu [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of)

    2013-04-20

    We present an updated and revised analysis of the relationship between the H{beta} broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions of the host galaxies of nine new AGNs imaged with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create ''AGN-free'' images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new reverberation-mapping measurements of the H{beta} time lag, which is assumed to yield the average H{beta} BLR radius. The final sample includes 41 AGNs covering four orders of magnitude in luminosity. The additions and updates incorporated here primarily affect the low-luminosity end of the R{sub BLR}-L relationship. The best fit to the relationship using a Bayesian analysis finds a slope of {alpha}= 0.533{sup +0.035}{sub -0.033}, consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy of their reported time lags. The scatter around the relationship is found to be 0.19 {+-} 0.02 dex, but would be decreased to 0.13 dex by the removal of these two suspect measurements. A large fraction of the remaining scatter in the relationship is likely due to the inaccurate distances to the AGN host galaxies. Our results help support the possibility that the R{sub BLR}-L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts.

  13. An Investigation of X-ray Luminosity versus Crystalline Powder Granularity

    Energy Technology Data Exchange (ETDEWEB)

    Borade, Ramesh; Bourret-Courchesne, Edith; ,

    2012-03-07

    At the High-throughput Discovery of Scintillator Materials Facility at Lawrence Berkeley National Laboratory, scintillators are synthesized by solid-state reaction or melt mixing, forming crystalline powders. These powders are formed in various granularity and the crystal grain size affects the apparent luminosity of the scintillator. To accurately predict a "full-size" scintillator's crystal luminosity, the crystal luminosity as a function of crystal granularity size has to be known. In this study, we examine Bi{sub 4}Ge{sub 3}O{sub 12} (BGO), Lu{sub 2}SiO{sub 5}:Ce (LSO), YAlO{sub 3}:Ce (YAP:Ce), and CsBa{sub 2}I{sub 5}:Eu{sup 2+} (CBI) luminosities as a function of crystalline grain size. The highest luminosities were measured for 600- to 1000-{micro}m crystal grain sizes for BGO and LSO, for 310- to 600-{micro}m crystal grain sizes for CBI, and for crystal grains larger than 165{micro}m for YAP:Ce. Crystal grains that were larger than 1 mm had a lower packing fraction, and smaller grains were affected by internal scattering. We measured a 34% decrease in luminosity for BGO when decreasing from the 600- to 1000- {micro}m crystal grain size range down to the 20- to 36-{micro}m range. The corresponding luminosity decrease for LSO was 44% for the same grain size decrease. YAP:Ce exhibited a luminosity decrease of 47% when the grain size decreased from the 165- to 310-{micro}m crystal grains to the 20- to 36-{micro}m range, and CBI exhibited a luminosity decrease of 98% when the grain size decreased from the 310- to 600-{micro}m crystal grain range to the 36- to 50-{micro}m range. We were able to very accurately estimate full-size crystal luminosities from crystalline grains that are larger than 90 {micro}m.

  14. Beam-beam effect and luminosity in SPEAR

    International Nuclear Information System (INIS)

    Wiedemann, H.

    1980-07-01

    Measurements performed at SPEAR have been discussed and scaling laws for the maximum luminosity and the maximum linear tune shift parameter with energy are shown. There are two distinct regimes, one below 2 GeV where the linear tune shift parameter scales like xi/sub y/ approx. E 2 4 and the other regime where this parameter is constant xi/sub y/ approx. = 0.05 to 0.06. In the lower energy regime the limit is reached when the vertical beam size is blown up to the acceptance of the storage ring. A significant (< 10%) horizontal beam blow up is not observed and the value of the horizontal linear tune shift parameter xi/sub x/ does not seem to be related to the beam-beam limit

  15. A passive CMOS pixel sensor for the high luminosity LHC

    Energy Technology Data Exchange (ETDEWEB)

    Daas, Michael; Gonella, Laura; Hemperek, Tomasz; Huegging, Fabian; Janssen, Jens; Krueger, Hans; Pohl, David-Leon; Wermes, Norbert [Physikalisches Institut der Universitaet Bonn (Germany); Macchiolo, Anna [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2016-07-01

    The high luminosity upgrade for the Large Hadron Collider at CERN requires a new inner tracking detector for the ATLAS experiment. About 200 m{sup 2} of silicon detectors are needed demanding new, low cost hybridization- and sensor technologies. One promising approach is to use commercial CMOS technologies to produce the passive sensor for a hybrid pixel detector design. In this talk a fully functional prototype of a 300 μm thick, backside biased CMOS pixel sensor in 150 nm LFoundry technology is presented. The sensor is bump bonded to the ATLAS FE-I4 with AC and DC coupled pixels. Results like leakage current, noise performance, and charge collection efficiency are presented and compared to the actual ATLAS pixel sensor design.

  16. Liquid droplet radiator performance studies

    Science.gov (United States)

    Mattick, A. T.; Hertzberg, A.

    By making use of droplets rather than solid surfaces to radiate waste heat in space, the liquid droplet radiator (LDR) achieves a radiating area/mass much larger than that of conventional radiators which use fins or heat pipes. The lightweight potential of the LDR is shown to be limited primarily by the radiative properties of the droplets. The requirement that the LDR heat transfer fluid have a very low vapor pressure limits the choice of fluids to relatively few—several liquid metals and Dow 705 silicone fluid are the only suitable candidates so far identified. An experimental determination of the emittance of submillimeter droplets of Dow 705 fluid indicates than an LDR using this fluid at temperatures of 275-335 K would be ⋍ 10 times lighter than the lightest solid surface radiators. Although several liquid metals appear to offer excellent performance in LDR applications at temperatures between 200 K and 975 K, experimental determination of liquid metal emissivities is needed for a conclusive assessment.

  17. Design and performance studies of a hadronic calorimeter for a FCC-hh experiment

    Science.gov (United States)

    Faltova, J.

    2018-03-01

    The hadron-hadron Future Circular Collider (FCC-hh) project studies the physics reach of a proton-proton machine with a centre-of-mass-energy of 100 TeV and five times greater peak luminosities than at the High-Luminosity LHC (HL-LHC). The high-energy regime of the FCC-hh opens new opportunities for the discovery of physics beyond the standard model. At 100 TeV a large fraction of the W, Z, H bosons and top quarks are produced with a significant boost. It implies an efficient reconstruction of very high energetic objects decaying hadronically. The reconstruction of those boosted objects sets the calorimeter performance requirements in terms of energy resolution, containment of highly energetic hadron showers, and high transverse granularity. We present the current baseline technologies for the calorimeter system in the barrel region of the FCC-hh reference detector: a liquid argon electromagnetic and a scintillator-steel hadronic calorimeters. The focus of this paper is on the hadronic calorimeter and the performance studies for hadrons. The reconstruction of single particles and the achieved energy resolution for the combined system of the electromagnetic and hadronic calorimeters are discussed.

  18. Fast measurement of luminosity at LEP by detecting the single bremsstrahlung photons

    International Nuclear Information System (INIS)

    Bini, C.; De Zorzi, G.; Diambrini Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Gauzzi, P.; Zanello, D.

    1991-01-01

    Luminosity and beam angular divergence have been measured at LEP with a fast monitor based on the single bremsstrahlung process e + e - → e + e - γ. The photons emitted at the interaction point 1 are detected by an electromagnetic calorimeter: both the photon energy and the impact point are measured. The beam angular divergence and the luminosity are determined in few minutes with a statistical error of 1%. With the present experimental layout the systematic error is of few percent; it would be reduced by performing the measurement on an experimental interaction point. (orig.)

  19. Elastic cross-section and luminosity measurement in Atlas at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Efthymiopoulos, I. [Conseil Europeen pour la recherche nucleaire, AB Dept., Geneve (Switzerland)

    2005-07-01

    Recently the Atlas experiment was complemented with a set of ultra-small-angle detectors located in 'Roman Pot' inserts at 240 m on either side of the interaction point, aiming at the absolute determination of the LHC luminosity by measuring the elastic scattering rate at the Coulomb Nuclear Interference region. Details of the proposed measurement the detector construction and the expected performance as well as the challenges involved are discussed here. Our aim is to determine the luminosity within a 2% error and give a competitive measurement on other parameters like the {rho}-parameter, the total cross-section and the nuclear slope.

  20. A Level 1 Tracking Trigger for the CMS Experiment at the LHC Phase 2 Luminosity Upgrade

    CERN Document Server

    Pozzobon, Nicola

    2011-01-01

    The second decade of Large Hadron Collider operations, from about 2020 onwards, envisages a remarkable increase in collider instantaneous luminosity, one order of magnitude above the project one. This luminosity increase presents several challenges to the LHC experiments. The present tracker of the Compact Muon Solenoid experiment must be replaced with a system providing excellent tracking quality at higher luminosities, as well as Tracking Trigger inputs to the existing “Level 0” CMS trigger system at the full 40 MHz bunch-crossing rate. The minimal requirements for a Tracking Trigger would be the capability to confirm the presence of high-pT tracks associated with Calorimeter and/or Muon Level 0 triggers. The ability to provide eective isolation criteria may also be required, and would in any case substantially improve the Trigger performance. Maintaining the data rates generated by Tracking Trigger inputs within a manageable bandwidth requires sensor modules able to locally sparsify the data. Measuring...

  1. Luminosity measurement in H1; Mesure de la luminosite pour l'experience H1

    Energy Technology Data Exchange (ETDEWEB)

    Frisson, T

    2006-10-15

    At HERA, luminosity is determined on-line and bunch by bunch by measuring the Bremsstrahlung spectrum from e-p collisions. The Hl collaboration has built a completely new luminosity system in order to sustain the harsh running conditions after the fourfold luminosity increase. Namely, the higher synchrotron radiation doses and the increased event pile-up have governed the design of the two major components, a radiation resistant quartz-fibre electro-magnetic calorimeter, and a fast read-out electronic with on-line energy histogram loading at a rate of 500 kHz. The group was in charge of the electronic and the on-line data analysis of the new luminosity system. In this thesis, I present analysis tools and methods to improve the precision of the luminosity measurement. The energy scale and acceptance calculation methods set out in this thesis permit these values to be determined every four minutes, to an accuracy of 0.5 parts per thousand for the energy scale and 2 parts per thousand for the acceptance. From these results, the degree of accuracy obtained on the luminosity measurement is between 6.5 and 9.5 parts per thousand. These results are currently undergoing validation, with the aim of becoming the standard H1 method. I also studied quasi-elastic Compton events to cross-check the luminosity measurement using the 2003- 2004 and 2005 data. Indeed, this process has a well calculable cross section and a clear experimental signature. The leptonic final state consists of a coplanar e-gamma system, both observable in the central H1 detector. (author)

  2. Nuclear mid-infrared properties of nearby low-luminosity AGN

    International Nuclear Information System (INIS)

    Asmus, D; Duschl, W J; Hönig, S F; Gandhi, P; Smette, A

    2012-01-01

    We present ground-based high-spatial resolution mid-infrared (MIR) observations of 20 nearby low-luminosity AGN (LLAGN) with VLT/VISIR and the preliminary analysis of a new sample of 10 low-luminosity Seyferts observed with Gemini/Michelle. LLAGN are of great interest because these objects are the most common among active galaxies, especially in the nearby universe. Studying them in great detail makes it possible to investigate the AGN evolution over cosmic timescale. Indeed, many LLAGN likely represent the final stage of an AGN's lifetime. We show that even at low luminosities and accretion rates nuclear unresolved MIR emission is present in most objects. Compared to lower spatial resolution Spitzer/IRS spectra, the high-resolution MIR photometry exhibits significantly lower fluxes and different PAH emission feature properties in many cases. By using scaled Spitzer/IRS spectra of typical starburst galaxies, we show that the star formation contribution to the 12 μm emission is minor in the central parsecs of most LLAGN. Therefore, the observed MIR emission in the VISIR and Michelle data is most likely emitted by the AGN itself, which, for higher luminosity AGN, is interpreted as thermal emission from a dusty torus. Furthermore, the 12 /amemission of the LLAGN is strongly correlated with the absorption corrected 2-10 keV luminosity and the MIR- X-ray correlation found previously for AGN is extended to a range from 10 40 to 10 45 erg/s. This correlation is independent of the object type, and in particular the low-luminosity Seyferts observed with Michelle fall exactly on the power-law fit valid for brighter AGN. In addition, no dependency of the MIR-X-ray ratio on the accretion rate is found. These results are consistent with the unification model being applicable even in the probed low-luminosity regime.

  3. Intrinsic luminosities of the Jovian planets

    International Nuclear Information System (INIS)

    Hubbard, W.B.

    1980-01-01

    We review available data and theories on the size and nature of interior power sources in the Jovian planets. Broad band infrared measurements indicate that Jupiter and Saturn have interior heat fluxes about 150 and 50 times larger, respectively, than the terrestrial value. While Neptune has a modest heat flux (approx.5 times terrestrial), it is clearly detected by earth-based measurements. Only Uranus seems to lack a detectable interior heat flow. Various models, ranging from simple cooling to gravitational layering to radioactivity, are discussed. Current evidence seems to favor a cooling model in which the escape of heat is regulated by the atmosphere. This model seems capable of explaining phenomena such as the uniformity of effective temperature over Jupiter's surface and the different emission rates of Uranus and Neptune. In such a model the heat radiated from the atmosphere may derived from depletion of a thermal reservoir in the interior, or it may derive from separation of chemical elements during formation of a core. Calculations indicate that in the earlier stages of cooling, Jupiter and Saturn may have more homogeneous abundances of hydrogen and helium and radiate energy derived from simple cooling. At a subsequent phase (which may be later than the present time), hydrogen and helium will separate and supply grativational energy. Either model is consistent with a hot, high-luminosity origin for the Jovian Planets

  4. Galaxy luminosity function: evolution at high redshift

    Science.gov (United States)

    Martinet, N.; Durret, F.; Guennou, L.; Adami, C.

    2014-12-01

    There are some disagreements about the abundance of faint galaxies in high redshift clusters. DAFT/FADA (Dark energy American French Team) is a medium redshift (0.4luminosity functions (GLFs) based on photometric redshifts for 30 clusters in B, V, R and I restframe bands. We show that completeness is a key parameter to understand the different observed behaviors when fitting the GLFs. We also investigate the evolution of GLFs with redshift for red and blue galaxy populations separately. We find a drop of the faint end of red GLFs which is more important at higher redshift while the blue GLF faint end remains flat in our redshift range. These results can be interpreted in terms of galaxy quenching. Faint blue galaxies transform into red ones which enrich the red sequence from high to low redshifts in clusters while some blue galaxies are still accreted from the environment, compensating for this evolution so that the global GLF does not seem to evolve.

  5. ATLAS gets its own luminosity detector

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    During the winter shutdown, the ATLAS collaboration has completed the installation of ALFA, the detector system that aims at the LHC absolute luminosity at Point 1 analysing the elastic scattering of protons at small angles.   Upper and lower ALFA Roman Pots as installed in sector 8-1 of the LHC tunnel, 240 metres from the ATLAS Interaction Point. The detectors of the ALFA system are installed at ± 240 meters from the interaction point 1, on either side of the ATLAS detector. The whole system consists of four stations, two on each side of the interaction point. Each station is equipped with two Roman Pots; each pot – that is separated from the vacuum of the accelerator by a thin window but is connected with bellows to the beam-pipe – can be moved very close to the beam. “The Roman Pot technique has been used successfully in the past for the measurement of elastic scattering very close to the circulating beam,” says Patrick Fassn...

  6. Luminosity Tuning at the Large Hadron Collider

    CERN Document Server

    Wittmer, W

    2006-01-01

    By measuring and adjusting the beta-functions at the interaction point (IP the luminosity is being optimized. In LEP (Large Electron Positron Collider) this was done with the two closest doublet magnets. This approach is not applicable for the LHC (Large Hadron Collider) and RHIC (Relativistic Heavy Ion Collider) due to the asymmetric lattice. In addition in the LHC both beams share a common beam pipe through the inner triplet magnets (in these region changes of the magnetic field act on both beams). To control and adjust the beta-functions without perturbation of other optics functions, quadrupole groups situated on both sides further away from the IP have to be used where the two beams are already separated. The quadrupoles are excited in specific linear combinations, forming the so-called "tuning knobs" for the IP beta-functions. For a specific correction one of these knobs is scaled by a common multiplier. The different methods which were used to compute such knobs are discussed: (1) matching in MAD, (2)i...

  7. Flavour Physics with High-Luminosity Experiments

    CERN Document Server

    2016-01-01

    With the first dedicated B-factory experiments BaBar (USA) and BELLE (Japan) Flavour Physics has entered the phase of precision physics. LHCb (CERN) and the high luminosity extension of KEK-B together with the state of the art BELLE II detector will further push this precision frontier. Progress in this field always relied on close cooperation between experiment and theory, as extraction of fundamental parameters often is very indirect. To extract the full physics information from existing and future data, this cooperation must be further intensified. This MIAPP programme aims in particular to prepare for this task by joining experimentalists and theorists in the various relevant fields, with the goal to build the necessary tools in face of the challenge of new large data sets. The programme will begin with a focus on physics with non-leptonic final states, continued by semileptonic B meson decays and Tau decays, and on various aspects of CP symmetry violation closer to the end. In addition, in the final ...

  8. Beam, background and luminosity monitoring in LHCb and upgrade of the LHCb fast readout control

    CERN Document Server

    Alessio, Federico; Le Gac, R

    2011-01-01

    The work described in this thesis was developed, implemented and completely put in operations during the first year of physics data taking at the LHC. It is shown here that it is aimed at studying beam and background characteristics, monitor the global timing of the experiment, monitor online the luminosity at LHCb and monitor most the experimental conditions which can affect the LHCb physics data quality. The many functionalities of the presented systems are outlined in great detail and some selected topics of analysis are presented in order to validate the good performance. The various systems in fact showed high reliability, completeness and robustness and hence it heavily contributed to the global efficiency of the LHCb experiment and also contributed directly to the commissioning and running of the LHC machine for first physics runs. Some important concepts are also brought to attention in this thesis as possible solutions to be taken into account at the LHC. A scintillator system for beam, background an...

  9. Pile-up Rejection in the High Granularity Time Detector for the High Luminosity LHC

    CERN Document Server

    McNulty, Paul

    2016-01-01

    The High Granularity Timing Detector, a proposed upgrade to the Liquid Argon Calorimeter during the transition to the High Luminosity LHC, will provide increased resolution in the time domain and offer an avenue for efficiently mitigating the expected increase in pile-up jets. This study analyzes how effectively current algorithms are using a signal jet peak calculation to disentangle desired information from other events. Two samples, one with only hard-scattering events and another that also included pile-up events, were used. A transverse momentum range of 30GeV to 70GeV and pseudo-rapidity range of 2.4 to 4.8 divided the sample to see how the HGTD performed when calculating the signal peak for each jet and how many cells had detections in and out of that peak for each sample.

  10. NbTi Superferric Corrector Magnets for the LHC Luminosity Upgrade

    CERN Document Server

    Volpini, G; Bellomo, G; Broggi, F; Paccalini, A; Pedrini, D; Leone, A; Quadrio, M; Somaschini, L; Sorbi, M; Todero, M; Uva, C; Fessia, P; Todesco, E; Toral, F

    2015-01-01

    CERN and INFN, Italy, have signed an agreement for R&D activities relating to high-luminosity LHC superconducting magnets, which include the design, construction, and cryogenic test of a set of five prototypes, one for each type foreseen, from the skew quadrupole to the dodecapole. The reference layout of these magnets is based on a superferric design type, which allows reaching the required integrated field strength with a relatively simple design. Since the number of magnets of all the types required for the series is 36, emphasis has been put on modularity, reliability, ease of construction, and on the use of an available superconducting wire. This paper presents the status of the development work being performed at INFN, LASA Laboratory, and at CERN, focusing on the following issues: the electromagnetic 2- and 3-D design including harmonic component study; the fringe field analysis; the magnet powering and quench protection; mechanical and construction main choices.

  11. Commissioning of the Absolute Luminosity For ATLAS Detector at the LHC

    DEFF Research Database (Denmark)

    Jakobsen, Sune

    To determine the total cross section and absolute luminosity in the ATLAS detector at the LHC via pp scattering under very small angles, a dedicated sub-detector called ALFA has been made. Several performance evaluation tests including a test beam campaign lead to improvements of the detector...

  12. Overview of a high luminosity μ+μ- collider

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.

    1997-03-01

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should be regarded as complementary. Parameters are given of a 4 TeV high luminosity μ + μ - collider, and of a 0.5 TeV lower luminosity demonstration machine. The authors discuss the various systems in such muon colliders

  13. ISOTROPIC LUMINOSITY INDICATORS IN A COMPLETE AGN SAMPLE

    International Nuclear Information System (INIS)

    Diamond-Stanic, Aleksandar M.; Rieke, George H.; Rigby, Jane R.

    2009-01-01

    The [O IV] λ25.89 μm line has been shown to be an accurate indicator of active galactic nucleus (AGN) intrinsic luminosity in that it correlates well with hard (10-200 keV) X-ray emission. We present measurements of [O IV] for 89 Seyfert galaxies from the unbiased revised Shapley-Ames (RSA) sample. The [O IV] luminosity distributions of obscured and unobscured Seyferts are indistinguishable, indicating that their intrinsic AGN luminosities are quite similar and that the RSA sample is well suited for tests of the unified model. In addition, we analyze several commonly used proxies for AGN luminosity, including [O III] λ5007 A, 6 cm radio, and 2-10 keV X-ray emission. We find that the radio luminosity distributions of obscured and unobscured AGNs show no significant difference, indicating that radio luminosity is a useful isotropic luminosity indicator. However, the observed [O III] and 2-10 keV luminosities are systematically smaller for obscured Seyferts, indicating that they are not emitted isotropically.

  14. VY Canis Majoris: The Astrophysical Basis of Its Luminosity

    Science.gov (United States)

    Gehrz, Robert D.; Humphreys, R. M.; Jones, T. J.

    2006-12-01

    The luminosity of the famous red supergiant VY CMa ( L = 4 5 x 105 L ) is well-determined from its spectral energy distribution and distance, and places it near the empirical upper luminosity limit for cool hypergiants. In contrast, its surface temperature is fundamentally ill-defined. Implications for its location on the HR Diagram and its apparent size are discussed.

  15. Physics at high luminosity muon colliders and a facility overview

    International Nuclear Information System (INIS)

    Parsa, Z.

    2001-01-01

    Physics potentials at future colliders including high luminosity μ + μ - colliders are discussed. Luminosity requirement, estimates for Muon collider energies of interest (0.1 TeV to 100 TeV) are calculated. Schematics and an overview of Muon Collider facility concept are also included

  16. High Luminosity LHC (HL-LHC) general infographics

    CERN Multimedia

    Landua, Fabienne

    2016-01-01

    The High-Luminosity LHC, which is expected to be operational after 2025, will increase the LHC’s luminosity by a factor of 10. To achieve this major upgrade, several technologies, some of which are completely innovative, are being developed.

  17. Challenges in Finding AGNs in the Low Luminosity Regime

    Science.gov (United States)

    Satyapal, Shobita; Abel, Nick; Secrest, Nathan; Singh, Amrit; Ellison, Sara

    2016-08-01

    Low luminosity AGNs are an important component of the AGN population. They are often found in the lowest mass galaxies or galaxies that lack classical bulges, a demographic that places important constraints to models of supermassive black hole seed formation and merger-free models of AGN fueling. The detection of AGNs in this low luminosity regime is challenging both because star formation in the host galaxy can dominate the optical spectrum and gas and dust can obscure the central engine at both optical and X-ray wavelengths. Thus while mid-infrared color selection and X-ray observations at energies <10 keV are often powerful tools in uncovering optically unidentified AGNs at higher luminosities, this is not the case in the low luminosity regime. In this talk, I will review the effectiveness of uncovering AGNs in the low luminosity regime using multiwavength investigations, with a focus on infrared spectroscopic signatures.

  18. Possible relationship between metal abundance and luminosity for disk galaxies

    International Nuclear Information System (INIS)

    Bothun, G.D.; Romanishin, W.; Strom, S.E.; Strom, K.M.

    1984-01-01

    Near-infrared colors have been measured for a sample of 31 late-type galaxies in the Pegasus I and Pisces clusters; system luminosities in the sample cover the range -19< M/sub H/<-23.5. The color index (J-K) correlates strongly with the absolute H magnitude; lower-luminosity systems have bluer colors. These observations are consistent with the assumption that the mean metal abundance of the old disk population decreases systematically with luminosity. The systematic variation of (B-H) with absolute H magnitude reported recently by Tully et al. derives in part from this proposed systematic change of metallicity with luminosity. However, one must still posit a relative increase in the number of newly formed stars and/or a systematic smaller age for lower-luminosity disks in order to fully explain the observed (B-H), H relation

  19. Luminosity monitor topics for RHIC spin and AA, and pA interactions

    International Nuclear Information System (INIS)

    Underwood, D.

    1998-01-01

    This is a note to define topics to be studied in more depth for the Luminosity monitoring for Spin Asymmetries. My numerical examples here are to stimulate discussion and should be taken with a grain of salt. The RHIC Spin experiments will require a very high degree of coordination between the experiments and the accelerator. For example see AGS/RHIC/SN 035. In this note we list some of the issues to be considered in monitoring the relative luminosity between various beam-beam spin combinations and beam-gas combinations. We give simplified numerical examples of the problems encountered in doing the luminosity monitoring to the 10 -4 level. It is hoped that this will provide a framework for serious study of these problems with simulations and other means. Many of the issues may also be relevant to pA and AA running where there may be sizable beam-gas backgrounds

  20. High luminosity liquid-argon calorimeter test beam

    Energy Technology Data Exchange (ETDEWEB)

    Novgorodova, Olga; Straessner, Arno [TU Dresden, IKTP (Germany)

    2016-07-01

    In the future HL-LHC the luminosity will increase by factor of 5-7 with respect to the original LHC design. The HiLum collaboration studied the impact on small-sized modules of the ATLAS electromagnetic, hadronic, and forward calorimeters also instrumented by various intensity and position detectors. The intensity of beam varied over a wide range (10{sup 6} to 10{sup 12} p/s) and beyond the maximum expected at HL-LHC for these calorimeters. Results from the last test beam campaign in 2013 on the signal shape analysis from the calorimeter modules are compared with MC simulations. The correlation between high-voltage return currents of the electromagnetic calorimeter and beam intensity is used to estimate critical parameters and compared with predictions.

  1. CKM fits as a function of luminosity (Time)

    International Nuclear Information System (INIS)

    Hoecker, A.; Lacker, H.; Laplace, S.; Le Diberder, F.

    2001-05-01

    Possible scenarios for CKM fits in the years 2005 and 2010 are presented using B- and K - physics results from extrapolated luminosities for B-factories at the γ(4S), for the hadron machines at Tevatron and LHC and experiments for rare kaon decays. The study provides an estimate of what precision for the CKM matrix elements can be achieved if all relevant experiments and accelerators, including upgrades for the existing e + e - machines, reach their design goals. It is intended to give information used to explore which type of future experiments are needed to cover all relevant physics topics related to the CKM matrix and the search of physics beyond the Standard Model. (authors)

  2. Upgrade of RHIC Vacuum Systems for High Luminosity Operation

    CERN Document Server

    Hseuh Hsiao Chaun; Smart, Loralie; Todd, Robert J; Weiss, Daniel

    2005-01-01

    With increasing ion beam intensity during recent RHIC operations, pressure rises of several decades were observed at most room temperature sections and at a few cold sections. The pressure rises are associated with electron multi-pacting, electron stimulated desorption and beam ion induced desorption and have been one of the major intensity and luminosity limiting factors for RHIC. Improvement of the warm sections has been carried out in the last few years. Extensive in-situ bakes, additional UHV pumping, anti-grazing ridges and beam tube solenoids have been implemented. Several hundred meters of NEG coated beam pipes have been installed and activated. Vacuum monitoring and interlock were enhanced to reduce premature beam aborts. Preliminary measures, such as pumping before cool down to reduce monolayer condensates, were also taken to suppress the pressure rises in the cold sections. The effectiveness of these measures in reducing the pressure rises during machine studies and during physics runs are discussed...

  3. The Physics Landscape of the High Luminosity LHC

    CERN Document Server

    Mangano, M

    2015-01-01

    We review the status of HEP after the first run of the LHC and discuss the opportunities offered by the HL-LHC, in light of the needs for future progress that are emerging from the data. The HL-LHC will push to the systematic limit the precision of most measurements of the Higgs boson, and will be necessary to firmly establish some of the more rare decays foreseen by the Standard Model, such as the decays to dimuons and to a Z+ photon pair. The HL-LHC luminosity will provide additional statistics required by the quantitative study of any discovery the LHC may achieve during the first 300 inverse femtobarn, and will further extend the discovery potential of the LHC, particularly for rare, elusive or low-sensitivity processes.

  4. ON THE SCATTER IN THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Kilerci Eser, E.; Vestergaard, M. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen Ø (Denmark); Peterson, B. M.; Denney, K. D. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Bentz, M. C., E-mail: ecekilerci@dark-cosmology.dk, E-mail: vester@dark-cosmology.dk, E-mail: kelly@astronomy.ohio-state.edu, E-mail: peterson@astronomy.ohio-state.edu, E-mail: bentz@chara.gsu.edu [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States)

    2015-03-01

    We investigate and quantify the observed scatter in the empirical relationship between the broad line region size R and the luminosity of the active galactic nucleus, in order to better understand its origin. This study is motivated by the indispensable role of this relationship in the mass estimation of cosmologically distant black holes, but may also be relevant to the recently proposed application of this relationship for measuring cosmic distances. We study six nearby reverberation-mapped active galactic nuclei (AGNs) for which simultaneous UV and optical monitoring data exist. We also examine the long-term optical luminosity variations of the Seyfert 1 galaxy NGC 5548 and employ Monte Carlo simulations to study the effects of the intrinsic variability of individual objects on the scatter in the global relationship for a sample of ∼40 AGNs. We find the scatter in this relationship has a correctable dependence on color. For individual AGNs, the size of the Hβ emitting region has a steeper dependence on the nuclear optical luminosity than on the UV luminosity, which can introduce a scatter of ∼0.08 dex into the global relationship, due the nonlinear relationship between the variations in the ionizing continuum and those in the optical continuum. Also, our analysis highlights the importance of understanding and minimizing the scatter in the relationship traced by the intrinsic variability of individual AGNs since it propagates directly into the global relationship. We find that using the UV luminosity as a substitute for the ionizing luminosity can reduce a sizable fraction of the current observed scatter of ∼0.13 dex.

  5. ON THE SCATTER IN THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Kilerci Eser, E.; Vestergaard, M.; Peterson, B. M.; Denney, K. D.; Bentz, M. C.

    2015-01-01

    We investigate and quantify the observed scatter in the empirical relationship between the broad line region size R and the luminosity of the active galactic nucleus, in order to better understand its origin. This study is motivated by the indispensable role of this relationship in the mass estimation of cosmologically distant black holes, but may also be relevant to the recently proposed application of this relationship for measuring cosmic distances. We study six nearby reverberation-mapped active galactic nuclei (AGNs) for which simultaneous UV and optical monitoring data exist. We also examine the long-term optical luminosity variations of the Seyfert 1 galaxy NGC 5548 and employ Monte Carlo simulations to study the effects of the intrinsic variability of individual objects on the scatter in the global relationship for a sample of ∼40 AGNs. We find the scatter in this relationship has a correctable dependence on color. For individual AGNs, the size of the Hβ emitting region has a steeper dependence on the nuclear optical luminosity than on the UV luminosity, which can introduce a scatter of ∼0.08 dex into the global relationship, due the nonlinear relationship between the variations in the ionizing continuum and those in the optical continuum. Also, our analysis highlights the importance of understanding and minimizing the scatter in the relationship traced by the intrinsic variability of individual AGNs since it propagates directly into the global relationship. We find that using the UV luminosity as a substitute for the ionizing luminosity can reduce a sizable fraction of the current observed scatter of ∼0.13 dex

  6. Beam delivery system tuning and luminosity monitoring in the Compact Linear Collider

    Directory of Open Access Journals (Sweden)

    B. Dalena

    2012-05-01

    Full Text Available Emittance preservation in the beam delivery system (BDS is one of the major challenges in the Compact Linear Collider (CLIC. The fast detuning of the final focus optics requires an on-line tuning procedure in order to keep luminosity close to the maximum. In this paper we discuss different tuning techniques to mitigate the displacement of magnets in the CLIC BDS and in particular in the final focus system. Some of them require a fast luminosity measurement. Here we study the possibility to use beam-beam background processes at CLIC 3 TeV c.m. energy as a fast luminosity signal. In particular, the hadron multiplicity in the detector region is investigated.

  7. Dust Grains and the Luminosity of Circumnuclear Water Masers in Active Galaxies

    Science.gov (United States)

    Collison, Alan J.; Watson, William D.

    1995-01-01

    In previous calculations for the luminosities of 22 GHz water masers, the pumping is reduced and ultimately quenched with increasing depth into the gas because of trapping of the infrared (approximately equals 30-150 micrometers), spectral line radiation of the water molecule. When the absorption (and reemission) of infrared radiation by dust grains is included, we demonstrate that the pumping is no longer quenched but remains constant with increasing optical depth. A temperature difference between the grains and the gas is required. Such conditions are expected to occur, for example, in the circumnuclear masing environments created by X-rays in active galaxies. Here, the calculated 22 GHz maser luminosities are increased by more than an order of magnitude. Application to the well-studied, circumnuclear masing disk in the galaxy NGC 4258 yields a maser luminosity near that inferred from observations if the observed X-ray flux is assumed to be incident onto only the inner surface of the disk.

  8. Luminosity Loss due to Beam Distortion and the Beam-Beam Instability

    CERN Document Server

    Wu, Juhao; Raubenheimer, Tor O; Seryi, Andrei; Sramek, Christopher K

    2005-01-01

    In a linear collider, sources of emittance dilution such as transverse wakefields or dispersive errors will couple the vertical phase space to the longitudinal position within the beam (the so-called ‘banana effect'). When the Intersection Point (IP) disruption parameter is large, these beam distortions will be amplified by a single bunch kink instability which will lead to luminosity loss. We study this phenomena both analytically using linear theory and via numerical simulation. In particular, we examine the dependence of the luminosity loss on the wavelength of the beam distortions and the disruption parameter. This analysis may prove useful when optimizing the vertical disruption parameter for luminosity operation with given beam distortions.

  9. Luminosity upgrade possibilities for the PEP-II B-Factory

    CERN Document Server

    Sullivan, M

    2003-01-01

    PEP-II is an asymmetric e sup + e sup - collider being constructed in the SLAC PEP tunnel by SLAC, LBNL, and LLNL. The two beams have energies of 3.1 GeV and 9.0 GeV and are made to collide at a single interaction point. PEP-II has a 2200 m circumference. The nominal parameters for PEP-II are listed in Table 1. The High Energy Ring (HER) of PEP-II started commissioning in 1997. The Low Energy Ring (LER) will be commissioned in the summer of 1998. The BaBar detector is to be installed starting January 1999. Studies for increasing the luminosity in PEP-II beyond the design are underway. A brief summary of the possibilities are presented here. Improvements to the integrated luminosity will be implemented gradually. Major luminosity improvements will likely come in two phased upgrades. Several of these possibilities are summarized in Table 1.

  10. LUMINOSITY UPGRADE POSSIBILITIES FOR THE PEP-II B-FACTORY

    International Nuclear Information System (INIS)

    Sullivan, Michael K

    2003-01-01

    PEP-II is an asymmetric e + e - collider being constructed in the SLAC PEP tunnel by SLAC, LBNL, and LLNL. The two beams have energies of 3.1 GeV and 9.0 GeV and are made to collide at a single interaction point. PEP-II has a 2200 m circumference. The nominal parameters for PEP-II are listed in Table 1. The High Energy Ring (HER) of PEP-II started commissioning in 1997. The Low Energy Ring (LER) will be commissioned in the summer of 1998. The BaBar detector is to be installed starting January 1999. Studies for increasing the luminosity in PEP-II beyond the design are underway. A brief summary of the possibilities are presented here. Improvements to the integrated luminosity will be implemented gradually. Major luminosity improvements will likely come in two phased upgrades. Several of these possibilities are summarized in Table 1

  11. Luminosity measurement and beam condition monitoring at CMS

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Jessica Lynn [DESY, Zeuthen (Germany)

    2015-07-01

    The BRIL system of CMS consists of instrumentation to measure the luminosity online and offline, and to monitor the LHC beam conditions inside CMS. An accurate luminosity measurement is essential to the CMS physics program, and measurement of the beam background is necessary to ensure safe operation of CMS. In expectation of higher luminosity and denser proton bunch spacing during LHC Run II, many of the BRIL subsystems are being upgraded and others are being added to complement the existing measurements. The beam condition monitor (BCM) consists of several sets of diamond sensors used to measure online luminosity and beam background with a single-bunch-crossing resolution. The BCM also detects when beam conditions become unfavorable for CMS running and may trigger a beam abort to protect the detector. The beam halo monitor (BHM) uses quartz bars to measure the background of the incoming beams at larger radii. The pixel luminosity telescope (PLT) consists of telescopes of silicon sensors designed to provide a CMS online and offline luminosity measurement. In addition, the forward hadronic calorimeter (HF) will deliver an independent luminosity measurement, making the whole system robust and allowing for cross-checks of the systematics. Data from each of the subsystems will be collected and combined in the BRIL DAQ framework, which will publish it to CMS and LHC. The current status of installation and commissioning results for the BRIL subsystems are given.

  12. Seeking the epoch of maximum luminosity for dusty quasars

    International Nuclear Information System (INIS)

    Vardanyan, Valeri; Weedman, Daniel; Sargsyan, Lusine

    2014-01-01

    Infrared luminosities νL ν (7.8 μm) arising from dust reradiation are determined for Sloan Digital Sky Survey (SDSS) quasars with 1.4 luminosity does not show a maximum at any redshift z < 5, reaching a plateau for z ≳ 3 with maximum luminosity νL ν (7.8 μm) ≳ 10 47 erg s –1 ; luminosity functions show one quasar Gpc –3 having νL ν (7.8 μm) > 10 46.6 erg s –1 for all 2 luminosity has not yet been identified at any redshift below 5. The most ultraviolet luminous quasars, defined by rest frame νL ν (0.25 μm), have the largest values of the ratio νL ν (0.25 μm)/νL ν (7.8 μm) with a maximum ratio at z = 2.9. From these results, we conclude that the quasars most luminous in the ultraviolet have the smallest dust content and appear luminous primarily because of lessened extinction. Observed ultraviolet/infrared luminosity ratios are used to define 'obscured' quasars as those having >5 mag of ultraviolet extinction. We present a new summary of obscured quasars discovered with the Spitzer Infrared Spectrograph and determine the infrared luminosity function of these obscured quasars at z ∼ 2.1. This is compared with infrared luminosity functions of optically discovered, unobscured quasars in the SDSS and in the AGN and Galaxy Evolution Survey. The comparison indicates comparable numbers of obscured and unobscured quasars at z ∼ 2.1 with a possible excess of obscured quasars at fainter luminosities.

  13. Z-boson-exchange contributions to the luminosity measurements at LEP and c.m.s.-energy-dependent theoretical errors

    International Nuclear Information System (INIS)

    Beenakker, W.; Martinez, M.; Pietrzyk, B.

    1995-02-01

    The precision of the calculation of Z-boson-exchange contributions to the luminosity measurements at LEP is studied for both the first and second generation of LEP luminosity detectors. It is shown that the theoretical errors associated with these contributions are sufficiently small so that the high-precision measurements at LEP, based on the second generation of luminosity detectors, are not limited. The same is true for the c.m.s.-energy-dependent theoretical errors of the Z line-shape formulae. (author) 19 refs.; 3 figs.; 7 tabs

  14. Protogalaxy interactions in newly formed clusters: Galaxy luminosities, colors, and intergalactic gas

    International Nuclear Information System (INIS)

    Silk, J.

    1978-01-01

    The role of protogalaxy interactions in galactic evolution is studied during the formation of galaxy clusters. In the early stages of the collapse, coalescent encounters of protogalaxies lead to the development of a galactic luminosity function. Once galaxies acquire appreciable random motions, mutual collisions between galaxies in rich clusters will trigger the collapse of interstellar clouds to form stars. This provides both a source for enriched intracluster gas and an interpretation of the correlation between luminosity and color for cluster elliptical galaxies. Other observational consequences that are considered include optical, X-ray, and diffuse nonthermal radio emission from newly formed clusters of galaxies

  15. Cosmological Evolution of the Central Engine in High-Luminosity, High-Accretion Rate AGN

    Directory of Open Access Journals (Sweden)

    Matteo Guainazzi

    2014-12-01

    Full Text Available In this paper I discuss the status of observational studies aiming at probing the cosmological evolution of the central engine in high-luminosity, high-accretion rate Active Galactic Nuclei (AGN. X-ray spectroscopic surveys, supported by extensive multi-wavelength coverage, indicate a remarkable invariance of the accretion disk plus corona system, and of their coupling up to redshifts z≈6. Furthermore, hard X-ray (E >10 keV surveys show that nearby Seyfert Galaxies share the same central engine notwithstanding their optical classication. These results suggest that the high-luminosity, high accretion rate quasar phase of AGN evolution is homogeneous over cosmological times.

  16. The spectrometer system for measuring ZEUS luminosity at HERA

    International Nuclear Information System (INIS)

    Helbich, M.; Ning, Y.; Paganis, S.; Ren, Z.; Schmidke, W.B.; Sciulli, F.; Schneekloth, U.; Buettner, C.; Caldwell, A.; Sutiak, J.

    2006-01-01

    The upgrade of the HERA accelerator has provided much increased collider luminosity. In turn, the improvements have necessitated a new design for the ZEUS luminosity measurements. The intense synchrotron radiation field, as well as the high probability of a bremsstrahlung photon in each bunch crossing, posed new experimental constraints. In this report, we describe how these challenges were met with the ZEUS luminosity spectrometer system. The design, testing and commissioning of the device are described, and the results from the initial operational experience are reported

  17. High precision measurements of the luminosity at LEP

    International Nuclear Information System (INIS)

    Pietrzyk, B.

    1994-01-01

    The art of the luminosity measurements at LEP is presented. First generation LEP detectors have measured the absolute luminosity with the precision of 0.3-0.5%. The most precise present detectors have reached the 0.07% precision and the 0.05% is not excluded in future. Center-of-mass energy dependent relative precision of the luminosity detectors and the use of the theoretical cross-section in the LEP experiments are also discussed. (author). 18 refs., 6 figs., 6 tabs

  18. On the existence of a luminosity threshold of GRB jets in massive stars

    Science.gov (United States)

    Aloy, M. A.; Cuesta-Martínez, C.; Obergaulinger, M.

    2018-05-01

    Motivated by the many associations of γ-ray bursts (GRBs) with energetic supernova (SN) explosions, we study the propagation of relativistic jets within the progenitor star in which a SN shock wave may be launched briefly before the jets start to propagate. Based on analytic considerations and verified with an extensive set of 2D axisymmetric relativistic hydrodynamic simulations, we have estimated a threshold intrinsic jet luminosity, L_j^thr, for successfully launching a jet. This threshold depends on the structure of the progenitor and, thus, it is sensitive to its mass and to its metallicity. For a prototype host of cosmological long GRBs, a low-metallicity star of 35 M⊙, it is L_j^thr˜eq 1.35× 10^{49} erg s-1. The observed equivalent isotropic γ-ray luminosity, L_{γ ,iso,BO} ˜eq 4 ɛ _γ L_j θ _BO^{-2}, crucially depends on the jet opening angle after breakout, θBO, and on the efficiency for converting the intrinsic jet luminosity into γ-radiation, ɛγ. Highly energetic jets can produce low-luminosity events if either their opening angle after the breakout is large, which is found in our models, or if the conversion efficiency of kinetic and internal energy into radiation is low enough. Beyond this theoretical analysis, we show how the presence of a SN shock wave may reduce this luminosity threshold by means of numerical simulations. We foresee that the high-energy transients released by jets produced near the luminosity threshold will be more similar to llGRBs or XRFs than to GRBs.

  19. Unified treatment of the luminosity distance in cosmology

    International Nuclear Information System (INIS)

    Yoo, Jaiyul; Scaccabarozzi, Fulvio

    2016-01-01

    Comparing the luminosity distance measurements to its theoretical predictions is one of the cornerstones in establishing the modern cosmology. However, as shown in Biern and Yoo, its theoretical predictions in literature are often plagued with infrared divergences and gauge-dependences. This trend calls into question the sanity of the methods used to derive the luminosity distance. Here we critically investigate four different methods—the geometric approach, the Sachs approach, the Jacobi mapping approach, and the geodesic light cone (GLC) approach to modeling the luminosity distance, and we present a unified treatment of such methods, facilitating the comparison among the methods and checking their sanity. All of these four methods, if exercised properly, can be used to reproduce the correct description of the luminosity distance.

  20. Unified treatment of the luminosity distance in cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jaiyul; Scaccabarozzi, Fulvio, E-mail: jyoo@physik.uzh.ch, E-mail: fulvio@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Zürich (Switzerland)

    2016-09-01

    Comparing the luminosity distance measurements to its theoretical predictions is one of the cornerstones in establishing the modern cosmology. However, as shown in Biern and Yoo, its theoretical predictions in literature are often plagued with infrared divergences and gauge-dependences. This trend calls into question the sanity of the methods used to derive the luminosity distance. Here we critically investigate four different methods—the geometric approach, the Sachs approach, the Jacobi mapping approach, and the geodesic light cone (GLC) approach to modeling the luminosity distance, and we present a unified treatment of such methods, facilitating the comparison among the methods and checking their sanity. All of these four methods, if exercised properly, can be used to reproduce the correct description of the luminosity distance.

  1. The CMS Outer Tracker Upgrade for the High Luminosity LHC

    CERN Document Server

    Luetic, Jelena

    2017-01-01

    The era of the High Luminosity Large Hadron Collider will pose unprecedented challenges for detector design and operation. The planned luminosity of the upgraded machine is $5$x$10^{34} $ cm$^{-2}$s$^{-1}$, reaching an integrated luminosity of more than 3000 fb$^{-1}$ by the end of 2037. The CMS Tracker detector will have to be replaced in order to fully exploit the delivered luminosity and cope with the demanding operating conditions. The new detector will provide robust tracking as well as input for the first level trigger. This report is focusing on the replacement of the CMS Outer Tracker system, describing the new layout and technological choices together with some highlights of research and development activities.

  2. Physics potential of precision measurements of the LHC luminosity

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The uncertainty in the determination of the LHC luminosity is rapidly becoming a limiting factor for the analysis and interpretation of many important LHC processes. In this talk first of all we discuss the theoretical accuracy of total cross sections and examine in which cases the luminosity error is or will be dominant. We then review the impact of LHC data in PDF determinations, with enphasis on the effects of the luminosity uncertainty. We explore the requirements for the accuracy of the 2011 luminosity determination from the point of view of standard candle cross section and other important processes. Finally we discuss what we can learn from the accurate measurement of cross section ratios at different center of mass energies for processes like W, ttbar and dijet production.

  3. The low-luminosity end of the radius-luminosity relationship for active galactic nuclei

    DEFF Research Database (Denmark)

    Bentz, M.C.; Denney, K.D.; Vestergaard, Marianne

    2013-01-01

    fit to the relationship using a Bayesian analysis finds a slope of , consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy...... with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create "AGN-free" images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new...... results help support the possibility that the R-L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts....

  4. Strip detector for the ATLAS detector upgrade for the high-luminosity LHC

    CERN Document Server

    Madaffari, Daniele; The ATLAS collaboration

    2017-01-01

    The planned HL-LHC (High Luminosity LHC) in 2025 is being designed to maximise the physics potential of the LHC through a sizeable increase in the luminosity, reaching 1x10$^{35}$ cm$^{-2}$s$^{-1}$ after 10 years of operation. A consequence of this increased luminosity is the expected radiation damage at an integrated luminosity of 3000 fb$^{-1}$, requiring the tracking detectors to withstand hadron fluencies to over 1x10$^{16}$ 1 MeV neutron equivalent per cm$^2$. With the addition of increased readout rates, a complete re-design of the current ATLAS Inner Detector (ID) is being developed as the Inner Tracker (ITk), which will consist of both strip and pixelated silicon detectors. The physics motivations, required performance characteristics and basic design of the proposed upgrade of the strip detector will be a subject of this talk. Present ideas and solutions for the strip detector and current research and development program will be discussed.

  5. Triggering at high luminosity: fake triggers from pile-up

    International Nuclear Information System (INIS)

    Johnson, R.

    1983-01-01

    Triggers based on a cut in transverse momentum (p/sub t/) have proved to be useful in high energy physics both because they indicte that a hard constituent scattering has occurred and because they can be made quickly enough to gate electronics. These triggers will continue to be useful at high luminosities if overlapping events do not cause an excessive number of fake triggers. In this paper, I determine if this is indeed a problem at high luminosity machines

  6. VY Canis Majoris: The Astrophysical Basis of Its Luminosity

    OpenAIRE

    Humphreys, Roberta M.

    2006-01-01

    The luminosity of the famous red supergiant VY CMa (L ~ 4 - 5 x 10e5 Lsun) is well-determined from its spectral energy distribution and distance, and places it near the empirical upper luminosity limit for cool hypergiants. In contrast, its surface temperature is fundamentally ill-defined. Both contradict a recent paper by Massey, Levesque and Plez (2006). Implications for its location on the HR Diagram and its apparent size are discussed.

  7. On the Luminosity Distance and the Hubble Constant

    OpenAIRE

    Yuri Heymann

    2013-01-01

    By differentiating luminosity distance with respect to time using its standard formula we find that the peculiar velocity is a time varying velocity of light. Therefore, a new definition of the luminosity distance is provided such that the peculiar velocity is equal to c. Using this definition a Hubble constant H0 = 67.3 km s−1 Mpc−1 is obtained from supernovae data.

  8. Performance appraisal of coaches: Acomparative study | Surujlal ...

    African Journals Online (AJOL)

    Within the sport environment, the performance appraisal of coaches continues to be an issue. The performance appraisal of coaches is critical to sport organizations since major decisions like rewarding or terminating coaches is based on it. The purpose of this study was to examine whether any differences exist with regard ...

  9. Upgrade of the ATLAS Calorimeters for Higher LHC Luminosities

    CERN Document Server

    Carbone, Ryne Michael; The ATLAS collaboration

    2016-01-01

    The upgrade of the LHC will bring instantaneous and total luminosities which are a factor 5-7 beyond the original design of the ATLAS Liquid Argon (LAr) and Tile Calorimeters and their read-out systems. Due to radiation requirements and a new hardware trigger concept the read-out electronics will be improved in two phases. In Phase-I, a dedicated read-out of the LAr Calorimeters will provide higher granularity input to the trigger, in order to mitigate pile-up effects and to reduce the background rates. In Phase-II, completely new read-out electronics will allow a digital processing of all LAr and Tile Calorimeter channels at the full 40 MHz bunch-crossing frequency and a transfer of calibrated energy inputs to the trigger. Results from system design and performance of the developed read-out components, including fully functioning demonstrator systems already operated on the detector, will be reported. Furthermore, the current Forward Calorimeter (FCal) may suffer from signal degradation and argon bubble form...

  10. US QCD computational performance studies with PERI

    International Nuclear Information System (INIS)

    Zhang, Y; Fowler, R; Huck, K; Malony, A; Porterfield, A; Reed, D; Shende, S; Taylor, V; Wu, X

    2007-01-01

    We report on some of the interactions between two SciDAC projects: The National Computational Infrastructure for Lattice Gauge Theory (USQCD), and the Performance Engineering Research Institute (PERI). Many modern scientific programs consistently report the need for faster computational resources to maintain global competitiveness. However, as the size and complexity of emerging high end computing (HEC) systems continue to rise, achieving good performance on such systems is becoming ever more challenging. In order to take full advantage of the resources, it is crucial to understand the characteristics of relevant scientific applications and the systems these applications are running on. Using tools developed under PERI and by other performance measurement researchers, we studied the performance of two applications, MILC and Chroma, on several high performance computing systems at DOE laboratories. In the case of Chroma, we discuss how the use of C++ and modern software engineering and programming methods are driving the evolution of performance tools

  11. Cosmic evolution of AGN with moderate-to-high radiative luminosity in the COSMOS field

    Science.gov (United States)

    Ceraj, L.; Smolčić, V.; Delvecchio, I.; Delhaize, J.; Novak, M.

    2018-05-01

    We study the moderate-to-high radiative luminosity active galactic nuclei (HLAGN) within the VLA-COSMOS 3 GHz Large Project. The survey covers 2.6 square degrees centered on the COSMOS field with a 1σ sensitivity of 2.3 μJy/beam across the field. This provides the simultaneously largest and deepest radio continuum survey available to date with exquisite multi-wavelength coverage. The survey yields 10,830 radio sources with signal-to-noise ratios >=5. A subsample of 1,604 HLAGN is analyzed here. These were selected via a combination of X-ray luminosity and mid-infrared colors. We derive luminosity functions for these AGN and constrain their cosmic evolution out to a redshift of z ~ 6, for the first time decomposing the star formation and AGN contributions to the radio continuum emission in the AGN. We study the evolution of number density and luminosity density finding a peak at z ~ 1.5 followed by a decrease out to a redshift z ~ 6.

  12. The Glare Effect Test and the Impact of Age on Luminosity Thresholds

    Directory of Open Access Journals (Sweden)

    Alessio Facchin

    2017-06-01

    Full Text Available The glare effect (GE is an illusion in which a white region appears self-luminous when surrounded by linearly decreasing luminance ramps. It has been shown that the magnitude of the luminosity effect can be modulated by manipulating the luminance range of the gradients. In the present study we tested the thresholds for the GE on two groups of adults: young (20–30 years old and elderly (60–75 years old. Purpose of our perspective study was to test the possibility of transforming the GE into a test that could easily measure thresholds for luminosity and discomfort glare. The Glare Effect Test (GET consisted in 101 printed cards that differed from each other for the range of luminance ramps. Participants were assessed with GET and a battery of visual tests: visual acuity, contrast sensitivity, illusion of length perception, and Ishihara test. Specifically in the GET, participants were required to classify cards on the basis of two reference cards (solid black-no gradient; full range black to white gradient. PSEs of the GE show no correlation with the other visual tests, revealing a divergent validity. A significant difference between young and elderly was found: contrary to our original expectations, luminosity thresholds of GE for elderly were higher than those for young, suggesting a non-direct relationship between luminosity perception and discomfort glare.

  13. Gamma-Ray Burst Host Galaxies Have "Normal" Luminosities.

    Science.gov (United States)

    Schaefer

    2000-04-10

    The galactic environment of gamma-ray bursts can provide good evidence about the nature of the progenitor system, with two old arguments implying that the burst host galaxies are significantly subluminous. New data and new analysis have now reversed this picture: (1) Even though the first two known host galaxies are indeed greatly subluminous, the next eight hosts have absolute magnitudes typical for a population of field galaxies. A detailed analysis of the 16 known hosts (10 with redshifts) shows them to be consistent with a Schechter luminosity function with R*=-21.8+/-1.0, as expected for normal galaxies. (2) Bright bursts from the Interplanetary Network are typically 18 times brighter than the faint bursts with redshifts; however, the bright bursts do not have galaxies inside their error boxes to limits deeper than expected based on the luminosities for the two samples being identical. A new solution to this dilemma is that a broad burst luminosity function along with a burst number density varying as the star formation rate will require the average luminosity of the bright sample (>6x1058 photons s-1 or>1.7x1052 ergs s-1) to be much greater than the average luminosity of the faint sample ( approximately 1058 photons s-1 or approximately 3x1051 ergs s-1). This places the bright bursts at distances for which host galaxies with a normal luminosity will not violate the observed limits. In conclusion, all current evidence points to gamma-ray burst host galaxies being normal in luminosity.

  14. Study of the performance of the data acquisition chain for BCM1F software upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria

    2011-05-15

    BCM1F, the Fast Beam Conditions Monitor, is a sub-detector of the CMS experiment at LHC. It monitors the beam halo and the collision product rates inside the CMS experiment. The data acquisition of BCM1F is independent from CMS. Major components of the BCM1F back-end are discriminators, ADCs, TDCs, look-up tables and a Veto module. In the thesis the performance of several components is investigated. For the TDC two different readout modes are compared, and the impact of a Ring Buffer in the readout software was investigated. For one discriminator the thresholds of all channels are investigated and offsets of about 10 mV are found. Data taken in the LHC runs with the TDC are presented and discussed. Also the application of BCM1F as a luminosity monitor is studied. (orig.)

  15. Study of the performance of the data acquisition chain for BCM1F software upgrade

    International Nuclear Information System (INIS)

    Hempel, Maria

    2011-05-01

    BCM1F, the Fast Beam Conditions Monitor, is a sub-detector of the CMS experiment at LHC. It monitors the beam halo and the collision product rates inside the CMS experiment. The data acquisition of BCM1F is independent from CMS. Major components of the BCM1F back-end are discriminators, ADCs, TDCs, look-up tables and a Veto module. In the thesis the performance of several components is investigated. For the TDC two different readout modes are compared, and the impact of a Ring Buffer in the readout software was investigated. For one discriminator the thresholds of all channels are investigated and offsets of about 10 mV are found. Data taken in the LHC runs with the TDC are presented and discussed. Also the application of BCM1F as a luminosity monitor is studied. (orig.)

  16. Development of Silicon Detectors for the High Luminosity LHC

    International Nuclear Information System (INIS)

    Eichhorn, Thomas Valentin

    2015-07-01

    The Large Hadron Collider (LHC) at CERN will be upgraded to a High Luminosity LHC in the year 2022, increasing the instantaneous luminosity by a factor of five. This will have major impacts on the experiments at the LHC, such as the Compact Muon Solenoid (CMS) experiment, and especially for their inner silicon tracking systems. Among other things, the silicon sensors used therein will be exposed to unprecedented levels of radiation damage, necessitating a replacement of the entire tracking detector. In order to maintain the excellent current performance, a new tracking detector has to be equipped with sensors of increased radiation hardness and higher granularity. The CMS experiment is undertaking an extensive R and D campaign in the search for the future silicon sensor technology baseline to be used in this upgrade. This thesis presents two methods suitable for use in this search: finite element TCAD simulations and test beam measurements. The simulations are focussed on the interstrip capacitance between sensor strips and are compared to measurements before and after the inclusion of radiation damage effects. A geometrical representation of the strip sensors used in the campaign has been found, establishing the predictive power of simulations. The test beam measurements make use of the high-precision pixel telescopes available at the DESY-II test beam facility. The performance of these telescopes has been assessed and their achievable pointing resolution has been found to be below 2 μm. Thin, epitaxial silicon is a candidate material for usage in radiation hard sensors for the future CMS tracking detector. Sample strip sensors of this material have been irradiated to fluences of up to 1.3 x 10 16 n eq /cm 2 with 800 MeV or 23 GeV protons. Test beam measurements with 5 GeV electrons have been performed to investigate the radiation hardness of epitaxial sensors using the pixel beam telescopes. The epitaxial device under test (DUT) has been integrated into the

  17. Pulse simulations and heat flow measurements for the ATLAS Forward Calorimeter under high-luminosity conditions

    CERN Document Server

    AUTHOR|(SzGeCERN)758133; Zuber, Kai

    The high luminosity phase of the Large Hadron Collider at CERN is an important step for further and more detailed studies of the Standard Model of particle physics as well as searches for new physics. The necessary upgrade of the ATLAS detector is a challenging task as the increased luminosity entails many problems for the different detector parts. The liquid-argon Forward Calorimeter suffers signal-degradation effects and a high voltage drop of the supply potential under high-luminosity conditions. It is possible that the argon starts to boil due to the large energy depositions. The effect of the high-luminosity environment on the liquid-argon Forward Calorimeter has been simulated in order to investigate the level of signal degradation. The results show a curvature of the triangular pulse shape that appears prolonged when increasing the energy deposit. This effect is caused by the drop in the electric potential that produces a decrease in the electric field across the liquid-argon gap in the Forward Calorim...

  18. Operator performance in non-destructive testing: A study of operator performance in a performance test

    Energy Technology Data Exchange (ETDEWEB)

    Enkvist, J.; Edland, A.; Svenson, Ola [Stockholm Univ. (Sweden). Dept. of Psychology

    2000-05-15

    In the process industries there is a need of inspecting the integrity of critical components without disrupting the process. Such in-service inspections are typically performed with non-destructive testing (NDT). In NDT the task of the operator is to (based on diagnostic information) decide if the component can remain in service or not. The present study looks at the performance in NDT. The aim is to improve performance, in the long run, by exploring the operators' decision strategies and other underlying factors and to this way find out what makes some operators more successful than others. Sixteen operators performed manual ultrasonic inspections of four test pieces with the aim to detect (implanted) cracks. In addition to these performance demonstration tests (PDT), the operators performed independent ability tests and filled out questionnaires. The results show that operators who trust their gut feeling more than the procedure (when the two come to different results) and that at the same time have a positive attitude towards the procedure have a higher PDT performance. These results indicate the need for operators to be motivated and confident when performing NDT. It was also found that the operators who performed better rated more decision criteria higher in the detection phase than the operators who performed worse. For characterizing it was the other way around. Also, the operators who performed better used more time, both detecting and characterizing, than the operators who performed worse.

  19. Operator performance in non-destructive testing: A study of operator performance in a performance test

    International Nuclear Information System (INIS)

    Enkvist, J.; Edland, A.; Svenson, Ola

    2000-05-01

    In the process industries there is a need of inspecting the integrity of critical components without disrupting the process. Such in-service inspections are typically performed with non-destructive testing (NDT). In NDT the task of the operator is to (based on diagnostic information) decide if the component can remain in service or not. The present study looks at the performance in NDT. The aim is to improve performance, in the long run, by exploring the operators' decision strategies and other underlying factors and to this way find out what makes some operators more successful than others. Sixteen operators performed manual ultrasonic inspections of four test pieces with the aim to detect (implanted) cracks. In addition to these performance demonstration tests (PDT), the operators performed independent ability tests and filled out questionnaires. The results show that operators who trust their gut feeling more than the procedure (when the two come to different results) and that at the same time have a positive attitude towards the procedure have a higher PDT performance. These results indicate the need for operators to be motivated and confident when performing NDT. It was also found that the operators who performed better rated more decision criteria higher in the detection phase than the operators who performed worse. For characterizing it was the other way around. Also, the operators who performed better used more time, both detecting and characterizing, than the operators who performed worse

  20. A Study of Vicon System Positioning Performance

    Directory of Open Access Journals (Sweden)

    Pierre Merriaux

    2017-07-01

    Full Text Available Motion capture setups are used in numerous fields. Studies based on motion capture data can be found in biomechanical, sport or animal science. Clinical science studies include gait analysis as well as balance, posture and motor control. Robotic applications encompass object tracking. Today’s life applications includes entertainment or augmented reality. Still, few studies investigate the positioning performance of motion capture setups. In this paper, we study the positioning performance of one player in the optoelectronic motion capture based on markers: Vicon system. Our protocol includes evaluations of static and dynamic performances. Mean error as well as positioning variabilities are studied with calibrated ground truth setups that are not based on other motion capture modalities. We introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments contrary to state-of-the art works that rely on inter-marker distances. The system performs well on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. Our dynamic experiments were carried out at speeds found in real applications. Our work suggests that the system error is less than 2 mm. We also found that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for our dynamic study.

  1. Absolute in situ energy calibration of luminosity calorimeters in the DELPHI experiment at LEP

    International Nuclear Information System (INIS)

    Bugge, L.; Dam, M.; Read, A.L.; Myrheim, J.; Skjevling, G.

    1993-01-01

    Methods to perform the absolute energy calibration of DELPHI's Small Angle Tagger luminosity calorimeters at LEP are presented and compared. The input was small angle Bhabha scattering events. A significant nonlinearity in the response of the calorimeters was observed. The conjugate gradient method was applied to solve the least squares problem. This method is particularly useful for least squares problems which are large, ill-behaved or even singular, and for cases with a sparse coefficient matrix. (orig.)

  2. SuperB A High-Luminosity Asymmetric $e^+ e^-$ Super Flavour Factory : Conceptual Design Report

    CERN Document Server

    Bona, M.; Grauges Pous, E.; Colangelo, P.; De Fazio, F.; Palano, A.; Manghisoni, M.; Re, V.; Traversi, G.; Eigen, G.; Venturini, M.; Soni, N.; Bruschi, M.; De Castro, S.; Faccioli, P.; Gabrieli, A.; Giacobbe, B.; Semprini Cesare, N.; Spighi, R.; Villa, M.; Zoccoli, A.; Hearty, C.; McKenna, J.; Soni, A.; Khan, A.; Barniakov, A.Y.; Barniakov, M.Y.; Blinov, V.E.; Druzhinin, V.P.; Golubev, V.B.; Kononov, S.A.; Koop, I.A.; Kravchenko, E.A.; Levichev, E.B.; Nikitin, S.A.; Onuchin, A.P.; Piminov, P.A.; Serednyakov, S.I.; Shatilov, D.N.; Skovpen, Y.I.; Solodov, E.A.; Cheng, C.H.; Echenard, B.; Fang, F.; Hitlin, D.J.; Porter, F.C.; Asner, D.M.; Pham, T.N.; Fleischer, R.; Giudice, G.F.; Hurth, T.; Mangano, M.; Mancinelli, G.; Meadows, B.T.; Schwartz, A.J.; Sokoloff, M.D.; Soffer, A.; Beard, C.D.; Haas, T.; Mankel, R.; Hiller, G.; Ball, P.; Pappagallo, M.; Pennington, M.R.; Gradl, W.; Playfer, S.; Abada, A.; Becirevic, D.; Descotes-Genon, S.; Pene, O.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabresi, R.; Cecchi, A.; Cibinetto, G.; Franchini, P.; Luppi, E.; Negrini, M.; Petrella, A.; Piemontese, L.; Prencipe, E.; Santoro, V.; Stancari, G.; Anulli, F.; Baldini-Ferroli, R.; Biagini, M.E.; Boscolo, M.; Calcaterra, A.; Drago, A.; Finocchiaro, G.; Guiducci, S.; Isidori, G.; Pacetti, S.; Patteri, P.; Peruzzi, I.M.; Piccolo, M.; Preger, M.A.; Raimondi, P.; Rama, M.; Vaccarezza, C.; Zallo, A.; Zobov, M.; De Sangro, R.; Buzzo, A.; Lo Vetere, M.; Macri, M.; Monge, M.R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Matias, J.; Panduro Vazquez, W.; Borzumati, F.; Eyges, V.; Prell, S.A.; Pedlar, T.K.; Korpar, S.; Pestonik, R.; Staric, M.; Neubert, M.; Denig, A.G.; Nierste, U.; Agoh, T.; Ohmi, K.; Ohnishi, Y.; Fry, J.R.; Touramanis, C.; Wolski, A.; Golob, B.; Krizan, P.; Flaecher, H.; Bevan, A.J.; Di Lodovico, F.; George, K.A.; Barlow, R.; Lafferty, G.; Jawahery, A.; Roberts, D.A.; Simi, G.; Patel, P.M.; Robertson, S.H.; Lazzaro, A.; Palombo, F.; Kaidalov, A.; Buras, A.J.; Tarantino, C.; Buchalla, G.; Sanda, A.I.; D'Ambrosio, G.; Ricciardi, G.; Bigi, I.; Jessop, C.P.; Losecco, J.M.; Honscheid, K.; Arnaud, N.; Chehab, R.; Fedala, Y.; Polci, F.; Roudeau, P.; Sordini, V.; Soskov, V.; Stocchi, A.; Variola, A.; Vivoli, A.; Wormser, G.; Zomer, F.; Bertolin, A.; Brugnera, R.; Gagliardi, N.; Gaz, A.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Bonneaud, G.R.; Lombardo, V.; Calderini, G.; Ratti, L.; Speziali, V.; Biasini, M.; Covarelli, R.; Manoni, E.; Servoli, L.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Dell'Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.; Lusiani, A.; Marchiori, G.; Massa, M.; Mazur, M.A.; Morsani, F.; Neri, N.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Walsh, J.; Braun, V.; Lenz, A.; Adams, G.S.; Danko, I.Z.; Baracchini, E.; Bellini, F.; Cavoto, G.; D'Orazio, A.; Del Re, D.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Gaspero, Mario; Jackson, P.; Martinelli, G.; Mazzoni, M.A.; Morganti, Silvio; Piredda, G.; Renga, F.; Silvestrini, L.; Voena, C.; Catani, L.; Di Ciaccio, A.; Messi, R.; Santovetti, E.; Satta, A.; Ciuchini, M.; Lubicz, V.; Wilson, F.F.; Godang, R.; Chen, X.; Liu, H.; Park, W.; Purohit, M.; Trivedi, A.; White, R.M.; Wilson, J.R.; Allen, M.T.; Aston, D.; Bartoldus, R.; Brodsky, S.J.; Cai, Y.; Coleman, J.; Convery, M.R.; DeBarger, S.; Dingfelder, J.C.; Dubois-Felsmann, G.P.; Ecklund, S.; Fisher, A.S.; Haller, G.; Heifets, S.A.; Kaminski, J.; Kelsey, M.H.; Kocian, M.L.; Leith, D.W.G.S.; Li, N.; Luitz, S.; Luth, V.; MacFarlane, D.; Messner, R.; Muller, D.R.; Nosochkov, Y.; Novokhatski, A.; Pivi, M.; Ratcliff, B.N.; Roodman, A.; Schwiening, J.; Seeman, J.; Snyder, A.; Sullivan, M.; Va'Vra, J.; Wienands, U.; Wisniewski, W.; Stoeck, H.; Cheng, H.Y.; Li, H.N.; Keum, Y.Y.; Gronau, M.; Grossman, Y.; Bianchi, F.; Gamba, D.; Gambino, P.; Marchetto, F.; Menichetti, Ezio A.; Mussa, R.; Pelliccioni, M.; Dalla Betta, G.F.; Bomben, M.; Bosisio, L.; Cartaro, C.; Lanceri, L.; Vitale, L.; Azzolini, V.; Bernabeu, J.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A.; Paradisi, P.; Pich, A.; Sanchis-Lozano, M.A.; Kowalewski, Robert V.; Roney, J.M.; Back, J.J.; Gershon, T.J.; Harrison, P.F.; Latham, T.E.; Mohanty, G.B.; Petrov, A.A.; Pierini, M.; INFN

    2007-01-01

    The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment.

  3. Time preferences, study effort, and academic performance

    NARCIS (Netherlands)

    Non, J.A.; Tempelaar, D.T.

    2014-01-01

    We analyze the relation between time preferences, study effort, and academic performance among first-year Business and Economics students. Time preferences are measured by stated preferences for an immediate payment over larger delayed payments. Data on study efforts are derived from an electronic

  4. MEASURING THE LUMINOSITY AND VIRIAL BLACK HOLE MASS DEPENDENCE OF QUASAR–GALAXY CLUSTERING AT z ∼ 0.8

    International Nuclear Information System (INIS)

    Krolewski, Alex G.; Eisenstein, Daniel J.

    2015-01-01

    We study the dependence of quasar clustering on quasar luminosity and black hole mass by measuring the angular overdensity of photometrically selected galaxies imaged by the Wide-field Infrared Survey Explorer (WISE) about z ∼ 0.8 quasars from SDSS. By measuring the quasar–galaxy cross-correlation function and using photometrically selected galaxies, we achieve a higher density of tracer objects and a more sensitive detection of clustering than measurements of the quasar autocorrelation function. We test models of quasar formation and evolution by measuring the luminosity dependence of clustering amplitude. We find a significant overdensity of WISE galaxies about z ∼ 0.8 quasars at 0.2–6.4 h −1 Mpc in projected comoving separation. We find no appreciable increase in clustering amplitude with quasar luminosity across a decade in luminosity, and a power-law fit between luminosity and clustering amplitude gives an exponent of −0.01 ± 0.06 (1 σ error). We also fail to find a significant relationship between clustering amplitude and black hole mass, although our dynamic range in true mass is suppressed due to the large uncertainties in virial black hole mass estimates. Our results indicate that a small range in host dark matter halo mass maps to a large range in quasar luminosity

  5. MEASURING THE LUMINOSITY AND VIRIAL BLACK HOLE MASS DEPENDENCE OF QUASAR–GALAXY CLUSTERING AT z ∼ 0.8

    Energy Technology Data Exchange (ETDEWEB)

    Krolewski, Alex G.; Eisenstein, Daniel J., E-mail: akrolewski@college.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2015-04-10

    We study the dependence of quasar clustering on quasar luminosity and black hole mass by measuring the angular overdensity of photometrically selected galaxies imaged by the Wide-field Infrared Survey Explorer (WISE) about z ∼ 0.8 quasars from SDSS. By measuring the quasar–galaxy cross-correlation function and using photometrically selected galaxies, we achieve a higher density of tracer objects and a more sensitive detection of clustering than measurements of the quasar autocorrelation function. We test models of quasar formation and evolution by measuring the luminosity dependence of clustering amplitude. We find a significant overdensity of WISE galaxies about z ∼ 0.8 quasars at 0.2–6.4 h{sup −1} Mpc in projected comoving separation. We find no appreciable increase in clustering amplitude with quasar luminosity across a decade in luminosity, and a power-law fit between luminosity and clustering amplitude gives an exponent of −0.01 ± 0.06 (1 σ error). We also fail to find a significant relationship between clustering amplitude and black hole mass, although our dynamic range in true mass is suppressed due to the large uncertainties in virial black hole mass estimates. Our results indicate that a small range in host dark matter halo mass maps to a large range in quasar luminosity.

  6. Very high-luminosity infrared galaxies - are they very young?

    International Nuclear Information System (INIS)

    Burbidge, G.

    1986-01-01

    It is proposed that most of the very high-luminosity IRAS galaxies, those which emit greater than or equal to 10 to the 12th solar luminosities nearly all in the far infrared out to 100 microns, are very young systems with ages less than or equal to 10 to the 9th years. The luminosity comes largely from stars with masses near 100 solar masses which evolve rapidly, ejecting much of their mass as elements heavier than hydrogen. The gas ejected condenses into dust in circumstellar shells. The prototype star in the Galaxy which shows all of these attributes is Eta Car. It is shown that total masses of order 10 to the 7th-10 to the 8th solar masses condensed into such stars can produce the observed luminosities, and that 10-100 generations of such stars will produce enough dust (about 10 to the 8th solar masses) to explain the observed infrared luminosities. If this hypothesis is correct the composition of gas and dust may well be highly anomalous, and there should be no old stars with ages about 10 to the 10th years present. Initial star formation is probably triggered by interactions with close companion galaxies. 40 references

  7. LOFAR/H-ATLAS: the low-frequency radio luminosity-star formation rate relation

    Science.gov (United States)

    Gürkan, G.; Hardcastle, M. J.; Smith, D. J. B.; Best, P. N.; Bourne, N.; Calistro-Rivera, G.; Heald, G.; Jarvis, M. J.; Prandoni, I.; Röttgering, H. J. A.; Sabater, J.; Shimwell, T.; Tasse, C.; Williams, W. L.

    2018-04-01

    Radio emission is a key indicator of star formation activity in galaxies, but the radio luminosity-star formation relation has to date been studied almost exclusively at frequencies of 1.4 GHz or above. At lower radio frequencies, the effects of thermal radio emission are greatly reduced, and so we would expect the radio emission observed to be completely dominated by synchrotron radiation from supernova-generated cosmic rays. As part of the LOFAR Surveys Key Science project, the Herschel-ATLAS NGP field has been surveyed with LOFAR at an effective frequency of 150 MHz. We select a sample from the MPA-JHU catalogue of Sloan Digital Sky Survey galaxies in this area: the combination of Herschel, optical and mid-infrared data enable us to derive star formation rates (SFRs) for our sources using spectral energy distribution fitting, allowing a detailed study of the low-frequency radio luminosity-star formation relation in the nearby Universe. For those objects selected as star-forming galaxies (SFGs) using optical emission line diagnostics, we find a tight relationship between the 150 MHz radio luminosity (L150) and SFR. Interestingly, we find that a single power-law relationship between L150 and SFR is not a good description of all SFGs: a broken power-law model provides a better fit. This may indicate an additional mechanism for the generation of radio-emitting cosmic rays. Also, at given SFR, the radio luminosity depends on the stellar mass of the galaxy. Objects that were not classified as SFGs have higher 150-MHz radio luminosity than would be expected given their SFR, implying an important role for low-level active galactic nucleus activity.

  8. The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

    Science.gov (United States)

    Schmidt, Burkhard

    2016-04-01

    In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

  9. The galaxy cluster mid-infrared luminosity function at 1.3 < z < 3.2

    Energy Technology Data Exchange (ETDEWEB)

    Wylezalek, Dominika; Vernet, Joël; De Breuck, Carlos [European Southern Observatory, Karl-Schwarzschildstr.2, D-85748 Garching bei München (Germany); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Brodwin, Mark [Department of Physics and Astronomy, University of Missouri, 5110 Rockhill Road, Kansas City, MO 64110 (United States); Galametz, Audrey [INAF-Osservatorio di Roma, Via Frascati 33, I-00040, Monteporzio (Italy); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Jarvis, Matt [Astrophysics, Department of Physics, Keble Road, Oxford OX1 3RH (United Kingdom); Hatch, Nina [School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Seymour, Nick [CASS, P.O. Box 76, Epping, NSW, 1710 (Australia); Stanford, Spencer A. [Physics Department, University of California, Davis, CA 95616 (United States)

    2014-05-01

    We present 4.5 μm luminosity functions for galaxies identified in 178 candidate galaxy clusters at 1.3 < z < 3.2. The clusters were identified as Spitzer/Infrared Array Camera (IRAC) color-selected overdensities in the Clusters Around Radio-Loud AGN project, which imaged 420 powerful radio-loud active galactic nuclei (RLAGNs) at z > 1.3. The luminosity functions are derived for different redshift and richness bins, and the IRAC imaging reaches depths of m* + 2, allowing us to measure the faint end slopes of the luminosity functions. We find that α = –1 describes the luminosity function very well in all redshift bins and does not evolve significantly. This provides evidence that the rate at which the low mass galaxy population grows through star formation gets quenched and is replenished by in-falling field galaxies does not have a major net effect on the shape of the luminosity function. Our measurements for m* are consistent with passive evolution models and high formation redshifts (z{sub f} ∼ 3). We find a slight trend toward fainter m* for the richest clusters, implying that the most massive clusters in our sample could contain older stellar populations, yet another example of cosmic downsizing. Modeling shows that a contribution of a star-forming population of up to 40% cannot be ruled out. This value, found from our targeted survey, is significantly lower than the values found for slightly lower redshift, z ∼ 1, clusters found in wide-field surveys. The results are consistent with cosmic downsizing, as the clusters studied here were all found in the vicinity of RLAGNs—which have proven to be preferentially located in massive dark matter halos in the richest environments at high redshift—and they may therefore be older and more evolved systems than the general protocluster population.

  10. The galaxy cluster mid-infrared luminosity function at 1.3 < z < 3.2

    International Nuclear Information System (INIS)

    Wylezalek, Dominika; Vernet, Joël; De Breuck, Carlos; Stern, Daniel; Brodwin, Mark; Galametz, Audrey; Gonzalez, Anthony H.; Jarvis, Matt; Hatch, Nina; Seymour, Nick; Stanford, Spencer A.

    2014-01-01

    We present 4.5 μm luminosity functions for galaxies identified in 178 candidate galaxy clusters at 1.3 < z < 3.2. The clusters were identified as Spitzer/Infrared Array Camera (IRAC) color-selected overdensities in the Clusters Around Radio-Loud AGN project, which imaged 420 powerful radio-loud active galactic nuclei (RLAGNs) at z > 1.3. The luminosity functions are derived for different redshift and richness bins, and the IRAC imaging reaches depths of m* + 2, allowing us to measure the faint end slopes of the luminosity functions. We find that α = –1 describes the luminosity function very well in all redshift bins and does not evolve significantly. This provides evidence that the rate at which the low mass galaxy population grows through star formation gets quenched and is replenished by in-falling field galaxies does not have a major net effect on the shape of the luminosity function. Our measurements for m* are consistent with passive evolution models and high formation redshifts (z f ∼ 3). We find a slight trend toward fainter m* for the richest clusters, implying that the most massive clusters in our sample could contain older stellar populations, yet another example of cosmic downsizing. Modeling shows that a contribution of a star-forming population of up to 40% cannot be ruled out. This value, found from our targeted survey, is significantly lower than the values found for slightly lower redshift, z ∼ 1, clusters found in wide-field surveys. The results are consistent with cosmic downsizing, as the clusters studied here were all found in the vicinity of RLAGNs—which have proven to be preferentially located in massive dark matter halos in the richest environments at high redshift—and they may therefore be older and more evolved systems than the general protocluster population.

  11. ATLAS physics prospects with the High-Luminosity LHC

    CERN Document Server

    Khanov, Alexander; The ATLAS collaboration

    2016-01-01

    Run-I at the LHC was very successful with the discovery of a new boson of about 125 GeV mass with properties compatible with those of the Higgs boson predicted by Standard Model.Precise measurements of the properties of this new boson, and the search for new physics beyond the Standard Model, are primary goals of the just restarted LHC running at 13 TeV collision energy and all future running at the LHC, including its luminosity upgrade, HL-LHC, that should allow the collection of 3000 fb-1 of data per experiment. The physics prospects with a pp centre-of-mass energy of 14 TeV are presented for 300 and 3000 fb-1. The ultimate precision attainable on measurements of the couplings of the 125 GeV boson to elementary fermions and bosons is discussed, as well as perspectives on the searches for partners associated with it. The electroweak sector is further studied with the analysis of the vector boson scattering, testing the SM predictions. Supersymmetry is one of the best motivated extensions of the Standard Mode...

  12. High-luminosity LHC prospects with the upgraded ATLAS detector

    CERN Document Server

    Slawinska, Magdalena; The ATLAS collaboration

    2016-01-01

    Run-I at the LHC was very successful with the discovery of a new boson with properties compatible with those of the Higgs boson predicted by Standard Model. Precise measurements of the boson properties, and the discovery of physics beyond the Standard Model, are primary goals of the just restarted LHC running at 13 TeV collision energy and all future running at the LHC. The physics prospects with a pp centre-of-mass energy of 14 TeV are presented for 300 and 3000 fb-1 at the high-luminosity LHC. The ultimate precision attainable on measurements of the couplings of the 125 GeV boson to elementary fermions and bosons is discussed, as well as perspectives on the searches for partners associated with it. Supersymmetry is one of the best motivated extensions of the Standard Model. The current searches at the LHC have yielded sensitivity to TeV scale gluinos and 1st and 2nd generation squarks, as well as to 3rd generation squarks and electro-weakinos in the hundreds of GeV mass range. Benchmark studies are presente...

  13. Carrier and symbol synchronization system performance study

    Science.gov (United States)

    Lindsey, W. C.

    1976-01-01

    Results pertinent to predicting the performance of convolutionally encoded binary phase-shift keyed communication links were presented. The details of the development are provided in four sections. These sections are concerned with developing the bit error probability performance degradations due to PN despreading by a time-shared delay locked loop, the Costas demodulation process, symbol synchronization effects and cycle slipping phenomena in the Costas loop. In addition, Costas cycle slipping probabilities are studied as functions of Doppler count time and signal-to-noise conditions. The effect of cycle slipping in the symbol synchronizer is also studied as a function of channel Doppler and other frequency uncertainties.

  14. Solar Luminosity on the Main Sequence, Standard Model and Variations

    Science.gov (United States)

    Ayukov, S. V.; Baturin, V. A.; Gorshkov, A. B.; Oreshina, A. V.

    2017-05-01

    Our Sun became Main Sequence star 4.6 Gyr ago according Standard Solar Model. At that time solar luminosity was 30% lower than current value. This conclusion is based on assumption that Sun is fueled by thermonuclear reactions. If Earth's albedo and emissivity in infrared are unchanged during Earth history, 2.3 Gyr ago oceans had to be frozen. This contradicts to geological data: there was liquid water 3.6-3.8 Gyr ago on Earth. This problem is known as Faint Young Sun Paradox. We analyze luminosity change in standard solar evolution theory. Increase of mean molecular weight in the central part of the Sun due to conversion of hydrogen to helium leads to gradual increase of luminosity with time on the Main Sequence. We also consider several exotic models: fully mixed Sun; drastic change of pp reaction rate; Sun consisting of hydrogen and helium only. Solar neutrino observations however exclude most non-standard solar models.

  15. ATLAS Future Plans: Upgrade and the Physics with High Luminosity

    Directory of Open Access Journals (Sweden)

    Rajagopalan S.

    2013-05-01

    Full Text Available The ATLAS experiment is planning a series of detector upgrades to cope with the planned increases in instantaneous luminosity and multiple interactions per crossing to maintain its physics capabilities. During the coming decade, the Large Hadron Collider will collide protons on protons at a center of mass energy up to 14 TeV with luminosities steadily increasing in a phased approach to over 5 × 1034 cm−2s−1. The resulting large data sets will significantly enhance the physics reach of the ATLAS detector building on the recent discovery of the Higgs-like boson. The planned detector upgrades being designed to cope with the increasing luminosity and its impact on the ATLAS physics program will be discussed.

  16. Reduction of beta* and increase of luminosity at RHIC

    International Nuclear Information System (INIS)

    Pilat, F.; Bai, M.; Bruno, D.; Cameron, P.; Della Penna, A.; Drees, A.; Litvinenko, V.; Luo, Y.; Malitsky, N.; Marr, G.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Trbojevic, D.

    2009-01-01

    The reduction of β* beyond the 1m design value at RHIC has been consistently achieved over the last 6 years of RHIC operations, resulting in an increase of luminosity for different running modes and species. During the recent 2007-08 deuteron-gold run the reduction to 0.70 from the design 1m achieved a 30% increase in delivered luminosity. The key ingredients allowing the reduction have been the capability of efficiently developing ramps with tune and coupling feedback, orbit corrections on the ramp, and collimation, to minimize beam losses in the final focus triplets, the main aperture limitations for the collision optics. We will describe the operational strategy used to reduce the β*, at first squeezing the beam at store, to test feasibility, followed by the operationally preferred option of squeezing the beam during acceleration, and the resulting luminosity increase. We will conclude with future plans for the beta squeeze

  17. Report of the Working Group on High Luminosities at LEP

    International Nuclear Information System (INIS)

    Blucher, E.; Jowett, J.; Merritt, F.; Mikenberg, G.; Panman, J.; Renard, F.M.; Treille, D.

    1991-01-01

    The availability of an order-of-magnitude increase in the luminosity of LEP (CERN's Large Electron-Positron Collider) can dramatically increase its physics output. With the help of a pretzel scheme, it should be possible to increase the peak luminosity beyond 10 32 cm -2 s -1 at the Z energy and to significantly increase the luminosity around the W-pari threshold. This report spells out the physics possibilities opened up by the availability of several 10 7 Z events. The three domains of physics that benefit mostly from this abundance are very accurate measurements of Standard Model parameters, rare decays of the Z, and the physics of fermion-antifermion states such as B physics. The possibilities and implications for the machine and the experiments are presented. The physics possibilities are explored and compared with those at other accelerators. (orig.)

  18. Luminosity Anti-leveling with Crossing Angle (MD 1669)

    CERN Document Server

    Gorzawski, Arkadiusz; Ponce, Laurette; Salvachua Ferrando, Belen Maria; Wenninger, Jorg; CERN. Geneva. ATS Department

    2016-01-01

    A significant fraction of the LHC luminosity ($\\sim$30\\% in 2016) is lost due to the presence (and necessity) of the crossing angles at the IPs. At the LHC the crossing angle is typically set to a value that provides sufficient separation of the beams at the start of fills for the peak bunch intensities. As the bunch intensity decays during a fill, it is possible to reduce the crossing angle and recover some luminosity. A smooth crossing angle reduction procedure must be developed to take advantage of this option during stable beam operation. During this MD a smooth procedure for luminosity leveling with crossing angle was tested. It was demonstrated that the orbit was well controlled, beam losses were low and the offset leveled experiments ALICE and LHCb were not affected by crossing angle leveling in ATLAS and CMS.

  19. Evolution of the cluster x-ray luminosity function slope

    International Nuclear Information System (INIS)

    Henry, J.P.; Soltan, A.; Briel, U.; Gunn, J.E.

    1982-01-01

    We report the results of an X-ray survey of 58 clusters of galaxies at moderate and high redshifts. Using a luminosity-limited subsample of 25 objects, we find that to a redshift of 0.5 the slope (i.e., power-law index) of the luminosity function of distant clusters is independent of redshift and consistent with that of nearby clusters. The time scale for change in the slope must be greater than 9 billion years. We cannot measure the normalization of the luminosity function because our sample is not complete. We discuss the implications of our data for theoretical models. In particular, Perrenod's models with high Ω are excluded by the present data

  20. LUCID Upgrade for ATLAS Luminosity Measurement in Run II.

    CERN Document Server

    Ucchielli, Giulia; The ATLAS collaboration

    2016-01-01

    The main ATLAS luminosity monitor LUCID and its read-out electronics has been completely rebuilt for the 2015 LHC run in order to cope with a higher center of mass energy (13 TeV) and with 25 ns bunch-spacing. The LUCID detector is measuring Cherenkov light produced in photomultiplier quartz windows and in quartz optical fibers. It has a novel calibration system that uses radioactive Bi$^{207}$ sources that produces internal conversion electrons above the Cherenkov threshold in quartz. The new electronics can count particle hits above a threshold but also the integrated pulseheight of the signals from the particles which makes it possible to measure luminosity with new methods. The new detector, calibration system and electronics will be covered by the contribution as well as the results of the luminosity measurements with the detector in 2015.

  1. LUCID Upgrade for ATLAS Luminosity Measurement in Run II

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00444244; The ATLAS collaboration

    2016-01-01

    The main ATLAS luminosity monitor, LUCID, and its read-out electronics have been completely rebuilt for the LHC Run II in order to cope with a higher center of mass energy ($\\sqrt{s}$=13 TeV) and the 25 ns bunch-spacing. The LUCID detector is measuring Cherenkov light produced in photomultiplier quartz windows and in quartz optical fibers. It has a novel calibration system that uses radioactive $^{207}$Bi sources that produce internal-conversion electrons with energy above the Cherenkov threshold in quartz. The new electronics can count signals with amplitude above a predefined threshold (hits) as well as the integrated pulseheight of the signals, which makes it possible to measure luminosity with complementary methods. The new detector, calibration system and electronics will be described, together with the results of the 2015 luminosity measurement.

  2. Luminosity and Redshift dependence of quasar spectral properties

    Energy Technology Data Exchange (ETDEWEB)

    Daniel E. Vanden Berk et al.

    2004-03-09

    Using a large sample of quasar spectra from the SDSS, we examine the composite spectral trends of quasars as functions of both redshift and luminosity, independently of one another. Aside from the well known Baldwin effect (BE)--the decrease of line equivalent width with luminosity--the average spectral properties are remarkably similar. Host galaxy contamination and the BE are the primary causes for apparent changes in the average spectral slope of the quasars. The BE is detected for most emission lines, including the Balmer lines, but with several exceptions including NV1240A. Emission line shifts of several lines are associated with the BE. The BE is mainly a function of luminosity, but also partly a function of redshift in that line equivalent widths become stronger with redshift. Some of the complex iron features change with redshift, particularly near the small blue bump region.

  3. CLIC crab cavity design optimisation for maximum luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Dexter, A.C., E-mail: a.dexter@lancaster.ac.uk [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Burt, G.; Ambattu, P.K. [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Dolgashev, V. [SLAC, Menlo Park, CA 94025 (United States); Jones, R. [University of Manchester, Manchester, M13 9PL (United Kingdom)

    2011-11-21

    The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

  4. MODELING THE RED SEQUENCE: HIERARCHICAL GROWTH YET SLOW LUMINOSITY EVOLUTION

    International Nuclear Information System (INIS)

    Skelton, Rosalind E.; Bell, Eric F.; Somerville, Rachel S.

    2012-01-01

    We explore the effects of mergers on the evolution of massive early-type galaxies by modeling the evolution of their stellar populations in a hierarchical context. We investigate how a realistic red sequence population set up by z ∼ 1 evolves under different assumptions for the merger and star formation histories, comparing changes in color, luminosity, and mass. The purely passive fading of existing red sequence galaxies, with no further mergers or star formation, results in dramatic changes at the bright end of the luminosity function and color-magnitude relation. Without mergers there is too much evolution in luminosity at a fixed space density compared to observations. The change in color and magnitude at a fixed mass resembles that of a passively evolving population that formed relatively recently, at z ∼ 2. Mergers among the red sequence population ('dry mergers') occurring after z = 1 build up mass, counteracting the fading of the existing stellar populations to give smaller changes in both color and luminosity for massive galaxies. By allowing some galaxies to migrate from the blue cloud onto the red sequence after z = 1 through gas-rich mergers, younger stellar populations are added to the red sequence. This manifestation of the progenitor bias increases the scatter in age and results in even smaller changes in color and luminosity between z = 1 and z = 0 at a fixed mass. The resultant evolution appears much slower, resembling the passive evolution of a population that formed at high redshift (z ∼ 3-5), and is in closer agreement with observations. We conclude that measurements of the luminosity and color evolution alone are not sufficient to distinguish between the purely passive evolution of an old population and cosmologically motivated hierarchical growth, although these scenarios have very different implications for the mass growth of early-type galaxies over the last half of cosmic history.

  5. Altered luminosity functions for relativistically beamed objects. II - Distribution of Lorentz factors and parent populations with complex luminosity functions

    International Nuclear Information System (INIS)

    Urry, C.M.; Padovani, P.

    1991-01-01

    In a previous paper, Urry and Shafer (1984) showed that the observed luminosity function (LF) of objects that have part or all of their emission relativistically beamed was a double power law, flat at the faint end and steep at the bright end, so that the ratio of beamed sources to parents was a strong function of luminosity. These calculations are extended here for more realistic LFs required for actual tests of a unified theory of AGN. The observed LF of the beam-dominated objects is generally flatter than the parent LF, so that the number density ratio is a strong function of luminosity and can easily be greater than unity at high luminosities, even for gradual low-luminosity cutoffs in the parent LF. Several characteristic break points can be identified depending on the details of the parent LF. The calculations can be used to test unified theories by predicting the observed LF for aligned objects from the LF of the proposed parent population. 6 refs

  6. Online calculation of the Tevatron collider luminosity using accelerator instrumentation

    International Nuclear Information System (INIS)

    Hahn, A.A.

    1997-07-01

    The luminosity of a collision region may be calculated if one understands the lattice parameters and measures the beam intensities, the transverse and longitudinal emittances, and the individual proton and antiproton beam trajectories (space and time) through the collision region. This paper explores an attempt to make this calculation using beam instrumentation during Run 1b of the Tevatron. The instrumentation used is briefly described. The calculations and their uncertainties are compared to luminosities calculated independently by the Collider Experiments (CDF and D0)

  7. Modified use of Van de Meer method for luminosity determination

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1975-01-01

    Modifications are suggested which should improve the accuracy of the Van de Meer method of determining beam luminosity at the CERN ISR. Four bending magnets would be inserted between the quadrupoles of a given experimental straight section, connected in series, and shimmed so that the machine parameters are not affected. The magnets would be driven with a zigzag current power supply with a uniform rate of current change. Experiments requiring accurate luminosity determination would be run while the deflection magnets are being driven with the oscillatory current pattern. (U.S.)

  8. Electron-positron annihilation at high luminosity colliding beams

    International Nuclear Information System (INIS)

    Grigoryan, G.V.; Khodzhamiryan, A.Yu.

    1977-01-01

    Experiments are discussed, which can be carried out at the electron-positron storage rings with increased luminosity (up to 10 34 cm -2 sec -1 ) and corresponding improvement of detectors at total energy region up to 10 GeV. This improvement of the experimental conditions may provide valuable physical information from the theoretical point of view. The comparison is made with analogous experimental possibilities of the projected high energy e + e - storage rings with luminosity up to 10 32 cm -2 sec -1

  9. The quasar luminosity function from a variability-selected sample

    Science.gov (United States)

    Hawkins, M. R. S.; Veron, P.

    1993-01-01

    A sample of quasars is selected from a 10-yr sequence of 30 UK Schmidt plates. Luminosity functions are derived in several redshift intervals, which in each case show a featureless power-law rise towards low luminosities. There is no sign of the 'break' found in the recent UVX sample of Boyle et al. It is suggested that reasons for the disagreement are connected with biases in the selection of the UVX sample. The question of the nature of quasar evolution appears to be still unresolved.

  10. Luminosity distribution in galaxies. I. The elliptical galaxy NGC 3379 as a luminosity distribution standard

    International Nuclear Information System (INIS)

    de Vaucouleurs, G.; Capaccioli, M.

    1979-01-01

    A standard mean luminosity profile in the B band of the El galaxy NGC 3379 along its east-west x-axis is derived from four sets of medium- and low-resolution photographic and photoelectric McDonald data. The 154 mean points cover a range in excess of 11 mag down to μ/sub B/=27.8 mag arcsec -2 (x=7'.3), with possible detection out to x=16'.3 (μ/sub B/approx. =30.9).The profile is presented within +- 0.08 mag at all x>10'' by μ 1 =14.076+3.0083 x/sup 1/4/ (x in arcsec). Near the center the galaxy is brighter than μ 1 by up to 0.35 mag; the excess can be represented by a Gaussian core μ/sub II/=18.565+0.03965 r 2 (r in arcsec) contributing 19.8% of the integrated magnitude B=11.97 within r* =12'' and 4.0% of the total magnitude B/sub T/=10.225 of the galaxy.This two-component model convolved by the appropriate point spread function represents the data within a standard deviation of 0.04 mag over the whole range. Other analytical formulae give generally poorer fits. There is no evidence for a tidal cutoff or a tidal extension.The integrated magnitudes derived from the model agree with aperture photometry (47 values) within 0.05 mag

  11. Design of the new ATLAS Inner Tracker for the High Luminosity LHC

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2017-01-01

    In the high luminosity era of the Large Hadron Collider (HL-LHC), the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with this high rate, the ATLAS Inner Detector is being completely redesigned, and will be replaced by an all-silicon system, the Inner Tracker (ITk). This new tracker will have both silicon pixel and silicon strip sub-systems. The components of the Inner Tracker will have to be resistant to the large radiation dose from the particles produced in HL-LHC collisions, and have low mass and sufficient sensor granularity to ensure a good tracking performance over the pseudorapidity range |η|<4. In this talk, first the challenges and second possible solutions to these challenges will be discussed, i.e. designs under consideration for the pixel and strip modules, and the mechanics of local supports in the barrel and endcaps.

  12. Design of the new ATLAS Inner Tracker for the High Luminosity LHC era

    CERN Document Server

    Vickey, Trevor; The ATLAS collaboration

    2017-01-01

    Abstract: In the high luminosity era of the Large Hadron Collider (HL-LHC), the instantaneous luminosity is expected to reach unprecedented values, resulting in about 200 proton-proton interactions in a typical bunch crossing. To cope with this high rate, the ATLAS Inner Detector is being completely redesigned, and will be replaced by an all-silicon system, the Inner Tracker (ITk). This new tracker will have both silicon pixel and silicon strip sub-systems. The components of the Inner Tracker will have to be resistant to the large radiation dose from the particles produced in HL-LHC collisions, and have low mass and sufficient sensor granularity to ensure a good tracking performance over the pseudorapidity range |η|<4. In this talk, first the challenges and second possible solutions to these challenges will be discussed, i.e. designs under consideration for the pixel and strip modules, and the mechanics of local supports in the barrel and endcaps.

  13. Low mass hybrid pixel detectors for the high luminosity LHC upgrade

    CERN Document Server

    Gonella, Laura; Desch, Klaus

    2013-11-11

    Reducing material in silicon trackers is of major importance for a good overall detector performance, and poses severe challenges to the design of the tracking system. To match the low mass constraints for trackers in High Energy Physics experiments at high luminosity, dedicated technological developments are required. This dissertation presents three technologies to design low mass hybrid pixel detectors for the high luminosity upgrades of the LHC. The work targets specifically the reduction of the material from the detector services and modules, with novel powering schemes, flip chip and interconnection technologies. A serial powering scheme is prototyped, featuring a new regulator concept, a control and protection element, and AC-coupled data transmission. A modified flip chip technology is developed for thin, large area Front-End chips, and a via last Through Silicon Via process is demonstrated on existing pixel modules. These technologies, their developments, and the achievable material reduction are dis...

  14. Luminosity Measurement at ATLAS Development, Construction and Test of Scintillating Fibre Prototype Detectors

    CERN Document Server

    Ask, S; Braem, André; Cheiklali, C; Efthymiopoulos, I; Fournier, D; de La Taille, C; Di Girolamo, B; Grafström, P; Joram, C; Haguenauer, Maurice; Hedberg, V; Lavigne, B; Maio, A; Mapelli, A; Mjörnmark, U; Puzo, P; Rijssenbeek, M; Santos, J; Saraiva, J G; Stenzel, H; Thioye, M; Valladolid, E; Vorobel, V

    2006-01-01

    We are reporting about a scintillating fibre tracking detector which is proposed for the precise determination of the absolute luminosity of the CERN LHC at interaction point 1 where the ATLAS experiment is located. The detector needs to track protons elastically scattered under $\\mu$rad angles in direct vicinity to the LHC beam. It is based on square shaped scintillating plastic fibres read out by multi-anode photomultiplier tubes and is housed in Roman Pots. We describe the design and construction of prototype detectors and the results of a beam test experiment at DESY. The excellent detector performance established in this test validates the detector design and supports the feasibility of the proposed challenging method of luminosity measurement.

  15. On the correlation between radio and gamma-ray luminosities of active galactic nuclei

    DEFF Research Database (Denmark)

    Mücke, A.; Pohl, M.

    1997-01-01

    in flux-limited samples if intrinsic scatter does not exceed similar to 40 % of the original gamma-ray luminosity. However, if mean flux values of high variable sources are used we find the chance probability of high Spearman's correlation coefficient be significant underestimated. The analysis presented......The possibility of a correlation between the radio (cm)- and gamma-ray luminosity of variable AGN seen by EGRET is investigated. We perform Monte-Carlo simulations of typical data sets and apply different correlation techniques (partial correlation analysis, chi(2)-test applied on flux......-flux relations) in view of a truncation bias caused by sensitivity limits of the surveys. For K-corrected flux densities, we find that with the least squares method only a linear correlation can be recovered. Partial correlation analysis on the other side provides a robust tool to detect correlations even...

  16. Tracking with wire chambers at high luminosities

    International Nuclear Information System (INIS)

    Hanson, G.G.

    1989-12-01

    Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs

  17. EVA Health and Human Performance Benchmarking Study

    Science.gov (United States)

    Abercromby, A. F.; Norcross, J.; Jarvis, S. L.

    2016-01-01

    Multiple HRP Risks and Gaps require detailed characterization of human health and performance during exploration extravehicular activity (EVA) tasks; however, a rigorous and comprehensive methodology for characterizing and comparing the health and human performance implications of current and future EVA spacesuit designs does not exist. This study will identify and implement functional tasks and metrics, both objective and subjective, that are relevant to health and human performance, such as metabolic expenditure, suit fit, discomfort, suited postural stability, cognitive performance, and potentially biochemical responses for humans working inside different EVA suits doing functional tasks under the appropriate simulated reduced gravity environments. This study will provide health and human performance benchmark data for humans working in current EVA suits (EMU, Mark III, and Z2) as well as shirtsleeves using a standard set of tasks and metrics with quantified reliability. Results and methodologies developed during this test will provide benchmark data against which future EVA suits, and different suit configurations (eg, varied pressure, mass, CG) may be reliably compared in subsequent tests. Results will also inform fitness for duty standards as well as design requirements and operations concepts for future EVA suits and other exploration systems.

  18. Building Enclosure Hygrothermal Performance Study, Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Karagiozis, A.N.

    2002-08-08

    The moisture performance of three different classes of wall systems has been investigated in the context of the preliminary hygrothermal analysis of walls in Seattle. The results reported in this phase specifically address the moisture performance of walls designed with loads that have some unintentional water penetration. The results have been developed in a manner to present the relative performance of the walls in the same climate with similar water penetration effects. The analysis was performed with the best available input data. Several limitations should be recognized within the context of this study. Results showed that selection of wooden sheathing boards on interior vapor-tight assemblies does not significantly influence the performance of stucco-clad walls. A larger effect was observed when the interior vapor control is made vapor open. When continuous cavity ventilation is employed, the effect of the selection of the type of sheathing board on the hygrothermal performance of the wall was found to be negligible. When comparing oriented strand board sheathing performance against the performance of exterior grade gypsum, the differences are very significant in terms of the amount of moisture content present in the walls. Moisture content alone does not indicate their respective durability as durability is directly related to the combination of relative humidity and temperature, mechanical, chemical, and biological properties of the substrates. This study did not investigate the durability performance of either sheathing. In terms of interior vapor control, inhabitant behavior must be considered during the wall hygrothermal design stage. If interior relative humidity is maintained below 60%, then a latex primer and paint may perform better than the use of PVA or even a polyethylene sheet. When the interior environment is maintained at a higher relative humidity, then stricter vapor control is needed. Multilayered building paper was experimentally shown to

  19. Performances Study of a Hybrid Rocket Engine

    Directory of Open Access Journals (Sweden)

    Adrian-Nicolae BUTURACHE

    2018-06-01

    Full Text Available This paper presents a study which analyses the functioning and performances optimization of a hybrid rocket engine based on gaseous oxygen and polybutadiene polymer (HTPB. Calculations were performed with NASA CEA software in order to obtain the parameters resulted following the combustion process. Using these parameters, the main parameters of the hybrid rocket engine were optimized. Using the calculus previously stated, an experimental rocket engine producing 100 N of thrust was pre-dimensioned, followed by an optimization of the rocket engine as a function of several parameters. Having the geometry and the main parameters of the hybrid rocket engine combustion process, numerical simulations were performed in the CFX – ANSYS commercial software, which allowed visualizing the flow field and the jet expansion. Finally, the analytical calculus was validated through numerical simulations.

  20. Development of the Continuous Acquisition Pixel (CAP) sensor for high luminosity lepton colliders

    International Nuclear Information System (INIS)

    Varner, G.; Aihara, H.; Barbero, M.; Bozek, A.; Browder, T.; Hazumi, M.; Kennedy, J.; Martin, E.; Mueller, J.; Olsen, S.; Palka, H.; Rosen, M.; Ruckman, L.; Stanic, S.; Trabelsi, K.; Tsuboyama, T.; Uchida, K.; Yang, Q.; Yarema, R.

    2006-01-01

    A future higher luminosity B-factory detector and concept study detectors for the proposed International Linear Collider require precision vertex reconstruction while coping with high track densities and radiation exposures. Compared with current silicon strip and hybrid pixels, a significant reduction in the overall detector material thickness is needed to achieve the desired vertex resolution. Considerable progress in the development of thin CMOS-based Monolithic Active Pixel Sensors (MAPS) in recent years makes them a viable technology option and feasibility studies are being actively pursued. The most serious concerns are their radiation hardness and their readout speed. To address these, several prototypes denoted as the Continuous Acquisition Pixel (CAP) sensors have been developed and tested. The latest of the CAP sensor prototypes is CAP3, designed in the TSMC 0.25μm process with a 5-deep Correlated Double Sample (CDS) pair pipeline in each pixel. A setup with several CAP3 sensors is under evaluation to assess the performance of a full-scale pixel readout system running at realistic readout speed. Given the similarity in the occupancy numbers and hit throughput requirements, per unit area, between a Belle vertex detector upgradation and the requirements for a future ILC pixel detector, this effort can be considered a small-scale functioning prototype for such a future system. The results and plans for the next stages of R and D towards a full Belle Pixel Vertex Detector (PVD) are presented

  1. Flat bunch creation and acceleration: a possible path for the LHC luminosity upgrade

    International Nuclear Information System (INIS)

    Bhat, C.M.

    2009-01-01

    Increasing the collider luminosity by replacing bunches having Gaussian line-charge distribution with flat bunches, but with same beam-beam tune shift at collision, has been studied widely in recent years. But, creation of 'stable' flat bunches (and their acceleration) using a multiple harmonic RF system has not been fully explored. Here, we review our experience with long flat bunches in the barrier RF buckets at Fermilab.We presentsome preliminary results from beam dynamics simulations and recent beam studies in the LHC injectors to create stable flat bunches using double harmonic RF systems. The results deduced from these studies will be used to model the necessary scheme for luminosity upgrade in the LHC. We have also described a viable (and economical) way for creation and acceleration of flat bunches in the LHC. The flat bunch scheme may have many advantages over the LHC baseline scenario, particularly because of the reduced momentum spread of the bunch for increased intensities.

  2. Comparative Study of the Tuning Performances of the Nominal and Long L* CLIC Final Focus System at √s = 380 GeV

    CERN Document Server

    Plassard, F; Marin, E; Tomás, R

    2017-01-01

    Mitigation of static imperfections for emittance preservation is one of the most important and challenging tasks faced by the Compact Linear Collider (CLIC) beam delivery system. A simulation campaign has been performed to recover the nominal luminosity by means of different alignment procedures. The state of the art of the tuning studies is drawn up. Comparative studies of the tuning performances and a tuning-based final focus system design optimization for two L options are presented. The effectiveness of the tuning techniques applied to these different lattices will be decisive for the final layout of the CLIC final focus system at √s = 380 GeV.

  3. Physics of a high-luminosity Tau-Charm Factory

    International Nuclear Information System (INIS)

    King, M.E.

    1992-10-01

    This paper highlights the physics capabilities of a Tau-Charm Factory; i.e., high luminosity (∼10 33 cm -2 s -1 ) e + e - collider operating in the center-of-mass energy range of 3-5 GeV, with a high-precision, general-purpose detector. Recent developments in τ and charm physics are emphasized

  4. Attaining high luminosity in linear e+e- colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.

    1990-11-01

    The attainment of high luminosity in linear colliders is a complex problem because of the interdependence of the critical parameters. For instance, changing the number of particles per bunch affects the damping ring design and thus the emittance; it affects the wakefields in the linac and thus the momentum spread; the momentum spread affects the final focus design and thus the final β*; but the emittance change also affects the final focus design; and all these come together to determine the luminosity, disruption and beamstrahlung at the intersection. Changing the bunch length, or almost any other parameter, has a similar chain reaction. Dealing with this problem by simple scaling laws is very difficult because one does not know which parameter is going to be critical, and thus which should be held constant. One can only maximize the luminosity by a process of search and iteration. The process can be facilitated with the aid of a computer program. Examples can then be optimized for maximum luminosity, and compared to the optimized solutions with different approaches. This paper discusses these approaches

  5. Gauge-invariance and infrared divergences in the luminosity distance

    Energy Technology Data Exchange (ETDEWEB)

    Biern, Sang Gyu; Yoo, Jaiyul, E-mail: sgbiern@physik.uzh.ch, E-mail: jyoo@physik.uzh.ch [Center for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich (Switzerland)

    2017-04-01

    Measurements of the luminosity distance have played a key role in discovering the late-time cosmic acceleration. However, when accounting for inhomogeneities in the Universe, its interpretation has been plagued with infrared divergences in its theoretical predictions, which are in some cases used to explain the cosmic acceleration without dark energy. The infrared divergences in most calculations are artificially removed by imposing an infrared cut-off scale. We show that a gauge-invariant calculation of the luminosity distance is devoid of such divergences and consistent with the equivalence principle, eliminating the need to impose a cut-off scale. We present proper numerical calculations of the luminosity distance using the gauge-invariant expression and demonstrate that the numerical results with an ad hoc cut-off scale in previous calculations have negligible systematic errors as long as the cut-off scale is larger than the horizon scale. We discuss the origin of infrared divergences and their cancellation in the luminosity distance.

  6. ATLAS Plans for the High-Luminosity LHC

    CERN Document Server

    Walkowiak, Wolfgang; The ATLAS collaboration

    2018-01-01

    In this talk for BEAUTY 2018 the ATLAS upgrade plans for the high-luminosity phase of the LHC are presented. Especially, prospects for the flagship B physics analyses $B_s^0 \\to J/\\psi \\phi$ (with $J/\\psi \\to \\mu^+\\mu^-$) and $B_{(s)}^0 \\to \\mu^+\\mu^-$ analyses are discussed.

  7. TOTAL INFRARED LUMINOSITY ESTIMATION OF RESOLVED AND UNRESOLVED GALAXIES

    International Nuclear Information System (INIS)

    Boquien, M.; Calzetti, D.; Bendo, G.; Dale, D.; Engelbracht, C.; Kennicutt, R.; Lee, J. C.; Van Zee, L.; Moustakas, J.

    2010-01-01

    The total infrared (TIR) luminosity from galaxies can be used to examine both star formation and dust physics. We provide here new relations to estimate the TIR luminosity from various Spitzer bands, in particular from the 8 μm and 24 μm bands. To do so, we use data for 45'' subregions within a subsample of nearby face-on spiral galaxies from the Spitzer Infrared Nearby Galaxies Survey (SINGS) that have known oxygen abundances as well as integrated galaxy data from the SINGS, the Local Volume Legacy survey (LVL), and Engelbracht et al. samples. Taking into account the oxygen abundances of the subregions, the star formation rate intensity, and the relative emission of the polycyclic aromatic hydrocarbons at 8 μm, the warm dust at 24 μm, and the cold dust at 70 μm and 160 μm, we derive new relations to estimate the TIR luminosity from just one or two of the Spitzer bands. We also show that the metallicity and the star formation intensity must be taken into account when estimating the TIR luminosity from two wave bands, especially when data longward of 24 μm are not available.

  8. The Evolution of the Type Ia Supernova Luminosity Function

    NARCIS (Netherlands)

    Shen, K.J.; Toonen, S.; Graur, O.

    2017-01-01

    Type Ia supernovae (SNe Ia) exhibit a wide diversity of peak luminosities and light curve shapes: the faintest SNe Ia are 10 times less luminous and evolve more rapidly than the brightest SNe Ia. Their differing characteristics also extend to their stellar age distributions, with fainter SNe Ia

  9. Gauge-invariance and infrared divergences in the luminosity distance

    International Nuclear Information System (INIS)

    Biern, Sang Gyu; Yoo, Jaiyul

    2017-01-01

    Measurements of the luminosity distance have played a key role in discovering the late-time cosmic acceleration. However, when accounting for inhomogeneities in the Universe, its interpretation has been plagued with infrared divergences in its theoretical predictions, which are in some cases used to explain the cosmic acceleration without dark energy. The infrared divergences in most calculations are artificially removed by imposing an infrared cut-off scale. We show that a gauge-invariant calculation of the luminosity distance is devoid of such divergences and consistent with the equivalence principle, eliminating the need to impose a cut-off scale. We present proper numerical calculations of the luminosity distance using the gauge-invariant expression and demonstrate that the numerical results with an ad hoc cut-off scale in previous calculations have negligible systematic errors as long as the cut-off scale is larger than the horizon scale. We discuss the origin of infrared divergences and their cancellation in the luminosity distance.

  10. The luminosity function and formation rate history of GRBs

    International Nuclear Information System (INIS)

    Firmani, C.; Avila-Reese, V.; Ghisellini, G.; Tutukov, A.V.

    2005-01-01

    The isotropic luminosity function (LF) and formation rate history (FRH) of long GRBs is by the first time constrained by using jointly both the observed GRB peak-flux and redshift distributions. Our results support an evolving LF and a FRH that keeps increasing after z = 2. We discuss some interesting implications related to these results

  11. Pixel-Cluster Counting Luminosity Measurement in ATLAS

    CERN Document Server

    McCormack, William Patrick; The ATLAS collaboration

    2016-01-01

    A precision measurement of the delivered luminosity is a key component of the ATLAS physics program at the Large Hadron Collider (LHC). A fundamental ingredient of the strategy to control the systematic uncertainties affecting the absolute luminosity has been to compare the measurements of several luminometers, most of which use more than one counting technique. The level of consistency across the various methods provides valuable cross-checks as well as an estimate of the detector-related systematic uncertainties. This poster describes the development of a luminosity algorithm based on pixel-cluster counting in the recently installed ATLAS inner b-layer (IBL), using data recorded during the 2015 pp run at the LHC. The noise and background contamination of the luminosity-associated cluster count is minimized by a multi-component fit to the measured cluster-size distribution in the forward pixel modules of the IBL. The linearity, long-term stability and statistical precision of the cluster-counting method are ...

  12. Pixel-Cluster Counting Luminosity Measurement In ATLAS

    CERN Document Server

    AUTHOR|(SzGeCERN)782710; The ATLAS collaboration

    2017-01-01

    A precision measurement of the delivered luminosity is a key component of the ATLAS physics program at the Large Hadron Collider (LHC). A fundamental ingredient of the strategy to control the systematic uncertainties affecting the absolute luminosity has been to compare the measure- ments of several luminometers, most of which use more than one counting technique. The level of consistency across the various methods provides valuable cross-checks as well as an estimate of the detector-related systematic uncertainties. This poster describes the development of a luminosity algorithm based on pixel-cluster counting in the recently installed ATLAS inner b-layer (IBL), using data recorded during the 2015 pp run at the LHC. The noise and background contamination of the luminosity-associated cluster count is minimized by a multi-component fit to the measured cluster-size distribution in the forward pixel modules of the IBL. The linearity, long-term stability and statistical precision of the cluster- counting method a...

  13. The Radius-Luminosity Relationship for Active Galactic Nuclei

    DEFF Research Database (Denmark)

    Bentz, Misty C.; Peterson, Bradley M.; Netzer, Hagai

    2009-01-01

    We present high-resolution HST images of all 35 AGNs with optical reverberation-mapping results, which we have modeled to create a nucleus-free image of each AGN host galaxy. From the nucleus-free images, we determine the host-galaxy contribution to ground-based spectroscopic luminosity measureme...

  14. The Radius-Luminosity Relationship for Active Galactic Nuclei

    DEFF Research Database (Denmark)

    Bentz, Misty C.; Peterson, Bradley M.; Pogge, Richard W.

    2006-01-01

    We have obtained high resolution images of the central regions of 14 reverberation-mapped active galactic nuclei (AGN) using the Hubble Space Telescope Advanced Camera for Surveys High Resolution Camera to account for host-galaxy starlight contamination of measured AGN luminosities. We measure th...

  15. NGC 5548 in a Low-Luminosity State

    DEFF Research Database (Denmark)

    Bentz, Misty C.; Denney, Kelly D.; Cackett, Edward M.

    2007-01-01

    between the luminosity and the time lag in NGC 5548 and measure a slope that is consistent with alpha = 0.5, the naive expectation for the broad line region for an assumed form of r ~ L^alpha. This value is also consistent with the slope recently determined by Bentz et al. for the population...

  16. Fast and precise luminosity measurement at the international linear ...

    Indian Academy of Sciences (India)

    6. — journal of. December 2007 physics pp. 1151–1157. Fast and precise luminosity measurement ... The fast investigation of the collision quality for intrabunch feedback and the ... consisting of the sensor, the absorber and an interconnection structure. 2. ... outer radius of BeamCal is increased to keep the angular overlap.

  17. Spectral-luminosity evolution of active galactic nuclei (AGN)

    Science.gov (United States)

    Leiter, Darryl; Boldt, Elihu

    1992-01-01

    The origin of the cosmic X-ray and gamma-ray backgrounds is explained via the mechanism of AGN spectral-luminosity evolution. The spectral evolution of precursor active galaxies into AGN, and Newton-Raphson input and output parameters are discussed.

  18. Fast and precise luminosity measurement at the international linear

    Indian Academy of Sciences (India)

    The detectors of the ILC will feature a calorimeter system in the very forward region. The system comprises mainly two electromagnetic calorimeters: LumiCal, which is dedicated to the measurement of the absolute luminosity with highest precision and BeamCal, which uses the energy deposition from beamstrahlung pairs ...

  19. A Size-Luminosity Relationship for Protoplanetary Disks in Lupus

    Science.gov (United States)

    Terrell, Marie; Andrews, Sean

    2018-01-01

    The sizes of the 340 GHz continuum emission from 56 protoplanetary disks in the Lupus star-forming region were measured by modeling their ALMA visibility profiles. We describe the mechanism for these measurements and some preliminary results regarding the correlation between the continuum luminosities and sizes.

  20. A new record peak luminosity for the LHC

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Two weeks of dedicated machine development paid off last weekend when the LHC ran for physics with three nominal intensity (∼1011 protons) bunches in each beam.   This brought a new record peak luminosity of around 8×1029 cm-2 s-1, and allowed the LHC to double the integrated luminosity delivered to the experiments since 30 March from 16 to 32 inverse nanobarns over the weekend. After a few more fills in this configuration, the number of bunches will be raised to six per beam, which will in turn allow the peak luminosity to break the 1030 cm-2 s-1 barrier for the first time, well on the way to achieving the 2010 objective of 1032 cm-2 s-1. This peak luminosity goal requires 800 nominal bunches per beam squeezed to a beta of 3.5 metres. The plan for 2011 is to run the LHC in this configuration over about 10 months, thus achieving the objective of recording one inverse femtobarn of data in total. The machine development period also allowed the TOTEM detectors to be set up with 45...

  1. Upgrade of the CMS Tracker for the High Luminosity LHC

    CERN Document Server

    Auzinger, Georg

    2016-01-01

    The LHC machine is planning an upgrade program which will smoothly bring the luminosity to about $ 5 \\times 10^{34}$cm$^{-2}$s$^{-1}$ in 2028, possibly reaching an integrated luminosity of 3000 fb$^{-1}$ by the end of 2037. This High Luminosity LHC scenario, HL-LHC, will require a preparation program of the LHC detectors known as Phase-2 Upgrade. The current CMS Tracker, including both inner pixel and outer strip systems, is already running beyond design specifications and will not be able to survive HL-LHC radiation conditions. CMS will need a completely new device in order to fully exploit the demanding operating conditions and the delivered luminosity. The upgrade plan includes extending the Pixel Detector in the forward region from the current coverage of $ \\lvert \\eta \\rvert < 2.4 $ to $ \\lvert \\eta \\rvert < 4$, where up to seven forward- and four extension disks will compose the new detector. Additionally, the new outer system should also have trigger capabilities. To achieve such goals, R\\&...

  2. Machine constraints for experiments in an intermediate luminosity interaction region

    International Nuclear Information System (INIS)

    Groom, D.

    1989-05-01

    We summarize existing information about the luminosity as a function of clear space between the interaction point and the front of the final-focus triplet, and about the minimum beam pipe dimensions (stay-clear dimensions) in the region. 7 refs., 4 figs., 1 tab

  3. Introductory Overview of Intermediate-luminosity X-ray Objects

    Science.gov (United States)

    Colbert, E. J. M.

    2001-05-01

    Intermediate-luminosity X-ray Objects (IXOs) are defined as compact objects having X-ray luminosities between those of X-ray binaries and low-luminosity AGNs (i.e., 1039.0 erg s-1 < ~ LX [IXOs] < ~ 1041.0 erg s-1). It is not currently known if these objects are intermediate-mass (M ~ 102-104 Msun) black holes accreting near the Eddington limit, near-solar-mass black holes in a super-Eddington state, or are, in some cases, just supermassive black holes accreting at very low rates. However, the first idea has been popularized by recent press coverage. IXOs are quite common (present in about half of spiral galaxies) and are typically found displaced from the optical nucleus, reducing the likelihood that they are low-luminosity AGN. Nearly all of our knowledge of these objects comes from X-ray observations, as observations of optical, NIR and radio counterparts are not widely known. In this session, we will address (1) the phenomenology of the objects, (2) possible geometry and accretion mechanisms for these objects (i.e., are they more similar to black hole X-ray binaries or AGNs), (3) the central black hole masses, and (4) the formation mechanism for these black holes, if they are of intermediate mass. In this talk, I will focus primarily on giving background information of these fascinating objects.

  4. A Single Bremsstrahlung Monitor to Measure Luminosity at LEP

    CERN Multimedia

    2002-01-01

    The luminosity, the beam divergence and the longitudinal polarization can be measured at an interaction point of LEP by dectecting the energy, the angular distribution and the circular polarization of the single bremsstrahlung photons (SB) emitted at very forward angle. The luminosity can be measured by this met than by the conventional method of detecting small angle Bhabha scattering. The bunch to bunch relative luminosity can be monitored at a few per mil level in few minutes. Absolute values of the luminosity and of the polarization can be measured with a precision of the order of 1\\%. \\\\ \\\\ The apparatus to detect SB photons consists of a low Z absorber and of an EM calorimeter made of lead and scintillating fibres. Both the total energy and the space distribution of the SB photons are measured. This apparatus has been designed and built at the Department of Physics and INFN Section of the University of Rome ``La Sapienza''. Later on, together with suitable monocrystal converters, it may be used also for...

  5. Upgraded Fast Beam Conditions Monitor for CMS online luminosity measurement

    CERN Document Server

    Leonard, Jessica Lynn; Hempel, Maria; Henschel, Hans; Karacheban, Olena; Lange, Wolfgang; Lohmann, Wolfgang; Novgorodova, Olga; Penno, Marek; Walsh, Roberval; Dabrowski, Anne; Guthoff, Moritz; Loos, R; Ryjov, Vladimir; Burtowy, Piotr; Lokhovitskiy, Arkady; Odell, Nathaniel; Przyborowski, Dominik; Stickland, David P; Zagozdzinska, Agnieszka

    2014-01-01

    The CMS beam condition monitoring subsystem BCM1F during LHC Run I consisted of 8 individual diamond sensors situated around the beam pipe within the tracker detector volume, for the purpose of fast monitoring of beam background and collision products. Effort is ongoing to develop the use of BCM1F as an online bunch-by-bunch luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. To prepare for the expected increase in the LHC luminosity and the change from 50 ns to 25 ns bunch separation, several changes to the system are required, including a higher number of sensors and upgraded electronics. In particular, a new real-time digitizer with large memory was developed and is being integrated into a multi-subsystem framework for luminosity measurement. Current results from Run II preparation will be discussed, including results from the January 201...

  6. Upgraded Fast Beam Conditions Monitor for CMS online luminosity measurement

    CERN Document Server

    Leonard, Jessica Lynn

    2014-01-01

    The CMS beam and radiation monitoring subsystem BCM1F during LHC Run I consisted of 8 individual diamond sensors situated around the beam pipe within the tracker detector volume, for the purpose of fast monitoring of beam background and collision products. Effort is ongoing to develop the use of BCM1F as an online bunch-by-bunch luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. To prepare for the expected increase in the LHC luminosity and the change from 50 ns to 25 ns bunch separation, several changes to the system are required, including a higher number of sensors and upgraded electronics. In particular, a new real-time digitizer with large memory was developed and is being integrated into a multi-subsystem framework for luminosity measurement. Current results from Run II preparation will be shown, including results from the January 201...

  7. Pulsation of high luminosity helium stars

    International Nuclear Information System (INIS)

    King, D.S.; Wheeler, J.C.; Cox, J.P.; Cox, A.N.; Hodson, S.W.

    1979-01-01

    Preliminary calculations are made on a systematic restudy of the linear and nonlinear pulsations of helium stars allowing for more recent and higher estimates of the effective temperature and for the high carbon abundance. Linear and nonlinear models are used. Results show qualitative agreement with earlier ones, models with sufficiently large L/M have a very hot blue edge for their instability strip, very large L/M values lead to dynamically unstable models which would appear to eject mass and therefore may not be realistic models for the pulsating RCrB stars, for the sequence studied a reasonable mass could be greater than or equal to 1.5 Msub solar. 12 references

  8. The V Band Empirical Mass-Luminosity Relation for Main Sequence Stars

    Science.gov (United States)

    Xia, F.; Fu, Y. N.

    2010-01-01

    Stellar mass is an indispensable parameter in the studies of stellar physics and stellar dynamics. On the one hand, the most reliable way to determine the stellar dynamical mass is via orbital determination of binaries. On the other hand, however, most stellar masses have to be estimated by using the mass-luminosity relation (MLR). Therefore, it is important to obtain the empirical MLR through fitting the data of stellar dynamical mass and luminosity. The effect of metallicity can make this relation disperse in the V-band, but studies show that this is mainly limited to the case when the stellar mass is less than 0.6M⊙. Recently, many relevant data have been accumulated for main sequence stars with larger mass, which make it possible to significantly improve the corresponding MLR. Using a fitting method which can reasonably assign weight to the observational data including two quantities with different dimensions, we obtain a V-band MLR based on the dynamical masses and luminosities of 203 main sequence stars. Compared with the previous work, the improved MLR is statistically significant, and the relative error of mass estimation reaches about 5%. Therefore, our MLR is useful not only in studies of statistical nature, but also in studies of concrete stellar systems, such as the long-term dynamical study and the short-term positioning study of a specific multiple star system.

  9. The V-band Empirical Mass-luminosity Relation for Main Sequence Stars

    Science.gov (United States)

    Xia, Fang; Fu, Yan-Ning

    2010-07-01

    Stellar mass is an indispensable parameter in the studies of stellar physics and stellar dynamics. On the one hand, the most reliable way to determine the stellar dynamical mass is via orbital determinations of binaries. On the other hand, however, most stellar masses have to be estimated by using the mass luminosity relation (MLR). Therefore, it is important to obtain the empirical MLR through fitting the data of stellar dynamical mass and luminosity. The effect of metallicity can make this relation disperse in the V-band, but studies show that this is mainly limited to the case when the stellar mass is less than 0.6M⊙ Recently, many relevant data have been accumulated for main sequence stars with larger masses, which make it possible to significantly improve the corresponding MLR. Using a fitting method which can reasonably assign weights to the observational data including two quantities with different dimensions, we obtain a V-band MLR based on the dynamical masses and luminosities of 203 main sequence stars. In comparison with the previous work, the improved MLR is statistically significant, and the relative error of mass estimation reaches about 5%. Therefore, our MLR is useful not only in the studies of statistical nature, but also in the studies of concrete stellar systems, such as the long-term dynamical study and the short-term positioning study of a specific multiple star system.

  10. Performable Case Studies in Ethics Education.

    Science.gov (United States)

    Robeson, Richard; King, Nancy M P

    2017-09-12

    Bioethics education often includes the study of short stories, novels, plays, and films, because such materials present case examples that can highlight relevant issues and questions especially vividly for a wide range of students. In addition, creative writing is widely used in the education of health professional students and in continuing education settings for health professionals. There are very few academic or professional disciplines that do not use case studies, but the case study in dialogic form has not been standard practice for thousands of years. Dramatic arts casuistry-the creation and performance of short case studies designed specifically to raise bioethics issues for discussion-represents an application of literature and the medical humanities that is both unique and uniquely valuable. This essay describes the development and history of a course that has been successfully taught to medical students and graduate bioethics students, in which the class researches, writes, and performs a case study designed to elicit reflection and discussion about a topic and set of bioethics issues of current interest to both academic and general audiences. The model is also suited to the presentation and discussion of existing case studies, both live and via on-demand audio.

  11. Beam dynamics issues of high-luminosity asymmetric collider rings

    International Nuclear Information System (INIS)

    Sessler, A.M.

    1990-01-01

    Machines for use in high-energy physics are advancing along two frontiers. First, there is the frontier of energy, currently being pressed by the Fermilab collider (p bar p), and SLC and LEP (e + e - ) and in the near future by HERA (ep), the LHC, and the SSC (pp). Second, there is the frontier of intensity, currently being pressed by a variety of low-energy machines and, at higher energies, by various linacs such as those at KEK. Fermilab, GSI, and LAMPF (p) and CEBAF (e - ). In the future there should be, along this frontier, various ''factories'' such as those for Kaons at TRIUMF, and those proposed for var-phi mesons, τ-charm particles, and B mesons. It is with the intensity frontier that these proceedings are concerned. The elementary particle motivation to study the nonconservation of PC in the B-stringB system (which topic is not covered in these Proceedings, but is treated extensively in the literature) has motivated the study of very high intensity asymmetric collider rings. It was for this purpose that a Workshop on Beam Dynamics Issues of High-Luminosity Asymmetric Collider Rings was held, in Berkeley, during February 12--16, 1990. A general introduction to the subject has been given in an article which is reprinted here as an Appendix. The nonexpert may wish to start there. The volume consists of four parts. The first part consists of Summaries; first an overall summary of the Workshop and then, second, more detailed summaries from each of the working groups. The second part consists of the Invited Talks at the workshop. The third part contains various Contributed Papers, most of which represent work that came out of the workshop. Finally, there are, in the fourth part, brief Summaries of the Various Proposed B-Factory Projects in the world

  12. Conceptual design of the cryostat for the new high luminosity (HL-LHC) triplet magnets

    Science.gov (United States)

    Ramos, D.; Parma, V.; Moretti, M.; Eymin, C.; Todesco, E.; Van Weelderen, R.; Prin, H.; Berkowitz Zamora, D.

    2017-12-01

    The High Luminosity LHC (HL-LHC) is a project to upgrade the LHC collider after 2020-2025 to increase the integrated luminosity by about one order of magnitude and extend the physics production until 2035. An upgrade of the focusing triplets insertion system for the ATLAS and CMS experiments is foreseen using superconducting magnets operating in a pressurised superfluid helium bath at 1.9 K. This will require the design and construction of four continuous cryostats, each about sixty meters in length and one meter in diameter, for the final beam focusing quadrupoles, corrector magnets and beam separation dipoles. The design is constrained by the dimensions of the existing tunnel and accessibility restrictions imposing the integration of cryogenic piping inside the cryostat, thus resulting in a very compact integration. As the alignment and position stability of the magnets is crucial for the luminosity performance of the machine, the magnet support system must be carefully designed in order to cope with parasitic forces and thermo-mechanical load cycles. In this paper, we present the conceptual design of the cryostat and discuss the approach to address the stringent and often conflicting requirements of alignment, integration and thermal aspects.

  13. Upgrade of the ATLAS Liquid Argon Calorimeters for the High-Luminosity LHC

    CERN Document Server

    McCarthy, Tom; The ATLAS collaboration

    2016-01-01

    The increased particle flux at the high luminosity phase of the Large Hadron Collider (HL-LHC), with instantaneous luminosities of up to 7.5 times the original design value, will have an impact on many sub-systems of the ATLAS detector. This contribution highlights the particular impacts on the ATLAS liquid argon calorimeter system, together with an overview of the various upgrade plans leading up to the HL-LHC. The higher luminosities are of particular importance for the forward calorimeters (FCal), where the expected increase in the ionization load poses a number of problems that can degrade the FCal performance such as beam heating and space-charge effects in the liquid argon gaps and high-voltage drop due to increased current drawn over the current-limiting resistors. A proposed FCal replacement as a way to counter some of these problems is weighed against the risks associated with the replacement. To further mitigate the effects of increased pile-up, the installation of a high-granularity timing detector...

  14. D0 central tracking chamber performance studies

    International Nuclear Information System (INIS)

    Pizzuto, D.

    1991-12-01

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an RΦ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against γ → e + e - events

  15. High-energy high-luminosity electron-ion collider eRHIC

    International Nuclear Information System (INIS)

    Litvinenko, V.N.; Ben-Zvi, I.; Hammons, L.; Hao, Y.; Webb, S.

    2011-01-01

    In this paper, we describe a future electron-ion collider (EIC), based on the existing Relativistic Heavy Ion Collider (RHIC) hadron facility, with two intersecting superconducting rings, each 3.8 km in circumference. The replacement cost of the RHIC facility is about two billion US dollars, and the eRHIC will fully take advantage and utilize this investment. We plan adding a polarized 5-30 GeV electron beam to collide with variety of species in the existing RHIC accelerator complex, from polarized protons with a top energy of 325 GeV, to heavy fully-striped ions with energies up to 130 GeV/u. Brookhaven's innovative design, is based on one of the RHIC's hadron rings and a multi-pass energy-recovery linac (ERL). Using the ERL as the electron accelerator assures high luminosity in the 10 33 -10 34 cm -2 sec -1 range, and for the natural staging of eRHIC, with the ERL located inside the RHIC tunnel. The eRHIC will provide electron-hadron collisions in up to three interaction regions. We detail the eRHIC's performance in Section 2. Since first paper on eRHIC paper in 2000, its design underwent several iterations. Initially, the main eRHIC option (the so-called ring-ring, RR, design) was based on an electron ring, with the linac-ring (LR) option as a backup. In 2004, we published the detailed 'eRHIC 0th Order Design Report' including a cost-estimate for the RR design. After detailed studies, we found that an LR eRHIC has about a 10-fold higher luminosity than the RR. Since 2007, the LR, with its natural staging strategy and full transparency for polarized electrons, became the main choice for eRHIC. In 2009, we completed technical studies of the design and dynamics for MeRHIC with 3-pass 4 GeV ERL. We learned much from this evaluation, completed a bottom-up cost estimate for this $350M machine, but then shelved the design. In the same year, we turned again to considering the cost-effective, all-in-tunnel six-pass ERL for our design of the high-luminosity eRHIC. In it

  16. Low-luminosity Blazars in Wise: A Mid-infrared View of Unification

    Science.gov (United States)

    Plotkin, Richard M.; Anderson, S. F.; Brandt, W. N.; Markoff, S.; Shemmer, O.; Wu, J.

    2012-01-01

    We use the preliminary data release from the Wide-Field Infrared Survey Explorer (WISE) to perform the first statistical study on the mid-infrared (IR) properties of a large number ( 102) of BL Lac objects -- low-luminosity Active Galactic Nuclei (AGN) with a jet beamed toward the Earth. As expected, many BL Lac objects are so highly beamed that their jet synchrotron emission dominates their IR spectral energy distributions (SEDs), and the shape of their SEDs in the IR correlates well with SED peak frequency. In other BL Lac objects, the jet is not strong enough to completely dilute the rest of the AGN, and we do not see observational signatures of the dusty torus from these weakly beamed BL Lac objects. While at odds with simple unification, the missing torus is consistent with recent suggestions that BL Lac objects are fed by radiatively inefficient accretion flows. We discuss implications on the ``nature vs. nurture" debate for FR I and FR II galaxies, and also on the standard orientation-based AGN unification model.

  17. Upgrade of the ATLAS Tile Calorimeter for the High Luminosity LHC

    CERN Document Server

    Tang, Fukun; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS covering the central region of the ATLAS experiment. TileCal will undergo a major replacement of its on- and off-detector electronics in 2024 for the high luminosity program of the LHC. The calorimeter signals will be digitized and sent directly to the off-detector electronics, where the signals are reconstructed and transmitted to the first level of trigger at a rate of 40 MHz. This will provide a better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Three different options are presently being investigated for the front-end electronic upgrade. Extensive test beam studies are being employed to determine which option will be selected. The off-detector electronics are based on the Advanced Telecommunications Computing Architecture (ATCA) standard and are equipped with high performance optical connectors. The system is designed to operate in a high radiation envi...

  18. Upgrade of the ATLAS Tile Calorimeter for the High Luminosity LHC

    CERN Document Server

    Tang, Fukun; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS cover-ing the central region of the ATLAS experiment. TileCal will undergo a major replacement of its on- and off-detector electronics in 2024 for the high luminosity program of the LHC. The calorimeter signals will be digitized and sent directly to the off-detector electronics, where the signals are reconstructed and shipped to the first level of trigger at a rate of 40 MHz. This will provide a better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Three different options are presently being investigated for the front-end electronic upgrade. Extensive test beam studies are being employed to determine which option will be selected. The off-detector electronic is based on the Advanced Telecommunications Computing Architecture (ATCA) standard and is equipped with high performance optical connectors. The system is designed to operate in a high radiation environmen...

  19. Luminosity distance for Born-Infeld electromagnetic waves propagating in a cosmological magnetic background

    Energy Technology Data Exchange (ETDEWEB)

    Aiello, Matias; Bengochea, Gabriel R; Ferraro, Rafael, E-mail: aiello@iafe.uba.ar, E-mail: gabriel@iafe.uba.ar, E-mail: ferraro@iafe.uba.ar [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)

    2008-06-15

    Born-Infeld electromagnetic waves interacting with a static magnetic background in an expanding universe are studied. The non-linear character of Born-Infeld electrodynamics modifies the relation between the energy flux and the distance to the source, which gains a new dependence on the redshift that is governed by the background field. We compute the luminosity distance as a function of the redshift and compare with Maxwellian curves for supernovae type Ia.

  20. THE LUMINOSITIES OF PROTOSTARS IN THE SPITZER c2d AND GOULD BELT LEGACY CLOUDS

    International Nuclear Information System (INIS)

    Dunham, Michael M.; Arce, Héctor G.; Allen, Lori E.; Evans II, Neal J.; Harvey, Paul M.; Broekhoven-Fiene, Hannah; Matthews, Brenda C.; Chapman, Nicholas L.; Cieza, Lucas A.; Gutermuth, Robert A.; Hatchell, Jennifer; Huard, Tracy L.; Miller, Jennifer F.; Kirk, Jason M.; Merín, Bruno; Peterson, Dawn E.; Spezzi, Loredana

    2013-01-01

    Motivated by the long-standing 'luminosity problem' in low-mass star formation whereby protostars are underluminous compared to theoretical expectations, we identify 230 protostars in 18 molecular clouds observed by two Spitzer Space Telescope Legacy surveys of nearby star-forming regions. We compile complete spectral energy distributions, calculate L bol for each source, and study the protostellar luminosity distribution. This distribution extends over three orders of magnitude, from 0.01 L ☉ to 69 L ☉ , and has a mean and median of 4.3 L ☉ and 1.3 L ☉ , respectively. The distributions are very similar for Class 0 and Class I sources except for an excess of low luminosity (L bol ∼ ☉ ) Class I sources compared to Class 0. 100 out of the 230 protostars (43%) lack any available data in the far-infrared and submillimeter (70 μm bol underestimated by factors of 2.5 on average, and up to factors of 8-10 in extreme cases. Correcting these underestimates for each source individually once additional data becomes available will likely increase both the mean and median of the sample by 35%-40%. We discuss and compare our results to several recent theoretical studies of protostellar luminosities and show that our new results do not invalidate the conclusions of any of these studies. As these studies demonstrate that there is more than one plausible accretion scenario that can match observations, future attention is clearly needed. The better statistics provided by our increased data set should aid such future work.

  1. A high luminosity superconducting mini collider for Phi meson production and particle beam physics

    International Nuclear Information System (INIS)

    Pellegrini, C.; Robin, D.; Cline, D.; Kolonko, J.; Anderson, C.; Barletta, W.; Chargin, A.; Cornacchia, M.; Dalbacka, G.; Halbach, K.; Lueng, E.; Kimball, F.; Madura, D.; Patterson, L.

    1991-01-01

    A 510MeV electron-positron collider has been proposed at UCLA to study particle beam physics and Phi-Meson physics, at luminosities larger than 10 32 cm -2 s -1 . The collider consists of a single compact superconducting storage ring (SMC), with bending field of 4 T and a current larger than 1 A. The authors discuss the main characteristics of this system and its major technical components: superconducting dipoles, RF, vacuum, injection

  2. THE LUMINOSITIES OF PROTOSTARS IN THE SPITZER c2d AND GOULD BELT LEGACY CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, Michael M.; Arce, Hector G. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Allen, Lori E. [National Optical Astronomy Observatories, Tucson, AZ (United States); Evans II, Neal J.; Harvey, Paul M. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Broekhoven-Fiene, Hannah; Matthews, Brenda C. [Herzberg Institute, National Research Council of Canada, 5071 W. Saanich Road, Victoria, BC V9E 2E7 (Canada); Chapman, Nicholas L. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States); Cieza, Lucas A. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Gutermuth, Robert A. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Hatchell, Jennifer [Astrophysics Group, Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Huard, Tracy L.; Miller, Jennifer F. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Kirk, Jason M. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Merin, Bruno [Herschel Science Centre, ESAC-ESA, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Peterson, Dawn E. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); Spezzi, Loredana, E-mail: michael.dunham@yale.edu [European Southern Observatory (ESO), Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Muenchen (Germany)

    2013-04-15

    Motivated by the long-standing 'luminosity problem' in low-mass star formation whereby protostars are underluminous compared to theoretical expectations, we identify 230 protostars in 18 molecular clouds observed by two Spitzer Space Telescope Legacy surveys of nearby star-forming regions. We compile complete spectral energy distributions, calculate L{sub bol} for each source, and study the protostellar luminosity distribution. This distribution extends over three orders of magnitude, from 0.01 L{sub Sun} to 69 L{sub Sun }, and has a mean and median of 4.3 L{sub Sun} and 1.3 L{sub Sun }, respectively. The distributions are very similar for Class 0 and Class I sources except for an excess of low luminosity (L{sub bol} {approx}< 0.5 L{sub Sun }) Class I sources compared to Class 0. 100 out of the 230 protostars (43%) lack any available data in the far-infrared and submillimeter (70 {mu}m <{lambda} < 850 {mu}m) and have L{sub bol} underestimated by factors of 2.5 on average, and up to factors of 8-10 in extreme cases. Correcting these underestimates for each source individually once additional data becomes available will likely increase both the mean and median of the sample by 35%-40%. We discuss and compare our results to several recent theoretical studies of protostellar luminosities and show that our new results do not invalidate the conclusions of any of these studies. As these studies demonstrate that there is more than one plausible accretion scenario that can match observations, future attention is clearly needed. The better statistics provided by our increased data set should aid such future work.

  3. Performance Study of the First 2D Prototype of Vertically Integrated Pattern Recognition Associative Memory (VIPRAM)

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Gregory [Fermilab; Hoff, James [Fermilab; Jindariani, Sergo [Fermilab; Liu, Tiehui [Fermilab; Olsen, Jamieson [Fermilab; Tran, Nhan [Fermilab; Joshi, Siddhartha [Northwestern U.; Li, Dawei [Northwestern U.; Ogrenci-Memik, Seda [Northwestern U.

    2017-09-24

    Extremely fast pattern recognition capabilities are necessary to find and fit billions of tracks at the hardware trigger level produced every second anticipated at high luminosity LHC (HL-LHC) running conditions. Associative Memory (AM) based approaches for fast pattern recognition have been proposed as a potential solution to the tracking trigger. However, at the HL-LHC, there is much less time available and speed performance must be improved over previous systems while maintaining a comparable number of patterns. The Vertically Integrated Pattern Recognition Associative Memory (VIPRAM) Project aims to achieve the target pattern density and performance goal using 3DIC technology. The first step taken in the VIPRAM work was the development of a 2D prototype (protoVIPRAM00) in which the associative memory building blocks were designed to be compatible with the 3D integration. In this paper, we present the results from extensive performance studies of the protoVIPRAM00 chip in both realistic HL-LHC and extreme conditions. Results indicate that the chip operates at the design frequency of 100 MHz with perfect correctness in realistic conditions and conclude that the building blocks are ready for 3D stacking. We also present performance boundary characterization of the chip under extreme conditions.

  4. An HST Survey of Intermediate Luminosity X-ray Objects

    Science.gov (United States)

    Roye, E. W.; Colbert, E. J. M.; Heckman, T.; Ptak, R. F.; van der Marel, R. P.

    2003-03-01

    We searched for optical counterparts to 54 Intermediate-luminosity X-ray Objects (IXOs, a.k.a. ULXs) using HST WFPC2 archive data, and have uncovered a high yield of intriguing possible correlations. A total of 124 IXOs were identified from searching all of the Chandra ACIS archival galaxy data as of July 17, 2002. Archival WFPC2 data were available for 54 of these IXOs. The optical data utilized in this study consisted of 121 HST WFPC2 associations (stacked images). We will discuss the various methods used to register the HST WFPC2 images with the Chandra X-ray images. Our preliminary analysis indicates that 37 ( ˜70%) of the 54 IXOs have at least one 4 sigma counterpart within 1" of the IXO position, and ˜25% have unique counterparts (mostly in elliptical galaxies). The detection limit of the counterparts was typically 24-25 magnitudes in B, V, and R. The absolute magnitudes of many of the found counterparts appeared to correspond roughly to either the expected magnitudes for globular clusters, or the expected magnitudes for the brightest stars. Initial results illustrate that of the 37 IXOs with counterparts, 25 ( ˜70%) were in spiral, irregular, and merger galaxies, where the counterparts were often diffuse or clump-like sources. The counterparts found in elliptical galaxies were primarily single luminous point-sources, most likely globular clusters. We will discuss the results of color analysis for fields where counterparts in multiple bands exist, particularly for cases where a single counterpart is found. A preliminary finding in elliptical galaxies is that globular clusters associated with IXOs tend to be red, suggesting that IXOs are not found in metal-poor globular clusters.

  5. Detector Developments for the High Luminosity LHC Era (2/4)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    Calorimetry and Muon Spectromers - Part II: When upgrading the LHC to higher luminosities, the detector and trigger performance shall be preserved - if not improved - with respect to the nominal performance. The ongoing R&D for new radiation tolerant front-end electronics for calorimeters with higher read-out bandwidth are summarized and new possibilities for the trigger systems are presented. Similar developments are foreseen for the muon spectrometers, where also radiation tolerance of the muon detectors and functioning at high background rates is important. The corresponding plans and research work for the calorimeter and muon detectors at a LHC with highest luminsity are presented.

  6. Performance study of thermo-electric generator

    Science.gov (United States)

    Rohit, G.; Manaswini, D.; Kotebavi, Vinod; R, Nagaraja S.

    2017-07-01

    Devices like automobiles, stoves, ovens, boilers, kilns and heaters dissipate large amount of waste heat. Since most of this waste heat goes unused, the efficiency of these devices is drastically reduced. A lot of research is being conducted on the recovery of the waste heat, among which Thermoelectric Generators (TEG) is one of the popular method. TEG is a semiconductor device that produces electric potential difference when a thermal gradient develops on it. This paper deals with the study of performance of a TEG module for different hot surface temperatures. Performance characteristics used here are voltage, current and power developed by the TEG. One side of the TEG was kept on a hot plate where uniform heat flux was supplied to that. And the other side was cooled by supplying cold water. The results show that the output power increases significantly with increase in the temperature of the hot surface.

  7. Study on dynamic performance of SOFC

    Science.gov (United States)

    Zhan, Haiyang; Liang, Qianchao; Wen, Qiang; Zhu, Runkai

    2017-05-01

    In order to solve the problem of real-time matching of load and fuel cell power, it is urgent to study the dynamic response process of SOFC in the case of load mutation. The mathematical model of SOFC is constructed, and its performance is simulated. The model consider the influence factors such as polarization effect, ohmic loss. It also takes the diffusion effect, thermal effect, energy exchange, mass conservation, momentum conservation. One dimensional dynamic mathematical model of SOFC is constructed by using distributed lumped parameter method. The simulation results show that the I-V characteristic curves are in good agreement with the experimental data, and the accuracy of the model is verified. The voltage response curve, power response curve and the efficiency curve are obtained by this way. It lays a solid foundation for the research of dynamic performance and optimal control in power generation system of high power fuel cell stack.

  8. THE RELATION OF OPTICAL/ULTRAVIOLET AND X-RAY EMISSION IN LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Xu Yadi

    2011-01-01

    We study the relation of optical/UV and X-ray emission in the low luminosity active galactic nuclei (LLAGNs), using a sample of 49 sources including 28 local Seyfert galaxies and 21 low-ionization nuclear emission-line regions with optical/UV spectral luminosity at wavelength λ = 2500 A, 23.0 ≤ log L ν(2500A) (erg s -1 Hz -1 ) ≤ 27.7, and X-ray spectral luminosity at 2 keV, 20.5 ≤ log L ν(2keV) ≤ 25.3. Strong correlations are found between the X-ray luminosity and the optical/UV-to-X-ray index, α ox , with the optical/UV luminosity, with slopes very similar to the findings for the luminous AGNs in previous works. The correlation between α ox and L ν(2keV) is very weak, as is that found for the luminous AGNs in the majority of previous similar works. We also study the relation between α ox and the Eddington ratio L bol /L Edd for our sample and find a significant anti-correlation for the sources with L bol /L Edd ∼ -3 , which is opposite to the correlation between the two variables for the luminous AGNs. Using the advection-dominated accretion flow (ADAF) model, we roughly reproduce this anti-correlationship for the two variables for the LLAGNs. This result strongly supports the ADAF as a candidate for the accretion mode in LLAGNs.

  9. Study of the timing performance of the SKIROC2-CMS for the CMS HGCAL

    CERN Document Server

    Huiberts, Simon Kristian

    2017-01-01

    The High Luminosity phase of the LHC (starting operation in 2025) will provide unprecedented instantaneous and integrated luminosity, with 25 ns bunch crossing intervals and up to 140 pileup events. In this context, the High Granularity Calorimeter will provide electromagnetic and hadronic energy measurement in the forward direction of the upgraded CMS. The test beam campaign of the first HGCal modules, started in Summer 2016 at CERN with 8 fully equipped layers of the EE section, will continue in Summer 2017 aiming at the test of a full prototype including the electronic and the hadronic parts. The assessment of the calorimeter performance on a beam test bench is a fundamental phase for the development of a new detector, allowing to test the mechanical structure and electronic chain, characterize the modules performance and measure the shower developments for electrons and hadrons. The aim of the work was to determine the timing performance and the timing characteristics of the single module tested in May 2...

  10. GAMMA-RAY BURST LUMINOSITY RELATIONS: TWO-DIMENSIONAL VERSUS THREE-DIMENSIONAL CORRELATIONS

    International Nuclear Information System (INIS)

    Yu Bo; Qi Shi; Lu Tan

    2009-01-01

    The large scatters of luminosity relations of gamma-ray bursts (GRBs) have been one of the most important reasons that prevent the extensive applications of GRBs in cosmology. In this paper, we extend the two-dimensional (2D) luminosity relations with τ lag , V, E peak , and τ RT as the luminosity indicators to three dimensions (3D) using the same set of luminosity indicators to explore the possibility of decreasing the intrinsic scatters. We find that, for the 3D luminosity relations between the luminosity and an energy scale (E peak ) and a timescale (τ lag or τ RT ), their intrinsic scatters are considerably smaller than those of corresponding 2D luminosity relations. Enlightened by the result and the definition of the luminosity (energy released in units of time), we discussed possible reasons behind this result, which may give us helpful suggestions on seeking more precise luminosity relations for GRBs in the future.

  11. Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider

    Science.gov (United States)

    Yee-Rendon, Bruce; Lopez-Fernandez, Ricardo; Barranco, Javier; Calaga, Rama; Marsili, Aurelien; Tomás, Rogelio; Zimmermann, Frank; Bouly, Frédéric

    2014-05-01

    Crab cavities (CCs) are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC) project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

  12. MID-IR LUMINOSITIES AND UV/OPTICAL STAR FORMATION RATES AT z < 1.4

    International Nuclear Information System (INIS)

    Salim, Samir; Dickinson, Mark; Michael Rich, R.; Charlot, Stephane; Lee, Janice C.; Schiminovich, David; Perez-Gonzalez, Pablo G.; Ashby, Matthew L. N.; Noeske, Kai; Papovich, Casey; Weiner, Benjamin J.; Faber, S. M.; Ivison, Rob J.; Frayer, David T.; Walton, Josiah M.; Chary, Ranga-Ram; Bundy, Kevin; Koekemoer, Anton M.

    2009-01-01

    Ultraviolet (UV) nonionizing continuum and mid-infrared (IR) emission constitute the basis of two widely used star formation (SF) indicators at intermediate and high redshifts. We study 2430 galaxies with z 10 -10 12 L sun ). We show that the IR luminosity can be estimated from the UV and optical photometry to within a factor of 2, implying that most z IR >10 11 L sun , yet with little current SF. For them a reasonable amount of dust absorption of stellar light (but presumably higher than in nearby early-type galaxies) is sufficient to produce the observed levels of IR, which includes a large contribution from intermediate and old stellar populations. In our sample, which contains very few ultraluminous IR galaxies, optical and X-ray active galactic nuclei do not contribute on average more than ∼50% to the mid-IR luminosity, and we see no evidence for a large population of 'IR excess' galaxies.

  13. Effect of perturbation of convective energy transport on the luminosity and radius of the sun

    International Nuclear Information System (INIS)

    Endal, A.S.; Twigg, L.W.

    1982-01-01

    The response of solar models to perturbations of the efficiency of convective energy transport is studied for a number of cases. Such perturbations primarily affect the shallow superadiabatic layer of the convective envelope (at depths 3 km below the photosphere). Independent of the details of the perturbation scheme, the resulting change in the solar radius (ΔR/R) is always very small compared to the change in luminosity (ΔL/L). This appears to be true for any physical mechanism of solar variability which operates in the outer layers of the convection zone. Changes of the solar radius have been inferred by Dunham et al. from historical observations of solar eclipses in 1715 and 1925. Considering the constraints on concurrent luminosity changes, this type of solar variability must be indicative of changes in the solar structure at substantial depths below the superadiabatic layer of the convective envelope

  14. Absolute luminosity and proton-proton total cross section measurement for the ATLAS experiment at LHC

    International Nuclear Information System (INIS)

    Heller, Matthieu

    2010-01-01

    The Large Hadron Collider (LHC) at CERN in Geneva will soon deliver collisions with an energy never reached in a particle accelerator. An energy in the center of mass of 10 and ultimately 14 TeV will allow to go beyond the borders of the physics known so far. ATLAS, the largest detector ever built, will hunt the Higgs boson and search for new physics beyond the Standard Model. Any physical process is described by a cross section that measures its probability to occur. The events resulting from a given process are registered by ATLAS. To determine their according cross section, one has to know the luminosity. For the ATLAS experiment, a relative measurement of the luminosity can be done using the response of several sub-detectors. However to calibrate these detectors, an absolute measurement has to be performed. The ALFA detector has been designed to measure the elastic scattering spectrum that will allow to determine the absolute luminosity and the proton-proton total cross section. This provides an accurate calibration tool at a percent level. These detectors, located 240 m away from the interaction point, are called roman pots, a mechanical system that allows to approach a scintillating fiber tracker a few millimeters to the beam center. The simulation of the measurement requires to use a charged particles transport program. This program has to be carefully chosen because the determination of the protons lost during their travel from the interaction point to the detector has a major impact on the acceptance computation. The systematical uncertainties affecting the luminosity and the total cross section measurements are also determined using the full simulation chain. The ALFA detector operates in a complex environment and consequently its design requires a great care. A large tests campaign has been performed on the front end electronics. The results and the corresponding data analysis have shown that all requirement where fulfilled. A test beam has been

  15. Package performance study: developments since PATRAM 13

    International Nuclear Information System (INIS)

    Tegeler, B.; Snyder, A.; Lewis, R.; Sorenson, K.

    2004-01-01

    The United States Nuclear Regulatory Commission (NRC) initiated a research program in 1999 to study the response of spent nuclear fuel transportation casks to extreme accident conditions. This confirmatory research program is called the Package Performance Study (PPS) and is founded on an enhanced public participatory process that is used to obtain public comments throughout all project phases. The study objectives are to: 1) assess the analysis tools and methods used to predict spent nuclear fuel transportation cask response to extreme mechanical and thermal environments, and 2) demonstrate the inherent safety in spent fuel cask design. Public outreach is a significant element in both of these objectives. The NRC Commission recently approved the full-scale testing of a single NRC certified spent nuclear fuel rail transportation cask. To satisfy Commission direction, NRC staff has developed, for Commission approval, detailed test plans for conducting a full-scale demonstration test on a spent fuel rail transportation cask. The staff proposes to perform a demonstration test involving the collision of a locomotive with a rail cask attached to a conveyance (i.e., railcar) and a subsequent fire test. Further, the staff plans to conduct detailed pre and post -test analysis to compare numerical calculations with data obtained from the test. This paper discusses the process for selection of this scenario and the uncertainties associated with demonstration testing and analysis predictions. The staff's proposal is currently under review by the Commission

  16. Package performance study: developments since PATRAM 13

    Energy Technology Data Exchange (ETDEWEB)

    Tegeler, B.; Snyder, A.; Lewis, R. [U.S. Nuclear Regulatory Commission, Washington, DC (United States); Sorenson, K. [Sandia National Labs., Albuquerque, NM (United States)

    2004-07-01

    The United States Nuclear Regulatory Commission (NRC) initiated a research program in 1999 to study the response of spent nuclear fuel transportation casks to extreme accident conditions. This confirmatory research program is called the Package Performance Study (PPS) and is founded on an enhanced public participatory process that is used to obtain public comments throughout all project phases. The study objectives are to: 1) assess the analysis tools and methods used to predict spent nuclear fuel transportation cask response to extreme mechanical and thermal environments, and 2) demonstrate the inherent safety in spent fuel cask design. Public outreach is a significant element in both of these objectives. The NRC Commission recently approved the full-scale testing of a single NRC certified spent nuclear fuel rail transportation cask. To satisfy Commission direction, NRC staff has developed, for Commission approval, detailed test plans for conducting a full-scale demonstration test on a spent fuel rail transportation cask. The staff proposes to perform a demonstration test involving the collision of a locomotive with a rail cask attached to a conveyance (i.e., railcar) and a subsequent fire test. Further, the staff plans to conduct detailed pre and post -test analysis to compare numerical calculations with data obtained from the test. This paper discusses the process for selection of this scenario and the uncertainties associated with demonstration testing and analysis predictions. The staff's proposal is currently under review by the Commission.

  17. Study on performance of centripetal fan, 1

    International Nuclear Information System (INIS)

    Ejiri, Eiji; Shirakura, Masaaki; Tagori, Tetsuo; Enomoto, Hisao.

    1984-01-01

    Centripetal fans are radial flow type fans which gather air from outer side into inner side. The construction is simple, and when heat exchangers are arranged around them, cooled air can be discharged upward only by connecting simple ducts, accordingly, centripetal fans are suitable to the ventilating fans for superlarge cooling towers of nuclear power plants. The static pressure rise is obtained only by the diffuser action of impellers, therefore, they are not suitable to pumps and compressors, and their use is limited only to fans. Centrifugal force exerts negative effect on static pressure rise, accordingly, the ratio of internal diameter/external diameter of impellers cannot be made very small. In this study, a small model with impeller diameter of 0.6 m was used, and its overall performance, the performance of moving blades in the range of stable operation, the rotating stall characteristics in the region of low flow rate, and the effect of side wind on the overall performance in outdoor use were examined. By changing the angle of inclination of entrance guide vanes, the range of stable operation was expanded, and the pressure coefficient and efficiency were increased. (Kako, I.)

  18. Studies on denitrification performance of tricking filters

    International Nuclear Information System (INIS)

    Ruediger, A.

    1993-01-01

    Trickling filters are one of the oldest methods of biological waste water purification, widely used ever since they were first developed. These filters are mostly used for aerobic purification of water as highly polluted or lightly polluted reactors. While these systems are very useful for the elemination of organic pollution and the nitrification of the waste waters, denitrification of the whole plant poses considerable problems. The question is in how far trickling filters can be used as denitrification reactors. The conditions of successful denitrification in trickling filters is investigated, denitrification performance is established. Studies were conducted in laboratory, semi-industrial and industrial scale. (BBR) [de

  19. The Seven Sisters DANCe. I. Empirical isochrones, luminosity, and mass functions of the Pleiades cluster

    Science.gov (United States)

    Bouy, H.; Bertin, E.; Sarro, L. M.; Barrado, D.; Moraux, E.; Bouvier, J.; Cuillandre, J.-C.; Berihuete, A.; Olivares, J.; Beletsky, Y.

    2015-05-01

    Context. The DANCe survey provides photometric and astrometric (position and proper motion) measurements for approximately 2 million unique sources in a region encompassing ~80 deg2 centered on the Pleiades cluster. Aims: We aim at deriving a complete census of the Pleiades and measure the mass and luminosity functions of the cluster. Methods: Using the probabilistic selection method previously described, we identified high probability members in the DANCe (i ≥ 14 mag) and Tycho-2 (V ≲ 12 mag) catalogues and studied the properties of the cluster over the corresponding luminosity range. Results: We find a total of 2109 high-probability members, of which 812 are new, making it the most extensive and complete census of the cluster to date. The luminosity and mass functions of the cluster are computed from the most massive members down to ~0.025 M⊙. The size, sensitivity, and quality of the sample result in the most precise luminosity and mass functions observed to date for a cluster. Conclusions: Our census supersedes previous studies of the Pleiades cluster populations, in terms of both sensitivity and accuracy. Based on service observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.Table 1 and Appendices are available in electronic form at http://www.aanda.orgDANCe catalogs (Tables 6 and 7) and full Tables 2-5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A148

  20. The evolution of temperature and bolometric luminosity in Type II supernovae

    Science.gov (United States)

    Faran, T.; Nakar, E.; Poznanski, D.

    2018-01-01

    In this work, we present a uniform analysis of the temperature evolution and bolometric luminosity of a sample of 29 Type II supernovae (SNe), by fitting a blackbody model to their multiband photometry. Our sample includes only SNe with high quality multiband data and relatively well-sampled time coverage. Most of the SNe in our sample were detected less than a week after explosion so their light curves cover the evolution both before and after recombination starts playing a role. We use this sample to study the signature of hydrogen recombination, which is expected to appear once the observed temperature drops to ≈7000 K. Theory predicts that before recombination starts affecting the light curve, both the luminosity and the temperature should drop relatively fast, following a power law in time. Once the recombination front reaches inner parts of the outflow, it sets the observed temperature to be nearly constant, and slows the decline of the luminosity (or even leads to a re-brightening). We compare our data to analytic studies and find strong evidence for the signature of recombination. We also find that the onset of the optical plateau in a given filter, is effectively the time at which the blackbody peak reaches the central wavelength of the filter, as it cools, and it does not correspond to the time at which recombination starts affecting the emission.

  1. The physics program of a high-luminosity asymmetric B Factory at SLAC

    International Nuclear Information System (INIS)

    1989-10-01

    A high-luminosity asymmetric energy B Factory, proposed as an upgrade to the PEP storage ring at SLAC, provides the best opportunity to study CP violation as a means of testing the consistency of the Standard Model. If the phenomenon of CP violation is explained by the Standard Model simply through the non-zero angles and phase of the Kobayashi-Maskawa matrix, then there are precise relations between the K-M parameters and the various measurable CP-violating asymmetries in B meson decay. Should these consistency relations fail, the origin of CP violation must lie outside the Standard Model framework. Our measurements would then lead to the first experiment-driven extensions of the Standard Model. The B Factory will also carry out a varied, high-quality program of studies of other aspects of the physics of b quarks, as well as high-precision measurements in τ and charm physics. We describe a detailed series of measurements to be carried out in the first few years at a peak luminosity of 3 x 10 33 cm -2 sec -1 , the initial luminosity goal of the B Factory, as well as the program accessible to a larger data sample

  2. ECFA 2016: Prospects for selected standard model measurements with the CMS experiment at the High-Luminosity LHC

    CERN Document Server

    CMS Collaboration

    2017-01-01

    The prospects for selected standard model measurements at the High-Luminosity LHC presented at ECFA 2016 workshop are summarized. The extrapolations assume proton-proton collision data at a centre-of-mass energy of 14$\\,$TeV corresponding to an integrated luminosity of up to $3\\,\\text{ab}^{-1}$. The achievable precision for top quark mass measurements based on different analysis strategies is estimated. Searches for flavour-changing neutral currents in top quark decays are studied and expected limits are set, based on different scenarios for the extrapolation of systematic uncertainties to the High-Luminosity LHC run conditions. The feasibility of a dedicated track trigger for the $B_s \\rightarrow \\phi \\phi$ decay studies is discussed.

  3. Waste package performance allocation system study report

    International Nuclear Information System (INIS)

    Memory, R.D.

    1994-01-01

    The Waste Package Performance Allocation system study was performed in order to provide a technical basis for the selection of the waste package period of substantially complete containment and its resultant contribution to the overall total system performance. This study began with a reference case based on the current Mined Geologic Disposal System (MGDS) baseline design and added a number of alternative designs. The waste package designs were selected from the designs being considered in detail during Advanced Conceptual Design (ACD). The waste packages considered were multi-barrier packages with a 0.95 cm Alloy 825 inner barrier and a 10, 20, or 45 cm thick carbon steel outer barrier. The waste package capacities varied from 6 to 12 to 21 Pressurized Water Reactor (PWR) fuel assemblies. The vertical borehole and in-drift emplacement modes were also considered, as were thermal loadings of 25, 57, and 114 kW/acre. The repository cost analysis indicated that the 21 PWR in-drift emplacement mode option with the 10 cm and 20 cm outer barrier thicknesses are the least expensive and that the 12 PWR in-drift case has approximately the same cost as the 6 PWR vertical borehole. It was also found that the cost increase from the 10 cm outer barrier waste package to the 20 cm waste package was less per centimeter than the increase from the 20 cm outer barrier waste package to the 45 cm outer barrier waste package. However, the repository cost was nearly linear with the outer barrier thickness for the 21 PWR in-drift case. Finally, corrosion rate estimates are provided and the relationship of repository cost versus waste package lifetime is discussed as is cumulative radionuclide release from the waste package and to the accessible environment for time periods of 10,000 years and 100,000 years

  4. Absolute luminosity measurement at LHCb with beam-gas imaging

    CERN Document Server

    Barschel, C

    2013-01-01

    A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam-Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used *van der Meer scan* method (VDM). The technique has been used in 10 LHC fills during 2012 including and also provided a first luminosity measurement for proton-lead collisions. This talk presents the principles of the gas injection and the improvements reached with the increased pressure. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch. Those uncertainties are becoming the dominating factor because the uncertainty on the total beam current have been reduced.

  5. SLC-2000: A luminosity upgrade for the SLC

    International Nuclear Information System (INIS)

    Breidenbach, M.; Decker, F.-J.; Helm, R.; Napoly, O.; Phinney, N.; Raimondi, P.; Raubenheimer, T.O.; Siemann, R.; Zimmermann, F.; Hertzbach, S.

    1996-01-01

    We discuss a possible upgrade to the Stanford Linear Collider (SLC), whose objective is to increase the SLC luminosity by at least a factor 7, to an average Z production rate of more than 35,000 per week. The centerpiece of the upgrade is the installation of a new superconducting final doublet with a field gradient of 240 T/m, which will be placed at a distance of only 70 cm from the interaction point. In addition, several bending magnets in each final focus will be lengthened and two octupole correctors are added. A complementary upgrade of damping rings and bunch compressors will allow optimum use of the modified final focus and can deliver, or exceed, the targeted luminosity. The proposed upgrade will place the SLC physics program in a very competitive position, and will also enable it to pursue its pioneering role as the first and only linear collider. (author)

  6. Temperatures and luminosities of white dwarfs in dwarf novae

    International Nuclear Information System (INIS)

    Smak, J.

    1984-01-01

    Far ultraviolet radiation observed in dwarf novae at minimum can only be attributed to their white dwarfs. In three systems white dwarfs are detected directly through their eclipses. These data are used to determine the effective temperatures and luminosities of white dwarfs. The resulting temperatures range from about logT e = 4.1 to about 4.9, with typical values of about 4.5. The luminosities range from about logL 1 = 31.0 to about 33.5 and show correlation with the average accretion rates. Radiation from white dwarfs is likely to be the source of excitation of the emission lines from disks. It is also argued that the heating by the white dwarf can significantly modify the structure of the innermost parts of the disk and, particularly, inhibit the incidence of thermal instability in that region. 26 refs., 2 figs., 1 tab. (author)

  7. The CMS High Granularity Calorimeter for the High Luminosity LHC

    CERN Document Server

    Sauvan, Jean-baptiste

    2017-01-01

    The High Luminosity LHC (HL-LHC) will integrate 10 times more luminosity than the LHC, posing significant challenges for radiation tolerance and event pileup on detectors, especially for forward calorimetry, and hallmarks the issue for future colliders. As part of its HL-LHC upgrade program, the CMS collaboration is designing a High Granularity Calorimeter to replace the existing endcap calorimeters. It features unprecedented transverse and longitudinal segmentation for both electromagnetic (ECAL) and hadronic (HCAL) compartments. This will facilitate particle-flow calorimetry, where the fine structure of showers can be measured and used to enhance pileup rejection and particle identification, whilst still achieving good energy resolution. The ECAL and a large fraction of HCAL will be based on hexagonal silicon sensors of 0.5 - 1 cm$^2$ cell size, with the remainder of the HCAL based on highly-segmented scintillators with silicon photomultiplier (SiPM) readout. The intrinsic high-precision timing capabilities...

  8. Evolution of the cluster X-ray luminosity function

    DEFF Research Database (Denmark)

    Mullis, C.R.; Vikhlinin, A.; Henry, J.P.

    2004-01-01

    We report measurements of the cluster X-ray luminosity function out to z = 0.8 based on the final sample of 201 galaxy systems from the 160 Square Degree ROSAT Cluster Survey. There is little evidence for any measurable change in cluster abundance out to z similar to 0.6 at luminosities of less...... than a few times 10(44) h(50)(-2) ergs s(-1) (0.5 - 2.0 keV). However, for 0.6 cluster deficit using integrated number counts...... independently confirm the presence of evolution. Whereas the bulk of the cluster population does not evolve, the most luminous and presumably most massive structures evolve appreciably between z = 0.8 and the present. Interpreted in the context of hierarchical structure formation, we are probing sufficiently...

  9. Using Micromegas in ATLAS to Monitor the Luminosity

    CERN Document Server

    The ATLAS collaboration

    2013-01-01

    Five small prototype micromegas detectors were positioned in the ATLAS detector during LHC running at $\\sqrt{s} = 8\\, \\mathrm{TeV}$. A $9\\times 4.5\\, \\mathrm{cm^2}$ two-gap detector was placed in front of the electromagnetic calorimeter and four $9\\times 10\\, \\mathrm{cm^2}$ detectors on the ATLAS Small Wheels, the first station of the forward muon spectrometer. The one attached to the calorimeter was exposed to interaction rates of about $70\\,\\mathrm{kHz/cm^2}$ at ATLAS luminosity $\\mathcal{L}=5\\times 10^{33}\\,\\mathrm{cm^{-2}s^{-1}}$ two orders of magnitude higher than the rates in the Small Wheel. We compare the currents drawn by the detector installed in front of the electromagnetic calorimeter with the luminosity measurement in ATLAS experiment.

  10. SLHC, the High-Luminosity Upgrade (public event)

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    In the morning of June 23rd a public event is organised in CERN's Council Chamber with the aim of providing the particle physics community with up-to-date information about the strategy for the LHC luminosity upgrade and to describe the current status of preparation work. The presentations will provide an overview of the various accelerator sub-projects, the LHC physics prospects and the upgrade plans of ATLAS and CMS. This event is organised in the framework of the SLHC-PP project, which receives funding from the European Commission for the preparatory phase of the LHC High Luminosity Upgrade project. Informing the public is among the objectives of this EU-funded project. A simultaneous transmission of this meeting will be broadcast, available at the following address: http://webcast.cern.ch/

  11. MASSIVE BLACK HOLES IN STELLAR SYSTEMS: 'QUIESCENT' ACCRETION AND LUMINOSITY

    International Nuclear Information System (INIS)

    Volonteri, M.; Campbell, D.; Mateo, M.; Dotti, M.

    2011-01-01

    Only a small fraction of local galaxies harbor an accreting black hole, classified as an active galactic nucleus. However, many stellar systems are plausibly expected to host black holes, from globular clusters to nuclear star clusters, to massive galaxies. The mere presence of stars in the vicinity of a black hole provides a source of fuel via mass loss of evolved stars. In this paper, we assess the expected luminosities of black holes embedded in stellar systems of different sizes and properties, spanning a large range of masses. We model the distribution of stars and derive the amount of gas available to a central black hole through a geometrical model. We estimate the luminosity of the black holes under simple, but physically grounded, assumptions on the accretion flow. Finally, we discuss the detectability of 'quiescent' black holes in the local universe.

  12. ATLAS Fast Tracker Status and Tracking at High luminosity LHC

    CERN Document Server

    Ilic, Nikolina; The ATLAS collaboration

    2018-01-01

    The LHC’s increase in centre of mass energy and luminosity in 2015 makes controlling trigger rates with high efficiency challenging. The ATLAS Fast TracKer (FTK) is a hardware processor built to reconstruct tracks at a rate of up to 100 kHz and provide them to the high level trigger. The FTK reconstructs tracks by matching incoming detector hits with pre-defined track patterns stored in associative memory on custom ASICs. Inner detector hits are fit to these track patterns using modern FPGAs. This talk describes the electronics system used for the FTK’s massive parallelization. The installation, commissioning and running of the system is happening in 2016, and is detailed in this talk. Tracking at High luminosity LHC is also presented.

  13. Stellar bars and the spatial distribution of infrared luminosity

    International Nuclear Information System (INIS)

    Devereux, N.

    1987-01-01

    Ground-based 10 micron observations of the central region of over 100 infrared luminous galaxies are presented. A first order estimate of the spatial distribution of infrared emission in galaxies is obtained through a combination of ground-based and Infrared Astronomy Satellite (IRAS) data. The galaxies are nearby and primarily noninteracting, permitting an unbiased investigation of correlations with Hubble type. Approximately 40% of the early-type barred galaxies in this sample are associated with enhanced luminosity in the central (approximately 1 kpc diameter) region. The underlying luminosity source is attributed to both Seyfert and star formation activity. Late-type spirals are different in that the spatial distribution of infrared emission and the infrared luminoisty are not strongly dependent on barred morphology

  14. Truncation of the Inner Accretion Disk Around a Black Hole at Low Luminosity

    Science.gov (United States)

    Tomsick, John A.; Yamoka, Kazutaka; Corbel, Stephane; Kaaret, Philip; Kalemci, Emrah; Migliari, Simone

    2011-01-01

    Most black hole binaries show large changes in X-ray luminosity caused primarily by variations in mass accretion rate. An important question for understanding black hole accretion and jet production is whether the inner edge of the accretion disk recedes at low accretion rate. Measurements of the location of the inner edge (R(sub in)) can be made using iron emission lines that arise due to fluorescence of iron in the disk, and these indicate that R(sub in) is very close to the black hole at high and moderate luminosities (greater than or equal to 1% of the Eddington luminosity, L(sub Edd). Here, we report on X-ray observations of the black hole GX 339-4 in the hard state by Suzaku and the Rossi X-ray Timing Explorer that extend iron line studies to 0.14% L(sub Edd) and show that R(sub in) increases by a factor of greater than 27 over the value found when GX 339-4 was bright. The exact value of R(sub in) depends on the inclination of the inner disk (i), and we derive 90% confidence limits of R(sub in) greater than 35 R(sub g) at i = 0 degrees and R(sub in) greater than 175 R(sub g) at i = 30 degrees. This provides direct evidence that the inner portion of the disk is not present at low luminosity, allowing for the possibility that the inner disk is replaced by advection- or magnetically dominated accretion flows.

  15. The luminosities of cool supergiants in the Magellanic Clouds, and the Humphreys-Davidson limit revisited

    Science.gov (United States)

    Davies, Ben; Crowther, Paul A.; Beasor, Emma R.

    2018-05-01

    The empirical upper luminosity boundary Lmax of cool supergiants, often referred to as the Humphreys-Davidson limit, is thought to encode information on the general mass-loss behaviour of massive stars. Further, it delineates the boundary at which single stars will end their lives stripped of their hydrogen-rich envelope, which in turn is a key factor in the relative rates of Type-II to Type-Ibc supernovae from single star channels. In this paper we have revisited the issue of Lmax by studying the luminosity distributions of cool supergiants (SGs) in the Large and Small Magellanic Clouds (LMC/SMC). We assemble samples of cool SGs in each galaxy which are highly-complete above log L/L⊙=5.0, and determine their spectral energy distributions from the optical to the mid-infrared using modern multi-wavelength survey data. We show that in both cases Lmax appears to be lower than previously quoted, and is in the region of log L/L⊙=5.5. There is no evidence for Lmax being higher in the SMC than in the LMC, as would be expected if metallicity-dependent winds were the dominant factor in the stripping of stellar envelopes. We also show that Lmax aligns with the lowest luminosity of single nitrogen-rich Wolf-Rayet stars, indicating of a change in evolutionary sequence for stars above a critical mass. From population synthesis analysis we show that the Geneva evolutionary models greatly over-predict the numbers of cool SGs in the SMC. We also argue that the trend of earlier average spectral types of cool SGs in lower metallicity environments represents a genuine shift to hotter temperatures. Finally, we use our new bolometric luminosity measurements to provide updated bolometric corrections for cool supergiants.

  16. Luminosity optimization schemes in Compton experiments based on Fabry-Perot optical resonators

    Directory of Open Access Journals (Sweden)

    Alessandro Variola

    2011-03-01

    Full Text Available The luminosity of Compton x-ray and γ sources depends on the average current in electron bunches, the energy of the laser pulses, and the geometry of the particle bunch to laser pulse collisions. To obtain high power photon pulses, these can be stacked in a passive optical resonator (Fabry-Perot cavity especially when a high average flux is required. But, in this case, owing to the presence of the optical cavity mirrors, the electron bunches have to collide at an angle with the laser pulses with a consequent luminosity decrease. In this article a crab-crossing scheme is proposed for Compton sources, based on a laser amplified in a Fabry-Perot resonator, to eliminate the luminosity losses given by the crossing angle, taking into account that in laser-electron collisions only the electron bunches can be tilted at the collision point. We report the analytical study on the crab-crossing scheme for Compton gamma sources. The analytical expression for the total yield of photons generated in Compton sources with the crab-crossing scheme of collision is derived. The optimal collision angle of the bunch was found to be equal to half of the collision angle. At this crabbing angle, the maximal yield of scattered off laser photons is attained thanks to the maximization, in the collision process, of the time spent by the laser pulse in the electron bunch. Estimations for some Compton source projects are presented. Furthermore, some schemes of the optical cavities configuration are analyzed and the luminosity calculated. As illustrated, the four-mirror two- or three-dimensional scheme is the most appropriate for Compton sources.

  17. High-field Magnet Development toward the High Luminosity LHC

    Energy Technology Data Exchange (ETDEWEB)

    Apollinari, Giorgio [Fermilab

    2014-07-01

    The upcoming Luminosity upgrade of the LHC (HL-LHC) will rely on the use of Accelerator Quality Nb3Sn Magnets which have been the focus of an intense R&D effort in the last decade. This contribution will describe the R&D and results of Nb3Sn Accelerator Quality High Field Magnets development efforts, with emphasis on the activities considered for the HL-LHC upgrades.

  18. Progenitors of low-luminosity Type II-Plateau supernovae

    Science.gov (United States)

    Lisakov, Sergey M.; Dessart, Luc; Hillier, D. John; Waldman, Roni; Livne, Eli

    2018-01-01

    The progenitors of low-luminosity Type II-Plateau supernovae (SNe II-P) are believed to be red supergiant (RSG) stars, but there is much disparity in the literature concerning their mass at core collapse and therefore on the main sequence. Here, we model the SN radiation arising from the low-energy explosion of RSG stars of 12, 25 and 27 M⊙ on the main sequence and formed through single star evolution. Despite the narrow range in ejecta kinetic energy (2.5-4.2 × 1050 erg) in our model set, the SN observables from our three models are significantly distinct, reflecting the differences in progenitor structure (e.g. surface radius, H-rich envelope mass and He-core mass). Our higher mass RSG stars give rise to Type II SNe that tend to have bluer colours at early times, a shorter photospheric phase, and a faster declining V-band light curve (LC) more typical of Type II-linear SNe, in conflict with the LC plateau observed for low-luminosity SNe II. The complete fallback of the CO core in the low-energy explosions of our high-mass RSG stars prevents the ejection of any 56Ni (nor any core O or Si), in contrast to low-luminosity SNe II-P, which eject at least 0.001 M⊙ of 56Ni. In contrast to observations, Type II SN models from higher mass RSGs tend to show an H α absorption that remains broad at late times (due to a larger velocity at the base of the H-rich envelope). In agreement with the analyses of pre-explosion photometry, we conclude that low-luminosity SNe II-P likely arise from low-mass rather than high-mass RSG stars.

  19. RESOLVING THE LUMINOSITY PROBLEM IN LOW-MASS STAR FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, Michael M. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Vorobyov, Eduard I., E-mail: michael.dunham@yale.edu, E-mail: eduard.vorobiev@univie.ac.at [Institute of Astronomy, University of Vienna, Vienna 1180 (Austria)

    2012-03-01

    We determine the observational signatures of protostellar cores by coupling two-dimensional radiative transfer calculations with numerical hydrodynamical simulations that predict accretion rates that both decline with time and feature short-term variability and episodic bursts caused by disk gravitational instability and fragmentation. We calculate the radiative transfer of the collapsing cores throughout the full duration of the collapse, using as inputs the core, disk, protostellar masses, radii, and mass accretion rates predicted by the hydrodynamical simulations. From the resulting spectral energy distributions, we calculate standard observational signatures (L{sub bol}, T{sub bol}, L{sub bol}/L{sub smm}) to directly compare to observations. We show that the accretion process predicted by these models reproduces the full spread of observed protostars in both L{sub bol}-T{sub bol} and L{sub bol}-M{sub core} space, including very low luminosity objects, provides a reasonable match to the observed protostellar luminosity distribution, and resolves the long-standing luminosity problem. These models predict an embedded phase duration shorter than recent observationally determined estimates (0.12 Myr versus 0.44 Myr), and a fraction of total time spent in Stage 0 of 23%, consistent with the range of values determined by observations. On average, the models spend 1.3% of their total time in accretion bursts, during which 5.3% of the final stellar mass accretes, with maximum values being 11.8% and 35.5% for the total time and accreted stellar mass, respectively. Time-averaged models that filter out the accretion variability and bursts do not provide as good of a match to the observed luminosity problem, suggesting that the bursts are required.

  20. Luminosity geometric reduction factor from colliding bunches with different lengths

    Energy Technology Data Exchange (ETDEWEB)

    Verdu-Andres, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-09-29

    In the interaction point of the future electron-Ion collider eRHIC, the electron beam bunches are at least one order of magnitude shorter than the proton beam bunches. With the introduction of a crossing angle, the actual number of collisions resulting from the bunch collision gets reduced. Here we derive the expression for the luminosity geometric reduction factor when the bunches of the two incoming beams are not equal.

  1. Silicon Sensors for High-Luminosity Trackers - RD50 Collaboration Status Report

    CERN Document Server

    Kuehn, Susanne

    2014-01-01

    The revised schedule for the Large Hadron Collider (LHC) upg rade foresees a significant increase of the luminosity of the LHC by upgrading towards the HL-LHC ( High Luminosity-LHC). The final upgrade is planned for around the year 2023, followed by the HL-LHC running. This is motivated by the need to harvest the maximum physics potenti al from the machine. It is clear that the high integrated luminosity of 3000 fb − 1 will result in very high radiation levels, which manifest a serious challenge for the detectors. This is espe cially true for the tracking detectors installed close to the interaction point. For HL-LHC, all-s ilicon central trackers are being studied in ATLAS, CMS and LHCb, with extremely radiation hard silico n sensors to be employed in the innermost layers. Within the RD50 Collaboration, a massive R&D; program is underway, with an open cooperation across experimental boundaries to deve lop silicon sensors with sufficient radiation tolerance. This report presents several researc h topics...

  2. THE BLACK HOLE MASS-GALAXY LUMINOSITY RELATIONSHIP FOR SLOAN DIGITAL SKY SURVEY QUASARS

    International Nuclear Information System (INIS)

    Salviander, S.; Shields, G. A.; Bonning, E. W.

    2015-01-01

    We investigate the relationship between the mass of the central supermassive black hole, M BH , and the host galaxy luminosity, L gal , in a sample of quasars from the Sloan Digital Sky Survey Data Release 7. We use composite quasar spectra binned by black hole mass and redshift to assess galaxy features that would otherwise be overwhelmed by noise in individual spectra. The black hole mass is calculated using the photoionization method, and the host galaxy luminosity is inferred from the depth of the Ca II H+K features in the composite spectra. We evaluate the evolution in the M BH -L gal relationship by examining the redshift dependence of Δ log M BH , the offset in M BH from the local M BH -L gal relationship. There is little systematic trend in Δ log M BH out to z = 0.8. Using the width of the [O III] emission line as a proxy for the stellar velocity dispersion, σ * , we find agreement of our derived host luminosities with the locally observed Faber-Jackson relation. This supports the utility of the width of the [O III] line as a proxy for σ * in statistical studies

  3. ON THE DEPENDENCE OF TYPE Ia SNe LUMINOSITIES ON THE METALLICITY OF THEIR HOST GALAXIES

    International Nuclear Information System (INIS)

    Moreno-Raya, Manuel E.; Mollá, Mercedes; López-Sánchez, Ángel R.; Galbany, Lluís; Vílchez, José Manuel; Rosell, Aurelio Carnero; Domínguez, Inmaculada

    2016-01-01

    The metallicity of the progenitor system producing a type Ia supernova (SN Ia) could play a role in its maximum luminosity, as suggested by theoretical predictions. We present an observational study to investigate if such a relationship exists. Using the 4.2 m William Herschel Telescope (WHT) we have obtained intermediate-resolution spectroscopy data of a sample of 28 local galaxies hosting SNe Ia, for which distances have been derived using methods independent of those based on SN Ia parameters. From the emission lines observed in their optical spectra, we derived the gas-phase oxygen abundance in the region where each SN Ia exploded. Our data show a trend, with an 80% of chance not being due to random fluctuation, between SNe Ia absolute magnitudes and the oxygen abundances of the host galaxies, in the sense that luminosities tend to be higher for galaxies with lower metallicities. This result seems likely to be in agreement with both the theoretically expected behavior and with other observational results. This dependence M B –Z might induce systematic errors when it is not considered when deriving SNe Ia luminosities and then using them to derive cosmological distances

  4. Spectral Properties, Generation Order Parameters, and Luminosities for Spin-powered X-Ray Pulsars

    Science.gov (United States)

    Wang, Wei; Zhao, Yongheng

    2004-02-01

    We show the spectral properties of 15 spin-powered X-ray pulsars, and the correlation between the average power-law photon index and spin-down rate. Generation order parameters (GOPs) based on polar cap models are introduced to characterize the X-ray pulsars. We calculate three definitions of generation order parameters arising from the different effects of magnetic and electric fields on photon absorption during cascade processes, and study the relations between the GOPs and spectral properties of X-ray pulsars. There exists a possible correlation between the photon index and GOP in our pulsar sample. Furthermore, we present a method stemming from the concept of GOPs to estimate the nonthermal X-ray luminosity for spin-powered pulsars. Then X-ray luminosity is calculated in the context of our polar cap accelerator model, which is consistent with most observed X-ray pulsar data. The ratio between the X-ray luminosity estimated by our method and the pulsar's spin-down power is consistent with the LX~10-3Lsd feature.

  5. ATLAS ITk Strip Detector for High-Luminosity LHC

    CERN Document Server

    Kroll, Jiri; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment is currently preparing for an upgrade of the tracking system in the course of the High-Luminosity LHC that is scheduled for 2026. The expected peak instantaneous luminosity up to 7.5E34 per second and cm2 corresponding to approximately 200 inelastic proton-proton interactions per beam crossing, radiation damage at an integrated luminosity of 3000/fb and hadron fluencies over 1E16 1 MeV neutron equivalent per cm2, as well as fast hardware tracking capability that will bring Level-0 trigger rate of a few MHz down to a Level-1 trigger rate below 1 MHz require a replacement of existing Inner Detector by an all-silicon Inner Tracker (ITk) with a pixel detector surrounded by a strip detector. The current prototyping phase, that is working with ITk Strip Detector consisting of a four-layer barrel and a forward region composed of six discs on each side of the barrel, has resulted in the ATLAS ITk Strip Detector Technical Design Report (TDR), which starts the pre-production readiness phase at the ...

  6. Theoretical stellar luminosity functions and globular cluster ages and compositions

    International Nuclear Information System (INIS)

    Ratcliff, S.J.

    1985-01-01

    The ages and chemical compositions of the stars in globular clusters are of great interest, particularly because age estimates from the well-known exercise of fitting observed color-magnitude diagrams to theoretical predictions tend to yield ages in excess of the Hubble time (an estimate to the age of the Universe) in standard cosmological models, for currently proposed high values of Hubble's constant (VandenBerg 1983). Relatively little use has been made of stellar luminosity functions of the globular clusters, for which reliable observations are now becoming available, to constrain the ages or compositions. The comparison of observed luminosity functions to theoretical ones allows one to take advantage of information not usually used, and has the advantage of being relatively insensitive to our lack of knowledge of the detailed structure of stellar envelopes and atmospheres. A computer program was developed to apply standard stellar evolutionary theory, using the most recently available input physics (opacities, nuclear reaction rates), to the calculation of the evolution of low-mass Population II stars. An algorithm for computing luminosity functions from the evolutionary tracks was applied to sets of tracks covering a broad range of chemical compositions and ages, such as may be expected for globular clusters

  7. ATLAS ITk Strip Detector for High-Luminosity LHC

    CERN Document Server

    Kroll, Jiri; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment is currently preparing for an upgrade of the tracking system in the course of the High-Luminosity LHC that is scheduled for 2026. The expected peak instantaneous luminosity up to $7.5\\times10^{34}\\;\\mathrm{cm}^{-2}\\mathrm{s}^{-1}$ corresponding to approximately 200 inelastic proton-proton interactions per beam crossing, radiation damage at an integrated luminosity of $3000\\;\\mathrm{fb}^{-1}$ and hadron fluencies over $2\\times10^{16}\\;\\mathrm{n}_{\\mathrm{eq}}/\\mathrm{cm}^{2}$, as well as fast hardware tracking capability that will bring Level-0 trigger rate of a few MHz down to a Level-1 trigger rate below 1 MHz require a replacement of existing Inner Detector by an all-silicon Inner Tracker with a pixel detector surrounded by a strip detector. The current prototyping phase, that is working with ITk Strip Detector consisting of a four-layer barrel and a forward region composed of six disks on each side of the barrel, has resulted in the ATLAS Inner Tracker Strip Detector Technical Design R...

  8. THE z = 5 QUASAR LUMINOSITY FUNCTION FROM SDSS STRIPE 82

    International Nuclear Information System (INIS)

    McGreer, Ian D.; Fan Xiaohui; Jiang Linhua; Richards, Gordon T.; Strauss, Michael A.; Ross, Nicholas P.; White, Martin; Shen Yue; Schneider, Donald P.; Brandt, W. Niel; Myers, Adam D.; DeGraf, Colin; Glikman, Eilat; Ge Jian; Streblyanska, Alina

    2013-01-01

    We present a measurement of the Type I quasar luminosity function at z = 5 using a large sample of spectroscopically confirmed quasars selected from optical imaging data. We measure the bright end (M 1450 2 , then extend to lower luminosities (M 1450 2 of deep, coadded imaging in the SDSS Stripe 82 region (the celestial equator in the Southern Galactic Cap). The faint sample includes 14 quasars with spectra obtained as ancillary science targets in the SDSS-III Baryon Oscillation Spectroscopic Survey, and 59 quasars observed at the MMT and Magellan telescopes. We construct a well-defined sample of 4.7 1450 * ∼-27). The bright-end slope is steep (β ∼ 1450 < –26) from z = 5 to z = 6 than from z = 4 to z = 5, suggesting a more rapid decline in quasar activity at high redshift than found in previous surveys. Our model for the quasar luminosity function predicts that quasars generate ∼30% of the ionizing photons required to keep hydrogen in the universe ionized at z = 5.

  9. An ionization chamber shower detector for the LHC luminosity monitor

    CERN Document Server

    Beche, J F; Datte, P S; Haguenauer, Maurice; Manfredi, P F; Millaud, J E; Placidi, Massimo; Ratti, L; Re, V; Riot, V J; Schmickler, Hermann; Speziali, V; Turner, W C

    2000-01-01

    The front IR quadrupole absorbers (TAS) and the IR neutral particle absorbers (TAN) in the high luminosity insertions of the Large Hadron Collider (LHC) each absorb approximately 1.8 TeV of forward collision products on average per pp interaction (~235 W at design luminosity 10/sup 34/ cm/sup -2/ s/sup -1/). This secondary particle flux can be exploited to provide a useful storage ring operations tool for optimization of luminosity. A novel segmented, multi-gap, pressurized gas ionization chamber is being developed for sampling the energy deposited near the maxima of the hadronic/electromagnetic showers in these absorbers. The system design choices have been strongly influenced by optimization of signal to noise ratio and by the very high radiation environment. The ionization chambers are instrumented with low noise, fast, pulse shaping electronics to be capable of resolving individual bunch crossings at 40 MHz. Data on each bunch are to be separately accumulated over multiple bunch crossings until the desire...

  10. A Search for Low-Luminosity BL Lacertae Objects

    Science.gov (United States)

    Rector, Travis A.; Stocke, John T.; Perlman, Eric S.

    1999-05-01

    Many properties of BL Lacs have become explicable in terms of the ``relativistic beaming'' hypothesis, whereby BL Lacs are FR 1 radio galaxies viewed nearly along the jet axis. However, a possible problem with this model is that a transition population between beamed BL Lacs and unbeamed FR 1 galaxies has not been detected. A transition population of ``low-luminosity BL Lacs'' was predicted to exist in abundance in X-ray-selected samples such as the Einstein Extended Medium Sensitivity Survey (EMSS) by Browne & Marcha. However, these BL Lacs may have been misidentified as clusters of galaxies. We have conducted a search for such objects in the EMSS with the ROSAT High-Resolution Imager (HRI) here we present ROSAT HRI images, optical spectra, and VLA radio maps for a small number of BL Lacs that were previously misidentified in the EMSS catalog as clusters of galaxies. While these objects are slightly lower in luminosity than other EMSS BL Lacs, their properties are too similar to the other BL Lacs in the EMSS sample to ``bridge the gap'' between BL Lacs and FR 1 radio galaxies. Also, the number of new BL Lacs found is too low to alter significantly the X-ray luminosity function or value for the X-ray-selected EMSS BL Lac sample. Thus, these observations do not explain fully the discrepancy between the X-ray- and radio-selected BL Lac samples.

  11. The GRB variability/peak luminosity correlation: new results

    International Nuclear Information System (INIS)

    Guidorzi, C.; Rossi, F.; Hurley, K.; Mundell, C.G.

    2005-01-01

    We test the correlation between time variability and isotropic-equivalent peak luminosity found by Reichart et al. (ApJ, 552 (2001) 57) using a set of 26 Gamma-Ray Bursts (GRBs) with known redshift. We confirm the correlation, thought with a larger spread around the best-fit power-law obtained by Reichart et al. which in turn does not provide an acceptable description any longer. In addiction, we find no evidence for correlation between variability and beaming-corrected peak luminosity for a subset of 14 GRBs whose beaming angles have been taken from Ghirlanda et al. (ApJ, 616 (2004) 331). Finally, we investigate the possible connection for some GRBs between the location in the variability/peak luminosity space and some afterglow properties, such as the detectability in the optical band, by adding some GRBs whose redshifts, unknown from direct measurements, have been derived assuming the Amati at al. (AeA, 390 (2002) 81) relationship

  12. Study on explosives and their quality performance

    Energy Technology Data Exchange (ETDEWEB)

    Nabiullah, M.; Pingua, B.M.P.; Jagdish Khan, M.; Emranuzzaman [Central Mining Research Institute, Dhanbad (India)

    2005-07-01

    There are about forty suppliers of explosive and blasting accessories in India manufacturing site mixed emulsion, site mixed slurry, ANFO, HANFO, packed products, and blasting accessories of use in surface and underground mines. A field laboratory was set up to measure explosive properties of explosive samples, cast booster, detonating fuse, detonators, cord relay, MS connector, and shock tubes. Density, velocity of detonation, water percentage, water resistance, and energy output were considered as the important properties of explosives. A rating system was designed for selection of good explosive products. The delay interval and delay scattering in cord relay and shock tube was studied to improve blast performance. This paper describes in detail the method of measurement and vender rating system for explosive products as per marking system accepted by Coal India. 12 refs., 4 figs., 22 tabs.

  13. A PHYSICAL MODEL FOR THE 0 {approx}< z {approx}< 8 REDSHIFT EVOLUTION OF THE GALAXY ULTRAVIOLET LUMINOSITY AND STELLAR MASS FUNCTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Tacchella, Sandro; Carollo, C. Marcella [Department of Physics, Institute for Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland); Trenti, Michele, E-mail: tasandro@phys.ethz.ch [Kavli Institute for Cosmology and Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom)

    2013-05-10

    We present a model to understand the redshift evolution of the UV luminosity and stellar mass functions of Lyman break galaxies. Our approach is based on the assumption that the luminosity and stellar mass of a galaxy is related to its dark-matter (DM) halo assembly and gas infall rate. Specifically, galaxies experience a burst of star formation at the halo assembly time, followed by a constant star formation rate, representing a secular star formation activity sustained by steady gas accretion. Star formation from steady gas accretion is the dominant contribution to the galaxy UV luminosity at all redshifts. The model is calibrated by constructing a galaxy luminosity versus halo mass relation at z = 4 via abundance matching. After this luminosity calibration, the model naturally fits the z = 4 stellar mass function, and correctly predicts the evolution of both luminosity and stellar mass functions from z = 0 to z = 8. While the details of star formation efficiency and feedback are hidden within our calibrated luminosity versus halo mass relation, our study highlights that the primary driver of galaxy evolution across cosmic time is the buildup of DM halos, without the need to invoke a redshift-dependent efficiency in converting gas into stars.

  14. Improved luminosity determination in pp collisions at $\\sqrt{s}$ = 7 TeV using the ATLAS detector at the LHC

    CERN Document Server

    Aad, Georges; Abbott, Brad; Abdallah, Jalal; Abdel Khalek, Samah; Abdelalim, Ahmed Ali; Abdinov, Ovsat; Aben, Rosemarie; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Agustoni, Marco; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Francisco; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Ammosov, Vladimir; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Atkinson, Markus; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Basye, Austin; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertolucci, Federico; Besana, Maria Ilaria; Besjes, Geert-Jan; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bittner, Bernhard; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boek, Thorsten Tobias; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Booth, Chris; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Branchini, Paolo; Brandenburg, George; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Brelier, Bertrand; Bremer, Johan; Brendlinger, Kurt; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brown, Gareth; Brown, Heather; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Bugge, Lars; Bulekov, Oleg; Bundock, Aaron Colin; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Büscher, Volker; Bussey, Peter; Buszello, Claus-Peter; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Byszewski, Marcin; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cameron, David; Caminada, Lea Michaela; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Cantrill, Robert; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavaliere, Viviana; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chan, Kevin; Chang, Philip; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Xin; Chen, Yujiao; Cheplakov, Alexander; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Ilektra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Cirkovic, Predrag; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Cole, Stephen; Colijn, Auke-Pieter; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colombo, Tommaso; Colon, German; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Dassoulas, James; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davignon, Olivier; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lorenzi, Francesco; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; De Zorzi, Guido; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dechenaux, Benjamin; Dedovich, Dmitri; Degenhardt, James; Del Papa, Carlo; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dinut, Florin; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobinson, Robert; Dobos, Daniel; Dobson, Ellie; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Dohmae, Takeshi; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dotti, Andrea; Dova, Maria-Teresa; Doxiadis, Alexander; Doyle, Tony; Dressnandt, Nandor; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Duda, Dominik; Dudarev, Alexey; Dudziak, Fanny; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edson, William; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fonseca Martin, Teresa; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fowler, Andrew; Fox, Harald; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Frank, Tal; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Conrad; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gaponenko, Andrei; Garberson, Ford; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilchriese, Murdock; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Giusti, Paolo; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Goeringer, Christian; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gonzalez, Saul; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Göpfert, Thomas; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Gosdzik, Bjoern; Goshaw, Alfred; Gosselink, Martijn; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guest, Daniel; Guicheney, Christophe; Guindon, Stefan; Gul, Umar; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Haller, Johannes; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hawkins, Donovan; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hayward, Helen; Haywood, Stephen; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Henß, Tobias; Medina Hernandez, Carlos; Hernández Jiménez, Yesenia; Herrberg, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Hong, Tae Min; Hooft van Huysduynen, Loek; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jana, Dilip; Jansen, Eric; Jansen, Hendrik; Jantsch, Andreas; Janus, Michel; Jared, Richard; Jarlskog, Göran; Jeanty, Laura; Jen-La Plante, Imai; Jennens, David; Jenni, Peter; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Joram, Christian; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagounis, Michael; Karakostas, Konstantinos; Karnevskiy, Mikhail; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazama, Shingo; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Kekelidze, George; Keller, John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kitamura, Takumi; Kittelmann, Thomas; Kiuchi, Kenji; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Knecht, Neil; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koenig, Sebastian; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollefrath, Michael; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Köneke, Karsten; König, Adriaan; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Koperny, Stefan; Köpke, Lutz; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kreiss, Sven; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lambourne, Luke; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lane, Jenna; Lang, Valerie Susanne; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larner, Aimee; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Lepold, Florian; Leroy, Claude; Lessard, Jean-Raphael; Lester, Christopher; Lester, Christopher Michael; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Lulu; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Losty, Michael; Lou, XinChou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lukas, Wolfgang; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lundberg, Björn; Lundberg, Johan; Lundberg, Olof; Lund-Jensen, Bengt; Lundquist, Johan; Lungwitz, Matthias; Lynn, David; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Maddocks, Harvey Jonathan; Mader, Wolfgang; Maenner, Reinhard; Maeno, Mayuko; Maeno, Tadashi; Magnoni, Luca; Magradze, Erekle; Mahboubi, Kambiz; Mahmoud, Sara; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Mangeard, Pierre-Simon; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany Andreina; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marroquim, Fernando; Marshall, Zach; Martens, Kalen; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian; Martin, Brian Thomas; Martin, Jean-Pierre; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martin-Haugh, Stewart; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mättig, Peter; Mättig, Stefan; Mattravers, Carly; Maurer, Julien; Maxfield, Stephen; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzaferro, Luca; Mazzanti, Marcello; Mc Donald, Jeffrey; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Mitrevski, Jovan; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Moeller, Victoria; Mohapatra, Soumya; Mohr, Wolfgang; Moles-Valls, Regina; Molfetas, Angelos; Mönig, Klaus; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Möser, Nicolas; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mueller, Felix; Mueller, James; Mueller, Klemens; Mueller, Timo; Muenstermann, Daniel; Müller, Thomas; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Negrini, Matteo; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Norberg, Scarlet; Nordberg, Markus; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Pani, Priscilla; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Paredes Hernandez, Daniela; Park, Woochun; Parker, Michael Andrew; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pashapour, Shabnaz; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Lopez, Sebastian; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Pelikan, Daniel; Peng, Haiping; Penning, Bjoern; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Pinto, Belmiro; Pizio, Caterina; Plamondon, Mathieu; Pleier, Marc-Andre; Plotnikova, Elena; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Pohl, David-leon; Pohl, Martin; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Price, Darren; Price, Joe; Price, Lawrence; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radeka, Veljko; Radescu, Voica; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Roe, Adam; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romeo, Gaston; Romero Adam, Elena; Rompotis, Nikolaos; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Anthony; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Christian; Rudolph, Gerald; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rumyantsev, Leonid; Rurikova, Zuzana; Rusakovich, Nikolai; Rutherfoord, John; Ruwiedel, Christoph; Ruzicka, Pavel; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salek, David; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Tanya; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Yuichi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Emmanuel; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savu, Dan Octavian; Sawyer, Lee; Saxon, David; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scannicchio, Diana; Scarcella, Mark; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R. Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitz, Martin; Schneider, Basil; Schnoor, Ulrike; Schoening, Andre; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schroeder, Christian; Schroer, Nicolai; Schultens, Martin Johannes; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwegler, Philipp; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Schwindt, Thomas; Schwoerer, Maud; Sciolla, Gabriella; Scott, Bill; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekula, Stephen; Selbach, Karoline Elfriede; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Seuster, Rolf; Severini, Horst; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shiyakova, Mariya; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silbert, Ohad; Silva, José; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simoniello, Rosa; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sircar, Anirvan; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skottowe, Hugh Philip; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snyder, Scott; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Solovyev, Victor; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soualah, Rachik; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St Denis, Richard Dante; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Staude, Arnold; Stavina, Pavel; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stern, Sebastian; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Styles, Nicholas Adam; Su, Dong; Subramania, Halasya Siva; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Suzuki, Yuta; Svatos, Michal; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanasijczuk, Andres Jorge; Tani, Kazutoshi; Tannoury, Nancy; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Tayalati, Yahya; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teinturier, Marthe; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Terada, Susumu; Terashi, Koji; Terron, Juan; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Theveneaux-Pelzer, Timothée; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thong, Wai Meng; Thun, Rudolf; Tian, Feng; Tibbetts, Mark James; Tic, Tomáš; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tisserant, Sylvain; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tudorache, Alexandra; Tudorache, Valentina; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Turra, Ruggero; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valenta, Jan; Valentinetti, Sara; Valero, Alberto; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Vulpen, Ivo; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vazquez Schroeder, Tamara; Vegni, Guido; Veillet, Jean-Jacques; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Virzi, Joseph; Vitells, Ofer; Viti, Michele; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Adrian; Vokac, Petr; Volpi, Guido; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wahrmund, Sebastian; Wakabayashi, Jun; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Walsh, Brian; Wang, Chiho; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Rui; Wang, Song-Ming; Wang, Tan; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watanabe, Ippei; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weigell, Philipp; Weingarten, Jens; Weiser, Christian; Wells, Phillippa; Wenaus, Torre; Wendland, Dennis; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Wetter, Jeffrey; Weydert, Carole; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wijeratne, Peter Alexander; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Wei-Cheng; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wraight, Kenneth; Wright, Michael; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wynne, Benjamin; Xella, Stefania; Xiao, Meng; Xie, Song; Xu, Chao; Xu, Da; Yabsley, Bruce; Yacoob, Sahal; Yamada, Miho; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamanaka, Takashi; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Liwen; Yao, Yushu; Yasu, Yoshiji; Ybeles Smit, Gabriel Valentijn; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Rikutaro; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, Dantong; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zanello, Lucia; Zanzi, Daniele; Zaytsev, Alexander; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Ženiš, Tibor; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zimin, Nikolai; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Zinonos, Zinonas; Ziolkowski, Michael; Zitoun, Robert; Živković, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz

    2013-08-14

    The luminosity calibration for the ATLAS detector at the LHC during pp collisions at $\\sqrt{s}$ = 7 TeV in 2010 and 2011 is presented. Evaluation of the luminosity scale is performed using several luminosity-sensitive detectors, and comparisons are made of the long-term stability and accuracy of this calibration applied to the pp collisions at $\\sqrt{s}$ = 7 TeV. A luminosity uncertainty of $\\delta L/L = \\pm$ 3.5% is obtained for the 47 pb-1 of data delivered to ATLAS in 2010, and an uncertainty of $\\delta L/L = \\pm$ 1.8% is obtained for the 5.5 fb-1 delivered in 2011.

  15. EVOLUTION OF GALAXY LUMINOSITY FUNCTION USING PHOTOMETRIC REDSHIFTS

    International Nuclear Information System (INIS)

    Ramos, B. H. F.; Pellegrini, P. S.; Da Costa, L. N.; Maia, M. A. G.; Ogando, R. L. C.; De Simoni, F.; Benoist, C.; Makler, M.; Mesquita, A. A.

    2011-01-01

    We examine the impact of using photometric redshifts for studying the evolution of both the global galaxy luminosity function (LF) and that for different galaxy types. To this end, we compare the LFs obtained using photometric redshifts from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) D1 field with those from the spectroscopic survey VIMOS VLT Deep Survey (VVDS) comprising ∼4800 galaxies. We find that for z ≤ 2.0, in the interval of magnitudes considered by this survey, the LFs obtained using photometric and spectroscopic redshifts show a remarkable agreement. This good agreement led us to use all four Deep fields of the CFHTLS comprising ∼386,000 galaxies to compute the LF of the combined fields and directly estimate the error in the parameters based on the field-to-field variation. We find that the characteristic absolute magnitude M* of Schechter fits fades by ∼0.7 mag from z ∼ 1.8 to z ∼ 0.3, while the characteristic density φ* increases by a factor of ∼4 in the same redshift interval. We use the galaxy classification provided by the template fitting program used to compute photometric redshifts and split the sample into galaxy types. We find that these Schechter parameters evolve differently for each galaxy type, an indication that their evolution is a combination of several effects: galaxy merging, star formation quenching, and mass assembly. All these results are compatible with those obtained by different spectroscopic surveys such as VVDS, DEEP2, and zCosmos, which reinforces the fact that photometric redshifts can be used to study galaxy evolution, at least for the redshift bins adopted so far. This is of great interest since future very large imaging surveys containing hundreds of millions of galaxies will allow us to obtain important precise measurements to constrain the evolution of the LF and to explore the dependence of this evolution on morphology and/or color helping constrain the mechanisms of galaxy evolution.

  16. A composite plot of far-infrared versus radio luminosity, and the origin of far-infrared luminosity in quasars

    International Nuclear Information System (INIS)

    Sopp, H.M.; Alexander, P.

    1991-01-01

    We have constructed a composite plot of far-infrared versus radioluminosity for late-type galaxies, Seyferts, quasars and radio galaxies. The most striking result is that the radio and far-infrared luminosities of radio-quiet quasars are correlated and follow the same correlation as normal star-forming galaxies and ultra-luminous infrared galaxies, whereas the radio-loud quasars have luminosities in both bands similar to those of radio galaxies. We conclude that the far-infrared emission from radio-quiet quasars is from star-forming host galaxies and not from active galactic nuclei. The far-infrared radio plot may be a powerful discriminator between host galaxy type. (author)

  17. Absolute in situ energy calibration of luminosity calorimeters in the DELPHI experiment at LEP

    International Nuclear Information System (INIS)

    Bugge, L.; Dam, M.; Read, A.L.; Myrheim, J.; Skjevling, G.

    1992-07-01

    Methods to perform the absolute energy calibration of DELPHI's Small Angle Tagger luminosity calorimeters at LEP are presented and compared. The input was small angle Bhabha scattering events. A significant non-linearity in the response of the calorimeters was observed. The conjugate gradient method was applied to solve the least square problem. This method is particularly useful for least squares problems which are large, ill-behaved or even singular, and for cases with a sparse coefficient matrix. 8 refs., 14 figs., 2 tabs

  18. A SYSTEMATIC SEARCH FOR MOLECULAR OUTFLOWS TOWARD CANDIDATE LOW-LUMINOSITY PROTOSTARS AND VERY LOW LUMINOSITY OBJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Kamber R.; Shirley, Yancy L. [Steward Observatory, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Dunham, Michael M. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States)

    2012-10-01

    We present a systematic single-dish search for molecular outflows toward a sample of nine candidate low-luminosity protostars and 30 candidate very low luminosity objects (VeLLOs; L{sub int} {<=} 0.1 L{sub Sun }). The sources are identified using data from the Spitzer Space Telescope cataloged by Dunham et al. toward nearby (D < 400 pc) star-forming regions. Each object was observed in {sup 12}CO and {sup 13}CO J = 2 {yields} 1 simultaneously using the sideband separating ALMA Band-6 prototype receiver on the Heinrich Hertz Telescope at 30'' resolution. Using five-point grid maps, we identify five new potential outflow candidates and make on-the-fly maps of the regions surrounding sources in the dense cores B59, L1148, L1228, and L1165. Of these new outflow candidates, only the map of B59 shows a candidate blue outflow lobe associated with a source in our survey. We also present larger and more sensitive maps of the previously detected L673-7 and the L1251-A-IRS4 outflows and analyze their properties in comparison to other outflows from VeLLOs. The accretion luminosities derived from the outflow properties of the VeLLOs with detected CO outflows are higher than the observed internal luminosity of the protostars, indicating that these sources likely had higher accretion rates in the past. The known L1251-A-IRS3 outflow is detected but not re-mapped. We do not detect clear, unconfused signatures of red and blue molecular wings toward the other 31 sources in the survey indicating that large-scale, distinct outflows are rare toward this sample of candidate protostars. Several potential outflows are confused with the kinematic structure in the surrounding core and cloud. Interferometric imaging is needed to disentangle large-scale molecular cloud kinematics from these potentially weak protostellar outflows.

  19. A SYSTEMATIC SEARCH FOR MOLECULAR OUTFLOWS TOWARD CANDIDATE LOW-LUMINOSITY PROTOSTARS AND VERY LOW LUMINOSITY OBJECTS

    International Nuclear Information System (INIS)

    Schwarz, Kamber R.; Shirley, Yancy L.; Dunham, Michael M.

    2012-01-01

    We present a systematic single-dish search for molecular outflows toward a sample of nine candidate low-luminosity protostars and 30 candidate very low luminosity objects (VeLLOs; L int ≤ 0.1 L ☉ ). The sources are identified using data from the Spitzer Space Telescope cataloged by Dunham et al. toward nearby (D 12 CO and 13 CO J = 2 → 1 simultaneously using the sideband separating ALMA Band-6 prototype receiver on the Heinrich Hertz Telescope at 30'' resolution. Using five-point grid maps, we identify five new potential outflow candidates and make on-the-fly maps of the regions surrounding sources in the dense cores B59, L1148, L1228, and L1165. Of these new outflow candidates, only the map of B59 shows a candidate blue outflow lobe associated with a source in our survey. We also present larger and more sensitive maps of the previously detected L673-7 and the L1251-A-IRS4 outflows and analyze their properties in comparison to other outflows from VeLLOs. The accretion luminosities derived from the outflow properties of the VeLLOs with detected CO outflows are higher than the observed internal luminosity of the protostars, indicating that these sources likely had higher accretion rates in the past. The known L1251-A-IRS3 outflow is detected but not re-mapped. We do not detect clear, unconfused signatures of red and blue molecular wings toward the other 31 sources in the survey indicating that large-scale, distinct outflows are rare toward this sample of candidate protostars. Several potential outflows are confused with the kinematic structure in the surrounding core and cloud. Interferometric imaging is needed to disentangle large-scale molecular cloud kinematics from these potentially weak protostellar outflows.

  20. The Quest for High Luminosity in Hadron Colliders (413th Brookhaven Lecture)

    International Nuclear Information System (INIS)

    Fischer, Wolfram

    2006-01-01

    In 1909, by bombarding a gold foil with alpha particles from a radioactive source, Ernest Rutherford and coworkers learned that the atom is made of a nucleus surrounded by an electron cloud. Ever since, scientists have been probing deeper and deeper into the structure of matter using the same technique. With increasingly powerful machines, they accelerate beams of particles to higher and higher energies, to penetrate more forcefully into the matter being investigated and reveal more about the contents and behavior of the unknown particle world. To achieve the highest collision energies, projectile particles must be as heavy as possible, and collide not with a fixed target but another beam traveling in the opposite direction. These experiments are done in machines called hadron colliders, which are some of the largest and most complex research tools in science. Five such machines have been built and operated, with Brookhaven's Relativistic Heavy Ion Collider (RHIC) currently the record holder for the total collision energy. One more such machine is under construction. Colliders have two vital performance parameters on which their success depends: one is their collision energy, and the other, the number of particle collisions they can produce, which is proportional to a quantity known as the luminosity. One of the tremendous achievements in the world's latest collider, RHIC, is the amazing luminosity that it produces in addition to its high energy. To learn about the performance evolution of these colliders and the way almost insurmountable difficulties can be overcome, especially in RHIC, join Wolfram Fischer, a physicist in the Collider-Accelerator (C-A) Department, who will give the next Brookhaven Lecture, on 'The Quest for High Luminosity in Hadron Colliders.'

  1. Construction of the ATLAS end cap electromagnetic calorimeter and study of its performances; Construction du bouchon du calorimetre electromagnetique d'ATLAS et etudes de ses performances

    Energy Technology Data Exchange (ETDEWEB)

    Barrillon, P

    2002-09-01

    ATLAS is one of the four experiments which will take place at the LHC, the CERN future protons collider. This accelerator, which should start in 2007, will allow to continue the studies carried out by its predecessors, as the standard model Higgs boson and new physics searches. The very high luminosity -10 fb{sup -1} during the first three functioning years, then 100 fb{sup -1}- and the 14 TeV in the frame center will ease these studies. The Centre de Physique des Particules de Marseille took part in the ATLAS collaboration, taking in charge half of the End-cap electromagnetic calorimeter modules construction. The description of this sub-detector and the construction steps, in particular the electrical tests which allow the stacking validation, are presented in this document. These tests results, obtained for the live first production modules, are analysed. The pre-series module (module 0) performances, obtained with beam tests performed at CERN in 1999, are also presented. The detector uniformity studies have allowed to perform important improvements on the calorimeter components. A 0.6% global constant term has been determined in the End-cap internal region (wheel). (author)

  2. Planetary Nebulae in the Solar Neighbourhood: Statistics, Distance Scale and Luminosity Function

    Science.gov (United States)

    Frew, David J.

    2008-07-01

    An accurate census of the nearest planetary nebulae (PNe) is needed for calculations of the total number, space density, scale height, and birth rate of PNe in the Galaxy, to understand the dynamics of an evolving nebula and its relationship to the cooling history of the central star, and also to provide an unbiased sample to investigate the frequency of binary central stars and their role in the formation and shaping of these objects. This study presents the most refined volume-limited survey of PNe known to date. Integrated H-alpha fluxes for over 400 mostly evolved PNe are presented, based primarily on data from the Southern H-alpha Sky Survey Atlas (SHASSA) and the Virginia Tech Spectral-Line Survey (VTSS). Aperture photometry on the digital images was performed to extract H-alpha+[NII] fluxes. The [NII] contribution was then de-convolved using literature data, new data from slit spectra, or spectrophotometric data from the Wisconsin H-Alpha Mapper (WHAM) also obtained as part of this project. Comparison with previous work shows that the flux scale presented here has no significant zero-point error. The H-alpha fluxes are used to determine new Zanstra temperatures for those PNe with accurate central star photometry, calculating surface-brightness distances for each PN in the sample, and in conjunction with accurate [OIII] fluxes, new absolute PN magnitudes for delineating the faint end of the PN luminosity function. A spectroscopic survey of a range of MASH PNe is also presented. New emission-line intensities for 60 PNe are given, including a preliminary discussion of the chemical abundances of this sample. New distances have been determined for a large number of PNe, by either critically examining the literature, or by deriving new extinction and kinematic distances where suitable. For all PNe not amenable to these approaches, distances were estimated from a new H-alpha surface brightness-radius (SB-r) relation. The Hα SB-r relation covers >6 dex in SB, and

  3. Experimental Study on Revetec Engine Cam Performance

    International Nuclear Information System (INIS)

    Gasim, Maisara Mohyeldin; Chui, Lee Giok; Anwar, Khirul Azhar bin

    2012-01-01

    In Revetec engine (three-lobed) cam replaces the crankshaft to convert the reciprocating motion of the engine piston, to a rotating motion in the drive line. Since the cam controls the piston movement, the cam profile has a great effect on engine performance. In this paper an experimental study was done to a (three- lobed) cam with Cycloidal motion profile but with different ratios between the base circle radius of the cam and the radius of the roller follower. DEWESoft was used to find the displacement and the vibration of the piston, and compare the actual results from the test with the theoretical results from the cam profile equation. The results showed that there is a periods of miss contact between the follower and the cam when the ratio between the base circle radius of the cam and the radius of the roller follower is less than a certain value, and also increasing of vibration. The suggested ratio between the cam and follower radius is to be more than 2:1.

  4. Tack Coat Performance and Materials Study

    Science.gov (United States)

    2017-06-01

    A good bond provided by a tack coat can improve performance of asphalt overlays. The objectives of this research were: (1) develop a method for testing the bond between pavement layers; (2) evaluate the bond performance and predict long-term performa...

  5. Cooperation, Technology, and Performance: A Case Study.

    Science.gov (United States)

    Cavanagh, Thomas; Dickenson, Sabrina; Brandt, Suzanne

    1999-01-01

    Describes the CTP (Cooperation, Technology, and Performance) model and explains how it is used by the Department of Veterans Affairs-Veteran's Benefit Administration (VBA) for training. Discusses task analysis; computer-based training; cooperative-based learning environments; technology-based learning; performance-assessment methods; courseware…

  6. Near-IR period-luminosity relations for pulsating stars in ω Centauri (NGC 5139)

    Science.gov (United States)

    Navarrete, C.; Catelan, M.; Contreras Ramos, R.; Alonso-García, J.; Gran, F.; Dékány, I.; Minniti, D.

    2017-08-01

    Aims: The globular cluster ω Centauri (NGC 5139) hosts hundreds of pulsating variable stars of different types, thus representing a treasure trove for studies of their corresponding period-luminosity (PL) relations. Our goal in this study is to obtain the PL relations for RR Lyrae and SX Phoenicis stars in the field of the cluster, based on high-quality, well-sampled light curves in the near-infrared (IR). Methods: Observations were carried out using the VISTA InfraRed CAMera (VIRCAM) mounted on the Visible and Infrared Survey Telescope for Astronomy (VISTA). A total of 42 epochs in J and 100 epochs in KS were obtained, spanning 352 days. Point-spread function photometry was performed using DoPhot and DAOPHOT crowded-field photometry packages in the outer and inner regions of the cluster, respectively. Results: Based on the comprehensive catalog of near-IR light curves thus secured, PL relations were obtained for the different types of pulsators in the cluster, both in the J and KS bands. This includes the first PL relations in the near-IR for fundamental-mode SX Phoenicis stars. The near-IR magnitudes and periods of Type II Cepheids and RR Lyrae stars were used to derive an updated true distance modulus to the cluster, with a resulting value of (m - M)0 = 13.708 ± 0.035 ± 0.10 mag, where the error bars correspond to the adopted statistical and systematic errors, respectively. Adding the errors in quadrature, this is equivalent to a heliocentric distance of 5.52 ± 0.27 kpc. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, with the VISTA telescope (project ID 087.D-0472, PI R. Angeloni).

  7. Simulating the X-ray luminosity of Be X-ray binaries: the case for black holes versus neutron stars

    Science.gov (United States)

    Brown, R. O.; Ho, W. C. G.; Coe, M. J.; Okazaki, A. T.

    2018-04-01

    There are over 100 Be stars that are known to have neutron star companions but only one such system with a black hole. Previous theoretical work suggests this is not due to their formation but due to differences in X-ray luminosity. It has also been proposed that the truncation of the Be star's circumstellar disc is dependent on the mass of the compact object. Hence, Be star discs in black hole binaries are smaller. Since accretion onto the compact object from the Be star's disc is what powers the X-ray luminosity, a smaller disc in black hole systems leads to a lower luminosity. In this paper, simulations are performed with a range of eccentricities and compact object mass. The disc's size and density are shown to be dependent on both quantities. Mass capture and, in turn, X-ray luminosity are heavily dependent on the size and density of the disc. Be/black hole binaries are expected to be up to ˜10 times fainter than Be/neutron star binaries when both systems have the same eccentricity and can be 100 times fainter when comparing systems with different eccentricity.

  8. The luminosity function at z ∼ 8 from 97 Y-band dropouts: Inferences about reionization

    International Nuclear Information System (INIS)

    Schmidt, Kasper B.; Treu, Tommaso; Kelly, Brandon C.; Trenti, Michele; Bradley, Larry D.; Stiavelli, Massimo; Oesch, Pascal A.; Holwerda, Benne W.; Shull, J. Michael

    2014-01-01

    We present the largest search to date for Y-band dropout galaxies (z ∼ 8 Lyman break galaxies, LBGs) based on 350 arcmin 2 of Hubble Space Telescope observations in the V, Y, J, and H bands from the Brightest of Reionizing Galaxies (BoRG) survey. In addition to previously published data, the BoRG13 data set presented here includes approximately 50 arcmin 2 of new data and deeper observations of two previous BoRG pointings, from which we present 9 new z ∼ 8 LBG candidates, bringing the total number of BoRG Y-band dropouts to 38 with 25.5 ≤ m J ≤ 27.6 (AB system). We introduce a new Bayesian formalism for estimating the galaxy luminosity function, which does not require binning (and thus smearing) of the data and includes a likelihood based on the formally correct binomial distribution as opposed to the often-used approximate Poisson distribution. We demonstrate the utility of the new method on a sample of 97 Y-band dropouts that combines the bright BoRG galaxies with the fainter sources published in Bouwens et al. from the Hubble Ultra Deep Field and Early Release Science programs. We show that the z ∼ 8 luminosity function is well described by a Schechter function over its full dynamic range with a characteristic magnitude M ⋆ =−20.15 −0.38 +0.29 , a faint-end slope of α=−1.87 −0.26 +0.26 , and a number density of log 10  ϕ ⋆ [Mpc −3 ]=−3.24 −0.24 +0.25 . Integrated down to M = –17.7, this luminosity function yields a luminosity density log 10  ϵ[erg s −1 Hz −1 Mpc −3 ]=25.52 −0.05 +0.05 . Our luminosity function analysis is consistent with previously published determinations within 1σ. The error analysis suggests that uncertainties on the faint-end slope are still too large to draw a firm conclusion about its evolution with redshift. We use our statistical framework to discuss the implication of our study for the physics of reionization. By assuming theoretically motivated priors on the clumping factor and the photon

  9. The luminosity function at z ∼ 8 from 97 Y-band dropouts: Inferences about reionization

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Kasper B.; Treu, Tommaso; Kelly, Brandon C. [Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States); Trenti, Michele [Kavli Institute for Cosmology and Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Bradley, Larry D.; Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Oesch, Pascal A. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Holwerda, Benne W. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Shull, J. Michael, E-mail: kschmidt@physics.ucsb.edu [CASA, Department of Astrophysical and Planetary Science, University of Colorado, Center for Astrophysics and Space Astronomy, 389-UCB, Boulder, CO 80309 (United States)

    2014-05-01

    We present the largest search to date for Y-band dropout galaxies (z ∼ 8 Lyman break galaxies, LBGs) based on 350 arcmin{sup 2} of Hubble Space Telescope observations in the V, Y, J, and H bands from the Brightest of Reionizing Galaxies (BoRG) survey. In addition to previously published data, the BoRG13 data set presented here includes approximately 50 arcmin{sup 2} of new data and deeper observations of two previous BoRG pointings, from which we present 9 new z ∼ 8 LBG candidates, bringing the total number of BoRG Y-band dropouts to 38 with 25.5 ≤ m{sub J} ≤ 27.6 (AB system). We introduce a new Bayesian formalism for estimating the galaxy luminosity function, which does not require binning (and thus smearing) of the data and includes a likelihood based on the formally correct binomial distribution as opposed to the often-used approximate Poisson distribution. We demonstrate the utility of the new method on a sample of 97 Y-band dropouts that combines the bright BoRG galaxies with the fainter sources published in Bouwens et al. from the Hubble Ultra Deep Field and Early Release Science programs. We show that the z ∼ 8 luminosity function is well described by a Schechter function over its full dynamic range with a characteristic magnitude M{sup ⋆}=−20.15{sub −0.38}{sup +0.29}, a faint-end slope of α=−1.87{sub −0.26}{sup +0.26}, and a number density of log{sub 10} ϕ{sup ⋆}[Mpc{sup −3}]=−3.24{sub −0.24}{sup +0.25}. Integrated down to M = –17.7, this luminosity function yields a luminosity density log{sub 10} ϵ[erg s{sup −1} Hz{sup −1} Mpc{sup −3}]=25.52{sub −0.05}{sup +0.05}. Our luminosity function analysis is consistent with previously published determinations within 1σ. The error analysis suggests that uncertainties on the faint-end slope are still too large to draw a firm conclusion about its evolution with redshift. We use our statistical framework to discuss the implication of our study for the physics of

  10. Performance testing of extremity dosimeters, Study 2

    International Nuclear Information System (INIS)

    Harty, R.; Reece, W.D.; Hooker, C.D.

    1990-04-01

    The Health Physics Society Standards Committee (HPSSC) Working Group on Performance Testing of Extremity Dosimeters has issued a draft of a proposed standard for extremity dosimeters. The draft standard proposes methods to be used for testing dosimetry systems that determine occupational radiation dose to the extremities and the performance criterion used to determine compliance with the standard. Pacific Northwest Laboratory (PNL) has conducted two separate evaluations of the performance of extremity dosimeter processors to determine the appropriateness of the draft standard, as well as to obtain information regarding the performance of extremity dosimeters. Based on the information obtained during the facility visits and the results obtained from the performance testing, it was recommended that changes be made to ensure that the draft standard is appropriate for extremity dosimeters. The changes include: subdividing the mixture category and the beta particle category; eliminating the neutron category until appropriate flux-to-dose equivalent conversion factors are derived; and changing the tolerance level for the performance criterion to provide consistency with the performance criterion for whole body dosimeters, and to avoid making the draft standard overly difficult for processors of extremity dosimeters to pass. 20 refs., 10 figs., 6 tabs

  11. The evolution of CMS software performance studies

    CERN Document Server

    Kortelainen, Matti J

    2010-01-01

    CMS has had an ongoing and dedicated effort to optimize software performance for several years. Initially this effort focused primarily on the cleanup of many issues coming from basic C++ errors, namely reducing dynamic memory churn, unnecessary copies/temporaries and tools to routinely monitor these things. Over the past 1.5 years, however, the transition to 64bit, newer versions of the gcc compiler, newer tools and the enabling of techniques like vectorization have made possible more sophisticated improvements to the software performance. This presentation will cover this evolution and describe the current avenues being pursued for software performance, as well as the corresponding gains.

  12. AngularJS Performance: A Survey Study

    OpenAIRE

    Ramos, Miguel; Valente, Marco Tulio; Terra, Ricardo

    2017-01-01

    AngularJS is a popular JavaScript MVC-based framework to construct single-page web applications. In this paper, we report the results of a survey with 95 professional developers about performance issues of AngularJS applications. We report common practices followed by developers to avoid performance problems (e.g., use of third-party or custom components), the general causes of performance problems in AngularJS applications (e.g., inadequate architecture decisions taken by AngularJS users), a...

  13. The evolution of CMS software performance studies

    Science.gov (United States)

    Kortelainen, M. J.; Elmer, P.; Eulisse, G.; Innocente, V.; Jones, C. D.; Tuura, L.

    2011-12-01

    CMS has had an ongoing and dedicated effort to optimize software performance for several years. Initially this effort focused primarily on the cleanup of many issues coming from basic C++ errors, namely reducing dynamic memory churn, unnecessary copies/temporaries and tools to routinely monitor these things. Over the past 1.5 years, however, the transition to 64bit, newer versions of the gcc compiler, newer tools and the enabling of techniques like vectorization have made possible more sophisticated improvements to the software performance. This presentation will cover this evolution and describe the current avenues being pursued for software performance, as well as the corresponding gains.

  14. Sky luminosity for Rio de Janeiro City - Brazil

    International Nuclear Information System (INIS)

    Corbella, O.D.

    1995-12-01

    This paper presents sky luminosity data for Rio de Janeiro City, useful to be used in daylighting design in architecture. The data are presented as monthly graphics that correlate sunshine-hours with the frequency of occurrence during the day of a specific type of sky, that would present one of five defined characteristics (among clear and overcast sky). These results were derived from the knowledge of daily solar radiation and sunshine-hours data, for every day for a twelve year period. (author). 10 refs, 13 figs, 16 tabs

  15. ATLAS Higgs Physics Prospects at the High Luminosity LHC

    CERN Document Server

    Varol, Tulin; The ATLAS collaboration

    2017-01-01

    The Higgs physics prospects at the high-luminosity LHC are presented, assuming an energy of $\\sqrt s = 14$ TeV and a data sample of 3000-4000 fb$^{-1}$. In particular, the ultimate precision attainable on the couplings measurements of the 125 GeV Higgs boson with SM fermions and bosons is discussed, as well as perspectives on the search for the Standard Model di-Higgs production, which could lead to the measurement of the Higgs boson self-coupling.

  16. Prospects for physics at high luminosity with CMS

    Directory of Open Access Journals (Sweden)

    Varela João

    2013-05-01

    Full Text Available The precision measurements of the properties of the recently discovered Higgs-like boson will be central to the future LHC physics program. In parallel the search for New Physics beyond the SM will continue. Higher luminosity will extend the mass reach and allow sensitive searches for possible subtle signatures for new physics. In this paper we review the potential sensitivity of CMS to a selection of relevant future physics scenarios accessible with the LHC upgrades and a correspondingly upgraded CMS detector.

  17. Tunnel Boring Machine Performance Study. Final Report

    Science.gov (United States)

    1984-06-01

    Full face tunnel boring machine "TBM" performance during the excavation of 6 tunnels in sedimentary rock is considered in terms of utilization, penetration rates and cutter wear. The construction records are analyzed and the results are used to inves...

  18. Large Magellanic Cloud Near-infrared Synoptic Survey. V. Period–Luminosity Relations of Miras

    International Nuclear Information System (INIS)

    Yuan, Wenlong; Macri, Lucas M.; He, Shiyuan; Huang, Jianhua Z.; Kanbur, Shashi M.; Ngeow, Chow-Choong

    2017-01-01

    We study the near-infrared properties of 690 Mira candidates in the central region of the Large Magellanic Cloud, based on time-series observations at JHK s . We use densely sampled I -band observations from the OGLE project to generate template light curves in the near-infrared and derive robust mean magnitudes at those wavelengths. We obtain near-infrared Period–Luminosity relations for oxygen-rich Miras with a scatter as low as 0.12 mag at K s . We study the Period–Luminosity–Color relations and the color excesses of carbon-rich Miras, which show evidence for a substantially different reddening law.

  19. THE RELATIONSHIP BETWEEN X-RAY LUMINOSITY AND MAJOR FLARE LAUNCHING IN GRS 1915+105

    International Nuclear Information System (INIS)

    Punsly, Brian; Rodriguez, Jérôme

    2013-01-01

    We perform the most detailed analysis to date of the X-ray state of the Galactic black hole candidate GRS 1915+105 just prior to (0-4 hr) and during the brief (1-7 hr) ejection of major (superluminal) radio flares. A very strong model independent correlation is found between the 1.2 keV-12 keV X-ray flux 0-4 hr before flare ejections with the peak optically thin 2.3 GHz emission of the flares. This suggests a direct physical connection between the energy in the ejection and the luminosity of the accretion flow preceding the ejection. In order to quantify this concept, we develop techniques to estimate the intrinsic (unabsorbed) X-ray luminosity, L intrinsic , from RXTE All Sky Monitor data and to implement known methods to estimate the time-averaged power required to launch the radio emitting plasmoids, Q (sometimes called jet power). We find that the distribution of intrinsic luminosity from 1.2 keV-50 keV, L intrinsic (1.2-50), is systematically elevated just before ejections compared to arbitrary times when there are no major ejections. The estimated Q is strongly correlated with L intrinsic (1.2-50) 0-4 hr before the ejection, the increase in L intrinsic (1.2-50) in the hours preceding the ejection and the time-averaged L intrinsic (1.2-50) during the flare rise. Furthermore, the total time-averaged power during the ejection (Q + the time average of L intrinsic (1.2-50) during ejection) is strongly correlated with L intrinsic (1.2-50) just before launch with near equality if the distance to the source is ≈10.5 kpc.

  20. A proposal to upgrade the ATLAS RPC system for the High Luminosity LHC

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2015-01-01

    The architecture of the present trigger system in the ATLAS Muon Barrel was designed according to a reference luminosity of 10^34 cm-2 s-1 with a safety factor of 5, with respect to the simulated background rates, now confirmed by LHC Run-1 data. HL-LHC will provide a luminosity 5 times higher and an order of magnitude higher background. As a result, the performance demand increases, while the detector being susceptible to ageing effects. Moreover, the present muon trigger acceptance in the barrel is just above 70%, due to the presence of the barrel toroid structures. This scenario induced the ATLAS muon Collaboration to propose an appropriate upgrade plan, involving both detector and trigger-readout electronics, to guarantee the performance required by the physics program for the 20 years scheduled. This consists in installing a layer of new generation RPCs in the inner barrel, to increase the redundancy, the selectivity, and provide almost full acceptance. The first 10% of the system, corresponding to the e...

  1. Performance studies of the parallel VIM code

    International Nuclear Information System (INIS)

    Shi, B.; Blomquist, R.N.

    1996-01-01

    In this paper, the authors evaluate the performance of the parallel version of the VIM Monte Carlo code on the IBM SPx at the High Performance Computing Research Facility at ANL. Three test problems with contrasting computational characteristics were used to assess effects in performance. A statistical method for estimating the inefficiencies due to load imbalance and communication is also introduced. VIM is a large scale continuous energy Monte Carlo radiation transport program and was parallelized using history partitioning, the master/worker approach, and p4 message passing library. Dynamic load balancing is accomplished when the master processor assigns chunks of histories to workers that have completed a previously assigned task, accommodating variations in the lengths of histories, processor speeds, and worker loads. At the end of each batch (generation), the fission sites and tallies are sent from each worker to the master process, contributing to the parallel inefficiency. All communications are between master and workers, and are serial. The SPx is a scalable 128-node parallel supercomputer with high-performance Omega switches of 63 microsec latency and 35 MBytes/sec bandwidth. For uniform and reproducible performance, they used only the 120 identical regular processors (IBM RS/6000) and excluded the remaining eight planet nodes, which may be loaded by other's jobs

  2. Strategies employed for LHC software performance studies

    CERN Document Server

    Nowak, A

    2010-01-01

    The objective of this work is to collect and assess the software performance related strategies employed by the major players in the LHC software arena: the four main experiments (ALICE, ATLAS, CMS and LHCb) and the two main software frameworks (Geant4 and ROOT). As the software used differs between the parties, so do the directions and methods in optimization, and their intensity. The common feeling shared by nearly all interviewed parties is that performance is not one of their top priorities and that maintaining it at a constant level is a satisfactory solution, given the resources at hand. In principle, despite some organized efforts, a less structured approach seems to be the dominant one, and opportunistic optimization prevails. Four out of six surveyed groups are investigating memory management related effects, deemed to be the primary cause of their performance issues. The most commonly used tools include Valgrind and homegrown software. All questioned groups expressed the desire for advanced tools, s...

  3. The CMS High Granularity Calorimeter for the High Luminosity LHC

    Science.gov (United States)

    Sauvan, J.-B.

    2018-02-01

    The High Luminosity LHC (HL-LHC) will integrate 10 times more luminosity than the LHC, posing significant challenges for radiation tolerance and event pileup on detectors, especially for forward calorimetry, and hallmarks the issue for future colliders. As part of its HL-LHC upgrade program, the CMS collaboration is designing a High Granularity Calorimeter to replace the existing endcap calorimeters. It features unprecedented transverse and longitudinal segmentation for both electromagnetic (ECAL) and hadronic (HCAL) compartments. This will facilitate particle-flow calorimetry, where the fine structure of showers can be measured and used to enhance pileup rejection and particle identification, whilst still achieving good energy resolution. The ECAL and a large fraction of HCAL will be based on hexagonal silicon sensors of 0.5-1 cm2 cell size, with the remainder of the HCAL based on highly-segmented scintillators with silicon photomultiplier (SiPM) readout. The intrinsic high-precision timing capabilities of the silicon sensors will add an extra dimension to event reconstruction, especially in terms of pileup rejection.

  4. Disk accretion onto a black hole at subcritical luminosity

    International Nuclear Information System (INIS)

    Bisnovatyi-Kogan, G.S.; Blinnikov, S.I.

    1977-01-01

    The influence of radiation pressure on the structure of an accretion disk is considered when the total luminosity L approaches the Eddington limit Lsub(c). The motion of particles in the disk radiation field and gravitational field of a nonrotating black hole is investigated. It is shown that the disk accretion is destroyed when L approximately equal to (0.6 / 1.0) Lsub(c). Matter outflow from the central parts of the disk to infinity then sets in. We conclude that the luminosity cannot significantly exceed the Eddington limit. We show that for L > approximately 0.1 Lsub(c) the plasma in the upper layers of the central r