WorldWideScience

Sample records for perigee nov06 run2

  1. Nov 06 make up

    African Journals Online (AJOL)

    Winnie

    societies, women work longer hours at paid and unpaid labour and .... saw women's empowerment and the overturning of traditional ... to do, or to be like, it's a good thing … I think it's ..... GBV, and moreover fosters unsafe sexual practices in.

  2. Measuring the relativistic perigee advance with satellite laser ranging

    International Nuclear Information System (INIS)

    Iorio, Lorenzo; Ciufolini, Ignazio; Pavlis, Erricos C

    2002-01-01

    The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar ranging by the perihelion shift of Mercury and other planets in the gravitational field of the Sun, with a relative accuracy of the order of 10 -2 -10 -3 . In this paper, we explore the possibility of a measurement of the pericentric advance in the gravitational field of Earth by analysing the laser-ranged data of some orbiting, or proposed, laser-ranged geodetic satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction with a finite range of the order of 10 4 km. Thus, we show that, at the present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10 -3 . With the corresponding measured value of (2 + 2γ - β)/3, by using η = 4β - γ - 3 from lunar laser ranging, we could get an estimate of the PPN parameters γ and β with an accuracy of the order of 10 -2 -10 -3 . Nevertheless, these accuracies would be substantially improved in the near future with the new Earth gravity field models by the CHAMP and GRACE missions. The use of the perigee of LARES (LAser RElativity Satellite), with a suitable combination of orbital residuals including also the node and the perigee of LAGEOS II, would also further improve the accuracy of the proposed measurement

  3. Electroweak processes at Run 2

    CERN Document Server

    Spalla, Margherita; Sestini, Lorenzo

    2016-01-01

    We present a summary of the studies of the electroweak sector of the Standard Model at LHC after the first year of data taking of Run2, focusing on possible results to be achieved with the analysis of full 2015 and 2016 data. We discuss the measurements of W and Z boson production, with particular attention to the precision determination of basic Standard Model parameters, and the study of multi-boson interactions through the analysis of boson-boson final states. This work is the result of the collaboration between scientists from the ATLAS, CMS and LHCb experiments.

  4. Measuring the relativistic perigee advance with satellite laser ranging

    CERN Document Server

    Iorio, L; Pavlis, E C

    2002-01-01

    The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar ranging by the perihelion shift of Mercury and other planets in the gravitational field of the Sun, with a relative accuracy of the order of 10 sup - sup 2 -10 sup - sup 3. In this paper, we explore the possibility of a measurement of the pericentric advance in the gravitational field of Earth by analysing the laser-ranged data of some orbiting, or proposed, laser-ranged geodetic satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction with a finite range of the order of 10 sup 4 km. Thus, we show that, at the present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10 sup - sup 3. With the corresponding measured value of (2 + 2 gamma - beta)/3, ...

  5. Case Study of Ion Beams Observed By Cluster At Perigee

    Science.gov (United States)

    Sergeev, V.; Sauvaud, J.-A.; Perigee Beam Team

    During substorms the short beams of ions in the keV-to-tens keV energy range are injected into the auroral flux tubes from the magnetotail (sometimes extending up to >100 keV energy) carrying the information on the source distance, scale-size and temporal history of plasma acceleration. We present observations with the CLUSTER crossing inward the auroral zone flux tubes at ~4Re distance near its perigee during the substorm activity on February 14, 2001. The ion beams cover the same region (poleward half) of the auroral oval where the low-energy ions are extracted from the ionosphere, and where the small-scale transient transverse Alfven waves are observed which carry predominantly the downward parallel Poynting flux into the ionosphere. The multiple beams were basically confirmed to be the transient effects, although some effects including the (spatial) velocity filter and the parallel electric fields (im- posed by quasineutrality requirement) may complicate the interpretation. The gener- ation region of ion beams is not limited to most poleward, newly-reconnected flux tubes; the beam generation region could extend across magnetic field inward by as much as >100km (if mapped to the ionosphere). Surprising variety of injection dis- tances observed nearly simultaneously (ranging between >60 Re and ~10 Re) have been inferred when using the full available energy and time resolution, with shorter injection distances be possibly associated with the flow braking process. The beam multiplicity often displays the apparent ~3 min quasiperiodicity inherent to the basic dissipation process, it was not yet explained by any substorm theory.

  6. Run-2 Supersymmetry searches in ATLAS

    CERN Document Server

    Soffer, Abner; The ATLAS collaboration

    2016-01-01

    Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. With the large increase in collision energy with the LHC Run-2 (from 8TeV to 13 TeV) the sensitivity to heavy strongly produced SUSY particles (squarks and gluinos) increases tremendously. This talk presents recent ATLAS Run-2 searches for such particles in final states including jets, missing transverse momentum, and possibly light leptons.

  7. Run 2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Solovyanov, Oleg; The ATLAS collaboration

    2018-01-01

    The 2nd LHC run has started in June 2015 with a proton-proton centre-of-mass collision energy of 13 TeV. During the years 2016 and 2017, LHC delivered an unprecedented amount of luminosity under the ever-increasing challenging conditions in terms of peak luminosity, pile-up and trigger rates. In this talk, the LHC running conditions and the improvements made to the ATLAS experiment in the course of Run 2 will be discussed, and the latest ATLAS detector and ATLAS trigger performance results from the Run 2 will be presented.

  8. ATLAS data preparation in run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00037318; The ATLAS collaboration; Chelstowska, Magda Anna; Cuhadar Donszelmann, Tulay; Guenther, Jaroslav; Nairz, Armin Michael; Nicolaidou, Rosy; Shabalina, Elizaveta; Strandberg, Jonas; Taffard, Anyes; Wang, Song-Ming

    2017-01-01

    In this contribution, the data preparation workflows for Run 2 are presented. The challenges posed by the excellent performance and high live time fraction of the LHC are discussed, and the solutions implemented by ATLAS are described. The prompt calibration loop procedures are described and examples are given. Several levels of data quality assessment are used to quickly spot problems in the control room and prevent data loss, and to provide the final selection used for physics analysis. Finally the data quality efficiency for physics analysis is shown.

  9. Electron ID in ATLAS Run 2

    CERN Document Server

    Thais, Savannah Jennifer; The ATLAS collaboration

    2018-01-01

    Efficient and accurate electron identification is of critical importance to measuring many physics processes with leptons in the final state, including H->4l, dark vector boson searches, and various SUSY searches. This poster will describe the current status of the Likelihood driven Electron ID, highlighting the recent move from a MC driven ID to a data-driven ID. It will include the most recent identification efficiency and scale-factor measurements. Additionally, it will describe continued improvements for Run 2 electron ID, highlighting improvements in the low pt region and potential Machine Learning improvements.

  10. Abort Gap Cleaning for LHC Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Uythoven, Jan [CERN; Boccardi, Andrea [CERN; Bravin, Enrico [CERN; Goddard, Brennan [CERN; Hemelsoet, Georges-Henry [CERN; Höfle, Wolfgang [CERN; Jacquet, Delphine [CERN; Kain, Verena [CERN; Mazzoni, Stefano [CERN; Meddahi, Malika [CERN; Valuch, Daniel [CERN; Gianfelice-Wendt, Eliana [Fermilab

    2014-07-01

    To minimize the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

  11. Abort Gap Cleaning for LHC Run 2

    CERN Document Server

    Uythoven, J; Bravin, E; Goddard, B; Hemelsoet, GH; Höfle, W; Jacquet, D; Kain, V; Mazzoni, S; Meddahi, M; Valuch, D

    2015-01-01

    To minimise the beam losses at the moment of an LHC beam dump the 3 μs long abort gap should contain as few particles as possible. Its population can be minimised by abort gap cleaning using the LHC transverse damper system. The LHC Run 1 experience is briefly recalled; changes foreseen for the LHC Run 2 are presented. They include improvements in the observation of the abort gap population and the mechanism to decide if cleaning is required, changes to the hardware of the transverse dampers to reduce the detrimental effect on the luminosity lifetime and proposed changes to the applied cleaning algorithms.

  12. The Run-2 ATLAS Trigger System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00222798; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger successfully collected collision data during the first run of the LHC between 2009-2013 at different centre-of-mass energies between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software-based high level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV and higher luminosity, resulting in roughly five times higher trigger rates. A brief review of the ATLAS trigger system upgrades that were implemented between Run-1 and Run-2, allowing to cope with the increased trigger rates while maintaining or even improving the efficiency to select physics processes of interest, will be given. This includes changes to the Level-1 calorimeter and muon trigger systems, the introduction of a new Level-1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. A ...

  13. The Run-2 ATLAS Trigger System

    International Nuclear Information System (INIS)

    Martínez, A Ruiz

    2016-01-01

    The ATLAS trigger successfully collected collision data during the first run of the LHC between 2009-2013 at different centre-of-mass energies between 900 GeV and 8TeV. The trigger system consists of a hardware Level-1 and a software-based high level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV and higher luminosity, resulting in up to five times higher rates of processes of interest. A brief review of the ATLAS trigger system upgrades that were implemented between Run-1 and Run-2, allowing to cope with the increased trigger rates while maintaining or even improving the efficiency to select physics processes of interest, will be given. This includes changes to the Level-1 calorimeter and muon trigger systems, the introduction of a new Level-1 topological trigger module and the merging of the previously two-level HLT system into a single event processing farm. A few examples will be shown, such as the impressive performance improvements in the HLT trigger algorithms used to identify leptons, hadrons and global event quantities like missing transverse energy. Finally, the status of the commissioning of the trigger system and its performance during the 2015 run will be presented. (paper)

  14. Run-2 ATLAS Trigger and Detector Performance

    CERN Document Server

    Winklmeier, Frank; The ATLAS collaboration

    2016-01-01

    The 2nd LHC run has started in June 2015 with a pp centre-of-mass collision energy of 13 TeV, and ATLAS has taken first data at this new energy. In this talk the improvements made to the ATLAS experiment during the 2-year shutdown 2013/2014 will be discussed, and first detector and trigger performance results from the Run-2 will be shown. In general, reconstruction algorithms of tracks, e/gamma, muons, taus, jets and flavour tag- ging have been improved for Run-2. The new reconstruction algorithms and their performance measured using the data taken in 2015 at sqrt(s)=13 TeV will be discussed. Reconstruction efficiency, isolation performance, transverse momentum resolution and momentum scales are measured in various regions of the detector and in momentum intervals enlarged with respect to those measured in the Run-1. This presentation will also give an overview of the upgrades to the ATLAS trigger system that have been implemented during the LHC shutdown in order to deal with the increased trigger rates (fact...

  15. Perigee: Zero, a Unified Theory of Cultural Heritage and Geological History

    Science.gov (United States)

    Davias, M. E.

    2006-05-01

    Perigee: Zero proposes a unified theory to solve enigmas haunting our cultural heritage and the Earth's geological history. We maintain the theory is simple and provable. We document the terraforming of the Earth by the cratering and accretive action of impacting comets and resulting ejecta, during events occurring at regular intervals over the past 15,000 years. Visual evidence of geomorphed landscape is presented using the perspective of high-resolution satellite imaging and DEM data. Correlation of these images with physical and historic evidence has proven supportive. Sections of the lithosphere have been lofted thousands of kilometers. Excised trenches have filled with water, or left as barren desert. Blankets of ejecta have overlain the continents and their inhabitants. The atmosphere was disrupted by the influx of dust and energy. Composed of hydrated silica, the comets have added a significant percentage of the water and unusually pure silicate (as sand and clay) now present on earth. Human history is immersed in these events. Oral and written works comprising much of the world's cultural heritage provide us with accounts of catastrophic damage visited upon Earth and its inhabitants. Those accounts describe mountains being moved, large expanses of the earth being swept clean - or replaced with open ocean, civilizations buried, years of darkness, the world flooded. Our forefathers invoked deities from the heavens, or perhaps giant kangaroos. We invoke impactors from the Taurid Complex, a simple and natural process, as most of its progenitor's mass may be missing. The damage to the earth is interpreted as the result of hundreds of grazing and nearly tangential impacts, suggesting decaying orbits of earth-captured cosmic bodies as a plausible solution. The events are seen occurring when the low point of the orbit -the perigee- reaches the earth's surface; in effect Perigee: Zero.

  16. Prospettive per il Run 2 ad LHC

    CERN Document Server

    Ciulli, Vitaliano

    2015-01-01

    With the approach of resumption of the activity of the Large Hadron Collider at the CERN, scheduled for the spring of 2015, the physicists of the ATLAS and CMS experiments are pondering the prospects that will be opened up by the increase of centre-of-mass energy from 8 to 13 TeV, after the discovery of the Higgs boson. However the results from Run 2 go, they will mark an important new chapter in the physics of fundamental interactions, making it possible to explore the region up to around 1 TeV of mass in the search for new particles that can explain dark matter and the other unresolved questions of the Standard Model.

  17. ATLAS Distributed Computing in LHC Run2

    CERN Document Server

    Campana, Simone; The ATLAS collaboration

    2015-01-01

    The ATLAS Distributed Computing infrastructure has evolved after the first period of LHC data taking in order to cope with the challenges of the upcoming LHC Run2. An increased data rate and computing demands of the Monte-Carlo simulation, as well as new approaches to ATLAS analysis, dictated a more dynamic workload management system (ProdSys2) and data management system (Rucio), overcoming the boundaries imposed by the design of the old computing model. In particular, the commissioning of new central computing system components was the core part of the migration toward the flexible computing model. The flexible computing utilization exploring the opportunistic resources such as HPC, cloud, and volunteer computing is embedded in the new computing model, the data access mechanisms have been enhanced with the remote access, and the network topology and performance is deeply integrated into the core of the system. Moreover a new data management strategy, based on defined lifetime for each dataset, has been defin...

  18. ATLAS Distributed Computing in LHC Run2

    International Nuclear Information System (INIS)

    Campana, Simone

    2015-01-01

    The ATLAS Distributed Computing infrastructure has evolved after the first period of LHC data taking in order to cope with the challenges of the upcoming LHC Run-2. An increase in both the data rate and the computing demands of the Monte-Carlo simulation, as well as new approaches to ATLAS analysis, dictated a more dynamic workload management system (Prodsys-2) and data management system (Rucio), overcoming the boundaries imposed by the design of the old computing model. In particular, the commissioning of new central computing system components was the core part of the migration toward a flexible computing model. A flexible computing utilization exploring the use of opportunistic resources such as HPC, cloud, and volunteer computing is embedded in the new computing model; the data access mechanisms have been enhanced with the remote access, and the network topology and performance is deeply integrated into the core of the system. Moreover, a new data management strategy, based on a defined lifetime for each dataset, has been defined to better manage the lifecycle of the data. In this note, an overview of an operational experience of the new system and its evolution is presented. (paper)

  19. The Run-2 ATLAS Trigger System

    CERN Document Server

    Ruiz-Martinez, Aranzazu; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger systems, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. At hand of a few examples, we will show the ...

  20. ALICE HLT Run 2 performance overview.

    Science.gov (United States)

    Krzewicki, Mikolaj; Lindenstruth, Volker; ALICE Collaboration

    2017-10-01

    For the LHC Run 2 the ALICE HLT architecture was consolidated to comply with the upgraded ALICE detector readout technology. The software framework was optimized and extended to cope with the increased data load. Online calibration of the TPC using online tracking capabilities of the ALICE HLT was deployed. Offline calibration code was adapted to run both online and offline and the HLT framework was extended to support that. The performance of this schema is important for Run 3 related developments. An additional data transport approach was developed using the ZeroMQ library, forming at the same time a test bed for the new data flow model of the O2 system, where further development of this concept is ongoing. This messaging technology was used to implement the calibration feedback loop augmenting the existing, graph oriented HLT transport framework. Utilising the online reconstruction of many detectors, a new asynchronous monitoring scheme was developed to allow real-time monitoring of the physics performance of the ALICE detector, on top of the new messaging scheme for both internal and external communication. Spare computing resources comprising the production and development clusters are run as a tier-2 GRID site using an OpenStack-based setup. The development cluster is running continuously, the production cluster contributes resources opportunistically during periods of LHC inactivity.

  1. ATLAS Data Preparation in Run 2

    CERN Document Server

    Laycock, Paul; The ATLAS collaboration

    2016-01-01

    In this presentation, the data preparation workflows for Run 2 are presented. Online data quality uses a new hybrid software release that incorporates the latest offline data quality monitoring software for the online environment. This is used to provide fast feedback in the control room during a data acquisition (DAQ) run, via a histogram-based monitoring framework as well as the online Event Display. Data are sent to several streams for offline processing at the dedicated Tier-0 computing facility, including dedicated calibration streams and an "express" physics stream containing approximately 2% of the main physics stream. This express stream is processed as data arrives, allowing a first look at the offline data quality within hours of a run end. A prompt calibration loop starts once an ATLAS DAQ run ends, nominally defining a 48 hour period in which calibrations and alignments can be derived using the dedicated calibration and express streams. The bulk processing of the main physics stream starts on expi...

  2. The CMS trigger in Run 2

    CERN Document Server

    Tosi, Mia

    2018-01-01

    During its second period of operation (Run 2) which started in 2015, the LHC will reach a peak instantaneous luminosity of approximately 2$\\times 10^{34}$~cm$^{-2}s^{-1}$ with an average pile-up of about 55, far larger than the design value. Under these conditions, the online event selection is a very challenging task. In CMS, it is realised by a two-level trigger system: the Level-1 (L1) Trigger, implemented in custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the offline reconstruction software running on a computer farm.\\\\ In order to face this challenge, the L1 trigger has undergone a major upgrade compared to Run 1, whereby all electronic boards of the system have been replaced, allowing more sophisticated algorithms to be run online. Its last stage, the global trigger, is now able to perform complex selections and to compute high-level quantities, like invariant masses. Likewise, the algorithms that run in the HLT went through big improvements; in particular, new ap...

  3. LHCb siliicon detectors: the Run 1 to Run 2 transition and first experience of Run 2

    CERN Document Server

    Rinnert, Kurt

    2015-01-01

    LHCb is a dedicated experiment to study New Physics in the decays of heavy hadrons at the Large Hadron Collider (LHC) at CERN. The detector includes a high precision tracking system consisting of a silicon-strip vertex detector (VELO) surrounding the pp interaction region, a large- area silicon-strip detector located upstream of a dipole magnet (TT), and three stations of silicon- strip detectors (IT) and straw drift tubes placed downstream (OT). The operational transition of the silicon detectors VELO, TT and IT from LHC Run 1 to Run 2 and first Run 2 experiences will be presented. During the long shutdown of the LHC the silicon detectors have been maintained in a safe state and operated regularly to validate changes in the control infrastructure, new operational procedures, updates to the alarm systems and monitoring software. In addition, there have been some infrastructure related challenges due to maintenance performed in the vicinity of the silicon detectors that will be discussed. The LHCb silicon dete...

  4. PERIGEE computer codes for reactor simulation in 3 dimensions, using 1 or 2 neutron velocity groups

    International Nuclear Information System (INIS)

    Olson, A.P.

    1964-02-01

    PERIGEE is a code written in SNAP for the G-20 computer. It solves the one- or two-group neutron diffusion equations by finite-difference methods on a three-dimensional, uniform mesh having a common spacing in the two directions normal to the fuel channels. The positions of mesh points along a fuel channel, relative to points in adjacent channels, may correspond to either NPD or CANDU fuel bundle positions. The extrapolated flux boundary may be specified in sufficient detail to represent a tapered or stepped circumferential reflector, a variable axial length and, for a reactor with axis horizontal, a variable moderator level and a variable plane bottom surface equivalent to the CANDU dump structure. The neutron flux may be normalized to give a specified power output from the hottest fuel bundle or hottest channel, or to give a total thermal power limited by the turbine and generator. Reactor operation may be simulated in finite time steps, taking into account any fuel shifts, any changes in moderator level and the change in nuclear properties of the fuel with increasing irradiation. The appropriate properties are obtained by interpolation from tables supplied for as many as 8 types of fuel bundle. The mean fuel exit burnup can be calculated at equilibrium for a reactor in which the exit burnups for two zones may be adjusted to give radial power flattening and the fuelling schedules may be designed to give axial power flattening in one or both zones. (author)

  5. ATLAS inner detector: the Run 1 to Run 2 transition, and first experience from Run 2

    CERN Document Server

    Dobos, Daniel; The ATLAS collaboration

    2015-01-01

    The ATLAS experiment is equipped with a tracking system, the Inner Detector, built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. For the LHC Run II, the system has been upgraded; taking advantage of the long showdown, the Pixel Detector was extracted from the experiment and brought to surface, to equip it with new service quarter panels, to repair modules and to ease installation of the Insertable B-Layer (IBL), a fourth layer of pixel detectors, installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm from the beam axis. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point and the increase of Luminosity that LHC will face in Run-2, a new read-out chip within CMOS 130nm and two different silicon sensor pixel technologies (planar and 3D) have been developed. SCT and TRT systems consolidation was also carri...

  6. CMS software and computing for LHC Run 2

    CERN Document Server

    INSPIRE-00067576

    2016-11-09

    The CMS offline software and computing system has successfully met the challenge of LHC Run 2. In this presentation, we will discuss how the entire system was improved in anticipation of increased trigger output rate, increased rate of pileup interactions and the evolution of computing technology. The primary goals behind these changes was to increase the flexibility of computing facilities where ever possible, as to increase our operational efficiency, and to decrease the computing resources needed to accomplish the primary offline computing workflows. These changes have resulted in a new approach to distributed computing in CMS for Run 2 and for the future as the LHC luminosity should continue to increase. We will discuss changes and plans to our data federation, which was one of the key changes towards a more flexible computing model for Run 2. Our software framework and algorithms also underwent significant changes. We will summarize the our experience with a new multi-threaded framework as deployed on ou...

  7. Spanish ATLAS Tier-2: facing up to LHC Run 2

    CERN Document Server

    Gonzalez de la Hoz, Santiago; Fassi, Farida; Fernandez Casani, Alvaro; Kaci, Mohammed; Lacort Pellicer, Victor Ruben; Montiel Gonzalez, Almudena Del Rocio; Oliver Garcia, Elena; Pacheco Pages, Andres; Sánchez, Javier; Sanchez Martinez, Victoria; Salt, José; Villaplana Perez, Miguel

    2015-01-01

    The goal of this work is to describe the way of addressing the main challenges of Run-2 by the Spanish ATLAS Tier-2. The considerable increase of energy and luminosity for the upcoming Run-2 with respect to Run-1 has led to a revision of the ATLAS computing model as well as some of the main ATLAS computing tools. The adaptation on these changes will be shown, with the peculiarities that it is a distributed Tier-2 composed of three sites and its members are involved on ATLAS computing tasks with a hub of research, innovation and education.

  8. Heavy ion operation from run 2 to HL-LHC

    CERN Document Server

    Jowett, J M; Versteegen, R

    2014-01-01

    The nuclear collision programme of the LHC will continue with Pb-Pb and p-Pb collisions in Run 2 and beyond. Extrapolating from the performance at lower energies in Run 1, it is already clear that Run 2 will substantially exceed design performance. Beyond that, future high-luminosity heavy ion operation of LHC depends on a somewhat different set of (more modest) upgrades to the collider and its injectors from p-p. The high-luminosity phase will start sooner, in Run 3, when necessary upgrades to detectors should be completed. It follows that the upgrades for heavy-ion operation need high priority in LS2.

  9. The ATLAS Trigger algorithms upgrade and performance in Run 2

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    Title: The ATLAS Trigger algorithms upgrade and performance in Run 2 (TDAQ) The ATLAS trigger has been used very successfully for the online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a center-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. At the Level-1 trigger the undertaken impr...

  10. Tau lepton trigger and identification at CMS in Run-2

    CERN Document Server

    Davignon, Olivier

    2016-01-01

    In the context of LHC Run-2, the Compact Muon Solenoid (CMS) detector was upgraded. In particular, the CMS trigger system and particle reconstruction were improved. The CMS experiment implements a sophisticated trigger system composed of a Level-1 trigger, instrumented by custom-designed hardware boards, and software layers called High-Level-Triggers (HLT). A new Level-1 trigger architecture with improved performance has been installed and is now used to maintain the thresholds used in LHC Run-1 in the more challenging conditions experienced during Run-2. Optimized software selection techniques have also been developed at the HLT. The hadronic $\\tau$ reconstruction algorithm has been modified to better account for the $\\pi^0$(s) from $\\tau$ decays. In addition, improvements to discriminators against QCD-induced jets and electrons were also developed. The results of these improvements are presented and the validation of the $\\tau$ identification performance is shown.

  11. Performance of the ATLAS Muon Trigger in Run 2

    CERN Document Server

    Morgenstern, Marcus; The ATLAS collaboration

    2018-01-01

    Events containing muons in the final state are an important signature for many analyses being carried out at the Large Hadron Collider (LHC), including both standard model measurements and searches for new physics. To be able to study such events, it is required to have an efficient and well-understood muon trigger. The ATLAS muon trigger consists of a hardware based system (Level 1), as well as a software based reconstruction (High Level Trigger). Due to high luminosity and pile up conditions in Run 2, several improvements have been implemented to keep the trigger rate low while still maintaining a high efficiency. Some examples of recent improvements include requiring coincidence hits between different layers of the muon spectrometer, improvements for handling overlapping muons, and optimised muon isolation. We will present an overview of how we trigger on muons, recent improvements, and the performance of the muon trigger in Run 2 data.

  12. ATLAS simulation of boson plus jets processes in Run 2

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    This note describes the ATLAS simulation setup used to model the production of single electroweak bosons ($W$, $Z\\gamma^\\ast$ and prompt $\\gamma$) in association with jets in proton--proton collisions at centre-of-mass energies of 8 and 13 TeV. Several Monte Carlo generator predictions are compared in regions of phase space relevant for data analyses during the LHC Run-2, or compared to unfolded data distributions measured in previous Run-1 or early Run-2 ATLAS analyses. Comparisons are made for regions of phase space with or without additional requirements on the heavy-flavour content of the accompanying jets, as well as electroweak $Vjj$ production processes. Both higher-order corrections and systematic uncertainties are also discussed.

  13. The alignment of the ATLAS Inner Detector in Run 2

    CERN Document Server

    Ripellino, Giulia; The ATLAS collaboration

    2016-01-01

    The ATLAS reconstruction of charged particle trajectories relies on the Inner Detector tracking system. The accuracy of the reconstruction is limited by the finite resolution of the detector elements and the knowledge about their positions. A precise alignment of the detector is therefore essential. In this poster we present the strategy and the status of the Inner Detector alignment in ATLAS during the LHC Run 2.

  14. LHCb Particle Identification Strategy and Performance in Run 2

    CERN Multimedia

    Tilley, Matthew James

    2018-01-01

    For Run 2 of LHCb data taking, the selection of PID calibration samples is implemented in the high level trigger. A further processing is needed to provide calibration samples used for the determination the PID performance, which is achieved through a centralised production that makes highly efficient use of LHCb computing resources. This poster presents the major steps of the production procedure and the charged particle PID performance measured using these calibration samples.

  15. LHC(ATLAS, CMS, LHCb) Run 2 commissioning status

    CERN Document Server

    Zimmermann, Stephanie; The ATLAS collaboration

    2015-01-01

    After a very successful run-1, the LHC accelerator and the LHC experiments had undergone intensive consolidation, maintenance and upgrade activities during the last 2 years in what has become known as Long-Shutdown-1 (LS1). LS1 ended in February this year, with beams back in the LHC since Easter. This talk will give a summary on the major shutdown activities of ATLAS, CMS and LHCb and review the status of commissioning for run-2 physics data taking.

  16. The ATLAS Trigger system upgrade and performance in Run 2

    CERN Document Server

    Shaw, Savanna Marie; The ATLAS collaboration

    2017-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first part of the LHC Run-2 in 2015/16 at a centre-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. In order to prepare for the anticipated further luminosity increase of the LHC in 2017/18, improving the trigger performance remain...

  17. The CERN Data Centre readies for Run 2

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    While the world waits for Run 2 data with growing anticipation, the CERN Data Centre is battening down the hatches. Run 2 is set to see a significant increase in the amount of data produced by the LHC experiments, with more than one hundred additional petabytes expected over the next three years. How will CERN manage this flood of results? The Bulletin checks in with the IT Department to find out...   The CERN Data Centre: the heart of CERN's entire scientific, administrative, and computing infrastructure. With every second of run-time, gigabytes of data will come pouring into the CERN Data Centre to be stored, sorted and shared with physicists worldwide. To cope with this massive influx of Run 2 data, the CERN Data and Storage Services group focused on three areas: speed, capacity and reliability. First on the list, the group set out to increase the rate at which they could store data. "During Run 1, we were storing 1 gigabyte-per-second, with the occasional peak of 6 giga...

  18. The ATLAS Trigger Algorithms Upgrade and Performance in Run-2

    CERN Document Server

    Bernius, Catrin; The ATLAS collaboration

    2017-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a center-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. At the Level-1 trigger the undertaken improvements resulted in more pile-up robust selection efficiencies and event ra...

  19. The ATLAS Trigger system upgrade and performance in Run 2

    CERN Document Server

    Shaw, Savanna Marie; The ATLAS collaboration

    2018-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a centre-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger; it reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of about 1 kHz. The excellent performance of the ATLAS trigger has been vital for the ATLAS physics program of Run-2, selecting interesting collision events for wide variety of physics signatures with high efficiency. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and pile-up which are the result of the almost doubling of the center-of-mass collision energy and the increase in the instantaneous luminosity of the LHC. At the Level-1 trigger the undertaken improvements resulted in more pile-up robust selection efficiencies and event ra...

  20. LHCb's Real-Time Alignment in Run2

    CERN Multimedia

    Batozskaya, Varvara

    2015-01-01

    Stable, precise spatial alignment and PID calibration are necessary to achieve optimal detector performances. During Run2, LHCb will have a new real-time detector alignment and calibration to reach equivalent performances in the online and offline reconstruction. This offers the opportunity to optimise the event selection by applying stronger constraints as well as hadronic particle identification at the trigger level. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructure for the trigger.

  1. ATLAS LAr Calorimeter Performance in LHC Run-2

    CERN Document Server

    Yatsenko, Elena; The ATLAS collaboration

    2017-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 1034 cm−2 s−1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, and for hadronic calorimetry in the region from |η| = 1.5 to |η| = 4.9. In the first LHC run a total luminosity of 27 fb−1 has been collected at center-of-mass energies of 7-8 TeV between year of 2010 to 2012. Following a period of detector consolidation during a long shutdown, Run-2 started with approximately 3.9 fb-1 and 35.6 fb-1 of data at a center-of-mass energy of 13 TeV recorded in 2015 and 2016, respectively. In order to realize the level-1 acceptance rate of 100 kHz in Run-2 data taking, number of read-out samples for the energy and the time measurement has been modified from five to four with keeping the expected performance. The well calibrated and highly granular Liquid Ar...

  2. The Run-2 ATLAS Trigger System: Design, Performance and Plan

    CERN Document Server

    zur Nedden, Martin; The ATLAS collaboration

    2016-01-01

    In high-energy physics experiments, online selection is crucial to select interesting collisions from the large data volume. The ATLAS experiment at the Large Hadron Collider (LHC) utilizes the trigger system that consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT), reducing the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 1000 Hz. In the LHC Run-2 starting from in 2015, the LHC operates at centre-of-mass energy of 13 TeV providing a luminosity up to $1.2 \\cdot 10^{34} {\\rm cm^{-2}s^{-1}}$. The ATLAS trigger system has to cope with these challenges, while maintaining or even improving the efficiency to select relevant physics processes. In this paper, the ATLAS trigger system for LHC Run-2 is reviewed. Secondly, the impressive performance improvements in the HLT trigger algorithms used to identify leptons, hadrons and global event quantities like missing transverse energy is shown. Electron, muon and photon triggers covering trans...

  3. Optimisation of the ATLAS Track Reconstruction Software for Run-2

    CERN Document Server

    Salzburger, Andreas; The ATLAS collaboration

    2015-01-01

    The reconstruction of particle trajectories in the tracking detectors of experiments at the Large Hadron Collider (LHC) is one of the most complex parts in analysing the collected data from beam-beam collisions. To achieve the desired integrated luminosity during Run-1 of the LHC data taking period, the number of simultaneous proton-proton interactions per beam crossing (pile-up) was steadily increased. The track reconstruction is the most time consuming reconstruction component and scales non-linear in high luminosity environments. Flat budget projections (at best) for computing resources during the upcoming Run-2 of the LHC together with the demands of reconstructing higher pile-up collision data at rates more than double compared to Run-1 have put pressure on the track reconstruction software to stay within the available computing resources. The ATLAS experiment has thus performed a two year long software campaign which led to a reduction of the reconstruction time for Run-2 conditions by a factor of four:...

  4. The ATLAS Data Acquisition System in LHC Run 2

    Science.gov (United States)

    Panduro Vazquez, William; ATLAS Collaboration

    2017-10-01

    The LHC has been providing pp collisions with record luminosity and energy since the start of Run 2 in 2015. The Trigger and Data Acquisition system of the ATLAS experiment has been upgraded to deal with the increased performance required by this new operational mode. The dataflow system and associated network infrastructure have been reshaped in order to benefit from technological progress and to maximize the flexibility and efficiency of the data selection process. The new design is radically different from the previous implementation both in terms of architecture and performance, with the previous two-level structure merged into a single processing farm, performing incremental data collection and analysis. In addition, logical farm slicing, with each slice managed by a dedicated supervisor, has been dropped in favour of global management by a single farm master operating at 100 kHz. This farm master has also been integrated with a new software-based Region of Interest builder, replacing the previous VMEbus-based system. Finally, the Readout system has been completely refitted with new higher performance, lower footprint server machines housing a new custom front-end interface card. Here we will cover the overall design of the system, along with performance results from the start-up phase of LHC Run 2.

  5. Optimisation of the ATLAS Track Reconstruction Software for Run-2

    CERN Document Server

    Salzburger, Andreas; The ATLAS collaboration

    2015-01-01

    Track reconstruction is one of the most complex element of the reconstruction of events recorded by ATLAS from collisions delivered by the LHC. It is the most time consuming reconstruction component in high luminosity environments. The flat budget projections for computing resources for Run-2 of the LHC together with the demands of reconstructing higher pile-up collision data at rates more than double those in Run-1 (an increase from 400 Hz to 1 kHz in trigger output) have put stringent requirements on the track reconstruction software. The ATLAS experiment has performed a two year long software campaign which aimed to reduce the reconstruction rate by a factor of three to meet the resource limitations for Run-2: the majority of the changes to achieve this were improvements to the track reconstruction software. The CPU processing time of ATLAS track reconstruction was reduced by more than a factor of three during this campaign without any loss of output information of the track reconstruction. We present the ...

  6. ATLAS LAr Calorimeter Performance in LHC Run-2

    CERN Document Server

    Morgenstern, Stefanie; The ATLAS collaboration

    2018-01-01

    Liquid-argon (LAr) sampling calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region $\\eta<3.2$, and for hadronic and forward calorimetry in the region from $\\eta=1.5$ to $\\eta=4.9$. In the first LHC run a total luminosity of $27\\,\\mathrm{fb}^{-1}$ has been collected at centre-of-mass energies of $7-8\\,\\mathrm{TeV}$. After detector consolidation during a long shutdown, Run-2 started in 2015 and $86.4\\,\\mathrm{fb}^{-1}$ of data at a centre-of-mass energy of $13\\,\\mathrm{TeV}$ have been recorded. In order to realize the level-1 acceptance rate of $100\\,\\mathrm{kHz}$ in Run-2 data taking, the number of readout samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibrated and highly granular LAr calorimeter reached its design values both in energy measurement as well as in direction resolution. This contribution will give an overview of the detector operation, hardware...

  7. The ATLAS Tile Calorimeter DCS for Run 2

    CERN Document Server

    Pedro Martins, Filipe Manuel; The ATLAS collaboration

    2016-01-01

    TileCal is one of the ATLAS sub-detectors operating at the Large Hadron Collider (LHC), which is taking data since 2010. The Detector Control System (DCS) was developed to ensure the coherent and safe operation of the whole ATLAS detector. Seventy thousand (70000) parameters are used for control and monitoring purposes of TileCal, requiring an automated system. The TileCal DCS is mainly responsible for the control and monitoring of the high and low voltage systems but it also supervises the detector infrastructure (cooling and racks), calibration systems, data acquisition and safety. During the first period of data taking (Run 1, 2010-12) the TileCal DCS allowed a smooth detector operation and should continue to do so for the second period (Run 2) that started in 2015. The TileCal DCS was updated in order to cope with the hardware and software requirements for Run 2 operation. These updates followed the general ATLAS guidelines on the software and hardware upgrade but also the new requirements from the TileCa...

  8. The ATLAS Tile Calorimeter DCS for Run 2

    CERN Document Server

    Pedro Martins, Filipe Manuel; The ATLAS collaboration

    2016-01-01

    TileCal is one of the ATLAS subdetectors operating at the Large Hadron Collider (LHC), which is taking data since 2010. Seventy thousand (70000) parameters are used for control and monitoring purposes, requiring an automated system. The Detector Control System (DCS) was developed to ensure the coherent and safe operation of the whole ATLAS detector. The TileCal DCS is mainly responsible for the control and monitoring of the high and low voltage systems but it also supervises the detector infrastructure (cooling and racks), calibration systems, data acquisition and safety. During the first period of data taking (Run 1, 2010-12) the TileCal DCS allowed a smooth detector operation and should continue to do so for the second period (Run 2) that started in 2015. The TileCal DCS was updated in order to cope with the hardware and software requirements for Run 2 operation. These updates followed the general ATLAS guidelines on the software and hardware upgrade but also the new requirements from the TileCal detector. ...

  9. ATLAS LAr Calorimeter Performance in LHC Run-2

    CERN Document Server

    Morgenstern, Stefanie; The ATLAS collaboration

    2018-01-01

    Liquid argon (LAr) sampling calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region eta<3.2, and for hadronic and forward calorimetry in the region from eta=1.5 to eta=4.9. In the first LHC run a total luminosity of 27 fb-1 has been collected at c.o.m energies of 7-8 TeV. After detector consolidation during a long shutdown, Run-2 started in 2015 and 86.4fb-1 of data at a c.o.m energy of 13 TeV have been recorded. In order to realize the level-1 acceptance rate of 100 kHz in Run-2 data taking, the number of read-out samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibrated and highly granular LAr Calorimeter reached its design values both in energy measurement as well as in direction resolution. This contribution will give an overview of the detector operation, hardware improvements, changes in the monitoring and data quality procedures, to cope with increased ...

  10. ATLAS LAr Calorimeters Performance in LHC Run-2

    CERN Document Server

    Camincher, Clement; The ATLAS collaboration

    2018-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities above 1034 cm−2 s−1. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, and for hadronic and forward calorimetry in the region from |η| = 1.5 to |η| = 4.9. In the first LHC run a total luminosity of 27 fb−1 has been collected at center-of-mass energies of 7-8 TeV between year of 2010 to 2012. After a period of detector consolidation during a long shutdown, Run-2 started in 2015 and 3.9 fb-1, 35.6 fb-1 and 46.9 fb-1 of data at a center-of-mass energy of 13 TeV have been recorded up to now per year. In order to realize the level-1 acceptance rate of 100 kHz in Run-2 data taking, the number of read-out samples recorded and used for the energy and the time measurement has been modified from five to four while keeping the expected performance. The well calibra...

  11. The ATLAS Trigger in Run-2 - Design, Menu and Performance

    CERN Document Server

    Vazquez Schroeder, Tamara; The ATLAS collaboration

    2017-01-01

    The ATLAS trigger has been used very successfully for online event selection during the first part of the second LHC run (Run-2) in 2015/16 at a center-of-mass energy of 13 TeV. The trigger system is composed of a hardware Level-1 trigger and a software-based high-level trigger. 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. Taken together constitute the trigger menu, which reflects the physics goals of the collaboration while taking into account available data taking resources. The trigger selection capabilities of ATLAS during Run-2 have been significantly improved compared to Run-1, in order to cope with the higher event rates and number of interactions per bunch crossing (pileup) which are the result of the...

  12. Optimization of the muon reconstruction algorithms for LHCb Run 2

    CERN Document Server

    Aaij, Roel; Dettori, Francesco; Dungs, Kevin; Lopes, Helder; Martinez Santos, Diego; Prisciandaro, Jessica; Sciascia, Barbara; Syropoulos, Vasileios; Stahl, Sascha; Vazquez Gomez, Ricardo

    2017-01-01

    The muon identification algorithm in the LHCb HLT software trigger and offline reconstruction has been revisited in view of the LHC Run 2. This software has undergone a significant refactorisation, resulting in a modularized common code base between the HLT and offline event processing. Because of the latter, the muon identification is now identical in HLT and offline. The HLT1 algorithm sequence has been updated given the new rate and timing constraints. Also, information from the TT subdetector is used in order to reduce ghost tracks and optimize for low $p_T$ muons. The current software is presented here together with performance studies showing improved efficiencies and reduced timing.

  13. Calibration of the CMS hadron calorimeter in Run 2

    Science.gov (United States)

    Chadeeva, M.; Lychkovskaya, N.

    2018-03-01

    Various calibration techniques for the CMS Hadron calorimeter in Run 2 and the results of calibration using 2016 collision data are presented. The radiation damage corrections, intercalibration of different channels using the phi-symmetry technique for barrel, endcap and forward calorimeter regions are described, as well as the intercalibration with muons of the outer hadron calorimeter. The achieved intercalibration precision is within 3%. The in situ energy scale calibration is performed in the barrel and endcap regions using isolated charged hadrons and in the forward calorimeter using the Zarrow ee process. The impact of pileup and the developed technique of correction for pileup is also discussed. The achieved uncertainty of the response to hadrons is 3.4% in the barrel and 2.6% in the endcap region (at the pseudorapidity range |η|<2) and is dominated by the systematic uncertainty due to pileup contributions.

  14. Calibration of the CMS Hadron Calorimeter in Run 2

    CERN Document Server

    Chadeeva, Marina

    2017-01-01

    Various calibration techniques for the CMS Hadron calorimeter in Run2 and the results of calibration using 2016 collision data are presented. The radiation damage corrections, intercalibration of different channels using the phi-symmetry technique for barrel, endcap and forward calorimeter regions are described, as well as the intercalibration with muons of the outer hadron calorimeter. The achieved intercalibration precision is within 3\\%. The {\\it in situ} energy scale calibration is performed in the barrel and endcap regions using isolated charged hadrons and in the forward calorimeter using the Z$\\rightarrow ee$ process. The impact of pileup and the developed technique of correction for pileup is also discussed. The achieved uncertainty of the response to hadrons is 3.4\\% in the barrel and 2.6\\% in the endcap region (at $\\vert \\eta \\vert < 2$) and is dominated by the systematic uncertainty due to pileup contributions.

  15. A new Soft Muon Tagger for ATLAS Run 2

    CERN Document Server

    Sciandra, Andrea; The ATLAS collaboration

    2017-01-01

    b-tagging plays a fundamental role at LHC, as it helps in the identification of heavy particles that decay to bottom quarks, such as the top quark, Higgs boson or heavy exotic particles. The Soft Muon Tagger (SMT) allows jets from b-quarks to be identified, taking advantage of the presence of a muon coming from semileptonic decays of b-hadrons. The development of this new b-tagger in ATLAS will be described, showing that, despite the low efficiency of the jet-muon association (based on the angular distance), the discriminating power of the associated muon variables is sufficient to reject light jets. An enhanced performance has been reached for all light jet rejection working points by adding the SMT output to the best performing multivariate b-tagger in ATLAS (MV2). A good modeling of input and output variables is shown, comparing simulation with Run 2 data.

  16. Beam screen cryogenic control improvements for the LHC run 2

    CERN Document Server

    AUTHOR|(CDS)2068353; Rogez, Edouard; Blanco Vinuela, Enrique; Ferlin, Gerard; Tovar-Gonzalez, Antonio

    2017-01-01

    This paper presents the improvements made on the cryogenic control system for the LHC beam screens. The regulation objective is to maintain an acceptable temperature range around 20 K which simultaneously ensures a good LHC beam vacuum and limits cryogenic heat loads. In total, through the 27 km of the LHC machine, there are 485 regulation loops affected by beam disturbances. Due to the increase of the LHC performance during Run 2, standard PID controllers cannot keeps the temperature transients of the beam screens within desired limits. Several alternative control techniques have been studied and validated using dynamic simulation and then deployed on the LHC cryogenic control system in 2015. The main contribution is the addition of a feed-forward control in order to compensate the beam effects on the beam screen temperature based on the main beam parameters of the machine in real time.

  17. The ATLAS Data Acquisition System LHC Run 2

    CERN Document Server

    Panduro Vazquez, William; The ATLAS collaboration

    2016-01-01

    The LHC has been providing pp collisions with record luminosity and energy since the start of Run 2 in 2015. In the ATLAS experiment the Trigger and Data Acquisition system has been upgraded to deal with the increased event rates. The dataflow element of the system is distributed across hardware and software and is responsible for buffering and transporting event data from the Readout system to the High Level Trigger and on to event storage. The dataflow system has been reshaped in order benefit from technological progress and to maximize the flexibility and efficiency of the data selection process. The updated dataflow system is radically different from the previous implementation both in terms of architecture and performance. The previous two level software filtering architecture, known as L2 and the Event Filter, have been merged with the Event Builder function into a single process, performing incremental data collection and analysis. This design has many advantages, among which are: radical simplificatio...

  18. ATLAS Metadata Infrastructure Evolution for Run 2 and Beyond

    CERN Document Server

    van Gemmeren, Peter; The ATLAS collaboration; Malon, David; Vaniachine, Alexandre

    2015-01-01

    ATLAS developed and employed for Run 1 of the Large Hadron Collider a sophisticated infrastructure for metadata handling in event processing jobs. This infrastructure profits from a rich feature set provided by the ATLAS execution control framework, including standardized interfaces and invocation mechanisms for tools and services, segregation of transient data stores with concomitant object lifetime management, and mechanisms for handling occurrences asynchronous to the control framework’s state machine transitions. This metadata infrastructure is evolving and being extended for Run 2 to allow its use and reuse in downstream physics analyses, analyses that may or may not utilize the ATLAS control framework. At the same time, multiprocessing versions of the control framework and the requirements of future multithreaded frameworks are leading to redesign of components that use an incident-handling approach to asynchrony. The increased use of scatter-gather architectures, both local and distributed, requires ...

  19. CMS Software and Computing Ready for Run 2

    CERN Document Server

    Bloom, Kenneth

    2015-01-01

    In Run 1 of the Large Hadron Collider, software and computing was a strategic strength of the Compact Muon Solenoid experiment. The timely processing of data and simulation samples and the excellent performance of the reconstruction algorithms played an important role in the preparation of the full suite of searches used for the observation of the Higgs boson in 2012. In Run 2, the LHC will run at higher intensities and CMS will record data at a higher trigger rate. These new running conditions will provide new challenges for the software and computing systems. Over the two years of Long Shutdown 1, CMS has built upon the successes of Run 1 to improve the software and computing to meet these challenges. In this presentation we will describe the new features in software and computing that will once again put CMS in a position of physics leadership.

  20. The ATLAS High-Level Calorimeter Trigger in Run-2

    CERN Document Server

    Wiglesworth, Craig; The ATLAS collaboration

    2018-01-01

    The ATLAS Experiment uses a two-level triggering system to identify and record collision events containing a wide variety of physics signatures. It reduces the event rate from the bunch-crossing rate of 40 MHz to an average recording rate of 1 kHz, whilst maintaining high efficiency for interesting collision events. It is composed of an initial hardware-based level-1 trigger followed by a software-based high-level trigger. A central component of the high-level trigger is the calorimeter trigger. This is responsible for processing data from the electromagnetic and hadronic calorimeters in order to identify electrons, photons, taus, jets and missing transverse energy. In this talk I will present the performance of the high-level calorimeter trigger in Run-2, noting the improvements that have been made in response to the challenges of operating at high luminosity.

  1. The ATLAS Data Acquisition system in LHC Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00042480; The ATLAS collaboration

    2017-01-01

    The LHC has been providing pp collisions with record luminosity and energy since the start of Run 2 in 2015. The Trigger and Data Acquisition system of the ATLAS experiment has been upgraded to deal with the increased performance required by this new operational mode. The dataflow system and associated network infrastructure have been reshaped in order to benefit from technological progress and to maximize the flexibility and efficiency of the data selection process. The new design is radically different from the previous implementation both in terms of architecture and performance, with the previous two-level structure merged into a single processing farm, performing incremental data collection and analysis. In addition, logical farm slicing, with each slice managed by a dedicated supervisor, has been dropped in favour of global management by a single farm master operating at 100 kHz. This farm master has also been integrated with a new software-based Region of Interest builder, replacing the previous VMEbus...

  2. Testing ATLAS Z+MET excess with LHC run 2

    International Nuclear Information System (INIS)

    Lu, Xiaochuan; Terada, Takahiro

    2016-05-01

    The ATLAS collaboration reported a 3σ excess in the search of events containing on-Z dilepton, jets, and large missing momentum (MET) in the 8 TeV LHC run. Motivated by this excess, many models of new physics have been proposed. Recently, the ATLAS and CMS collaborations reported new results for similar Z+MET channels in the 13 TeV run. In this paper, we comprehensively discuss the consistency between the proposed models and the LHC results of Run 1 and Run 2. We find that in models with heavy gluino production, there is generically some tension between the 8 TeV and 13 TeV results. On the other hand, models with light squark production provide relatively better fitting to both results.

  3. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Maeda, Junpei; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software based high-level trigger that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the data-taking period of Run-2 the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. In these proceedings, we briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the Level-1 calorimeter and muon trigger system, the introduction of a new Level-1 topological trigger module and themerging of the previously two-level higher-level trigger system into a single even...

  4. The ATLAS Trigger System : Ready for Run-2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00211007; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware based Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the course of the ongoing Run-2 data-taking campaign at 13 TeV centre-of-mass energy the trigger rates will be approximately 5 times higher compared to Run-1. In these proceedings we briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger system, the introduction of a new L1 topological trigger subsystem and the merging of the previously two-level HLT system into a single ev...

  5. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    Nakahama, Yu; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been used very successfully for the online event selection during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the next data-taking period starting in early 2015 (Run-2) the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. We will review the upgrades to the ATLAS Trigger system that have been implemented during the shutdown and that will allow us to cope with these increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter trigger, the introduction of a new L1 topological trigger module, improvements in the L1 muon system and the merging of the prev...

  6. The Run-2 ATLAS Trigger System: Design, Performance and Plan

    CERN Document Server

    zur Nedden, Martin; The ATLAS collaboration

    2016-01-01

    In high-energy physics experiments, online selection is crucial to select interesting collisions from the large data volume. The ATLAS experiment at the Large Hadron Collider (LHC) utilizes the trigger system that consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT), reducing the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of about 1000 Hz. The ATLAS trigger has been successfully collecting collision data during the first run of the LHC (Run-1) between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. In the second run of LHC (Run-2) starting from 2015, the LHC operates at centre-of-mass energy of 13 TeV and provides a higher luminosity of collisions. Also, the number of collisions occurring in a same bunch crossing increases. The ATLAS trigger system has to cope with these challenges, while maintaining or even improving the efficiency to select relevant physics processes. In this talk, first we will review the ATLAS trigger ...

  7. Ceph-based storage services for Run2 and beyond

    CERN Document Server

    van der Ster, Daniel C; Mascetti, Luca; Peters, Andreas J; Rousseau, Herv

    2015-01-01

    In 2013, CERN IT evaluated then deployed a petabyte-scale Ceph cluster to support OpenStack use-cases in production. With now more than a year of smooth operations, we will present our experience and tuning best-practices. Beyond the cloud storage use-cases, we have been exploring Ceph-based services to satisfy the growing storage requirements during and after Run2. First, we have developed a Ceph back-end for CASTOR, allowing this service to deploy thin disk server nodes which act as gateways to Ceph, this feature marries the strong data archival and cataloging features of CASTOR with the resilient and high performance Ceph subsystem for disk. Second, we have developed RADOSFS, a lightweight storage API which builds a POSIX-like filesystem on top of the Ceph object layer. When combined with Xrootd, RADOSFS can offer a scalable object interface compatible with our HEP data processing applications. Lastly the same object layer is being used to build a scalable and inexpensive NFS service for several user commu...

  8. Upgrade of ATLAS-ALFA for Run2

    CERN Document Server

    Jakobsen, Sune; The ATLAS collaboration

    2016-01-01

    Early experience with the operation of the ALFA detectors in the LHC environment has shown significant beam-induced heating. Comprehensive studies on the effects of heating with a spare detector module have furthermore revealed that heating effects could be disastrous in the case of the larger beam intensities foreseen for higher luminosity. A temporary solution was implemented and kept the detectors below the critical temperature in 2012. In LS1 all ALFA stations have been removed from LHC and are undergoing an upgrade of the geometry of Roman Pots to minimize the impedance losses. When the stations were re-installed ~4 m distance was added between them to gain level arm in the angular measurement between the stations. The updated geometry of the Roman Pot, together with a system to improve the internal heat transfer and an air cooling system, is expected to keep the temperatures of ALFA detectors below critical limits throughout the LHC Run2 and first results from the performance in 2016 will be presented. ...

  9. LHC Report: getting in shape for the Run 2 marathon

    CERN Multimedia

    Mirko Pojer & Matteo Solfaroli

    2015-01-01

    The buzzword you'll hear most both inside and outside the CCC is "training". Rather than preparation for an athletic competition, it actually refers to the way the LHC is trying to get in shape for the long Run 2 marathon at 6.5 TeV.   Picture 1: progress of LHC superconducting circuit commissioning. In the previous edition of the Bulletin, we discussed the lengthy process of commissioning LHC superconducting circuits and the phenomenon of repetitive quenches accompanying the progressive increase in their performance. This is typical for superconducting magnets, but it is particularly intriguing for the LHC dipole magnets. Not only because each and every one of the 1,232 dipoles has to reach the same current target in order for beams to circulate at a certain energy (the weakest link of the chain determining or compromising the performance of all the others), but also because we know that every additional quench brings us closer to our 2015 objective. All...

  10. Ceph-based storage services for Run2 and beyond

    Science.gov (United States)

    van der Ster, Daniel C.; Lamanna, Massimo; Mascetti, Luca; Peters, Andreas J.; Rousseau, Hervé

    2015-12-01

    In 2013, CERN IT evaluated then deployed a petabyte-scale Ceph cluster to support OpenStack use-cases in production. With now more than a year of smooth operations, we will present our experience and tuning best-practices. Beyond the cloud storage use-cases, we have been exploring Ceph-based services to satisfy the growing storage requirements during and after Run2. First, we have developed a Ceph back-end for CASTOR, allowing this service to deploy thin disk server nodes which act as gateways to Ceph; this feature marries the strong data archival and cataloging features of CASTOR with the resilient and high performance Ceph subsystem for disk. Second, we have developed RADOSFS, a lightweight storage API which builds a POSIX-like filesystem on top of the Ceph object layer. When combined with Xrootd, RADOSFS can offer a scalable object interface compatible with our HEP data processing applications. Lastly the same object layer is being used to build a scalable and inexpensive NFS service for several user communities.

  11. THE ATLAS DATA ACQUISITION SYSTEM IN LHC RUN 2

    CERN Document Server

    Pozo Astigarraga, Mikel Eukeni; The ATLAS collaboration

    2017-01-01

    The LHC has been providing proton-proton collisions with record intensity and energy since the start of Run 2 in 2015. In the ATLAS experiment the Data Acquisition is responsible for the transport and storage of the more complex event data at higher rates that the new collision environment implies. Data from events selected by the first level hardware trigger are subject to further filtration from software running on a commodity server farm. During this time the data are transferred from detector electronics across 1900 optical links to custom buffer hardware hosted across 100 commodity server PCs, and then across the system for processing by high bandwidth network at an average throughput of 30 GB/s. Accepted events are transported to a data logging system for final packaging and transfer to permanent storage, with an average output rate of 1.5 GB/s. The whole system is actively monitored to maximise efficiency and minimise downtime. Due to the scale of the system and the challenging collision environment th...

  12. The ATLAS Data Acquisition System in LHC Run 2

    CERN Document Server

    Pozo Astigarraga, Mikel Eukeni; The ATLAS collaboration

    2017-01-01

    The LHC has been providing proton-proton collisions with record intensity and energy since the start of Run 2 in 2015. In the ATLAS experiment the Data Acquisition is responsible for the transport and storage of the more complex event data at higher rates that the new collision environment implies. Data from events selected by the first level hardware trigger are subject to further filtration from software running on a commodity load balanced processing farm of some 2000 servers. During this time the data transferred from detector electronics across 1900 optical links to custom buffer hardware hosted across 100 commodity server PCs, and transferred across the system for processing by high bandwidth network at an average throughput of 30 GB/s. Accepted events are then transported to a data logging system for final packaging and transfer to permanent storage, with a final average output bandwidth of 1.5 GB/s. The whole system is actively monitored to maximise efficiency and minimise downtime. Due to the scale o...

  13. The ATLAS Trigger System: Ready for Run-2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00211007; The ATLAS collaboration

    2015-01-01

    The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. During the next data-taking period starting in 2015 (Run-2) the LHC will operate at a centre-of-mass energy of about 13 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger system, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter fa...

  14. The performance of the CASTOR calorimeter during LHC Run 2

    CERN Document Server

    van de Klundert, Merijn H F

    2016-01-01

    CASTOR is an electromagnetic and hadronic tungsten-quartz sampling Cerenkov calorimeter located at the Compact Muon Solenoid experiment at the Large Hadron Collider. The detector has pseudorapidity borders at -5.2 and -6.6. An overview is presented on the various aspects of CASTOR’s performance and their relations during LHC Run 2. The equalisation of CASTOR’s channels is performed using beam-halo muons. Thereafter, CASTOR’s pedestal spectrum is studied. It is shown that noise estimates which are extracted using a fit, give on average a 10% lower threshold than statistical estimates. Gain correction factors, which are needed for the intercalibration, are obtained using a statistical, in-situ applicable method. The results of this method are shown to be reasonably consistent with laboratory measurements. Penultimately the absolute calibration is discussed, with emphasis on the relation between the scale uncertainty and CASTOR’s alignment. It is shown that the alignment’s contribution to the systemati...

  15. New LHCb Management readies for run 2 challenges

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    As of 1 July, LHCb, one of the four biggest experiments at the LHC, will have a new Management. Ahead are the huge challenges of run 2 and the following long technical shutdown during which LHCb will undergo a major upgrade. In the meantime, the discovery of new physics could be a dream within reach…   New LHCb Spokesperson, Guy Wilkinson.   “We have to make sure that the detector wakes up after its long hibernation and goes back to data taking in the most efficient way and that we are able to process all these data to produce high-quality physics results,” says Guy Wilkinson, new Spokesperson of the LHCb collaboration. Although this already sounds like a considerable “to-do” list for the coming months, it’s just the beginning of a much longer and ambitious plan. “The previous management has done an excellent job in analysing the data we took during run 1. They also put on a very sound footing the LHCb upgrade, whi...

  16. ATLAS strip detector: Operational Experience and Run1 → Run2 transition

    CERN Document Server

    NAGAI, K; The ATLAS collaboration

    2014-01-01

    The ATLAS SCT operational experience and the detector performance during the RUN1 period of LHC will be reported. Additionally the preparation outward to RUN2 during the long shut down 1 will be mentioned.

  17. The design and performance of the ATLAS Inner Detector trigger for Run 2

    CERN Document Server

    Penc, Ondrej; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the early LHC Run 2 data are discussed. The redesign of the ID trigger, which took place during the 2013-15 long shutdown, in order to satisfy the demands of the higher energy LHC Run 2 operation is described. The ID trigger HLT algorithms are essential for nearly all trigger signatures within the ATLAS trigger. The detailed performance of the tracking algorithms with the early Run 2 data for the different trigger signatures is presented, including the detailed timing performance for the algorithms running on the redesigned single stage ATLAS HLT Farm. Comparison with the Run 1 strategy are made and demonstrate the superior performance of the strategy adopted for Run 2.

  18. Low-$p_T$ dimuon triggers at LHCb in Run 2

    CERN Document Server

    Dettori, Francesco; Prisciandaro, Jessica

    2017-01-01

    The LHCb trigger efficiency for strange hadron decays to final states containing dimuon pairs was substantially improved for Run 2 of the LHC. This note describes the updated strategy, and its impact on the LHCb rare strange physics programme.

  19. Top quark production cross-section at the Tevatron Run 2

    OpenAIRE

    Cabrera, S.

    2003-01-01

    The top quark pair production cross-section ${\\sigma}_{t\\bar{t}}$ has been measured in $p\\bar{p}$ collisions at center of mass energies of 1.96 TeV using Tevatron Run 2 data. In the begining of Run 2 both CDF and D\\O\\ $\\sigma_{t\\bar{t}}$ measurements in the {\\it dilepton} channel $t\\bar{t}{\\to}WbW\\bar{b}{\\to}\\bar{\\ell}{\

  20. The ATLAS Liquid Argon Calorimeters At The Dawn Of LHC Run-2

    CERN Document Server

    Camincher, Clement; The ATLAS collaboration

    2015-01-01

    The Liquid Argon Calorimeters are key sub-detectors of ATLAS. They are essential to detect and measure the properties of electrons, photons and are also crucial for jets and missing transverse energy measurements. During the LHC shutdown in 2013-2014, the hardware and the software have been optimized to improve their reliability. The first collisions allows to assess the performance of the detector in the LHC Run-2 real conditions. In view of the next LHC Run in 2020, an upgrade of the level-1 trigger system is also under test. A status at the restart of the LHC Run-2 is presented in this document.

  1. ATLAS Strip Detector: Operational Experience and Run1-> Run2 Transition

    CERN Document Server

    Nagai, Koichi; The ATLAS collaboration

    2014-01-01

    Large hadron collider was operated very successfully during the Run1 and provided a lot of opportunities of physics studies. It currently has a consolidation work toward to the operation at $\\sqrt{s}=14 \\mathrm{TeV}$ in Run2. The ATLAS experiment has achieved excellent performance in Run1 operation, delivering remarkable physics results. The SemiConductor Tracker contributed to the precise measurement of momentum of charged particles. This paper describes the operation experience of the SemiConductor Tracker in Run1 and the preparation toward to the Run2 operation during the LS1.

  2. Spanish ATLAS Tier-2 facing up to Run-2 period of LHC

    CERN Document Server

    Gonzalez de la Hoz, Santiago; The ATLAS collaboration; Fassi, Farida; Fernandez Casani, Alvaro; Kaci, Mohammed; Lacort Pellicer, Victor Ruben; Montiel Gonzalez, Almudena Del Rocio; Oliver Garcia, Elena; Pacheco Pages, Andres; Salt, José; Villaplana Perez, Miguel; Sanchez Martinez, Victoria; Sánchez, Javier

    2015-01-01

    The goal of this work is to describe the way of addressing the main challenges of Run-2 by the Spanish ATLAS Tier-2. The considerable increase of energy and luminosity for the upcoming Run-2 w.r.t. Run-1 has led to a revision of the ATLAS computing model as well as some of the main ATLAS computing tools. The adaptation to these changes will be shown, with the peculiarities that it is a distributed Tier-2 composed of three sites and its members are involved on ATLAS computing tasks with a hub of research, innovation and education.

  3. Operation of the upgraded ATLAS Central Trigger Processor during the LHC Run 2

    DEFF Research Database (Denmark)

    Bertelsen, H.; Montoya, G. Carrillo; Deviveiros, P. O.

    2016-01-01

    The ATLAS Central Trigger Processor (CTP) is responsible for forming the Level-1 trigger decision based on the information from the calorimeter and muon trigger processors. In order to cope with the increase of luminosity and physics cross-sections in Run 2, several components of this system have...

  4. Comparison of fractions of inactive modules between Run1 and Run2

    CERN Document Server

    Motohashi, Kazuki; The ATLAS collaboration

    2015-01-01

    Fraction of inactive modules for each component of the ATLAS pixel detector at the end of Run 1 and the beginning of Run 2. A similar plot which uses a result of functionality tests during LS1 can be found in ATL-INDET-SLIDE-2014-388.

  5. Comparing effectiveness of combined transobturator tension-free vaginal mesh (Perigee) and transobturator tension-free vaginal tape (TVT-O) versus anterior colporrhaphy and TVT-O for associated cystocele and urodynamic stress incontinence.

    Science.gov (United States)

    Lau, Hei-Yu; Twu, Nae-Fang; Chen, Yi-Jen; Horng, Huann-Cheng; Juang, Chi-Mou; Chao, Kuan-Chong

    2011-06-01

    To evaluate the efficacy and safety of transobturator tension-free vaginal mesh (Perigee) and concomitant transobturator tension-free vaginal tape (TVT-O) for treating cystocele with urodynamic stress incontinence (UDSI). A retrospective study of 115 patients with symptomatic stages 2-3 cystocele and UDSI who were treated with a Perigee system (Group I, n=68) plus TVT-O procedure or traditional anterior colporrhaphy (Group II, n=47) plus TVT-O procedure. All patients were followed up for more than one year. Objective and subjective symptoms were evaluated at one year postoperatively. Statistical analysis was performed using SPSS software. The objective cure rates for cystocele at one year were significantly higher in Group I than in Group II (98.5% and 86.9%, P=0.018), respectively. The cure rates for UDSI in the two groups were 91.0% vs. 91.3% (P=1.000). Symptomatic improvement of frequency was better in Group I than Group II (87.7% vs. 70.0%, P=0.030). There were no significant differences with regard to intraoperative and postoperative complications between the two groups. The combination of the Perigee system and TVT-O offers a safe and effective treatment for cystocele with UDSI and may be performed as first-line treatment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  6. The ATLAS Tau Trigger Performance during LHC Run 1 and Prospects for Run 2

    CERN Document Server

    Mitani, T; The ATLAS collaboration

    2016-01-01

    The ATLAS tau trigger is designed to select hadronic decays of the tau leptons. Tau lepton plays an important role in Standard Model (SM) physics, such as in Higgs boson decays. Tau lepton is also important in beyond the SM (BSM) scenarios, such as supersymmetry and exotic particles, as they are often produced preferentially in these models. During the 2010-2012 LHC run (Run1), the tau trigger was accomplished successfully, which leads several rewarding results such as evidence for $H\\rightarrow \\tau\\tau$. From the 2015 LHC run (Run2), LHC will be upgraded and overlapping interactions per bunch crossing (pile-up) are expected to increase by a factor two. It will be challenging to control trigger rates while keeping interesting physics events. This paper summarized the tau trigger performance in Run1 and its prospects for Run2.

  7. Evolution of online algorithms in ATLAS and CMS in Run2

    CERN Document Server

    Tomei, Thiago R. F. P.

    2017-01-01

    The Large Hadron Collider has entered a new era in Run~2, with centre-of-mass energy of 13~TeV and instantaneous luminosity reaching $\\mathcal{L}_\\textrm{inst} = 1.4\\times$10\\textsuperscript{34}~cm\\textsuperscript{-2}~s\\textsuperscript{-1} for pp collisions. In order to cope with those harsher conditions, the ATLAS and CMS collaborations have improved their online selection infrastructure to keep a high efficiency for important physics processes -- like W, Z and Higgs bosons in their leptonic and diphoton modes -- whilst keeping the size of data stream compatible with the bandwidth and disk resources available. In this note, we describe some of the trigger improvements implemented for Run~2, including algorithms for selection of electrons, photons, muons and hadronic final states.

  8. The Higgs properties in the MSSM after the LHC Run-2

    Science.gov (United States)

    Zhao, Jun

    2018-04-01

    We scrutinize the parameter space of the SM-like Higgs boson in the minimal supersymmetric standard model (MSSM) under current experimental constraints. The constraints are from (i) the precision electroweak data and various flavor observables; (ii) the direct 22 separate ATLAS searches in Run-1; (iii) the latest LHC Run-2 Higgs data and tri-lepton search of electroweakinos. We perform a scan over the parameter space and find that the Run-2 data can further exclude a part of parameter space. For the property of the SM-like Higgs boson, its gauge couplings further approach to the SM values with a deviation below 0.1%, while its Yukawa couplings hbb¯ and hτ+τ‑ can still sizably differ from the SM predictions by several tens percent.

  9. The Performance and Development of the Inner Detector Trigger Algorithms at ATLAS for LHC Run 2

    CERN Document Server

    Sowden, Benjamin Charles; The ATLAS collaboration

    2015-01-01

    A description of the design and performance of the newly reimplemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is provided. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2 for the HLT. This new strategy will use a Fast Track Finder (FTF) algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 but with no significant reduction in efficiency. The performance and timing of the algorithms for numerous physics signatures in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performan...

  10. The new strategy for particle identification samples in Run 2 at LHCb

    CERN Multimedia

    Mathad, Abhijit

    2017-01-01

    For Run 2 of LHCb data taking, the selection of PID calibration samples is implemented in the high level trigger. A further processing is needed to provide background-subtracted samples to determine the PID performance, or to develop new algorithms for the evaluation of the detector performance in upgrade scenarios. This is achieved through a centralised production which makes efficient use of LHCb computing resources. This poster presents the major steps of the implementation.

  11. ATLAS Distributed Computing experience and performance during the LHC Run-2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00081160; The ATLAS collaboration

    2016-01-01

    ATLAS Distributed Computing during LHC Run-1 was challenged by steadily increasing computing, storage and network requirements. In addition, the complexity of processing task workflows and their associated data management requirements led to a new paradigm in the ATLAS computing model for Run-2, accompanied by extensive evolution and redesign of the workflow and data management systems. The new systems were put into production at the end of 2014, and gained robustness and maturity during 2015 data taking. ProdSys2, the new request and task interface; JEDI, the dynamic job execution engine developed as an extension to PanDA; and Rucio, the new data management system, form the core of the Run-2 ATLAS distributed computing engine. One of the big changes for Run-2 was the adoption of the Derivation Framework, which moves the chaotic CPU and data intensive part of the user analysis into the centrally organized train production, delivering derived AOD datasets to user groups for final analysis. The effectiveness of...

  12. ATLAS Distributed Computing experience and performance during the LHC Run-2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00081160; The ATLAS collaboration

    2017-01-01

    ATLAS Distributed Computing during LHC Run-1 was challenged by steadily increasing computing, storage and network requirements. In addition, the complexity of processing task workflows and their associated data management requirements led to a new paradigm in the ATLAS computing model for Run-2, accompanied by extensive evolution and redesign of the workflow and data management systems. The new systems were put into production at the end of 2014, and gained robustness and maturity during 2015 data taking. ProdSys2, the new request and task interface; JEDI, the dynamic job execution engine developed as an extension to PanDA; and Rucio, the new data management system, form the core of Run-2 ATLAS distributed computing engine. One of the big changes for Run-2 was the adoption of the Derivation Framework, which moves the chaotic CPU and data intensive part of the user analysis into the centrally organized train production, delivering derived AOD datasets to user groups for final analysis. The effectiveness of the...

  13. The ATLAS Level-1 Topological Trigger Design and Operation in Run-2

    CERN Document Server

    Igonkina, Olga; The ATLAS collaboration

    2018-01-01

    The ATLAS Level-1 Trigger system performs initial event selection using data from calorimeters and the muon spectrometer to reduce the LHC collision event rate down to about 100 kHz. Trigger decisions from the different sub-systems are combined in the Central Trigger Processor for the final Level-1 decision. A new FPGAs-based AdvancedTCA sub-system was introduced to calculate in real time complex kinematic observables: the Topological Processor System. It was installed during the shutdown and commissioning started in 2015 and continued during 2016. The design and operation of the Level-1 Topological Trigger in Run-2 will be illustrated.

  14. Performance of the ALICE PHOS trigger and improvements for RUN 2

    International Nuclear Information System (INIS)

    Zhao, C; Røed, K; Skaali, T B; Liu, L; Rohrich, D; Kharlov, Y; Bratrud, L; Alme, J

    2013-01-01

    This paper will discuss the performance of the PHOS level-0 trigger and planned improvements for RUN 2. Due to hardware constraints the Trigger Region Unit boards are limited to an operating frequency of 20 MHz. This has led to some ambiguity and biases of the trigger inputs. The trigger input generation scheme was therefore optimized to improve the performance. The PHOS level-0 trigger system has been working with an acceptable efficiency and purity. Proposed actions to further improve the performance and possibly eliminate the impact of the biased trigger inputs will also be presented

  15. Operation and Performance of the ATLAS Level-1 Calorimeter and Topological Triggers in Run 2

    CERN Document Server

    Weber, Sebastian Mario; The ATLAS collaboration

    2017-01-01

    In Run 2 at CERN's Large Hadron Collider, the ATLAS detector uses a two-level trigger system to reduce the event rate from the nominal collision rate of 40 MHz to the event storage rate of 1 kHz, while preserving interesting physics events. The first step of the trigger system, Level-1, reduces the event rate to 100 kHz within a latency of less than $2.5$ $\\mu\\text{s}$. One component of this system is the Level-1 Calorimeter Trigger (L1Calo), which uses coarse-granularity information from the electromagnetic and hadronic calorimeters to identify regions of interest corresponding to electrons, photons, taus, jets, and large amounts of transverse energy and missing transverse energy. In these proceedings, we discuss improved features and performance of the L1Calo system in the challenging, high-luminosity conditions provided by the LHC in Run 2. A new dynamic pedestal correction algorithm reduces pile-up effects and the use of variable thresholds and isolation criteria for electromagnetic objects allows for opt...

  16. Status and performance of the CMS muon system in Run2

    CERN Document Server

    Cabrera Mora, Andres Leonardo

    2016-01-01

    The CMS muon system has played a key role for many physics results obtained from the LHC Run1 and Run2 data. During the Long Shutdown (2013-2014), as well as during the last year-end technical stop (2015-2016), significant consolidation and upgrades have been carried out on the muon detectors and on the Level-1 (L1) muon trigger. The algorithms for muon reconstruction and identification have also been improved for both the High-Level Trigger (HLT) and the offline reconstruction. Results of the performance of muon detectors, reconstruction and trigger, obtained using data collected at 13 TeV center-of-mass energy during the 2015 and 2016 LHC runs, are presented. Comparison of simulation with experimental data is also discussed where relevant. The system's state of the art is also shown, as well the improvements foreseen to achieve excellent overall quality of muon reconstruction in the high-luminosity conditions expected during Run2.

  17. ALICE high-level trigger readout and FPGA processing in Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Engel, Heiko; Kebschull, Udo [IRI, Goethe-Universitaet Frankfurt (Germany); Collaboration: ALICE-Collaboration

    2016-07-01

    The ALICE experiment uses the optical Detector Data Link (DDL) protocol to connect the detectors to the computing clusters of Data Acquisition (DAQ) and High-Level Trigger (HLT). The interfaces between the clusters and the optical links are realized with FPGA boards. HLT has replaced all of its interface boards with the Common Read-Out Receiver Card (C-RORC) for Run 2. This enables the read-out of detectors at higher link rates and allows to extend the data pre-processing capabilities, like online cluster finding, already in the FPGA. The C-RORC is integrated transparently into the existing HLT data transport framework and the cluster monitoring and management infrastructure. The board is in use since the start of LHC Run 2 and all ALICE data from and to HLT as well as all data from the TPC and the TRD is handled by C-RORCs. This contribution gives an overview on the firmware and software status of the C-RORC in the HLT.

  18. Evolution of ATLAS conditions data and its management for LHC Run-2

    International Nuclear Information System (INIS)

    Böhler, Michael; Borodin, Mikhail; Formica, Andrea; Gallas, Elizabeth; Radescu, Voica

    2015-01-01

    The ATLAS detector at the LHC consists of several sub-detector systems. Both data taking and Monte Carlo (MC) simulation rely on an accurate description of the detector conditions from every subsystem, such as calibration constants, different scenarios of pile-up and noise conditions, size and position of the beam spot, etc. In order to guarantee database availability for critical online applications during data-taking, two database systems, one for online access and another one for all other database access, have been implemented.The long shutdown period has provided the opportunity to review and improve the Run-1 system: revise workflows, include new and innovative monitoring and maintenance tools and implement a new database instance for Run-2 conditions data. The detector conditions are organized by tag identification strings and managed independently by the different sub-detector experts. The individual tags are then collected and associated into a global conditions tag, assuring synchronization of various sub-detector improvements. Furthermore, a new concept was introduced to maintain conditions over all different data run periods into a single tag, by using Interval of Validity (IOV) dependent detector conditions for the MC database as well. This allows on the fly preservation of past conditions for data and MC and assures their sustainability with software evolution.This paper presents an overview of the commissioning of the new database instance, improved tools and workflows, and summarizes the actions taken during the Run-2 commissioning phase in the beginning of 2015. (paper)

  19. LHC Run 2 – reaching the top of the learning curve

    CERN Multimedia

    2015-01-01

    As the LHC Physics conference gets underway in St Petersburg, it’s a good time to take stock of where things stand with Run 2.    For all those involved with operating the LHC and its experiments in this new energy and intensity regime, 2015 was always going to be a learning curve. And learning we most certainly are. The main objective for this year has always been to set up the machine and experiments for production running at high energy and high intensity in 2016, 17 and 18.  That said, the experiments have all been able to collect quality data at 13 TeV, with the first Run 2 papers and conference presentations being written and delivered this summer. It would be unfair of me, however, to give the impression that it’s all been plain sailing. As well as the highs: smooth recommissioning of the machine, physics getting underway, and a successful transition to 25-nanosecond bunch spacing, we’ve also had our fair share of lows. There have been no sho...

  20. Analysis of the beam induced heat loads on the LHC arc beam screens during Run 2

    CERN Document Server

    Iadarola, Giovanni; Dijkstal, Philipp; Mether, Lotta; CERN. Geneva. ATS Department

    2017-01-01

    During Run 2 the Large Hadron Collider (LHC) has been routinely operated with 25 ns bunch spacing. In these conditions large heat loads have been measured on the beam screens of the superconducting magnets, together with other observations indicating that an electron cloud develops in the beam chambers. The analysis of these heat loads has revealed several interesting features allowing to pinpoint peculiar characteristics of the observed beam-induced heating. This document describes the main findings of this analysis including the evolution taking place during the run, the observed dependence on the beam conditions and the results from special tests and dedicated instrumentation. The differences observed in the behavior of the eight LHC arcs are also discussed.

  1. ATLAS Distributed Computing Experience and Performance During the LHC Run-2

    Science.gov (United States)

    Filipčič, A.; ATLAS Collaboration

    2017-10-01

    ATLAS Distributed Computing during LHC Run-1 was challenged by steadily increasing computing, storage and network requirements. In addition, the complexity of processing task workflows and their associated data management requirements led to a new paradigm in the ATLAS computing model for Run-2, accompanied by extensive evolution and redesign of the workflow and data management systems. The new systems were put into production at the end of 2014, and gained robustness and maturity during 2015 data taking. ProdSys2, the new request and task interface; JEDI, the dynamic job execution engine developed as an extension to PanDA; and Rucio, the new data management system, form the core of Run-2 ATLAS distributed computing engine. One of the big changes for Run-2 was the adoption of the Derivation Framework, which moves the chaotic CPU and data intensive part of the user analysis into the centrally organized train production, delivering derived AOD datasets to user groups for final analysis. The effectiveness of the new model was demonstrated through the delivery of analysis datasets to users just one week after data taking, by completing the calibration loop, Tier-0 processing and train production steps promptly. The great flexibility of the new system also makes it possible to execute part of the Tier-0 processing on the grid when Tier-0 resources experience a backlog during high data-taking periods. The introduction of the data lifetime model, where each dataset is assigned a finite lifetime (with extensions possible for frequently accessed data), was made possible by Rucio. Thanks to this the storage crises experienced in Run-1 have not reappeared during Run-2. In addition, the distinction between Tier-1 and Tier-2 disk storage, now largely artificial given the quality of Tier-2 resources and their networking, has been removed through the introduction of dynamic ATLAS clouds that group the storage endpoint nucleus and its close-by execution satellite sites. All stable

  2. Hierarchical vs degenerate 2HDM. The LHC run 1 legacy at the onset of run 2

    International Nuclear Information System (INIS)

    Dorsch, G.C.; Huber, S.J.; Mimasu, K.; No, J.M.

    2016-01-01

    Current discussions of the allowed two-Higgs-doublet model (2HDM) parameter space after LHC Run 1 and the prospects for Run 2 are commonly phrased in the context of a quasi-degenerate spectrum for the new scalars. Here we discuss the generic situation of a 2HDM with a non-degenerate spectrum for the new scalars. This is highly motivated from a cosmological perspective since it naturally leads to a strongly first order electroweak phase transition that could explain the matter-antimatter asymmetry in the Universe. While constraints from measurements of Higgs signal strengths do not change, those from searches of new scalar states get modified dramatically once a non-degenerate spectrum is considered.

  3. Novel time-dependent alignment of the ATLAS Inner Detector in the LHC Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00386283; The ATLAS collaboration

    2016-01-01

    ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require an unbiased and high resolution measurement of the charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system and the quality of the alignment of its components. For the LHC Run 2, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). ATLAS Inner Detector alignment framework has been adapted and upgraded to correct very short time scale movements of the sub-detectors. In particular, a mechanical distortion of the IBL staves up to 20 μm and a vertical displacement of the Pixel detector of ~6 μm have been observed during data-taking. The techniques used to correct for these effects and to match the required Inner Detector performance will be presented.

  4. Evolution of ATLAS conditions data and its management for LHC Run-2

    CERN Document Server

    Boehler, Michael; Formica, Andrea; Gallas, Elizabeth; Radescu, Voica

    2015-01-01

    The ATLAS detector at the LHC consists of several sub-detector systems. Both data taking and Monte Carlo (MC) simulation rely on an accurate description of the detector conditions from every subsystem, such as calibration constants, different scenarios of pile-up and noise conditions, size and position of the beam spot, etc. In order to guarantee database availability for critical online applications during data-taking, two database systems, one for online access and another one for all other database access have been implemented. The long shutdown period has provided the opportunity to review and improve the Run-1 system: revise workflows, include new and innovative monitoring and maintenance tools and implement a new database instance for Run-2 conditions data. The detector conditions are organized by tag identification strings and managed independently from the different sub-detector experts. The individual tags are then collected and associated into a global conditions tag, assuring synchronization of var...

  5. First measurement of the w boson mass with CDF in Run 2

    International Nuclear Information System (INIS)

    Stelzer-Chilton, Oliver; Toronto U.

    2005-01-01

    This thesis describes a first measurement of the W Boson mass through the decay into a muon and a neutrino in Run 2 of the Tevatron. The W Bosons are produced in proton-antiproton collisions at a center of mass energy of 1.96 TeV. The data sample used for this analysis corresponds to 200 pb -1 recorded by the upgraded Collider Detector at Fermilab. The most important quantity in this measurement is the momentum of the muon measured in a magnetic spectrometer which is calibrated using the two quarkonium resonances J/Ψ and Υ(1S). Systematic uncertainties arise from the modeling of the recoil when the W Boson is produced, the momentum calibration, the modeling of W Boson production and decay dynamics and backgrounds. The result is: M W = 80408 ± 50(stat.) ± 57(syst.) MeV/c 2

  6. The ATLAS Distributed Computing project for LHC Run-2 and beyond.

    CERN Document Server

    Di Girolamo, Alessandro; The ATLAS collaboration

    2015-01-01

    The ATLAS Distributed Computing infrastructure has evolved after the first period of LHC data taking in order to cope with the challenges of the upcoming LHC Run2. An increased data rate and computing demands of the Monte-Carlo simulation, as well as new approaches to ATLAS analysis, dictated a more dynamic workload management system (ProdSys2) and data management system (Rucio), overcoming the boundaries imposed by the design of the old computing model. In particular, the commissioning of new central computing system components was the core part of the migration toward the flexible computing model. The flexible computing utilization exploring the opportunistic resources such as HPC, cloud, and volunteer computing is embedded in the new computing model, the data access mechanisms have been enhanced with the remote access, and the network topology and performance is deeply integrated into the core of the system. Moreover a new data management strategy, based on defined lifetime for each dataset, has been defin...

  7. Operational experience of the upgraded LHC injection kicker magnets during Run 2 and future plans

    Science.gov (United States)

    Barnes, M. J.; Adraktas, A.; Bregliozzi, G.; Goddard, B.; Ducimetière, L.; Salvant, B.; Sestak, J.; Vega Cid, L.; Weterings, W.; Vallgren, C. Yin

    2017-07-01

    During Run 1 of the LHC, one of the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. In addition, there were also sporadic issues with vacuum activity and electrical flashover of the injection kickers. An extensive program of studies was launched and significant upgrades were carried out during Long Shutdown 1 (LS 1). These upgrades included a new design of beam screen to reduce both beam coupling impedance of the kicker magnet and the electric field associated with the screen conductors, hence decreasing the probability of electrical breakdown in this region. This paper presents operational experience of the injection kicker magnets during the first years of Run 2 of the LHC, including a discussion of faults and kicker magnet issues that limited LHC operation. In addition, in light of these issues, plans for further upgrades are briefly discussed.

  8. The ATLAS Trigger Menu Design for Higher Luminosities in Run-2

    CERN Document Server

    Wiglesworth, Craig; The ATLAS collaboration

    2018-01-01

    In this presentation we describe the design criteria for the trigger menu for Run-2. We discuss several aspects of the process of planning the trigger menu, starting from how ATLAS physics goals and the need for detector performance measurements enter the menu design, and how rate, bandwidth, and CPU constraints are folded in during the compilation of the menu. We present the tools that allow us to predict and optimize the trigger rates and CPU consumption for the anticipated LHC luminosities. We outline the online system that we implemented to monitor deviations from the individual trigger target rates and to quickly react to changing LHC conditions and data taking scenarios. Finally we give an overview of the updated 2E34 Trigger Menu, allowing the listener to get a taste of the vast physics program that the trigger is supporting.

  9. LHCb : First years of running for the LHCb calorimeter system and preparation for run 2

    CERN Multimedia

    Chefdeville, Maximilien

    2015-01-01

    The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN (Geneva). It comprises a calorimeter system composed of four subdetectors: a Scintillating Pad Detector (SPD) and a Pre-Shower detector (PS) in front of an electromagnetic calorimeter (ECAL) which is followed by a hadron calorimeter (HCAL). They are used to select transverse energy hadron, electron and photon candidates for the first trigger level and they provides the identification of electrons, photons and hadrons as well as the measurement of their energies and positions. The calorimeter has been pre-calibrated before its installation in the pit. The calibration techniques have been tested with data taken in 2010 and used regularly during run 1. For run 2, new calibration methods have been devised to follow and correct online the calorimeter detector response. The design and construction characteristics of the LHCb calorimeter will be recalled. Strategies for...

  10. First results from ALICE on anisotropic flow at Run 2 at LHC

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The goal of studies with relativistic heavy-ion collisions is to investigate the Quark-Gluon Plasma (QGP), a state of matter where quarks and gluons move freely over distances large in comparison to the typical size of a hadron. The exploration of QGP properties has broken new ground with the recent heavy-ion collisions from Run 2 operations at Large Hadron Collider, at the highest energies to date. The ALICE Collaboration has made the first observation of anisotropic flow of charged particles in lead-lead collisions at the record breaking energy of 5.02 TeV per nucleon pair. The talk presents these new results and discusses how they further enlighten the properties of matter produced in ultrarelativistic nuclear collisions.

  11. LHCb : Novel real-time alignment and calibration of the LHCb Detector in Run2

    CERN Multimedia

    Tobin, Mark

    2015-01-01

    LHCb has introduced a novel real-time detector alignment and calibration strategy for LHC Run 2. Data collected at the start of the fill will be processed in a few minutes and used to update the alignment, while the calibration constants will be evaluated for each run. This procedure will improve the quality of the online alignment. For example, the vertex locator is retracted and reinserted for stable beam collisions in each fill to be centred on the primary vertex position in the transverse plane. Consequently its position changes on a fill-by-fill basis. Critically, this new realtime alignment and calibration procedure allows identical constants to be used in the online and offline reconstruction, thus improving the correlation between triggered and offline selected events. This offers the opportunity to optimise the event selection in the trigger by applying stronger constraints. The online calibration facilitates the use of hadronic particle identification using the RICH detectors at the trigger level. T...

  12. Online calibration of the ALICE-TPC in LHC-Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Vorobyev, Ivan [Technische Universitaet Muenchen, Excellence Cluster Universe (Germany); Collaboration: ALICE-Collaboration

    2015-07-01

    The Time Projection Chamber (TPC) is the main tracking detector at the ALICE Experiment at the LHC. Its performance and calibration directly influence the calibration of other detectors in the ALICE central barrel. To address this issue during the first LHC running period, a two-step offline calibration was employed, in which first the TPC and then the other detectors were calibrated. However, such a scheme will not be feasible for the Run 3 period, because the TPC will run in a continuous readout mode, producing a vast amount of data that needs to be significantly compressed on the fly for data storage. This will require the calibration step to run online within the High Level Trigger environment. In this talk, the online calibration concept and the implementation for the ALICE-TPC already in Run 2 are discussed.

  13. GridPP - Preparing for LHC Run 2 and the Wider Context

    Science.gov (United States)

    Coles, Jeremy

    2015-12-01

    This paper elaborates upon the operational status and directions within the UK Computing for Particle Physics (GridPP) project as it approaches LHC Run 2. It details the pressures that have been gradually reshaping the deployed hardware and middleware environments at GridPP sites - from the increasing adoption of larger multicore nodes to the move towards alternative batch systems and cloud alternatives - as well as changes being driven by funding considerations. The paper highlights work being done with non-LHC communities and describes some of the early outcomes of adopting a generic DIRAC based job submission and management framework. The paper presents results from an analysis of how GridPP effort is distributed across various deployment and operations tasks and how this may be used to target further improvements in efficiency.

  14. The design and PCB layout of the CDF Run 2 calorimetry readout module

    International Nuclear Information System (INIS)

    Theresa Shaw

    1999-01-01

    The CDF Calorimetry Readout module, called the ADMEM, has been designed to contain both the analog circuitry which digitizes the phototube charge pulses, and the digital logic which supports the readout of the results through the CDF Run 2 DAQ system. The ADMEM module is a 9Ux400mm VMEbus module, which is housed in a CDF VMEbus VIPA crate. The ADMEM must support near deadtimeless operation, with data being digitized and stored for possible readout every 132ns or 7.6 Mhz. This paper will discuss the implementation of the analog and digital portions of the ADMEM module, and how the board was laid out to avoid the coupling of digital noise into the analog circuitry

  15. The ATLAS Data Management System Rucio: Supporting LHC Run-2 and beyond

    CERN Document Server

    Barisits, Martin-Stefan; The ATLAS collaboration; Garonne, Vincent

    2017-01-01

    With this contribution we present some recent developments made to Rucio, the data management system of the High-Energy Physics Experiment ATLAS. Already managing 300 Petabytes of both official and user data, Rucio has seen incremental improvements throughout LHC Run-2, and is currently laying the groundwork for HEP computing in the HL-LHC era. The focus of this contribution are (a) the automations that have been put in place such as data rebalancing or dynamic replication of user data, as well as their supporting infrastructures such as real-time networking metrics or transfer time predictions; (b) the flexible approach towards inclusion of heterogeneous storage systems, including object stores, while unifying the potential access paths using generally available tools and protocols; (c) machine learning approaches to help with transfer throughput estimation; and (d) the adoption of Rucio for two other experiments, AMS and Xenon1t. We conclude by presenting operational numbers and figures to quantify these im...

  16. 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...

  17. 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...

  18. Hierarchical vs degenerate 2HDM. The LHC run 1 legacy at the onset of run 2

    Energy Technology Data Exchange (ETDEWEB)

    Dorsch, G.C. [Sussex Univ. (United Kingdom). Dept. of Physics and Astronomy; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Huber, S.J.; Mimasu, K.; No, J.M. [Sussex Univ. (United Kingdom). Dept. of Physics and Astronomy

    2016-01-15

    Current discussions of the allowed two-Higgs-doublet model (2HDM) parameter space after LHC Run 1 and the prospects for Run 2 are commonly phrased in the context of a quasi-degenerate spectrum for the new scalars. Here we discuss the generic situation of a 2HDM with a non-degenerate spectrum for the new scalars. This is highly motivated from a cosmological perspective since it naturally leads to a strongly first order electroweak phase transition that could explain the matter-antimatter asymmetry in the Universe. While constraints from measurements of Higgs signal strengths do not change, those from searches of new scalar states get modified dramatically once a non-degenerate spectrum is considered.

  19. Main improvements of LHC Cryogenics Operation during Run 2 (2015-2018)

    Science.gov (United States)

    Delprat, L.; Bradu, B.; Brodzinski, K.; Ferlin, G.; Hafi, K.; Herblin, L.; Rogez, E.; Suraci, A.

    2017-12-01

    After the successful Run 1 (2010-2012), the LHC entered its first Long Shutdown period (LS1, 2013-2014). During LS1 the LHC cryogenic system went under a complete maintenance and consolidation program. The LHC resumed operation in 2015 with an increased beam energy from 4 TeV to 6.5 TeV. Prior to the new physics Run 2 (2015-2018), the LHC was progressively cooled down from ambient to the 1.9 K operation temperature. The LHC has resumed operation with beams in April 2015. Operational margins on the cryogenic capacity were reduced compared to Run 1, mainly due to the observed higher than expected electron-cloud heat load coming from increased beam energy and intensity. Maintaining and improving the cryogenic availability level required the implementation of a series of actions in order to deal with the observed heat loads. This paper describes the results from the process optimization and update of the control system, thus allowing the adjustment of the non-isothermal heat load at 4.5 - 20 K and the optimized dynamic behaviour of the cryogenic system versus the electron-cloud thermal load. Effects from the new regulation settings applied for operation on the electrical distribution feed-boxes and inner triplets will be discussed. The efficiency of the preventive and corrective maintenance, as well as the benefits and issues of the present cryogenic system configuration for Run 2 operational scenario will be described. Finally, the overall availability results and helium management of the LHC cryogenic system during the 2015-2016 operational period will be presented.

  20. Improvements of the ALICE HLT data transport framework for LHC Run 2

    Science.gov (United States)

    Rohr, David; Krzwicki, Mikolaj; Engel, Heiko; Lehrbach, Johannes; Lindenstruth, Volker; ALICE Collaboration

    2017-10-01

    The ALICE HLT uses a data transport framework based on the publisher- subscriber message principle, which transparently handles the communication between processing components over the network and between processing components on the same node via shared memory with a zero copy approach. We present an analysis of the performance in terms of maximum achievable data rates and event rates as well as processing capabilities during Run 1 and Run 2. Based on this analysis, we present new optimizations we have developed for ALICE in Run 2. These include support for asynchronous transport via Zero-MQ which enables loops in the reconstruction chain graph and which is used to ship QA histograms to DQM. We have added asynchronous processing capabilities in order to support long-running tasks besides the event-synchronous reconstruction tasks in normal HLT operation. These asynchronous components run in an isolated process such that the HLT as a whole is resilient even to fatal errors in these asynchronous components. In this way, we can ensure that new developments cannot break data taking. On top of that, we have tuned the processing chain to cope with the higher event and data rates expected from the new TPC readout electronics (RCU2) and we have improved the configuration procedure and the startup time in order to increase the time where ALICE can take physics data. We analyze the maximum achievable data processing rates taking into account processing capabilities of CPUs and GPUs, buffer sizes, network bandwidth, the incoming links from the detectors, and the outgoing links to data acquisition.

  1. Exploiting CMS data popularity to model the evolution of data management for Run-2 and beyond

    International Nuclear Information System (INIS)

    Bonacorsi, D; Neri, M; Boccali, T; Giordano, D; Girone, M; Magini, N; Kuznetsov, V; Wildish, T

    2015-01-01

    During the LHC Run-1 data taking, all experiments collected large data volumes from proton-proton and heavy-ion collisions. The collisions data, together with massive volumes of simulated data, were replicated in multiple copies, transferred among various Tier levels, transformed/slimmed in format/content. These data were then accessed (both locally and remotely) by large groups of distributed analysis communities exploiting the WorldWide LHC Computing Grid infrastructure and services. While efficient data placement strategies - together with optimal data redistribution and deletions on demand - have become the core of static versus dynamic data management projects, little effort has so far been invested in understanding the detailed data-access patterns which surfaced in Run-1. These patterns, if understood, can be used as input to simulation of computing models at the LHC, to optimise existing systems by tuning their behaviour, and to explore next-generation CPU/storage/network co-scheduling solutions. This is of great importance, given that the scale of the computing problem will increase far faster than the resources available to the experiments, for Run-2 and beyond. Studying data-access patterns involves the validation of the quality of the monitoring data collected on the “popularity of each dataset, the analysis of the frequency and pattern of accesses to different datasets by analysis end-users, the exploration of different views of the popularity data (by physics activity, by region, by data type), the study of the evolution of Run-1 data exploitation over time, the evaluation of the impact of different data placement and distribution choices on the available network and storage resources and their impact on the computing operations. This work presents some insights from studies on the popularity data from the CMS experiment. We present the properties of a range of physics analysis activities as seen by the data popularity, and make recommendations for

  2. Exploiting CMS data popularity to model the evolution of data management for Run-2 and beyond

    Science.gov (United States)

    Bonacorsi, D.; Boccali, T.; Giordano, D.; Girone, M.; Neri, M.; Magini, N.; Kuznetsov, V.; Wildish, T.

    2015-12-01

    During the LHC Run-1 data taking, all experiments collected large data volumes from proton-proton and heavy-ion collisions. The collisions data, together with massive volumes of simulated data, were replicated in multiple copies, transferred among various Tier levels, transformed/slimmed in format/content. These data were then accessed (both locally and remotely) by large groups of distributed analysis communities exploiting the WorldWide LHC Computing Grid infrastructure and services. While efficient data placement strategies - together with optimal data redistribution and deletions on demand - have become the core of static versus dynamic data management projects, little effort has so far been invested in understanding the detailed data-access patterns which surfaced in Run-1. These patterns, if understood, can be used as input to simulation of computing models at the LHC, to optimise existing systems by tuning their behaviour, and to explore next-generation CPU/storage/network co-scheduling solutions. This is of great importance, given that the scale of the computing problem will increase far faster than the resources available to the experiments, for Run-2 and beyond. Studying data-access patterns involves the validation of the quality of the monitoring data collected on the “popularity of each dataset, the analysis of the frequency and pattern of accesses to different datasets by analysis end-users, the exploration of different views of the popularity data (by physics activity, by region, by data type), the study of the evolution of Run-1 data exploitation over time, the evaluation of the impact of different data placement and distribution choices on the available network and storage resources and their impact on the computing operations. This work presents some insights from studies on the popularity data from the CMS experiment. We present the properties of a range of physics analysis activities as seen by the data popularity, and make recommendations for

  3. Improved performance of the LHCb Outer Tracker in LHC Run 2

    Science.gov (United States)

    d'Argent, P.; Dufour, L.; Grillo, L.; de Vries, J. A.; Ukleja, A.; Aaij, R.; Archilli, F.; Bachmann, S.; Berninghoff, D.; Birnkraut, A.; Blouw, J.; De Cian, M.; Ciezarek, G.; Färber, C.; Demmer, M.; Dettori, F.; Gersabeck, E.; Grabowski, J.; Hulsbergen, W. D.; Khanji, B.; Kolpin, M.; Kucharczyk, M.; Malecki, B. P.; Merk, M.; Mulder, M.; Müller, J.; Mueller, V.; Pellegrino, A.; Pikies, M.; Rachwal, B.; Schmelzer, T.; Spaan, B.; Szczekowski, M.; van Tilburg, J.; Tolk, S.; Tuning, N.; Uwer, U.; Wishahi, J.; Witek, M.

    2017-11-01

    The LHCb Outer Tracker is a gaseous detector covering an area of 5 × 6 m2 with 12 double layers of straw tubes. The performance of the detector is presented based on data of the LHC Run 2 running period from 2015 and 2016. Occupancies and operational experience for data collected in pp, pPb and PbPb collisions are described. An updated study of the ageing effects is presented showing no signs of gain deterioration or other radiation damage effects. In addition several improvements with respect to LHC Run 1 data taking are introduced. A novel real-time calibration of the time-alignment of the detector and the alignment of the single monolayers composing detector modules are presented, improving the drift-time and position resolution of the detector by 20%. Finally, a potential use of the improved resolution for the timing of charged tracks is described, showing the possibility to identify low-momentum hadrons with their time-of-flight.

  4. ATLAS Liquid Argon Calorimeter Performance in Run 1 and Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00286685; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{−2}$ s$^{−1}$ . Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudo-rapidity region $\\eta < 3.2$, and for hadronic calorimetry in the region from $\\eta = 1.5$ to $\\eta = 4.9$. In the first LHC run a total luminosity of $27$ fb$^{−1}$ has been collected at center-of-mass energies of 7-8 TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately $3.9$ fb$^{-1}$ of data at a center-of-mass energy of 13 TeV recorded in this year. The well calibrated and highly granular Liquid Argon Calorimeter achieved its design values both in energy measurement as well as in direction resolution, which was a main ingredient for the successful discovery of a Higgs boson in the di-photon decay channel. This contribution will give ...

  5. Performance of the ATLAS Liquid Argon Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    Benitez, Jose; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{-2}$ s${^-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|<3.2$, and for hadronic calorimetry in the region from $|\\eta|=1.5$ to $|\\eta|=4.9$. The calibration and performance of the LAr calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb$^{-1}$ of data have been collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~fb$^{-1}$ of data at a center-of-mass energy of 13~TeV recorded in this year. Results on the LAr calorimeter operation, monitoring and data quality, as we...

  6. Tracking and Vertexing with the ATLAS Inner Detector in the LHC Run2 and Beyond

    CERN Document Server

    Swift, Stewart Patrick; The ATLAS collaboration

    2017-01-01

    Run-2 of the LHC has provided new challenges to track and vertex reconstruction with higher centre-of-mass energies and luminosity leading to increasingly high-multiplicity environments, boosted, and highly-collimated physics objects. To achieve this goal, ATLAS is equipped with the Inner Detector tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. In addition, the Insertable B-layer (IBL) is a fourth pixel layer, which was inserted at the centre of ATLAS during the first long shutdown of the LHC. An overview of the use of each of these subdetectors in track and vertex reconstruction, as well as the algorithmic approaches taken to the specific tasks of pattern recognition and track fitting, is given. The performance of the Inner Detector tracking and vertexing will be summarised. These include a factor of three reduction in the reconstruction time, optimisation for the expected conditions, ...

  7. The TileCal Energy Reconstruction for LHC Run2 and Future Perspectives

    CERN Document Server

    Seixas, Jose; The ATLAS collaboration

    2015-01-01

    The Tile Calorimeter (TileCal) is the main hadronic calorimeter of ATLAS and it covers the central part of the detector (|η|<1.6). The energy deposited by the particles in TileCal is read out by approximately 10,000 channels. The signal provided by the readout electronics for each channel is digitized at 40 MHz and its amplitude is estimated by an optimal filtering algorithm. The increase of LHC luminosity leads to signal pile-up that deforms the signal of interest and compromises the amplitude estimation performance. This work presents the proposed algorithm for energy estimation during LHC Run 2. The method is based on the same approach used during LHC Run 1, namely the Optimal Filter (OF). The only difference is that the signal baseline (pedestal) will be subtracted from the received digitized samples, while in Run 1 this quantity was estimated on an event-by-event basis. The pedestal value is estimated through special calibration runs and it is stored in a data base for online and offline usage. Addit...

  8. The TileCal Energy Reconstruction for LHC Run2 and Future Perspectives

    CERN Document Server

    INSPIRE-00517880

    2015-01-01

    The TileCal is the main hadronic calorimeter of ATLAS and it covers the central part of the detector ($|\\eta|$ < 1.6). The energy deposited by the particles in TileCal is read out by approximately 10,000 channels. The signal provided by the readout electronics for each channel is digitized at 40 MHz and its amplitude is estimated by an optimal filtering algorithm. The increase of LHC luminosity leads to signal pile-up that deforms the signal of interest and compromises the amplitude estimation performance. This work presents the proposed algorithm for energy estimation during LHC Run 2. The method is based on the same approach used during LHC Run 1, namely the Optimal Filter. The only difference is that the signal baseline (pedestal) will be subtracted from the received digitized samples, while in Run 1 this quantity was estimated on an event-by-event basis. The pedestal value is estimated through special calibration runs and it is stored in a data base for online and offline usage. Additionally, the backg...

  9. The TileCal Energy Reconstruction for LHC Run2 and Future Perspectives

    CERN Document Server

    Seixas, Jose; The ATLAS collaboration

    2015-01-01

    The Tile Calorimeter (TileCal) is the main hadronic calorimeter of ATLAS and it covers the central part of the detector (|eta|<1.6). The energy deposited by the particles in TileCal is read out by approximately 10,000 channels. The signal provided by the readout electronics for each channel is digitized at 40 MHz and its amplitude is estimated by an optimal filtering algorithm. The increase of LHC luminosity leads to signal pile-up that deforms the signal of interest and compromises the amplitude estimation performance. This work presents the proposed algorithm for energy estimation during LHC Run 2. The method is based on the same approach used during LHC Run 1, namely the Optimal Filter (OF). The only difference is that the signal baseline (pedestal) will be subtracted from the received digitized samples, while in Run 1 this quantity was estimated on an event-by-event basis. The pedestal value is estimated through special calibration runs and it is stored in a data base for online and offline usage. Addi...

  10. Performance of the ATLAS Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    Burghgrave, Blake; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range |η|<4.9. The calibration and performance of the calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb−1 of data have been collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~fb−1 of data at a center-of-mass energy of 13~TeV recorded in this year. Results on the calorimeter operation, monitoring and data quality, as well as their performance will be presented, including the calibration and stability of the electromagnetic scale, response uniformit...

  11. Real time data analysis with the ATLAS Trigger at the LHC in Run-2

    CERN Document Server

    Beauchemin, Pierre-Hugues; The ATLAS collaboration

    2018-01-01

    The trigger selection capabilities of the ATLAS detector have been significantly enhanced for the LHC Run- 2 in order to cope with the higher event rates and with the large number of simultaneous interactions (pile-up) per protonproton bunch crossing. A new hardware system, designed to analyse real time event-topologies at Level-1 came to full use in 2017. A hardware-based track reconstruction system, expected to be used real-time in 2018, is designed to provide track information to the high-level software trigger at its full input rate. The high-level trigger selections are largely relying on offline-like reconstruction techniques, and in some cases multivariate analysis methods. Despite the sudden change in LHC operations during the second half of 2017, which caused an increase in pile-up and therefore also in CPU usage of the trigger algorithms, the set of triggers (so called trigger menu) running online has undergone only minor modifications thanks to the robustness and redundancy of the trigger system, a...

  12. Real time data analysis with the ATLAS trigger at the LHC in Run-2

    CERN Document Server

    Beauchemin, Pierre-Hugues; The ATLAS collaboration

    2018-01-01

    The trigger selection capabilities of the ATLAS detector have been significantly enhanced for the LHC Run-2 in order to cope with the higher event rates and with the large number of simultaneous interactions (pile-up) per proton-proton bunch crossing. A new hardware system, designed to analyse real time event-topologies at Level-1 came to full use in 2017. A hardware-based track reconstruction system, expected to be used real-time in 2018, is designed to provide track information to the high-level software trigger at its full input rate. The high-level trigger selections are largely relying on offline-like reconstruction techniques, and in some cases multi-variate analysis methods. Despite the sudden change in LHC operations during the second half of 2017, which caused an increase in pile-up and therefore also in CPU usage of the trigger algorithms, the set of triggers (so called trigger menu) running online has undergone only minor modifications thanks to the robustness and redundancy of the trigger system, ...

  13. TRACKING AND VERTEXING WITH THE ATLAS INNER DETECTOR IN THE LHC RUN2 AND BEYOND

    CERN Document Server

    Choi, Kyungeon; The ATLAS collaboration

    2017-01-01

    Run-2 of the LHC has provided new challenges to track and vertex reconstruction with higher centre-of-mass energies and luminosity leading to increasingly high-multiplicity environments, boosted, and highly-collimated physics objects. To achieve this goal, ATLAS is equipped with the Inner Detector tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. In addition, the Insertable B-layer (IBL) is a fourth pixel layer, which was inserted at the centre of ATLAS during the first long shutdown of the LHC. An overview of the use of each of these subdetectors in track and vertex reconstruction, as well as the algorithmic approaches taken to the specific tasks of pattern recognition and track fitting, is given. The performance of the Inner Detector tracking and vertexing will be summarised. These include a factor of three reduction in the reconstruction time, optimisation for the expected conditions, ...

  14. The upgraded Pixel Detector of the ATLAS Experiment for Run 2 at the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Backhaus, M., E-mail: malte.backhaus@cern.ch

    2016-09-21

    During Run 1 of the Large Hadron Collider (LHC), the ATLAS Pixel Detector has shown excellent performance. The ATLAS collaboration took advantage of the first long shutdown of the LHC during 2013 and 2014 and extracted the ATLAS Pixel Detector from the experiment, brought it to surface and maintained the services. This included the installation of new service quarter panels, the repair of cables, and the installation of the new Diamond Beam Monitor (DBM). Additionally, a completely new innermost pixel detector layer, the Insertable B-Layer (IBL), was constructed and installed in May 2014 between a new smaller beam pipe and the existing Pixel Detector. With a radius of 3.3 cm the IBL is located extremely close to the interaction point. Therefore, a new readout chip and two new sensor technologies (planar and 3D) are used in the IBL. In order to achieve best possible physics performance the material budget was improved with respect to the existing Pixel Detector. This is realized using lightweight staves for mechanical support and a CO{sub 2} based cooling system. This paper describes the improvements achieved during the maintenance of the existing Pixel Detector as well as the performance of the IBL during the construction and commissioning phase. Additionally, first results obtained during the LHC Run 2 demonstrating the distinguished tracking performance of the new Four Layer ATLAS Pixel Detector are presented.

  15. Minimum Bias Trigger Scintillators for ATLAS: Commissioning and Run 2 Initial Operation

    CERN Document Server

    Dano Hoffmann, Maria; The ATLAS collaboration

    2015-01-01

    The Minimum Bias Trigger Scintillators (MBTS) delivered the primary trigger for selecting events from low luminosity proton-proton, lead-lead and lead-proton collisions with the smallest possible bias during LHC Run 1 (2009-2013). Similarly, the MBTS will select events for the first Run 2 physics measurements, for instance charge multiplicity, proton-proton cross section, rapidity gap measurements, etc. at the unprecedented 13 TeV center of mass energy of proton-proton collisions. We will review the upgrades to the MBTS detector that have been implemented during the 2013-2014 shutdown. New scintillators have been installed to replace the radiation damaged ones, a modified optical readout scheme have been adopted to increase the light yield and an improved data acquisition chain has been used to cope with the few issues observed during Run 1 operations. Since late 2014, MBTS have been commissioned during cosmic data taking, first LHC beam splashes and single beam LHC fills. The goal is to have a fully commissi...

  16. Calibration and performance of the ATLAS Tile Calorimeter during the LHC Run 2

    Science.gov (United States)

    Cerda Alberich, L.

    2018-02-01

    The Tile Calorimeter (TileCal) is the hadronic sampling calorimeter of the ATLAS experiment at the Large Hadron Collider (LHC). TileCal uses iron absorbers and scintillators as active material and it covers the central region | η| < 1.7. Jointly with the other sub-detectors it is designed for measurements of hadrons, jets, tau-particles and missing transverse energy. It also assists in muon identification. TileCal is regularly monitored and calibrated by several different calibration systems: a Cs radioactive source, a laser light system to check the PMT response, and a charge injection system (CIS) to check the front-end electronics. These calibration systems, in conjunction with data collected during proton-proton collisions, Minimum Bias (MB) events, provide extensive monitoring of the instrument and a means for equalizing the calorimeter response at each stage of the signal propagation. The performance of the calorimeter has been established with cosmic ray muons and the large sample of the proton-proton collisions and compared to Monte Carlo (MC) simulations. The response of high momentum isolated muons is also used to study the energy response at the electromagnetic scale, isolated hadrons are used as a probe of the hadronic response. The calorimeter time resolution is studied with multijet events. A description of the different TileCal calibration systems and the results on the calorimeter performance during the LHC Run 2 are presented. The results on the pile-up noise and response uniformity studies are also discussed.

  17. Novel Real-time Alignment and Calibration of the LHCb detector in Run2

    Science.gov (United States)

    Martinelli, Maurizio; LHCb Collaboration

    2017-10-01

    LHCb has introduced a novel real-time detector alignment and calibration strategy for LHC Run2. Data collected at the start of the fill are processed in a few minutes and used to update the alignment parameters, while the calibration constants are evaluated for each run. This procedure improves the quality of the online reconstruction. For example, the vertex locator is retracted and reinserted for stable beam conditions in each fill to be centred on the primary vertex position in the transverse plane. Consequently its position changes on a fill-by-fill basis. Critically, this new real-time alignment and calibration procedure allows identical constants to be used in the online and offline reconstruction, thus improving the correlation between triggered and offline-selected events. This offers the opportunity to optimise the event selection in the trigger by applying stronger constraints. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructure for the trigger. The motivation for a real-time alignment and calibration of the LHCb detector is discussed from both the operational and physics performance points of view. Specific challenges of this novel configuration are discussed, as well as the working procedures of the framework and its performance.

  18. Managing the CMS Data and Monte Carlo Processing during LHC Run 2

    Science.gov (United States)

    Wissing, C.; CMS Collaboration

    2017-10-01

    In order to cope with the challenges expected during the LHC Run 2 CMS put in a number of enhancements into the main software packages and the tools used for centrally managed processing. In the presentation we will highlight these improvements that allow CMS to deal with the increased trigger output rate, the increased pileup and the evolution in computing technology. The overall system aims at high flexibility, improved operational flexibility and largely automated procedures. The tight coupling of workflow classes to types of sites has been drastically relaxed. Reliable and high-performing networking between most of the computing sites and the successful deployment of a data-federation allow the execution of workflows using remote data access. That required the development of a largely automatized system to assign workflows and to handle necessary pre-staging of data. Another step towards flexibility has been the introduction of one large global HTCondor Pool for all types of processing workflows and analysis jobs. Besides classical Grid resources also some opportunistic resources as well as Cloud resources have been integrated into that Pool, which gives reach to more than 200k CPU cores.

  19. Performance of the ATLAS track reconstruction algorithms in dense environments in LHC Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Aaboud, M. [Univ. Mohamed Premier et LPTPM, Oujda (Morocco). Faculte des Sciences; 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

    2017-10-15

    With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb{sup -1} of data collected by the ATLAS experiment and simulation of proton-proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 TeV. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600 GeV is quantified using a novel, data-driven, method. The method uses the energy loss, dE/dx, to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is 0.061 ± 0.006(stat.) ± 0.014(syst.) and 0.093 ± 0.017(stat.) ± 0.021(syst.) for jet transverse momenta of 200-400 GeV and 1400-1600 GeV, respectively. (orig.)

  20. Performance of the ATLAS Calorimeters in LHC Run-1 and Run-2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00354209; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range $|\\eta|<4.9$. The calibration and performance of the calorimetry system was established through beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~\\ifb of proton-proton collision data were collected at the center-of-mass energies of 7 and 8~TeV. Following a period of detector consolidation during a long shutdown, Run-2 started in 2015 with approximately 3.9~\\ifb of data at a center-of-mass energy of 13~TeV recorded in the first year. We present a summary of the calorimeter operation, monitoring and data quality, as well as their performance, including the calibration and stability of the electromagnetic scale...

  1. Novel real-time alignment and calibration of the LHCb detector in Run2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00144085

    2017-01-01

    LHCb has introduced a novel real-time detector alignment and calibration strategy for LHC Run2. Data collected at the start of the fill are processed in a few minutes and used to update the alignment parameters, while the calibration constants are evaluated for each run. This procedure improves the quality of the online reconstruction. For example, the vertex locator is retracted and reinserted for stable beam conditions in each fill to be centred on the primary vertex position in the transverse plane. Consequently its position changes on a fill-by-fill basis. Critically, this new real-time alignment and calibration procedure allows identical constants to be used in the online and offline reconstruction, thus improving the correlation between triggered and offline-selected events. This offers the opportunity to optimise the event selection in the trigger by applying stronger constraints. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructur...

  2. Performance of the ATLAS track reconstruction algorithms in dense environments in LHC Run 2.

    Science.gov (United States)

    Aaboud, M; Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; Abidi, S H; AbouZeid, O S; Abraham, N L; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, B S; Adachi, S; Adamczyk, L; Adelman, J; Adersberger, M; Adye, T; Affolder, A A; Agatonovic-Jovin, T; Agheorghiesei, C; Aguilar-Saavedra, J A; Ahlen, S P; Ahmadov, F; Aielli, G; Akatsuka, S; Akerstedt, H; Åkesson, T P A; Akimov, A V; Alberghi, G L; Albert, J; Albicocco, P; Alconada Verzini, M J; Aleksa, M; Aleksandrov, I N; Alexa, C; Alexander, G; Alexopoulos, T; Alhroob, M; Ali, B; Aliev, M; Alimonti, G; Alison, J; Alkire, S P; Allbrooke, B M M; Allen, B W; Allport, P P; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Alshehri, A A; Alstaty, M; Alvarez Gonzalez, B; Álvarez Piqueras, D; Alviggi, M G; Amadio, B T; Amaral Coutinho, Y; Amelung, C; Amidei, D; Santos, S P Amor Dos; Amorim, A; Amoroso, S; Amundsen, G; Anastopoulos, C; Ancu, L S; Andari, N; Andeen, T; Anders, C F; Anders, J K; Anderson, K J; Andreazza, A; Andrei, V; Angelidakis, S; Angelozzi, I; Angerami, A; Anisenkov, A V; Anjos, N; Annovi, A; Antel, C; Antonelli, M; Antonov, A; Antrim, D J; Anulli, F; Aoki, M; Aperio Bella, L; Arabidze, G; Arai, Y; Araque, J P; Araujo Ferraz, V; Arce, A T H; Ardell, R E; Arduh, F A; Arguin, J-F; Argyropoulos, S; Arik, M; Armbruster, A J; Armitage, L J; Arnaez, O; Arnold, H; Arratia, M; Arslan, O; Artamonov, A; Artoni, G; Artz, S; Asai, S; Asbah, N; Ashkenazi, A; Asquith, L; Assamagan, K; Astalos, R; Atkinson, M; Atlay, N B; Augsten, K; Avolio, G; Axen, B; Ayoub, M K; Azuelos, G; Baas, A E; Baca, M J; Bachacou, H; Bachas, K; Backes, M; Backhaus, M; Bagnaia, P; Bahrasemani, H; Baines, J T; Bajic, M; Baker, O K; Baldin, E M; Balek, P; Balli, F; Balunas, W K; Banas, E; Banerjee, Sw; Bannoura, A A E; Barak, L; Barberio, E L; Barberis, D; Barbero, M; Barillari, T; Barisits, M-S; Barklow, T; Barlow, N; Barnes, S L; Barnett, B M; Barnett, R M; Barnovska-Blenessy, Z; Baroncelli, A; Barone, G; Barr, A J; Barranco Navarro, L; Barreiro, F; Barreiro Guimarães da Costa, J; Bartoldus, R; Barton, A E; Bartos, P; Basalaev, A; Bassalat, A; Bates, R L; Batista, S J; Batley, J R; Battaglia, M; Bauce, M; Bauer, F; Bawa, H S; Beacham, J B; Beattie, M D; Beau, T; Beauchemin, P H; Bechtle, P; Beck, H P; Becker, K; Becker, M; Beckingham, M; Becot, C; Beddall, A J; Beddall, A; Bednyakov, V A; Bedognetti, M; Bee, C P; Beermann, T A; Begalli, M; Begel, M; Behr, J K; Bell, A S; Bella, G; Bellagamba, L; Bellerive, A; Bellomo, M; Belotskiy, K; Beltramello, O; Belyaev, N L; Benary, O; Benchekroun, D; Bender, M; Bendtz, K; Benekos, N; Benhammou, Y; Benhar Noccioli, E; Benitez, J; Benjamin, D P; Benoit, M; Bensinger, J R; Bentvelsen, S; Beresford, L; Beretta, M; Berge, D; Bergeaas Kuutmann, E; Berger, N; Beringer, J; Berlendis, S; Bernard, N R; Bernardi, G; Bernius, C; Bernlochner, F U; Berry, T; Berta, P; Bertella, C; Bertoli, G; Bertolucci, F; Bertram, I A; Bertsche, C; Bertsche, D; Besjes, G J; Bessidskaia Bylund, O; Bessner, M; Besson, N; Betancourt, C; Bethani, A; Bethke, S; Bevan, A J; Beyer, J; Bianchi, R M; Biebel, O; Biedermann, D; Bielski, R; Biesuz, N V; Biglietti, M; Billoud, T R V; Bilokon, H; Bindi, M; Bingul, A; Bini, C; Biondi, S; Bisanz, T; Bittrich, C; Bjergaard, D M; Black, C W; Black, J E; Black, K M; Blair, R E; Blazek, T; Bloch, I; Blocker, C; Blue, A; Blum, W; Blumenschein, U; Blunier, S; Bobbink, G J; Bobrovnikov, V S; Bocchetta, S S; Bocci, A; Bock, C; Boehler, M; Boerner, D; Bogavac, D; Bogdanchikov, A G; Bohm, C; Boisvert, V; Bokan, P; Bold, T; Boldyrev, A S; Bolz, A E; Bomben, M; Bona, M; Boonekamp, M; Borisov, A; Borissov, G; Bortfeldt, J; Bortoletto, D; Bortolotto, V; Boscherini, D; Bosman, M; Bossio Sola, J D; Boudreau, J; Bouffard, J; Bouhova-Thacker, E V; Boumediene, D; Bourdarios, C; Boutle, S K; Boveia, A; Boyd, J; Boyko, I R; Bracinik, J; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Breaden Madden, W D; Brendlinger, K; Brennan, A J; Brenner, L; Brenner, R; Bressler, S; Briglin, D L; Bristow, T M; Britton, D; Britzger, D; Brochu, F M; Brock, I; Brock, R; Brooijmans, G; Brooks, T; Brooks, W K; Brosamer, J; Brost, E; Broughton, J H; de Renstrom, P A Bruckman; Bruncko, D; Bruni, A; Bruni, G; Bruni, L S; Brunt, B H; Bruschi, M; Bruscino, N; Bryant, P; Bryngemark, L; Buanes, T; Buat, Q; Buchholz, P; Buckley, A G; Budagov, I A; Buehrer, F; Bugge, M K; Bulekov, O; Bullock, D; Burch, T J; Burckhart, H; Burdin, S; Burgard, C D; Burger, A M; Burghgrave, B; Burka, K; Burke, S; Burmeister, I; Burr, J T P; Busato, E; Büscher, D; Büscher, V; Bussey, P; Butler, J M; Buttar, C M; Butterworth, J M; Butti, P; Buttinger, W; Buzatu, A; Buzykaev, A R; Cabrera Urbán, S; Caforio, D; Cairo, V M; Cakir, O; Calace, N; Calafiura, P; Calandri, A; Calderini, G; Calfayan, P; Callea, G; Caloba, L P; Calvente Lopez, S; Calvet, D; Calvet, S; Calvet, T P; Camacho Toro, R; Camarda, S; Camarri, P; Cameron, D; Caminal Armadans, R; Camincher, C; Campana, S; Campanelli, M; Camplani, A; Campoverde, A; Canale, V; Cano Bret, M; Cantero, J; Cao, T; Capeans Garrido, M D M; Caprini, I; Caprini, M; Capua, M; Carbone, R M; Cardarelli, R; Cardillo, F; Carli, I; Carli, T; Carlino, G; Carlson, B T; Carminati, L; Carney, R M D; Caron, S; Carquin, E; Carrá, S; Carrillo-Montoya, G D; Carvalho, J; Casadei, D; Casado, M P; Casolino, M; Casper, D W; Castelijn, R; Castillo Gimenez, V; Castro, N F; Catinaccio, A; Catmore, J R; Cattai, A; Caudron, J; Cavaliere, V; Cavallaro, E; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Celebi, E; Ceradini, F; Cerda Alberich, L; Cerqueira, A S; Cerri, A; Cerrito, L; Cerutti, F; Cervelli, A; Cetin, S A; Chafaq, A; Chakraborty, D; Chan, S K; Chan, W S; Chan, Y L; Chang, P; Chapman, J D; Charlton, D G; Chau, C C; Chavez Barajas, C A; Che, S; Cheatham, S; Chegwidden, A; Chekanov, S; Chekulaev, S V; Chelkov, G A; Chelstowska, M A; Chen, C; Chen, H; Chen, S; Chen, S; Chen, X; Chen, Y; Cheng, H C; Cheng, H J; Cheplakov, A; Cheremushkina, E; Cherkaoui El Moursli, R; Chernyatin, V; Cheu, E; Chevalier, L; Chiarella, V; Chiarelli, G; Chiodini, G; Chisholm, A S; Chitan, A; Chiu, Y H; Chizhov, M V; Choi, K; Chomont, A R; Chouridou, S; Christodoulou, V; Chromek-Burckhart, D; Chu, M C; Chudoba, J; Chuinard, A J; Chwastowski, J J; Chytka, L; Ciftci, A K; Cinca, D; Cindro, V; Cioara, I A; Ciocca, C; Ciocio, A; Cirotto, F; Citron, Z H; Citterio, M; Ciubancan, M; Clark, A; Clark, B L; Clark, M R; Clark, P J; Clarke, R N; Clement, C; Coadou, Y; Cobal, M; Coccaro, A; Cochran, J; Colasurdo, L; Cole, B; Colijn, A P; Collot, J; Colombo, T; Conde Muiño, P; Coniavitis, E; Connell, S H; Connelly, I A; Constantinescu, S; Conti, G; Conventi, F; Cooke, M; Cooper-Sarkar, A M; Cormier, F; Cormier, K J R; Corradi, M; Corriveau, F; Cortes-Gonzalez, A; Cortiana, G; Costa, G; Costa, M J; Costanzo, D; Cottin, G; Cowan, G; Cox, B E; Cranmer, K; Crawley, S J; Creager, R A; Cree, G; Crépé-Renaudin, S; Crescioli, F; Cribbs, W A; Cristinziani, M; Croft, V; Crosetti, G; Cueto, A; Cuhadar Donszelmann, T; Cukierman, A R; Cummings, J; Curatolo, M; Cúth, J; Czirr, H; Czodrowski, P; D'amen, G; D'Auria, S; D'eramo, L; D'Onofrio, M; Da Cunha Sargedas De Sousa, M J; Via, C Da; Dabrowski, W; Dado, T; Dai, T; Dale, O; Dallaire, F; Dallapiccola, C; Dam, M; Dandoy, J R; Daneri, M F; Dang, N P; Daniells, A C; Dann, N S; Danninger, M; Hoffmann, M Dano; Dao, V; Darbo, G; Darmora, S; Dassoulas, J; Dattagupta, A; Daubney, T; Davey, W; David, C; Davidek, T; Davies, M; Davis, D R; Davison, P; Dawe, E; Dawson, I; De, K; de Asmundis, R; De Benedetti, A; De Castro, S; De Cecco, S; De Groot, N; de Jong, P; De la Torre, H; De Lorenzi, F; De Maria, A; De Pedis, D; De Salvo, A; De Sanctis, U; De Santo, A; De Vasconcelos Corga, K; De Vivie De Regie, J B; Dearnaley, W J; Debbe, R; Debenedetti, C; Dedovich, D V; Dehghanian, N; Deigaard, I; Del Gaudio, M; Del Peso, J; Prete, T Del; Delgove, D; Deliot, F; Delitzsch, C M; Dell'Acqua, A; Dell'Asta, L; Dell'Orso, M; Della Pietra, M; Della Volpe, D; Delmastro, M; Delporte, C; Delsart, P A; DeMarco, D A; Demers, S; Demichev, M; Demilly, A; Denisov, S P; Denysiuk, D; Derendarz, D; Derkaoui, J E; Derue, F; Dervan, P; Desch, K; Deterre, C; Dette, K; Devesa, M R; Deviveiros, P O; Dewhurst, A; Dhaliwal, S; Di Bello, F A; Di Ciaccio, A; Di Ciaccio, L; Di Clemente, W K; Di Donato, C; Di Girolamo, A; Di Girolamo, B; Di Micco, B; Di Nardo, R; Di Petrillo, K F; Di Simone, A; Di Sipio, R; Di Valentino, D; Diaconu, C; Diamond, M; Dias, F A; Diaz, M A; Diehl, E B; Dietrich, J; Díez Cornell, S; Dimitrievska, A; Dingfelder, J; Dita, P; Dita, S; Dittus, F; Djama, F; Djobava, T; Djuvsland, J I; do Vale, M A B; Dobos, D; Dobre, M; Doglioni, C; Dolejsi, J; Dolezal, Z; Donadelli, M; Donati, S; Dondero, P; Donini, J; Dopke, J; Doria, A; Dova, M T; Doyle, A T; Drechsler, E; Dris, M; Du, Y; Duarte-Campderros, J; Dubreuil, A; Duchovni, E; Duckeck, G; Ducourthial, A; Ducu, O A; Duda, D; Dudarev, A; Dudder, A Chr; Duffield, E M; Duflot, L; Dührssen, M; Dumancic, M; Dumitriu, A E; Duncan, A K; Dunford, M; Duran Yildiz, H; Düren, M; Durglishvili, A; Duschinger, D; Dutta, B; Dyndal, M; Eckardt, C; Ecker, K M; Edgar, R C; Eifert, T; Eigen, G; Einsweiler, K; Ekelof, T; Kacimi, M El; Kosseifi, R El; Ellajosyula, V; Ellert, M; Elles, S; Ellinghaus, F; Elliot, A A; Ellis, N; Elmsheuser, J; Elsing, M; Emeliyanov, D; Enari, Y; Endner, O C; Ennis, J S; Erdmann, J; Ereditato, A; Ernis, G; Ernst, M; Errede, S; Escalier, M; Escobar, C; Esposito, B; Estrada Pastor, O; Etienvre, A I; Etzion, E; Evans, H; Ezhilov, A; Ezzi, M; Fabbri, F; Fabbri, L; Facini, G; Fakhrutdinov, R M; Falciano, S; Falla, R J; Faltova, J; Fang, Y; Fanti, M; Farbin, A; Farilla, A; Farina, C; Farina, E M; Farooque, T; Farrell, S; Farrington, S M; Farthouat, P; Fassi, F; Fassnacht, P; Fassouliotis, D; Faucci Giannelli, M; Favareto, A; Fawcett, W J; Fayard, L; Fedin, O L; Fedorko, W; Feigl, S; Feligioni, L; Feng, C; Feng, E J; Feng, H; Fenton, M J; Fenyuk, A B; Feremenga, L; Fernandez Martinez, P; Fernandez Perez, S; Ferrando, J; Ferrari, A; Ferrari, P; Ferrari, R; Ferreira de Lima, D E; Ferrer, A; Ferrere, D; Ferretti, C; Fiedler, F; Filipčič, A; Filipuzzi, M; Filthaut, F; Fincke-Keeler, M; Finelli, K D; Fiolhais, M C N; Fiorini, L; Fischer, A; Fischer, C; Fischer, J; Fisher, W C; Flaschel, N; Fleck, I; Fleischmann, P; Fletcher, R R M; Flick, T; Flierl, B M; Flores Castillo, L R; Flowerdew, M J; Forcolin, G T; Formica, A; Förster, F A; Forti, A; Foster, A G; Fournier, D; Fox, H; Fracchia, S; Francavilla, P; Franchini, M; Franchino, S; Francis, D; Franconi, L; Franklin, M; Frate, M; Fraternali, M; Freeborn, D; Fressard-Batraneanu, S M; Freund, B; Froidevaux, D; Frost, J A; Fukunaga, C; Fusayasu, T; Fuster, J; Gabaldon, C; Gabizon, O; Gabrielli, A; Gabrielli, A; Gach, G P; Gadatsch, S; Gadomski, S; Gagliardi, G; Gagnon, L G; Galea, C; Galhardo, B; Gallas, E J; Gallop, B J; Gallus, P; Galster, G; Gan, K K; Ganguly, S; Gao, Y; Gao, Y S; Garay Walls, F M; García, C; García Navarro, J E; Garcia-Sciveres, M; Gardner, R W; Garelli, N; Garonne, V; Gascon Bravo, A; Gasnikova, K; Gatti, C; Gaudiello, A; Gaudio, G; Gavrilenko, I L; Gay, C; Gaycken, G; Gazis, E N; Gee, C N P; Geisen, J; Geisen, M; Geisler, M P; Gellerstedt, K; Gemme, C; Genest, M H; Geng, C; Gentile, S; Gentsos, C; George, S; Gerbaudo, D; Gershon, A; Geßner, G; Ghasemi, S; Ghneimat, M; Giacobbe, B; Giagu, S; Giannetti, P; Gibson, S M; Gignac, M; Gilchriese, M; Gillberg, D; Gilles, G; Gingrich, D M; Giokaris, N; Giordani, M P; Giorgi, F M; Giraud, P F; Giromini, P; Giugni, D; Giuli, F; Giuliani, C; Giulini, M; Gjelsten, B K; Gkaitatzis, S; Gkialas, I; Gkougkousis, E L; Gkountoumis, P; Gladilin, L K; Glasman, C; Glatzer, J; Glaysher, P C F; Glazov, A; Goblirsch-Kolb, M; Godlewski, J; Goldfarb, S; Golling, T; Golubkov, D; Gomes, A; Gonçalo, R; Goncalves Gama, R; Goncalves Pinto Firmino Da Costa, J; Gonella, G; Gonella, L; Gongadze, A; González de la Hoz, S; Gonzalez-Sevilla, S; Goossens, L; Gorbounov, P A; Gordon, H A; Gorelov, I; Gorini, B; Gorini, E; Gorišek, A; Goshaw, A T; Gössling, C; Gostkin, M I; Gottardo, C A; Goudet, C R; Goujdami, D; Goussiou, A G; Govender, N; Gozani, E; Graber, L; Grabowska-Bold, I; Gradin, P O J; Gramling, J; Gramstad, E; Grancagnolo, S; Gratchev, V; Gravila, P M; Gray, C; Gray, H M; Greenwood, Z D; Grefe, C; Gregersen, K; Gregor, I M; Grenier, P; Grevtsov, K; Griffiths, J; Grillo, A A; Grimm, K; Grinstein, S; Gris, Ph; Grivaz, J-F; Groh, S; Gross, E; Grosse-Knetter, J; Grossi, G C; Grout, Z J; Grummer, A; Guan, L; Guan, W; Guenther, J; Guescini, F; Guest, D; Gueta, O; Gui, B; Guido, E; Guillemin, T; Guindon, S; Gul, U; Gumpert, C; Guo, J; Guo, W; Guo, Y; Gupta, R; Gupta, S; Gustavino, G; Gutierrez, P; Gutierrez Ortiz, N G; Gutschow, C; Guyot, C; Guzik, M P; Gwenlan, C; Gwilliam, C B; Haas, A; Haber, C; Hadavand, H K; Haddad, N; Hadef, A; Hageböck, S; Hagihara, M; Hakobyan, H; Haleem, M; Haley, J; Halladjian, G; Hallewell, G D; Hamacher, K; Hamal, P; Hamano, K; Hamilton, A; Hamity, G N; Hamnett, P G; Han, L; Han, S; Hanagaki, K; Hanawa, K; Hance, M; Haney, B; Hanke, P; Hansen, J B; Hansen, J D; Hansen, M C; Hansen, P H; Hara, K; Hard, A S; Harenberg, T; Hariri, F; Harkusha, S; Harrington, R D; Harrison, P F; Hartmann, N M; Hasegawa, M; Hasegawa, Y; Hasib, A; Hassani, S; Haug, S; Hauser, R; Hauswald, L; Havener, L B; Havranek, M; Hawkes, C M; Hawkings, R J; Hayakawa, D; Hayden, D; Hays, C P; Hays, J M; Hayward, H S; Haywood, S J; Head, S J; Heck, T; Hedberg, V; Heelan, L; Heidegger, K K; Heim, S; Heim, T; Heinemann, B; Heinrich, J J; Heinrich, L; Heinz, C; Hejbal, J; Helary, L; Held, A; Hellman, S; Helsens, C; Henderson, R C W; Heng, Y; Henkelmann, S; Henriques Correia, A M; Henrot-Versille, S; Herbert, G H; Herde, H; Herget, V; Hernández Jiménez, Y; Herr, H; Herten, G; Hertenberger, R; Hervas, L; Herwig, T C; Hesketh, G G; Hessey, N P; Hetherly, J W; Higashino, S; Higón-Rodriguez, E; Hill, E; Hill, J C; Hiller, K H; Hillier, S J; Hils, M; Hinchliffe, I; Hirose, M; Hirschbuehl, D; Hiti, B; Hladik, O; Hoad, X; Hobbs, J; Hod, N; Hodgkinson, M C; Hodgson, P; Hoecker, A; Hoeferkamp, M R; Hoenig, F; Hohn, D; Holmes, T R; Homann, M; Honda, S; Honda, T; Hong, T M; Hooberman, B H; Hopkins, W H; Horii, Y; Horton, A J; Hostachy, J-Y; Hou, S; Hoummada, A; Howarth, J; Hoya, J; Hrabovsky, M; Hrdinka, J; Hristova, I; Hrivnac, J; Hryn'ova, T; Hrynevich, A; Hsu, P J; Hsu, S-C; Hu, Q; Hu, S; Huang, Y; Hubacek, Z; Hubaut, F; Huegging, F; Huffman, T B; Hughes, E W; Hughes, G; Huhtinen, M; Huo, P; Huseynov, N; Huston, J; Huth, J; Iacobucci, G; Iakovidis, G; Ibragimov, I; Iconomidou-Fayard, L; Idrissi, Z; Iengo, P; Igonkina, O; Iizawa, T; Ikegami, Y; Ikeno, M; Ilchenko, Y; Iliadis, D; Ilic, N; Introzzi, G; Ioannou, P; Iodice, M; Iordanidou, K; Ippolito, V; Isacson, M F; Ishijima, N; Ishino, M; Ishitsuka, M; Issever, C; Istin, S; Ito, F; Iturbe Ponce, J M; Iuppa, R; Iwasaki, H; Izen, J M; Izzo, V; Jabbar, S; Jackson, P; Jacobs, R M; Jain, V; Jakobi, K B; Jakobs, K; Jakobsen, S; Jakoubek, T; Jamin, D O; Jana, D K; Jansky, R; Janssen, J; Janus, M; Janus, P A; Jarlskog, G; Javadov, N; Javůrek, T; Javurkova, M; Jeanneau, F; Jeanty, L; Jejelava, J; Jelinskas, A; Jenni, P; Jeske, C; Jézéquel, S; Ji, H; Jia, J; Jiang, H; Jiang, Y; Jiang, Z; Jiggins, S; Jimenez Pena, J; Jin, S; Jinaru, A; Jinnouchi, O; Jivan, H; Johansson, P; Johns, K A; Johnson, C A; Johnson, W J; Jon-And, K; Jones, R W L; Jones, S D; Jones, S; Jones, T J; Jongmanns, J; Jorge, P M; Jovicevic, J; Ju, X; Rozas, A Juste; Köhler, M K; Kaczmarska, A; Kado, M; Kagan, H; Kagan, M; Kahn, S J; Kaji, T; Kajomovitz, E; Kalderon, C W; Kaluza, A; Kama, S; Kamenshchikov, A; Kanaya, N; Kanjir, L; Kantserov, V A; Kanzaki, J; Kaplan, B; Kaplan, L S; Kar, D; Karakostas, K; Karastathis, N; Kareem, M J; Karentzos, E; Karpov, S N; Karpova, Z M; Karthik, K; Kartvelishvili, V; Karyukhin, A N; Kasahara, K; Kashif, L; Kass, R D; Kastanas, A; Kataoka, Y; Kato, C; Katre, A; Katzy, J; Kawade, K; Kawagoe, K; Kawamoto, T; Kawamura, G; Kay, E F; Kazanin, V F; Keeler, R; Kehoe, R; Keller, J S; Kempster, J J; Kendrick, J; Keoshkerian, H; Kepka, O; Kerševan, B P; Kersten, S; Keyes, R A; Khader, M; Khalil-Zada, F; Khanov, A; Kharlamov, A G; Kharlamova, T; Khodinov, A; Khoo, T J; Khovanskiy, V; Khramov, E; Khubua, J; Kido, S; Kilby, C R; Kim, H Y; Kim, S H; Kim, Y K; Kimura, N; Kind, O M; King, B T; Kirchmeier, D; Kirk, J; Kiryunin, A E; Kishimoto, T; Kisielewska, D; Kitali, V; Kiuchi, K; Kivernyk, O; Kladiva, E; Klapdor-Kleingrothaus, T; Klein, M H; Klein, M; Klein, U; Kleinknecht, K; Klimek, P; Klimentov, A; Klingenberg, R; Klingl, T; Klioutchnikova, T; Kluge, E-E; Kluit, P; Kluth, S; Kneringer, E; Knoops, E B F G; Knue, A; Kobayashi, A; Kobayashi, D; Kobayashi, T; Kobel, M; Kocian, M; Kodys, P; Koffas, T; Koffeman, E; Köhler, N M; Koi, T; Kolb, M; Koletsou, I; Komar, A A; Komori, Y; Kondo, T; Kondrashova, N; Köneke, K; König, A C; Kono, T; Konoplich, R; Konstantinidis, N; Kopeliansky, R; Koperny, S; Kopp, A K; Korcyl, K; Kordas, K; Korn, A; Korol, A A; Korolkov, I; Korolkova, E V; Kortner, O; Kortner, S; Kosek, T; Kostyukhin, V V; Kotwal, A; Koulouris, A; Kourkoumeli-Charalampidi, A; Kourkoumelis, C; Kourlitis, E; Kouskoura, V; Kowalewska, A B; Kowalewski, R; Kowalski, T Z; Kozakai, C; Kozanecki, W; Kozhin, A S; Kramarenko, V A; Kramberger, G; Krasnopevtsev, D; Krasny, M W; Krasznahorkay, A; Krauss, D; Kremer, J A; Kretzschmar, J; Kreutzfeldt, K; Krieger, P; Krizka, K; Kroeninger, K; Kroha, H; Kroll, J; Kroll, J; Kroseberg, J; Krstic, J; Kruchonak, U; Krüger, H; Krumnack, N; Kruse, M C; Kubota, T; Kucuk, H; Kuday, S; Kuechler, J T; Kuehn, S; Kugel, A; Kuger, F; Kuhl, T; Kukhtin, V; Kukla, R; Kulchitsky, Y; Kuleshov, S; Kulinich, Y P; Kuna, M; Kunigo, T; Kupco, A; Kupfer, T; Kuprash, O; Kurashige, H; Kurchaninov, L L; Kurochkin, Y A; Kurth, M G; Kus, V; Kuwertz, E S; Kuze, M; Kvita, J; Kwan, T; Kyriazopoulos, D; La Rosa, A; La Rosa Navarro, J L; La Rotonda, L; Lacasta, C; Lacava, F; Lacey, J; Lacker, H; Lacour, D; Ladygin, E; Lafaye, R; Laforge, B; Lagouri, T; Lai, S; Lammers, S; Lampl, W; Lançon, E; Landgraf, U; Landon, M P J; Lanfermann, M C; Lang, V S; Lange, J C; Langenberg, R J; Lankford, A J; Lanni, F; Lantzsch, K; Lanza, A; Lapertosa, A; Laplace, S; Laporte, J F; Lari, T; Manghi, F Lasagni; Lassnig, M; Laurelli, P; Lavrijsen, W; Law, A T; Laycock, P; Lazovich, T; Lazzaroni, M; Le, B; Le Dortz, O; Le Guirriec, E; Le Quilleuc, E P; LeBlanc, M; LeCompte, T; Ledroit-Guillon, F; Lee, C A; Lee, G R; Lee, S C; Lee, L; Lefebvre, B; Lefebvre, G; Lefebvre, M; Legger, F; Leggett, C; Lehan, A; Lehmann Miotto, G; Lei, X; Leight, W A; Leite, M A L; Leitner, R; Lellouch, D; Lemmer, B; Leney, K J C; Lenz, T; Lenzi, B; Leone, R; Leone, S; Leonidopoulos, C; Lerner, G; Leroy, C; Lesage, A A J; Lester, C G; Levchenko, M; Levêque, J; Levin, D; Levinson, L J; Levy, M; Lewis, D; Li, B; Li, H; Li, L; Li, Q; Li, S; Li, X; Li, Y; Liang, Z; Liberti, B; Liblong, A; Lie, K; Liebal, J; Liebig, W; Limosani, A; Lin, S C; Lin, T H; Lindquist, B E; Lionti, A E; Lipeles, E; Lipniacka, A; Lisovyi, M; Liss, T M; Lister, A; Litke, A M; Liu, B; Liu, H; Liu, H; Liu, J K K; Liu, J; Liu, J B; Liu, K; Liu, L; Liu, M; Liu, Y L; Liu, Y; Livan, M; Lleres, A; Llorente Merino, J; Lloyd, S L; Lo, C Y; Sterzo, F Lo; Lobodzinska, E M; Loch, P; Loebinger, F K; Loesle, A; Loew, K M; Loginov, A; Lohse, T; Lohwasser, K; Lokajicek, M; Long, B A; Long, J D; Long, R E; Longo, L; Looper, K A; Lopez, J A; Lopez Mateos, D; Lopez Paz, I; Solis, A Lopez; Lorenz, J; Lorenzo Martinez, N; Losada, M; Lösel, P J; Lou, X; Lounis, A; Love, J; Love, P A; Lu, H; Lu, N; Lu, Y J; Lubatti, H J; Luci, C; Lucotte, A; Luedtke, C; Luehring, F; Lukas, W; Luminari, L; Lundberg, O; Lund-Jensen, B; Luzi, P M; Lynn, D; Lysak, R; Lytken, E; Lyubushkin, V; Ma, H; Ma, L L; Ma, Y; Maccarrone, G; Macchiolo, A; Macdonald, C M; Maček, B; Machado Miguens, J; Madaffari, D; Madar, R; Mader, W F; Madsen, A; Maeda, J; Maeland, S; Maeno, T; Maevskiy, A S; Magerl, V; Mahlstedt, J; Maiani, C; Maidantchik, C; Maier, A A; Maier, T; Maio, A; Majersky, O; Majewski, S; Makida, Y; Makovec, N; Malaescu, B; Malecki, Pa; Maleev, V P; Malek, F; Mallik, U; Malon, D; Malone, C; Maltezos, S; Malyukov, S; Mamuzic, J; Mancini, G; Mandelli, L; Mandić, I; Maneira, J; Manhaes de Andrade Filho, L; Manjarres Ramos, J; Mann, A; Manousos, A; Mansoulie, B; Mansour, J D; Mantifel, R; Mantoani, M; Manzoni, S; Mapelli, L; Marceca, G; March, L; Marchese, L; Marchiori, G; Marcisovsky, M; Marjanovic, M; Marley, D E; Marroquim, F; Marsden, S P; Marshall, Z; Martensson, M U F; Marti-Garcia, S; Martin, C B; Martin, T A; Martin, V J; Martin Dit Latour, B; Martinez, M; Martinez Outschoorn, V I; Martin-Haugh, S; Martoiu, V S; Martyniuk, A C; Marzin, A; Masetti, L; Mashimo, T; Mashinistov, R; Masik, J; Maslennikov, A L; Massa, L; Mastrandrea, P; Mastroberardino, A; Masubuchi, T; Mättig, P; Maurer, J; Maxfield, S J; Maximov, D A; Mazini, R; Maznas, I; Mazza, S M; Mc Fadden, N C; Goldrick, G Mc; Mc Kee, S P; McCarn, A; McCarthy, R L; McCarthy, T G; McClymont, L I; McDonald, E F; Mcfayden, J A; Mchedlidze, G; McMahon, S J; McNamara, P C; McPherson, R A; Meehan, S; Megy, T J; Mehlhase, S; Mehta, A; Meideck, T; Meier, K; Meirose, B; Melini, D; Mellado Garcia, B R; Mellenthin, J D; Melo, M; Meloni, F; Menary, S B; Meng, L; Meng, X T; Mengarelli, A; Menke, S; Meoni, E; Mergelmeyer, S; Mermod, P; Merola, L; Meroni, C; Merritt, F S; Messina, A; Metcalfe, J; Mete, A S; Meyer, C; Meyer, J-P; Meyer, J; Meyer Zu Theenhausen, H; Miano, F; Middleton, R P; Miglioranzi, S; Mijović, L; Mikenberg, G; Mikestikova, M; Mikuž, M; Milesi, M; Milic, A; Miller, D W; Mills, C; Milov, A; Milstead, D A; Minaenko, A A; Minami, Y; Minashvili, I A; Mincer, A I; Mindur, B; Mineev, M; Minegishi, Y; Ming, Y; Mir, L M; Mistry, K P; Mitani, T; Mitrevski, J; Mitsou, V A; Miucci, A; Miyagawa, P S; Mizukami, A; Mjörnmark, J U; Mkrtchyan, T; Mlynarikova, M; Moa, T; Mochizuki, K; Mogg, P; Mohapatra, S; Molander, S; Moles-Valls, R; Monden, R; Mondragon, M C; Mönig, K; Monk, J; Monnier, E; Montalbano, A; Montejo Berlingen, J; Monticelli, F; Monzani, S; Moore, R W; Morange, N; Moreno, D; Moreno Llácer, M; Morettini, P; Morgenstern, S; Mori, D; Mori, T; Morii, M; Morinaga, M; Morisbak, V; Morley, A K; Mornacchi, G; Morris, J D; Morvaj, L; Moschovakos, P; Mosidze, M; Moss, H J; Moss, J; Motohashi, K; Mount, R; Mountricha, E; Moyse, E J W; Muanza, S; Mudd, R D; Mueller, F; Mueller, J; Mueller, R S P; Muenstermann, D; Mullen, P; Mullier, G A; Munoz Sanchez, F J; Murray, W J; Musheghyan, H; Muškinja, M; Myagkov, A G; Myska, M; Nachman, B P; Nackenhorst, O; Nagai, K; Nagai, R; Nagano, K; Nagasaka, Y; Nagata, K; Nagel, M; Nagy, E; Nairz, A M; Nakahama, Y; Nakamura, K; Nakamura, T; Nakano, I; Naranjo Garcia, R F; Narayan, R; Narrias Villar, D I; Naryshkin, I; Naumann, T; Navarro, G; Nayyar, R; Neal, H A; Nechaeva, P Yu; Neep, T J; Negri, A; Negrini, M; Nektarijevic, S; Nellist, C; Nelson, A; Nelson, M E; Nemecek, S; Nemethy, P; Nessi, M; Neubauer, M S; Neumann, M; Newman, P R; Ng, T Y; Nguyen Manh, T; Nickerson, R B; Nicolaidou, R; Nielsen, J; Nikolaenko, V; Nikolic-Audit, I; Nikolopoulos, K; Nilsen, J K; Nilsson, P; Ninomiya, Y; Nisati, A; Nishu, N; Nisius, R; Nitsche, I; Nobe, T; Noguchi, Y; Nomachi, M; Nomidis, I; Nomura, M A; Nooney, T; Nordberg, M; Norjoharuddeen, N; Novgorodova, O; Nowak, S; Nozaki, M; Nozka, L; Ntekas, K; Nurse, E; Nuti, F; O'connor, K; O'Neil, D C; O'Rourke, A A; O'Shea, V; Oakham, F G; Oberlack, H; Obermann, T; Ocariz, J; Ochi, A; Ochoa, I; Ochoa-Ricoux, J P; Oda, S; Odaka, S; Ogren, H; Oh, A; Oh, S H; Ohm, C C; Ohman, H; Oide, H; Okawa, H; Okumura, Y; Okuyama, T; Olariu, A; Oleiro Seabra, L F; Olivares Pino, S A; Oliveira Damazio, D; Olszewski, A; Olszowska, J; Onofre, A; Onogi, K; Onyisi, P U E; Oppen, H; Oreglia, M J; Oren, Y; Orestano, D; Orlando, N; Orr, R S; Osculati, B; Ospanov, R; Otero Y Garzon, G; Otono, H; Ouchrif, M; Ould-Saada, F; Ouraou, A; Oussoren, K P; Ouyang, Q; Owen, M; Owen, R E; Ozcan, V E; Ozturk, N; Pachal, K; Pacheco Pages, A; Pacheco Rodriguez, L; Padilla Aranda, C; Pagan Griso, S; Paganini, M; Paige, F; Palacino, G; Palazzo, S; Palestini, S; Palka, M; Pallin, D; Panagiotopoulou, E St; Panagoulias, I; Pandini, C E; Panduro Vazquez, J G; Pani, P; Panitkin, S; Pantea, D; Paolozzi, L; Papadopoulou, Th D; Papageorgiou, K; Paramonov, A; Paredes Hernandez, D; Parker, A J; Parker, M A; Parker, K A; Parodi, F; Parsons, J A; Parzefall, U; Pascuzzi, V R; Pasner, J M; Pasqualucci, E; Passaggio, S; Pastore, Fr; Pataraia, S; Pater, J R; Pauly, T; Pearson, B; Pedraza Lopez, S; Pedro, R; Peleganchuk, S V; Penc, O; Peng, C; Peng, H; Penwell, J; Peralva, B S; Perego, M M; Perepelitsa, D V; Perini, L; Pernegger, H; Perrella, S; Peschke, R; Peshekhonov, V D; Peters, K; Peters, R F Y; Petersen, B A; Petersen, T C; Petit, E; Petridis, A; Petridou, C; Petroff, P; Petrolo, E; Petrov, M; Petrucci, F; Pettersson, N E; Peyaud, A; Pezoa, R; Phillips, F H; Phillips, P W; Piacquadio, G; Pianori, E; Picazio, A; Piccaro, E; Pickering, M A; Piegaia, R; Pilcher, J E; Pilkington, A D; Pin, A W J; Pinamonti, M; Pinfold, J L; Pirumov, H; Pitt, M; Plazak, L; Pleier, M-A; Pleskot, V; Plotnikova, E; Pluth, D; Podberezko, P; Poettgen, R; Poggi, R; Poggioli, L; Pohl, D; Polesello, G; Poley, A; Policicchio, A; Polifka, R; Polini, A; Pollard, C S; Polychronakos, V; Pommès, K; Ponomarenko, D; Pontecorvo, L; Pope, B G; Popeneciu, G A; Poppleton, A; Pospisil, S; Potamianos, K; Potrap, I N; Potter, C J; Poulard, G; Poulsen, T; Poveda, J; Pozo Astigarraga, M E; Pralavorio, P; Pranko, A; Prell, S; Price, D; Price, L E; Primavera, M; Prince, S; Proklova, N; Prokofiev, K; Prokoshin, F; Protopopescu, S; Proudfoot, J; Przybycien, M; Puri, A; Puzo, P; Qian, J; Qin, G; Qin, Y; Quadt, A; Queitsch-Maitland, M; Quilty, D; Raddum, S; Radeka, V; Radescu, V; Radhakrishnan, S K; Radloff, P; Rados, P; Ragusa, F; Rahal, G; Raine, J A; Rajagopalan, S; Rangel-Smith, C; Rashid, T; Raspopov, S; Ratti, M G; Rauch, D M; Rauscher, F; Rave, S; Ravinovich, I; Rawling, J H; Raymond, M; Read, A L; Readioff, N P; Reale, M; Rebuzzi, D M; Redelbach, A; Redlinger, G; Reece, R; Reed, R G; Reeves, K; Rehnisch, L; Reichert, J; Reiss, A; Rembser, C; Ren, H; Rescigno, M; Resconi, S; Resseguie, E D; Rettie, S; Reynolds, E; Rezanova, O L; Reznicek, P; Rezvani, R; Richter, R; Richter, S; Richter-Was, E; Ricken, O; Ridel, M; Rieck, P; Riegel, C J; Rieger, J; Rifki, O; Rijssenbeek, M; Rimoldi, A; Rimoldi, M; Rinaldi, L; Ripellino, G; Ristić, B; Ritsch, E; Riu, I; Rizatdinova, F; Rizvi, E; Rizzi, C; Roberts, R T; Robertson, S H; Robichaud-Veronneau, A; Robinson, D; Robinson, J E M; Robson, A; Rocco, E; Roda, C; Rodina, Y; Rodriguez Bosca, S; Rodriguez Perez, A; Rodriguez Rodriguez, D; Roe, S; Rogan, C S; Røhne, O; Roloff, J; Romaniouk, A; Romano, M; Romano Saez, S M; Romero Adam, E; Rompotis, N; Ronzani, M; Roos, L; Rosati, S; Rosbach, K; Rose, P; Rosien, N-A; Rossi, E; Rossi, L P; Rosten, J H N; Rosten, R; Rotaru, M; Roth, I; Rothberg, J; Rousseau, D; Rozanov, A; Rozen, Y; Ruan, X; Rubbo, F; Rühr, F; Ruiz-Martinez, A; Rurikova, Z; Rusakovich, N A; Russell, H L; Rutherfoord, J P; Ruthmann, N; Ryabov, Y F; Rybar, M; Rybkin, G; Ryu, S; Ryzhov, A; Rzehorz, G F; Saavedra, A F; Sabato, G; Sacerdoti, S; Sadrozinski, H F-W; Sadykov, R; Safai Tehrani, F; Saha, P; Sahinsoy, M; Saimpert, M; Saito, M; Saito, T; Sakamoto, H; Sakurai, Y; Salamanna, G; Salazar Loyola, J E; Salek, D; De Bruin, P H Sales; Salihagic, D; Salnikov, A; Salt, J; Salvatore, D; Salvatore, F; Salvucci, A; Salzburger, A; Sammel, D; Sampsonidis, D; Sampsonidou, D; Sánchez, J; Sanchez Martinez, V; Sanchez Pineda, A; Sandaker, H; Sandbach, R L; Sander, C O; Sandhoff, M; Sandoval, C; Sankey, D P C; Sannino, M; Sansoni, A; Santoni, C; Santonico, R; Santos, H; Santoyo Castillo, I; Sapronov, A; Saraiva, J G; Sarrazin, B; Sasaki, O; Sato, K; Sauvan, E; Savage, G; Savard, P; Savic, N; Sawyer, C; Sawyer, L; Saxon, J; Sbarra, C; Sbrizzi, A; Scanlon, T; Scannicchio, D A; Scarcella, M; Scarfone, V; Schaarschmidt, J; Schacht, P; Schachtner, B M; Schaefer, D; Schaefer, L; Schaefer, R; Schaeffer, J; Schaepe, S; Schaetzel, S; Schäfer, U; Schaffer, A C; Schaile, D; Schamberger, R D; Scharf, V; Schegelsky, V A; Scheirich, D; Schernau, M; Schiavi, C; Schier, S; Schildgen, L K; Schillo, C; Schioppa, M; Schlenker, S; Schmidt-Sommerfeld, K R; Schmieden, K; Schmitt, C; Schmitt, S; Schmitz, S; Schnoor, U; Schoeffel, L; Schoening, A; Schoenrock, B D; Schopf, E; Schott, M; Schouwenberg, J F P; Schovancova, J; Schramm, S; Schuh, N; Schulte, A; Schultens, M J; Schultz-Coulon, H-C; Schulz, H; Schumacher, M; Schumm, B A; Schune, Ph; Schwartzman, A; Schwarz, T A; Schweiger, H; Schwemling, Ph; Schwienhorst, R; Schwindling, J; Sciandra, A; Sciolla, G; Scuri, F; Scutti, F; Searcy, J; Seema, P; Seidel, S C; Seiden, A; Seixas, J M; Sekhniaidze, G; Sekhon, K; Sekula, S J; Semprini-Cesari, N; Senkin, S; Serfon, C; Serin, L; Serkin, L; Sessa, M; Seuster, R; Severini, H; Sfiligoj, T; Sforza, F; Sfyrla, A; Shabalina, E; Shaikh, N W; Shan, L Y; Shang, R; Shank, J T; Shapiro, M; Shatalov, P B; Shaw, K; Shaw, S M; Shcherbakova, A; Shehu, C Y; Shen, Y; Sherafati, N; Sherwood, P; Shi, L; Shimizu, S; Shimmin, C O; Shimojima, M; Shipsey, I P J; Shirabe, S; Shiyakova, M; Shlomi, J; Shmeleva, A; Shoaleh Saadi, D; Shochet, M J; Shojaii, S; Shope, D R; Shrestha, S; Shulga, E; Shupe, M A; Sicho, P; Sickles, A M; Sidebo, P E; Sideras Haddad, E; Sidiropoulou, O; Sidoti, A; Siegert, F; Sijacki, Dj; Silva, J; Silverstein, S B; Simak, V; Simic, Lj; Simion, S; Simioni, E; Simmons, B; Simon, M; Sinervo, P; Sinev, N B; Sioli, M; Siragusa, G; Siral, I; Sivoklokov, S Yu; Sjölin, J; Skinner, M B; Skubic, P; Slater, M; Slavicek, T; Slawinska, M; Sliwa, K; Slovak, R; Smakhtin, V; Smart, B H; Smiesko, J; Smirnov, N; Smirnov, S Yu; Smirnov, Y; Smirnova, L N; Smirnova, O; Smith, J W; Smith, M N K; Smith, R W; Smizanska, M; Smolek, K; Snesarev, A A; Snyder, I M; Snyder, S; Sobie, R; Socher, F; Soffer, A; Søgaard, A; Soh, D A; Sokhrannyi, G; Solans Sanchez, C A; Solar, M; Soldatov, E Yu; Soldevila, U; Solodkov, A A; Soloshenko, A; Solovyanov, O V; Solovyev, V; Sommer, P; Son, H; Sopczak, A; Sosa, D; Sotiropoulou, C L; Soualah, R; Soukharev, A M; South, D; Sowden, B C; Spagnolo, S; Spalla, M; Spangenberg, M; Spanò, F; Sperlich, D; Spettel, F; Spieker, T M; Spighi, R; Spigo, G; Spiller, L A; Spousta, M; St Denis, R D; Stabile, A; Stamen, R; Stamm, S; Stanecka, E; Stanek, R W; Stanescu, C; Stanitzki, M M; Stapf, B S; Stapnes, S; Starchenko, E A; Stark, G H; Stark, J; Stark, S H; Staroba, P; Starovoitov, P; Stärz, S; Staszewski, R; Steinberg, P; Stelzer, B; Stelzer, H J; Stelzer-Chilton, O; Stenzel, H; Stewart, G A; Stockton, M C; Stoebe, M; Stoicea, G; Stolte, P; Stonjek, S; Stradling, A R; Straessner, A; Stramaglia, M E; Strandberg, J; Strandberg, S; Strauss, M; Strizenec, P; Ströhmer, R; Strom, D M; Stroynowski, R; Strubig, A; Stucci, S A; Stugu, B; Styles, N A; Su, D; Su, J; Suchek, S; Sugaya, Y; Suk, M; Sulin, V V; Sultan, Dms; Sultansoy, S; Sumida, T; Sun, S; Sun, X; Suruliz, K; Suster, C J E; Sutton, M R; Suzuki, S; Svatos, M; Swiatlowski, M; Swift, S P; Sykora, I; Sykora, T; Ta, D; Tackmann, K; Taenzer, J; Taffard, A; Tafirout, R; Tahirovic, E; Taiblum, N; Takai, H; Takashima, R; Takasugi, E H; Takeshita, T; Takubo, Y; Talby, M; Talyshev, A A; Tanaka, J; Tanaka, M; Tanaka, R; Tanaka, S; Tanioka, R; Tannenwald, B B; Tapia Araya, S; Tapprogge, S; Tarem, S; Tartarelli, G F; Tas, P; Tasevsky, M; Tashiro, T; Tassi, E; Tavares Delgado, A; Tayalati, Y; Taylor, A C; Taylor, G N; Taylor, P T E; Taylor, W; Teixeira-Dias, P; Temple, D; Ten Kate, H; Teng, P K; Teoh, J J; Tepel, F; Terada, S; Terashi, K; Terron, J; Terzo, S; Testa, M; Teuscher, R J; Theveneaux-Pelzer, T; Thomas, J P; Thomas-Wilsker, J; Thompson, P D; Thompson, A S; Thomsen, L A; Thomson, E; Tibbetts, M J; Ticse Torres, R E; Tikhomirov, V O; Tikhonov, Yu A; Timoshenko, S; Tipton, P; Tisserant, S; Todome, K; Todorova-Nova, S; Tojo, J; Tokár, S; Tokushuku, K; Tolley, E; Tomlinson, L; Tomoto, M; Tompkins, L; Toms, K; Tong, B; Tornambe, P; Torrence, E; Torres, H; Torró Pastor, E; Toth, J; Touchard, F; Tovey, D R; Treado, C J; Trefzger, T; Tresoldi, F; Tricoli, A; Trigger, I M; Trincaz-Duvoid, S; Tripiana, M F; Trischuk, W; Trocmé, B; Trofymov, A; Troncon, C; Trottier-McDonald, M; Trovatelli, M; Truong, L; Trzebinski, M; Trzupek, A; Tsang, K W; Tseng, J C-L; Tsiareshka, P V; Tsipolitis, G; Tsirintanis, N; Tsiskaridze, S; Tsiskaridze, V; Tskhadadze, E G; Tsui, K M; Tsukerman, I I; Tsulaia, V; Tsuno, S; Tsybychev, D; Tu, Y; Tudorache, A; Tudorache, V; Tulbure, T T; Tuna, A N; Tupputi, S A; Turchikhin, S; Turgeman, D; Turk Cakir, I; Turra, R; Tuts, P M; Ucchielli, G; Ueda, I; Ughetto, M; Ukegawa, F; Unal, G; Undrus, A; Unel, G; Ungaro, F C; Unno, Y; Unverdorben, C; Urban, J; Urquijo, P; Urrejola, P; Usai, G; Usui, J; Vacavant, L; Vacek, V; Vachon, B; Vadla, K O H; Vaidya, A; Valderanis, C; Valdes Santurio, E; Valente, M; Valentinetti, S; Valero, A; Valéry, L; Valkar, S; Vallier, A; Valls Ferrer, J A; Van Den Wollenberg, W; van der Graaf, H; van Gemmeren, P; Van Nieuwkoop, J; van Vulpen, I; van Woerden, M C; Vanadia, M; Vandelli, W; Vaniachine, A; Vankov, P; Vardanyan, G; Vari, R; Varnes, E W; Varni, C; Varol, T; Varouchas, D; Vartapetian, A; Varvell, K E; Vasquez, J G; Vasquez, G A; Vazeille, F; Vazquez Schroeder, T; Veatch, J; Veeraraghavan, V; Veloce, L M; Veloso, F; Veneziano, S; Ventura, A; Venturi, M; Venturi, N; Venturini, A; Vercesi, V; Verducci, M; Verkerke, W; Vermeulen, A T; Vermeulen, J C; Vetterli, M C; Viaux Maira, N; Viazlo, O; Vichou, I; Vickey, T; Vickey Boeriu, O E; Viehhauser, G H A; Viel, S; Vigani, L; Villa, M; Villaplana Perez, M; Vilucchi, E; Vincter, M G; Vinogradov, V B; Vishwakarma, A; Vittori, C; Vivarelli, I; Vlachos, S; Vlasak, M; Vogel, M; Vokac, P; Volpi, G; von der Schmitt, H; von Toerne, E; Vorobel, V; Vorobev, K; Vos, M; Voss, R; Vossebeld, J H; Vranjes, N; Vranjes Milosavljevic, M; Vrba, V; Vreeswijk, M; Vuillermet, R; Vukotic, I; Wagner, P; Wagner, W; Wagner-Kuhr, J; Wahlberg, H; Wahrmund, S; Wakabayashi, J; Walder, J; Walker, R; Walkowiak, W; Wallangen, V; Wang, C; Wang, C; Wang, F; Wang, H; Wang, H; Wang, J; Wang, J; Wang, Q; Wang, R; Wang, S M; Wang, T; Wang, W; Wang, W; Wang, Z; Wanotayaroj, C; Warburton, A; Ward, C P; Wardrope, D R; Washbrook, A; Watkins, P M; Watson, A T; Watson, M F; Watts, G; Watts, S; Waugh, B M; Webb, A F; Webb, S; Weber, M S; Weber, S W; Weber, S A; Webster, J S; Weidberg, A R; Weinert, B; Weingarten, J; Weirich, M; Weiser, C; Weits, H; Wells, P S; Wenaus, T; Wengler, T; Wenig, S; Wermes, N; Werner, M D; Werner, P; Wessels, M; Weston, T D; Whalen, K; Whallon, N L; Wharton, A M; White, A S; White, A; White, M J; White, R; Whiteson, D; Whitmore, B W; Wickens, F J; Wiedenmann, W; Wielers, M; Wiglesworth, C; Wiik-Fuchs, L A M; Wildauer, A; Wilk, F; Wilkens, H G; Williams, H H; Williams, S; Willis, C; Willocq, S; Wilson, J A; Wingerter-Seez, I; Winkels, E; Winklmeier, F; Winston, O J; Winter, B T; Wittgen, M; Wobisch, M; Wolf, T M H; Wolff, R; Wolter, M W; Wolters, H; Wong, V W S; Worm, S D; Wosiek, B K; Wotschack, J; Wozniak, K W; Wu, M; Wu, S L; Wu, X; Wu, Y; Wyatt, T R; Wynne, B M; Xella, S; Xi, Z; Xia, L; Xu, D; Xu, L; Yabsley, B; Yacoob, S; Yamaguchi, D; Yamaguchi, Y; Yamamoto, A; Yamamoto, S; Yamanaka, T; Yamatani, M; Yamauchi, K; Yamazaki, Y; Yan, Z; Yang, H; Yang, H; Yang, Y; Yang, Z; Yao, W-M; Yap, Y C; Yasu, Y; Yatsenko, E; Yau Wong, K H; Ye, J; Ye, S; Yeletskikh, I; Yigitbasi, E; Yildirim, E; Yorita, K; Yoshihara, K; Young, C; Young, C J S; Yu, J; Yu, J; Yuen, S P Y; Yusuff, I; Zabinski, B; Zacharis, G; Zaidan, R; Zaitsev, A M; Zakharchuk, N; Zalieckas, J; Zaman, A; Zambito, S; Zanzi, D; Zeitnitz, C; Zemaityte, G; Zemla, A; Zeng, J C; Zeng, Q; Zenin, O; Ženiš, T; Zerwas, D; Zhang, D; Zhang, F; Zhang, G; Zhang, H; Zhang, J; Zhang, L; Zhang, L; Zhang, M; Zhang, P; Zhang, R; Zhang, R; Zhang, X; Zhang, Y; Zhang, Z; Zhao, X; Zhao, Y; Zhao, Z; Zhemchugov, A; Zhou, B; Zhou, C; Zhou, L; Zhou, M; Zhou, M; Zhou, N; Zhu, C G; Zhu, H; Zhu, J; Zhu, Y; Zhuang, X; Zhukov, K; Zibell, A; Zieminska, D; Zimine, N I; Zimmermann, C; Zimmermann, S; Zinonos, Z; Zinser, M; Ziolkowski, M; Živković, L; Zobernig, G; Zoccoli, A; Zou, R; Zur Nedden, M; Zwalinski, L

    2017-01-01

    With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 [Formula: see text] for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb[Formula: see text] of data collected by the ATLAS experiment and simulation of proton-proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 [Formula: see text]. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600 [Formula: see text] is quantified using a novel, data-driven, method. The method uses the energy loss, [Formula: see text], to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is [Formula: see text] and [Formula: see text] for jet transverse momenta of 200-400 [Formula: see text] and 1400-1600 [Formula: see text], respectively.

  3. The ATLAS Data Management System Rucio: Supporting LHC Run-2 and beyond

    CERN Document Server

    Barisits, Martin-Stefan; The ATLAS collaboration; Garonne, Vincent

    2017-01-01

    With this contribution we present the recent developments made to Rucio, the data management system of the High-Energy Physics Experiment ATLAS. Already managing 260 Petabytes of both official and user data, Rucio has seen incremental improvements throughout LHC Run-2, and is currently laying the groundwork for HEP computing in the HL-LHC era. The focus of this contribution are (a) the automations that have been put in place such as data rebalancing or dynamic replication of user data, as well as their supporting infrastructures such as real-time networking metrics or transfer time predictions; (b) the flexible approach towards inclusion of heterogeneous storage systems, including object stores, while unifying the potential access paths using generally available tools and protocols; (c) the improvements made to the real time monitoring of the system to alleviate the work of our human shifters; and (d) the adoption of Rucio for two other experiments, AMS and Xenon1t. We conclude by presenting operational numbe...

  4. The ATLAS Muon Trigger Performance : Run 1 and initial Run 2.

    CERN Document Server

    Kasahara, Kota; The ATLAS collaboration

    2015-01-01

    The ATLAS Muon Trigger Performance: Run 1 and Initial Run 2 Performance

Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run 1, the instantaneous luminosity of the LHC reached 7.7x10^33 cm -2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. 
The performance of muon triggers during the LHC Run 1 data-taking campaigns i...

  5. Performance of the ATLAS Track Reconstruction Algorithms in Dense Environments in LHC run 2

    CERN Document Server

    Aaboud, M.; ATLAS Collaboration; Abbott, Brad; Abdallah, Jalal; Abdinov, Ovsat; Abeloos, Baptiste; Abidi, Syed Haider; AbouZeid, Ossama; Abraham, Nicola; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adachi, Shunsuke; Adamczyk, Leszek; Adelman, Jahred; Adersberger, Michael; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agheorghiesei, Catalin; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akatsuka, Shunichi; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albicocco, Pietro; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Ali, Babar; Aliev, Malik; Alimonti, Gianluca; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allen, Benjamin William; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Alshehri, Azzah Aziz; Alstaty, Mahmoud; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Angerami, Aaron; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antel, Claire; Antonelli, Mario; Antonov, Alexey; Antrim, Daniel Joseph; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Araujo Ferraz, Victor; Arce, Ayana; Ardell, Rose Elisabeth; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Armitage, Lewis James; Arnaez, Olivier; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Artz, Sebastian; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Augsten, Kamil; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baas, Alessandra; Baca, Matthew John; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagnaia, Paolo; Bahrasemani, Sina; Baines, John; Bajic, Milena; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balli, Fabrice; Balunas, William Keaton; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisits, Martin-Stefan; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska-Blenessy, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barranco Navarro, Laura; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Bechtle, Philip; Beck, Hans~Peter; Becker, Kathrin; Becker, Maurice; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bedognetti, Matteo; Bee, Christopher; Beermann, Thomas; Begalli, Marcia; Begel, Michael; Behr, Janna Katharina; Bell, Andrew Stuart; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Belyaev, Nikita; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez, Jose; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Beringer, Jürg; Berlendis, Simon; Bernard, Nathan Rogers; Bernardi, Gregorio; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertram, Iain Alexander; Bertsche, Carolyn; Bertsche, David; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethani, Agni; Bethke, Siegfried; Bevan, Adrian John; Beyer, Julien-christopher; Bianchi, Riccardo-Maria; Biebel, Otmar; Biedermann, Dustin; Bielski, Rafal; Biesuz, Nicolo Vladi; Biglietti, Michela; Bilbao De Mendizabal, Javier; Billoud, Thomas Remy Victor; Bilokon, Halina; Bindi, Marcello; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Bisanz, Tobias; Bittrich, Carsten; Bjergaard, David Martin; Black, Curtis; Black, James; Black, Kevin; Blair, Robert; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blue, Andrew; Blum, Walter; Blumenschein, Ulrike; Blunier, Sylvain; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boehler, Michael; Boerner, Daniela; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bokan, Petar; Bold, Tomasz; Boldyrev, Alexey; Bolz, Arthur Eugen; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Bortfeldt, Jonathan; Bortoletto, Daniela; Bortolotto, Valerio; Boscherini, Davide; Bosman, Martine; Bossio Sola, Jonathan David; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Boutle, Sarah Kate; Boveia, Antonio; Boyd, James; Boyko, Igor; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Briglin, Daniel Lawrence; Bristow, Timothy Michael; Britton, Dave; Britzger, Daniel; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Broughton, James; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruni, Alessia; Bruni, Graziano; Bruni, Lucrezia Stella; Brunt, Benjamin; Bruschi, Marco; Bruscino, Nello; Bryant, Patrick; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Budagov, Ioulian; Buehrer, Felix; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burch, Tyler James; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burger, Angela Maria; Burghgrave, Blake; Burka, Klaudia; Burke, Stephen; Burmeister, Ingo; Burr, Jonathan Thomas Peter; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Butler, John; Buttar, Craig; Butterworth, Jonathan; Butti, Pierfrancesco; Buttinger, William; Buzatu, Adrian; Buzykaev, Aleksey; Cabrera Urbán, Susana; Caforio, Davide; Cairo, Valentina; Cakir, Orhan; Calace, Noemi; Calafiura, Paolo; Calandri, Alessandro; Calderini, Giovanni; Calfayan, Philippe; Callea, Giuseppe; Caloba, Luiz; Calvente Lopez, Sergio; Calvet, David; Calvet, Samuel; Calvet, Thomas Philippe; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Camincher, Clement; Campana, Simone; Campanelli, Mario; Camplani, Alessandra; Campoverde, Angel; Canale, Vincenzo; Cano Bret, Marc; Cantero, Josu; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Carbone, Ryne Michael; Cardarelli, Roberto; Cardillo, Fabio; Carli, Ina; Carli, Tancredi; Carlino, Gianpaolo; Carlson, Benjamin Taylor; Carminati, Leonardo; Carney, Rebecca; Caron, Sascha; Carquin, Edson; Carrá, Sonia; Carrillo-Montoya, German D; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Casper, David William; Castelijn, Remco; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavallaro, Emanuele; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Celebi, Emre; Ceradini, Filippo; Cerda Alberich, Leonor; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Stephen Kam-wah; Chan, Wing Sheung; Chan, Yat Long; Chang, Philip; Chapman, John Derek; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Che, Siinn; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Shion; Chen, Xin; Chen, Ye; Cheng, Hok Chuen; Cheng, Huajie; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Chiodini, Gabriele; Chisholm, Andrew; Chitan, Adrian; Chiu, Yu Him Justin; Chizhov, Mihail; Choi, Kyungeon; Chomont, Arthur Rene; Chouridou, Sofia; Christodoulou, Valentinos; Chromek-Burckhart, Doris; Chu, Ming Chung; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Ciftci, Abbas Kenan; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocca, Claudia; Ciocio, Alessandra; Cirotto, Francesco; Citron, Zvi Hirsh; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Brian Lee; Clark, Michael; Clark, Philip James; Clarke, Robert; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Colasurdo, Luca; Cole, Brian; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Conde Muiño, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Constantinescu, Serban; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper-Sarkar, Amanda; Cormier, Felix; Cormier, Kyle James Read; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Crawley, Samuel Joseph; Creager, Rachael; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cueto, Ana; Cuhadar Donszelmann, Tulay; Cukierman, Aviv Ruben; Cummings, Jane; Curatolo, Maria; Cúth, Jakub; Czirr, Hendrik; Czodrowski, Patrick; D'amen, Gabriele; D'Auria, Saverio; D'eramo, Louis; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dado, Tomas; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Dandoy, Jeffrey; Daneri, Maria Florencia; Dang, Nguyen Phuong; Daniells, Andrew Christopher; Dann, Nicholas Stuart; Danninger, Matthias; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Daubney, Thomas; Davey, Will; David, Claire; Davidek, Tomas; Davies, Merlin; Davis, Douglas; Davison, Peter; Dawe, Edmund; Dawson, Ian; De, Kaushik; de Asmundis, Riccardo; De Benedetti, Abraham; De Castro, Stefano; De Cecco, Sandro; De Groot, Nicolo; de Jong, Paul; De la Torre, Hector; De Lorenzi, Francesco; De Maria, Antonio; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vasconcelos Corga, Kevin; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Dehghanian, Nooshin; Deigaard, Ingrid; Del Gaudio, Michela; Del Peso, Jose; Del Prete, Tarcisio; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delporte, Charles; Delsart, Pierre-Antoine; DeMarco, David; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Denysiuk, Denys; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Dette, Karola; Devesa, Maria Roberta; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Bello, Francesco Armando; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Clemente, William Kennedy; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Micco, Biagio; Di Nardo, Roberto; Di Petrillo, Karri Folan; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Díez Cornell, Sergio; Dimitrievska, Aleksandra; Dingfelder, Jochen; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Djuvsland, Julia Isabell; Barros do Vale, Maria Aline; Dobos, Daniel; Dobre, Monica; Doglioni, Caterina; Dolejsi, Jiri; Dolezal, Zdenek; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dris, Manolis; Du, Yanyan; Duarte-Campderros, Jorge; Dubreuil, Arnaud; Duchovni, Ehud; Duckeck, Guenter; Ducourthial, Audrey; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Dudder, Andreas Christian; Duffield, Emily Marie; Duflot, Laurent; Dührssen, Michael; Dumancic, Mirta; Dumitriu, Ana Elena; Duncan, Anna Kathryn; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dutta, Baishali; Dyndal, Mateusz; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; El Kosseifi, Rima; Ellajosyula, Venugopal; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Ennis, Joseph Stanford; Erdmann, Johannes; Ereditato, Antonio; Ernis, Gunar; Ernst, Michael; Errede, Steven; Escalier, Marc; Escobar, Carlos; Esposito, Bellisario; Estrada Pastor, Oscar; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Ezzi, Mohammed; Fabbri, Federica; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farina, Christian; Farina, Edoardo Maria; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fawcett, William James; Fayard, Louis; Fedin, Oleg; Fedorko, Wojciech; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; Fenton, Michael James; Fenyuk, Alexander; Feremenga, Last; Fernandez Martinez, Patricia; Fernandez Perez, Sonia; Ferrando, James; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrere, Didier; Ferretti, Claudio; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Fischer, Adam; Fischer, Cora; Fischer, Julia; Fisher, Wade Cameron; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fletcher, Rob Roy MacGregor; Flick, Tobias; Flierl, Bernhard Matthias; Flores Castillo, Luis; Flowerdew, Michael; Forcolin, Giulio Tiziano; Formica, Andrea; Förster, Fabian Alexander; Forti, Alessandra; Foster, Andrew Geoffrey; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Franchino, Silvia; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; Fressard-Batraneanu, Silvia; Freund, Benjamin; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fusayasu, Takahiro; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Louis Guillaume; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Ganguly, Sanmay; Gao, Yanyan; Gao, Yongsheng; Garay Walls, Francisca; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gascon Bravo, Alberto; Gasnikova, Ksenia; Gatti, Claudio; Gaudiello, Andrea; Gaudio, Gabriella; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Gee, Norman; Geisen, Jannik; Geisen, Marc; Geisler, Manuel Patrice; Gellerstedt, Karl; Gemme, Claudia; Genest, Marie-Hélène; Geng, Cong; Gentile, Simonetta; Gentsos, Christos; George, Simon; Gerbaudo, Davide; Gershon, Avi; Geß{}ner, Gregor; Ghasemi, Sara; Ghneimat, Mazuza; Giacobbe, Benedetto; Giagu, Stefano; Giannetti, Paola; Gibson, Stephen; Gignac, Matthew; Gilchriese, Murdock; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giraud, Pierre-Francois; Giromini, Paolo; Giugni, Danilo; Giuli, Francesco; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos Leonidas; Gkountoumis, Panagiotis; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gonçalo, Ricardo; Goncalves Gama, Rafael; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Giulia; Gonella, Laura; Gongadze, Alexi; González de la Hoz, Santiago; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Gottardo, Carlo Alberto; Goudet, Christophe Raymond; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Gozani, Eitan; Graber, Lars; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Gratchev, Vadim; Gravila, Paul Mircea; Gray, Chloe; Gray, Heather; Greenwood, Zeno Dixon; Grefe, Christian; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Grevtsov, Kirill; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Groh, Sabrina; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Grout, Zara Jane; Grummer, Aidan; Guan, Liang; Guan, Wen; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Gui, Bin; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Wen; Guo, Yicheng; Gupta, Ruchi; Gupta, Shaun; Gustavino, Giuliano; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guyot, Claude; Guzik, Marcin Pawel; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Hadef, Asma; Hageböck, Stephan; Hagihara, Mutsuto; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamilton, Andrew; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Han, Shuo; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Haney, Bijan; Hanke, Paul; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Maike Christina; Hansen, Peter Henrik; Hara, Kazuhiko; Hard, Andrew; Harenberg, Torsten; Hariri, Faten; Harkusha, Siarhei; Harrington, Robert; Harrison, Paul Fraser; Hartmann, Nikolai Marcel; Hasegawa, Makoto; Hasegawa, Yoji; Hasib, Ahmed; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havener, Laura Brittany; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hayakawa, Daiki; Hayden, Daniel; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heidegger, Kim Katrin; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Jochen Jens; Heinrich, Lukas; Heinz, Christian; Hejbal, Jiri; Helary, Louis; Held, Alexander; Hellman, Sten; Helsens, Clement; Henderson, Robert; Heng, Yang; Henkelmann, Steffen; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Herde, Hannah; Herget, Verena; Hernández Jiménez, Yesenia; Herr, Holger; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Herwig, Theodor Christian; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Higashino, Satoshi; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillier, Stephen; Hils, Maximilian; Hinchliffe, Ian; Hirose, Minoru; Hirschbuehl, Dominic; Hiti, Bojan; Hladik, Ondrej; Hoad, Xanthe; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohn, David; Holmes, Tova Ray; Homann, Michael; Honda, Shunsuke; Honda, Takuya; Hong, Tae Min; Hooberman, Benjamin Henry; Hopkins, Walter; Horii, Yasuyuki; Horton, Arthur James; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howarth, James; Hoya, Joaquin; Hrabovsky, Miroslav; Hrdinka, Julia; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hrynevich, Aliaksei; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Qipeng; Hu, Shuyang; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Huo, Peng; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuriy; Iliadis, Dimitrios; Ilic, Nikolina; Introzzi, Gianluca; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Isacson, Max Fredrik; Ishijima, Naoki; Ishino, Masaya; Ishitsuka, Masaki; Issever, Cigdem; Istin, Serhat; Ito, Fumiaki; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jackson, Paul; Jacobs, Ruth Magdalena; Jain, Vivek; Jakobi, Katharina Bianca; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jamin, David Olivier; Jana, Dilip; Jansky, Roland; Janssen, Jens; Janus, Michel; Janus, Piotr Andrzej; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Javurkova, Martina; Jeanneau, Fabien; Jeanty, Laura; Jejelava, Juansher; Jelinskas, Adomas; Jenni, Peter; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Hai; Jiang, Yi; Jiang, Zihao; Jiggins, Stephen; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Jivan, Harshna; Johansson, Per; Johns, Kenneth; Johnson, Christian; Johnson, William Joseph; Jon-And, Kerstin; Jones, Roger; Jones, Samuel David; Jones, Sarah; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Jovicevic, Jelena; Ju, Xiangyang; Juste Rozas, Aurelio; Köhler, Markus Konrad; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kahn, Sebastien Jonathan; Kaji, Toshiaki; Kajomovitz, Enrique; Kalderon, Charles William; Kaluza, Adam; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kanjir, Luka; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kar, Deepak; Karakostas, Konstantinos; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kasahara, Kota; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Kato, Chikuma; Katre, Akshay; Katzy, Judith; Kawade, Kentaro; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kay, Ellis; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John; Kempster, Jacob Julian; Kendrick, James; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Keyes, Robert; Khader, Mazin; Khalil-zada, Farkhad; Khanov, Alexander; Kharlamov, Alexey; Kharlamova, Tatyana; Khodinov, Alexander; Khoo, Teng Jian; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kido, Shogo; Kilby, Callum; Kim, Hee Yeun; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver Maria; King, Barry; Kirchmeier, David; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiuchi, Kenji; Kivernyk, Oleh; Kladiva, Eduard; Klapdor-Kleingrothaus, Thorwald; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klingl, Tobias; Klioutchnikova, Tatiana; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Köhler, Nicolas Maximilian; Koi, Tatsumi; Kolb, Mathis; Koletsou, Iro; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Kortner, Oliver; Kortner, Sandra; Kosek, Tomas; Kostyukhin, Vadim; Kotwal, Ashutosh; Koulouris, Aimilianos; Kourkoumeli-Charalampidi, Athina; Kourkoumelis, Christine; Kourlitis, Evangelos; Kouskoura, Vasiliki; Kowalewska, Anna Bozena; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozakai, Chihiro; Kozanecki, Witold; Kozhin, Anatoly; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitrii; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Krauss, Dominik; Kremer, Jakub Andrzej; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Krizka, Karol; Kroeninger, Kevin; Kroha, Hubert; Kroll, Jiri; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Krumnack, Nils; Kruse, Mark; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuechler, Jan Thomas; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Thorsten; Kukhtin, Victor; Kukla, Romain; Kulchitsky, Yuri; Kuleshov, Sergey; Kulinich, Yakov Petrovich; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kupfer, Tobias; Kuprash, Oleg; Kurashige, Hisaya; Kurchaninov, Leonid; Kurochkin, Yurii; Kurth, Matthew Glenn; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwan, Tony; Kyriazopoulos, Dimitrios; La Rosa, Alessandro; La Rosa Navarro, Jose Luis; La Rotonda, Laura; Lacasta, Carlos; Lacava, Francesco; Lacey, James; Lacker, Heiko; Lacour, Didier; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lammers, Sabine; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lanfermann, Marie Christine; Lang, Valerie Susanne; Lange, J örn Christian; Langenberg, Robert Johannes; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Lapertosa, Alessandro; Laplace, Sandrine; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Lazovich, Tomo; Lazzaroni, Massimo; Le, Brian; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Quilleuc, Eloi; LeBlanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne; Lee, Claire Alexandra; Lee, Graham Richard; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Benoit; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Lerner, Giuseppe; Leroy, Claude; Lesage, Arthur; Lester, Christopher; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Dave; Li, Bing; Li, Changqiao; Li, Haifeng; Li, Liang; Li, Qi; Li, Shu; Li, Xingguo; Li, Yichen; Liang, Zhijun; Liberti, Barbara; Liblong, Aaron; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Lindquist, Brian Edward; Lionti, Anthony Eric; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Hao; Liu, Hongbin; Liu, Jesse Kar Kee; Liu, Jian; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Minghui; Liu, Yanlin; Liu, Yanwen; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo, Cheuk Yee; Lo Sterzo, Francesco; Lobodzinska, Ewelina Maria; Loch, Peter; Loebinger, Fred; Loesle, Alena; Loew, Kevin Michael; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan David; Long, Robin Eamonn; Longo, Luigi; Looper, Kristina Anne; Lopez, Jorge; Lopez Mateos, David; Lopez Paz, Ivan; Lopez Solis, Alvaro; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Lösel, Philipp Jonathan; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lu, Haonan; Lu, Nan; Lu, Yun-Ju; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luedtke, Christian; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Luzi, Pierre Marc; Lynn, David; Lysak, Roman; Lytken, Else; Lyubushkin, Vladimir; Ma, Hong; Ma, Lian Liang; Ma, Yanhui; Maccarrone, Giovanni; Macchiolo, Anna; Macdonald, Calum Michael; Maček, Boštjan; Machado Miguens, Joana; Madaffari, Daniele; Madar, Romain; Mader, Wolfgang; Madsen, Alexander; Maeda, Junpei; Maeland, Steffen; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahlstedt, Joern; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maier, Thomas; Maio, Amélia; Majersky, Oliver; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Claire; Maltezos, Stavros; Malyukov, Sergei; Mamuzic, Judita; Mancini, Giada; Mandelli, Luciano; Mandić, Igor; Maneira, José; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany; Mann, Alexander; Manousos, Athanasios; Mansoulie, Bruno; Mansour, Jason Dhia; Mantifel, Rodger; Mantoani, Matteo; Manzoni, Stefano; Mapelli, Livio; Marceca, Gino; March, Luis; Marchese, Luigi; Marchiori, Giovanni; Marcisovsky, Michal; Marjanovic, Marija; Marley, Daniel; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Martensson, Mikael; Marti-Garcia, Salvador; Martin, Christopher Blake; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Lorenzo; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Maznas, Ioannis; Mazza, Simone Michele; Mc Fadden, Neil Christopher; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McClymont, Laurie; McDonald, Emily; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McNamara, Peter Charles; McPherson, Robert; Meehan, Samuel; Megy, Theo Jean; Mehlhase, Sascha; Mehta, Andrew; Meideck, Thomas; Meier, Karlheinz; Meirose, Bernhard; Melini, Davide; Mellado Garcia, Bruce Rafael; Mellenthin, Johannes Donatus; Melo, Matej; Meloni, Federico; Menary, Stephen Burns; Meng, Lingxin; Meng, Xiangting; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mergelmeyer, Sebastian; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer Zu Theenhausen, Hanno; Miano, Fabrizio; Middleton, Robin; Miglioranzi, Silvia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Milesi, Marco; Milic, Adriana; Miller, David; Mills, Corrinne; Milov, Alexander; Milstead, David; Minaenko, Andrey; Minami, Yuto; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Minegishi, Yuji; Ming, Yao; Mir, Lluisa-Maria; Mistry, Khilesh; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mizukami, Atsushi; Mjörnmark, Jan-Ulf; Mkrtchyan, Tigran; Mlynarikova, Michaela; Moa, Torbjoern; Mochizuki, Kazuya; Mogg, Philipp; Mohapatra, Soumya; Molander, Simon; Moles-Valls, Regina; Monden, Ryutaro; Mondragon, Matthew Craig; Mönig, Klaus; Monk, James; Monnier, Emmanuel; Montalbano, Alyssa; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Stefanie; Mori, Daniel; Mori, Tatsuya; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Morvaj, Ljiljana; Moschovakos, Paris; Mosidze, Maia; Moss, Harry James; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey; Munoz Sanchez, Francisca Javiela; Murray, Bill; Musheghyan, Haykuhi; Muškinja, Miha; Myagkov, Alexey; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nagai, Koichi; Nagai, Ryo; Nagano, Kunihiro; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Narrias Villar, Daniel Isaac; Naryshkin, Iouri; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nelson, Michael Edward; Nemecek, Stanislav; Nemethy, Peter; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Newman, Paul; Ng, Tsz Yu; Nguyen Manh, Tuan; Nickerson, Richard; Nicolaidou, Rosy; Nielsen, Jason; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Jon Kerr; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishu, Nishu; Nisius, Richard; Nitsche, Isabel; Nobe, Takuya; Noguchi, Yohei; Nomachi, Masaharu; Nomidis, Ioannis; Nomura, Marcelo Ayumu; Nooney, Tamsin; Nordberg, Markus; Norjoharuddeen, Nurfikri; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nurse, Emily; Nuti, Francesco; O'connor, Kelsey; O'Neil, Dugan; O'Rourke, Abigail Alexandra; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Obermann, Theresa; Ocariz, Jose; Ochi, Atsuhiko; Ochoa, Ines; Ochoa-Ricoux, Juan Pedro; Oda, Susumu; Odaka, Shigeru; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohman, Henrik; Oide, Hideyuki; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Oleiro Seabra, Luis Filipe; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onogi, Kouta; Onyisi, Peter; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Pacheco Rodriguez, Laura; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganini, Michela; Paige, Frank; Palacino, Gabriel; Palazzo, Serena; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Panagiotopoulou, Evgenia; Panagoulias, Ilias; Pandini, Carlo Enrico; Panduro Vazquez, William; Pani, Priscilla; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Adam Jackson; Parker, Michael Andrew; Parker, Kerry Ann; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pascuzzi, Vincent; Pasner, Jacob Martin; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Francesca; Pataraia, Sophio; Pater, Joleen; Pauly, Thilo; Pearson, Benjamin; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Penc, Ondrej; Peng, Cong; Peng, Haiping; Penwell, John; Peralva, Bernardo; Perego, Marta Maria; Perepelitsa, Dennis; Perini, Laura; Pernegger, Heinz; Perrella, Sabrina; Peschke, Richard; Peshekhonov, Vladimir; Peters, Krisztian; Peters, Yvonne; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petroff, Pierre; Petrolo, Emilio; Petrov, Mariyan; Petrucci, Fabrizio; Pettersson, Nora Emilia; Peyaud, Alan; Pezoa, Raquel; Phillips, Forrest Hays; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Pickering, Mark Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pin, Arnaud Willy J; Pinamonti, Michele; Pinfold, James; Pirumov, Hayk; Pitt, Michael; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Pluth, Daniel; Podberezko, Pavel; Poettgen, Ruth; Poggi, Riccardo; Poggioli, Luc; Pohl, David-leon; Polesello, Giacomo; Poley, Anne-luise; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Ponomarenko, Daniil; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Poppleton, Alan; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Poulard, Gilbert; Poulsen, Trine; Poveda, Joaquin; Pozo Astigarraga, Mikel Eukeni; Pralavorio, Pascal; Pranko, Aliaksandr; Prell, Soeren; Price, Darren; Price, Lawrence; Primavera, Margherita; Prince, Sebastien; Proklova, Nadezda; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Puri, Akshat; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Raddum, Silje; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Raine, John Andrew; Rajagopalan, Srinivasan; Rangel-Smith, Camila; Rashid, Tasneem; Raspopov, Sergii; Ratti, Maria Giulia; Rauch, Daniel; Rauscher, Felix; Rave, Stefan; Ravinovich, Ilia; Rawling, Jacob Henry; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Reale, Marilea; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reed, Robert; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reiss, Andreas; Rembser, Christoph; Ren, Huan; Rescigno, Marco; Resconi, Silvia; Resseguie, Elodie Deborah; Rettie, Sebastien; Reynolds, Elliot; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rieger, Julia; Rifki, Othmane; Rijssenbeek, Michael; Rimoldi, Adele; Rimoldi, Marco; Rinaldi, Lorenzo; Ripellino, Giulia; Ristić, Branislav; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Rizzi, Chiara; Roberts, Rhys Thomas; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Rocco, Elena; Roda, Chiara; Rodina, Yulia; Rodriguez Bosca, Sergi; Rodriguez Perez, Andrea; Rodriguez Rodriguez, Daniel; Roe, Shaun; Rogan, Christopher Sean; Røhne, Ole; Roloff, Jennifer; Romaniouk, Anatoli; Romano, Marino; Romano Saez, Silvestre Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosien, Nils-Arne; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Jonatan; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Russell, Heather; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryu, Soo; Ryzhov, Andrey; Rzehorz, Gerhard Ferdinand; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Saha, Puja; Sahinsoy, Merve; Saimpert, Matthias; Saito, Masahiko; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salazar Loyola, Javier Esteban; Salek, David; Sales De Bruin, Pedro Henrique; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sammel, Dirk; Sampsonidis, Dimitrios; Sampsonidou, Despoina; Sánchez, Javier; Sanchez Martinez, Victoria; Sanchez Pineda, Arturo Rodolfo; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Christian Oliver; Sandhoff, Marisa; Sandoval, Carlos; Sankey, Dave; Sannino, Mario; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sasaki, Osamu; Sato, Koji; Sauvan, Emmanuel; Savage, Graham; Savard, Pierre; Savic, Natascha; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schachtner, Balthasar Maria; Schaefer, Douglas; Schaefer, Leigh; Schaefer, Ralph; Schaeffer, Jan; Schaepe, Steffen; Schaetzel, Sebastian; Schäfer, Uli; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R Dean; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Schiavi, Carlo; Schier, Sheena; Schildgen, Lara Katharina; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt-Sommerfeld, Korbinian Ralf; Schmieden, Kristof; Schmitt, Christian; Schmitt, Stefan; Schmitz, Simon; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schopf, Elisabeth; Schott, Matthias; Schouwenberg, Jeroen; Schovancova, Jaroslava; Schramm, Steven; Schuh, Natascha; Schulte, Alexandra; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Sciandra, Andrea; Sciolla, Gabriella; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seixas, José; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen; Semprini-Cesari, Nicola; Senkin, Sergey; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Sessa, Marco; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shaikh, Nabila Wahab; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shehu, Ciwake Yusufu; Shen, Yu-Ting; Sherafati, Nima; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shipsey, Ian Peter Joseph; Shirabe, Shohei; Shiyakova, Mariya; Shlomi, Jonathan; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyed Ruhollah; Shope, David Richard; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Sicho, Petr; Sickles, Anne Marie; Sidebo, Per Edvin; Sideras Haddad, Elias; Sidiropoulou, Ourania; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silverstein, Samuel; Simak, Vladislav; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simon, Manuel; Sinervo, Pekka; Sinev, Nikolai; Sioli, Maximiliano; Siragusa, Giovanni; Siral, Ismet; Sivoklokov, Serguei; Sjölin, Jörgen; Skinner, Malcolm Bruce; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Slawinska, Magdalena; Sliwa, Krzysztof; Slovak, Radim; Smakhtin, Vladimir; Smart, Ben; Smiesko, Juraj; Smirnov, Nikita; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Joshua Wyatt; Smith, Matthew; Smith, Russell; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snyder, Ian Michael; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Sokhrannyi, Grygorii; Solans Sanchez, Carlos; Solar, Michael; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Son, Hyungsuk; Sopczak, Andre; Sosa, David; Sotiropoulou, Calliope Louisa; Soualah, Rachik; Soukharev, Andrey; South, David; Sowden, Benjamin; Spagnolo, Stefania; Spalla, Margherita; Spangenberg, Martin; Spanò, Francesco; Sperlich, Dennis; Spettel, Fabian; Spieker, Thomas Malte; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; St Denis, Richard Dante; Stabile, Alberto; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stanitzki, Marcel Michael; Stapf, Birgit Sylvia; Stapnes, Steinar; Starchenko, Evgeny; Stark, Giordon; Stark, Jan; Stark, Simon Holm; Staroba, Pavel; Starovoitov, Pavel; Stärz, Steffen; Staszewski, Rafal; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stewart, Graeme; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Suchek, Stanislav; Sugaya, Yorihito; Suk, Michal; Sulin, Vladimir; Sultan, D M S; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Suruliz, Kerim; Suster, Carl; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swiatlowski, Maximilian; Swift, Stewart Patrick; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takasugi, Eric Hayato; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tanaka, Junichi; Tanaka, Masahiro; Tanaka, Reisaburo; Tanaka, Shuji; Tanioka, Ryo; Tannenwald, Benjamin Bordy; Tapia Araya, Sebastian; Tapprogge, Stefan; Tarem, Shlomit; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Aaron; Taylor, Geoffrey; Taylor, Pierre Thor Elliot; Taylor, Wendy; Teixeira-Dias, Pedro; Temple, Darren; Ten Kate, Herman; Teng, Ping-Kun; Teoh, Jia Jian; Tepel, Fabian-Phillipp; Terada, Susumu; Terashi, Koji; Terron, Juan; Terzo, Stefano; Testa, Marianna; Teuscher, Richard; Theveneaux-Pelzer, Timothée; Thomas, Juergen; Thomas-Wilsker, Joshuha; Thompson, Paul; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Tibbetts, Mark James; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorova-Nova, Sharka; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tong, Baojia(Tony); Tornambe, Peter; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Treado, Colleen Jennifer; Trefzger, Thomas; Tresoldi, Fabio; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Trofymov, Artur; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; Truong, Loan; Trzebinski, Maciej; Trzupek, Adam; Tsang, Ka Wa; Tseng, Jeffrey; Tsiareshka, Pavel; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsui, Ka Ming; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tu, Yanjun; Tudorache, Alexandra; Tudorache, Valentina; Tulbure, Traian Tiberiu; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turgeman, Daniel; Turk Cakir, Ilkay; Turra, Ruggero; Tuts, Michael; Ucchielli, Giulia; Ueda, Ikuo; Ughetto, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urban, Jozef; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Usui, Junya; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valderanis, Chrysostomos; Valdes Santurio, Eduardo; Valentinetti, Sara; Valero, Alberto; Valéry, Lo\\"ic; Valkar, Stefan; Vallier, Alexis; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; van der Graaf, Harry; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varni, Carlo; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vasquez, Jared Gregory; Vasquez, Gerardo; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veeraraghavan, Venkatesh; Veloce, Laurelle Maria; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Ambrosius Thomas; Vermeulen, Jos; Vetterli, Michel; Viaux Maira, Nicolas; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigani, Luigi; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vishwakarma, Akanksha; Vittori, Camilla; Vivarelli, Iacopo; Vlachos, Sotirios; Vlasak, Michal; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; von der Schmitt, Hans; von Toerne, Eckhard; Vorobel, Vit; Vorobev, Konstantin; Vos, Marcel; Voss, Rudiger; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Peter; Wagner, Wolfgang; Wagner-Kuhr, Jeannine; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wallangen, Veronica; Wang, Chao; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Qing; Wang, Rui; Wang, Song-Ming; Wang, Tingting; Wang, Wei; Wang, Wenxiao; Wang, Zirui; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Washbrook, Andrew; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Aaron Foley; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Weber, Stephen; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weirich, Marcel; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Michael David; Werner, Per; Wessels, Martin; Whalen, Kathleen; Whallon, Nikola Lazar; Wharton, Andrew Mark; White, Aaron; White, Andrew; White, Martin; White, Ryan; Whiteson, Daniel; Whitmore, Ben William; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wildauer, Andreas; Wilk, Fabian; Wilkens, Henric George; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, John; Wingerter-Seez, Isabelle; Winkels, Emma; Winklmeier, Frank; Winston, Oliver James; Winter, Benedict Tobias; Wittgen, Matthias; Wobisch, Markus; Wolf, Tim Michael Heinz; Wolff, Robert; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wong, Vincent Wai Sum; Worm, Steven; Wosiek, Barbara; Wotschack, Jorg; Wozniak, Krzysztof; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xi, Zhaoxu; Xia, Ligang; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yamaguchi, Daiki; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Shimpei; Yamanaka, Takashi; Yamatani, Masahiro; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Yi; Yang, Zongchang; Yao, Weiming; Yap, Yee Chinn; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yigitbasi, Efe; Yildirim, Eda; Yorita, Kohei; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Yu, Jaehoon; Yu, Jie; Yuen, Stephanie P; Yusuff, Imran; Zabinski, Bartlomiej; Zacharis, Georgios; Zaidan, Remi; Zaitsev, Alexander; Zakharchuk, Nataliia; Zalieckas, Justas; Zaman, Aungshuman; Zambito, Stefano; Zanzi, Daniele; Zeitnitz, Christian; Zemaityte, Gabija; Zemla, Andrzej; Zeng, Jian Cong; Zeng, Qi; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Guangyi; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Liqing; Zhang, Matt; Zhang, Peng; Zhang, Rui; Zhang, Ruiqi; Zhang, Xueyao; Zhang, Yu; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhou, Bing; Zhou, Chen; Zhou, Li; Zhou, Maosen; Zhou, Mingliang; Zhou, Ning; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Junjie; Zhu, Yingchun; Zhuang, Xuai; Zhukov, Konstantin; Zibell, Andre; Zieminska, Daria; Zimine, Nikolai; Zimmermann, Christoph; Zimmermann, Stephanie; Zinonos, Zinonas; Zinser, Markus; Ziolkowski, Michael; Živković, Lidija; Zobernig, Georg; Zoccoli, Antonio; Zou, Rui; zur Nedden, Martin; Zwalinski, Lukasz

    2017-10-11

    Abstract: With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb$^{-1}$ of data collected by the ATLAS experiment and simulation of proton-proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 TeV. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The efficiency in the cores of jets with transverse momenta between 200 GeV and 1600 GeV is quantified using a novel, data-driven, method. The method uses the energy loss, dE/dx, to identify pixel clusters originating from two charged particles. Of the charged particles creating the...

  6. Constraining flavor changing interactions from LHC Run-2 dilepton bounds with vector mediators

    Directory of Open Access Journals (Sweden)

    Farinaldo S. Queiroz

    2016-12-01

    Full Text Available Within the context of vector mediators, is a new signal observed in flavor changing interactions, particularly in the neutral mesons systems K0−K¯0, D0−D¯0 and B0−B0¯, consistent with dilepton resonance searches at the LHC? In the attempt to address this very simple question, we discuss the complementarity between flavor changing neutral current (FCNC and dilepton resonance searches at the LHC run 2 at 13 TeV with 3.2 fb−1 of integrated luminosity, in the context of vector mediators at tree level. Vector mediators, are often studied in the flavor changing framework, specially in the light of the recent LHCb anomaly observed at the rare B decay. However, the existence of stringent dilepton bound severely constrains flavor changing interactions, due to restrictive limits on the Z′ mass. We discuss this interplay explicitly in the well motivated framework of a 3-3-1 scheme, where fermions and scalars are arranged in the fundamental representation of the weak SU(3 gauge group. Due to the paucity of relevant parameters, we conclude that dilepton data leave little room for a possible new physics signal stemming from these systems, unless a very peculiar texture parametrization is used in the diagonalization of the CKM matrix. In other words, if a signal is observed in such flavor changing interactions, it unlikely comes from a 3-3-1 model.

  7. The Upgraded Pixel Detector of the ATLAS Experiment for Run-2 at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00084948; The ATLAS collaboration

    2016-01-01

    Run-2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 at a radius of 3.3 cm between the existing Pixel Detector and a new smaller radius beam-pipe. The new detector, built to cope with high radiation and expected occupancy, is the first large scale application of 3D detectors and CMOS 130 nm technology. In addition the Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during run-1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning and performance of the 4-layer Pixel Detector, in particular the IBL, will be presented using collision data.

  8. The Upgraded Pixel Detector of the ATLAS Experiment for Run-2

    CERN Document Server

    Ferrere, Didier; The ATLAS collaboration

    2016-01-01

    Run-2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 at a radius of 3.3 cm between the existing Pixel Detector and a new smaller radius beam-pipe. The new detector, built to cope with high radiation and expected occupancy, is the first large scale application of 3D detectors and CMOS 130nm technology. In addition the Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during run-1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning and performance of the 4-layer Pixel Detector, in particular the IBL, will be presented, using collision data.

  9. The upgraded Pixel Detector of the ATLAS experiment for Run-2 at the Large Hadron Collider

    CERN Document Server

    Giordani, MarioPaolo; The ATLAS collaboration

    2016-01-01

    Run-2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 at a radius of 3.3 cm between the existing Pixel Detector and a new smaller radius beam-pipe. The new detector, built to cope with high radiation and expected occupancy, is the first large scale application of 3D detectors and CMOS 130nm technology. In addition the Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during run-1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning and performance of the 4-layer Pixel Detector, in particular the IBL, will be presented, using collision data.

  10. The Design and Performance of the ATLAS Inner Detector Trigger for Run 2 LHC Collisions at 13 TeV

    CERN Document Server

    Kilby, Callum; The ATLAS collaboration

    2016-01-01

    The design and performance of the ATLAS Inner Detector (ID) trigger algorithms running online on the high level trigger (HLT) processor farm with the LHC Run 2 data with collisions at both 50 ns and 25 ns are discussed. The HLT ID tracking algorithms are essential for the identification of nearly all physics signatures in the ATLAS trigger. In order to deal with the expected higher rates for LHC Run 2, the ID trigger was redesigned during the 2013-15 long shutdown to satisfy the demands of the higher energy LHC operation. The detailed performance of the tracking algorithms with the Run 2 data taken so far for the different trigger signatures in terms of both efficiency, and resolution is presented. The online processing times for running trigger tracking for the different trigger signatures are discussed in detail. Where appropriate, comparison of the new strategy for Run 2, with that adopted in Run 1 are made to demonstrate successful application and superior performance of the strategy adopted for Run 2.

  11. Test results of Run-1 and Run-2 in steam generator safety test facility (SWAT-3)

    International Nuclear Information System (INIS)

    Kurihara, A.; Yatabe, Toshio; Tanabe, Hiromi; Hiroi, Hiroshi

    2003-07-01

    Large leak sodium-water reaction tests were carried out using SWAT-1 rig and SWAT-3 facility in Power Reactor and Nuclear Fuel Development Corporation (PNC) O-arai Engineering Center to obtain the data on the design of the prototype LMFBR Monju steam generator against a large leak accident. This report provides the results of SWAT-3 Runs 1 and 2. In Runs 1 and 2, the heat transfer tube bundle of the evaporator, fabricated by TOSHIBA/IHI, were used, and the pressure relief line was located at the top of evaporator. The water injection rates in the evaporator were 6.7 kg/s and 14.2 (initial)-9.7 kg/s in Runs 1 and 2 respectively, which corresponded to 3.3 tubes and 7.1 (initial)-4.8 tubes failure in actual size system according to iso-velocity modeling. Approximately two hundreds of measurement points were provided to collect data such as pressure, temperature, strain, sodium level, void, thrust load, acceleration, displacement, flow rate, and so on in each run. Initial spike pressures were 1.13 MPa and 2.62 MPa nearest to injection point in Runs 1 and 2 respectively, and the maximum quasi-steady pressures in evaporator were 0.49 MPa and 0.67 MPa in Runs 1 and 2. No secondary tube failure was observed. The rupture disc of evaporator (RD601) burst at 1.1s in Run-1 and at 0.7s in Run-2 after water injected, and the pressure relief system was well-functioned though a few items for improvement were found. (author)

  12. Reconstruction, Energy Calibration, and Identification of Hadronically Decaying Tau Leptons in the ATLAS Experiment for Run-2 of the LHC

    CERN Document Server

    The ATLAS collaboration

    2015-01-01

    The reconstruction algorithm, energy calibration, and identification methods for hadronically decaying tau leptons in ATLAS used at the start of Run-2 of the Large Hadron Collider are described in this note. All algorithms have been optimised for Run-2 conditions. The energy calibration relies on Monte Carlo samples with hadronic tau lepton decays, and applies multiplicative factors based on the pT of the reconstructed tau lepton to the energy measurements in the calorimeters. The identification employs boosted decision trees. Systematic uncertainties on the energy scale, reconstruction efficiency and identification efficiency of hadronically decaying tau leptons are determined using Monte Carlo samples that simulate varying conditions.

  13. Dark Matter Benchmark Models for Early LHC Run-2 Searches. Report of the ATLAS/CMS Dark Matter Forum

    Energy Technology Data Exchange (ETDEWEB)

    Abercrombie, Daniel [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). et al.

    2015-07-06

    One of the guiding principles of this report is to channel the efforts of the ATLAS and CMS collaborations towards a minimal basis of dark matter models that should influence the design of the early Run-2 searches. At the same time, a thorough survey of realistic collider signals of Dark Matter is a crucial input to the overall design of the search program.

  14. Operation and performance of the ATLAS Level-1 Calorimeter and Level-1 Topological Triggers in Run 2 at the LHC

    CERN Document Server

    Whalen, Kate; The ATLAS collaboration

    2017-01-01

    In Run 2 at CERN's Large Hadron Collider, the ATLAS detector uses a two-level trigger system to reduce the event rate from the nominal collision rate of 40 MHz to the event storage rate of 1 kHz, while preserving interesting physics events. The first step of the trigger system, Level-1, reduces the event rate to 100 kHz with a latency of less than 2.5 μs. One component of this system is the Level-1 Calorimeter Trigger (L1Calo), which uses coarse-granularity information from the electromagnetic and hadronic calorimeters to identify regions of interest corresponding to electrons, photons, taus, jets, and large amounts of transverse energy and missing transverse energy. In this talk, we will discuss the improved performance of the L1Calo system in the challenging, high-luminosity conditions provided by the LHC in Run 2. As the LHC exceeds its design luminosity, it is becoming even more critical to reduce event rates while preserving physics. A new feature of the ATLAS trigger system for Run 2 is the Level-1 Top...

  15. Selected CPV Results from LHCb Run 1 and Prospects for CKM $\\gamma $ Angle Measurements in Run 2

    CERN Document Server

    Oblakowska-Mucha, Agniezka

    2016-01-01

    The LHCb detector is a single-arm forward spectrometer that collects data at the LHC, designed for studies of flavour physics with high precision. In this review, a few selected results regarding CP violation are discussed with particular emphasis on the CKM angle measurements. This sum- mary covers results based on the data collected by the LHCb detector during 2011 and 2012 proton–proton LHC runs at the centre-of-mass ener- gies of 7 and 8 TeV, respectively. Some remarks on prospects for analyses foreseen in the ongoing LHC Run 2 are also presented

  16. Dark Matter Benchmark Models for Early LHC Run-2 Searches: Report of the ATLAS/CMS Dark Matter Forum

    CERN Document Server

    Abercrombie, Daniel; Akilli, Ece; Alcaraz Maestre, Juan; Allen, Brandon; Alvarez Gonzalez, Barbara; Andrea, Jeremy; Arbey, Alexandre; Azuelos, Georges; Azzi, Patrizia; Backovic, Mihailo; Bai, Yang; Banerjee, Swagato; Beacham, James; Belyaev, Alexander; Boveia, Antonio; Brennan, Amelia Jean; Buchmueller, Oliver; Buckley, Matthew R.; Busoni, Giorgio; Buttignol, Michael; Cacciapaglia, Giacomo; Caputo, Regina; Carpenter, Linda; Filipe Castro, Nuno; Gomez Ceballos, Guillelmo; Cheng, Yangyang; Chou, John Paul; Cortes Gonzalez, Arely; Cowden, Chris; D'Eramo, Francesco; De Cosa, Annapaola; De Gruttola, Michele; De Roeck, Albert; De Simone, Andrea; Deandrea, Aldo; Demiragli, Zeynep; DiFranzo, Anthony; Doglioni, Caterina; du Pree, Tristan; Erbacher, Robin; Erdmann, Johannes; Fischer, Cora; Flaecher, Henning; Fox, Patrick J.; Fuks, Benjamin; Genest, Marie-Helene; Gomber, Bhawna; Goudelis, Andreas; Gramling, Johanna; Gunion, John; Hahn, Kristian; Haisch, Ulrich; Harnik, Roni; Harris, Philip C.; Hoepfner, Kerstin; Hoh, Siew Yan; Hsu, Dylan George; Hsu, Shih-Chieh; Iiyama, Yutaro; Ippolito, Valerio; Jacques, Thomas; Ju, Xiangyang; Kahlhoefer, Felix; Kalogeropoulos, Alexis; Kaplan, Laser Seymour; Kashif, Lashkar; Khoze, Valentin V.; Khurana, Raman; Kotov, Khristian; Kovalskyi, Dmytro; Kulkarni, Suchita; Kunori, Shuichi; Kutzner, Viktor; Lee, Hyun Min; Lee, Sung-Won; Liew, Seng Pei; Lin, Tongyan; Lowette, Steven; Madar, Romain; Malik, Sarah; Maltoni, Fabio; Martinez Perez, Mario; Mattelaer, Olivier; Mawatari, Kentarou; McCabe, Christopher; Megy, Theo; Morgante, Enrico; Mrenna, Stephen; Narayanan, Siddharth M.; Nelson, Andy; Novaes, Sergio F.; Padeken, Klaas Ole; Pani, Priscilla; Papucci, Michele; Paulini, Manfred; Paus, Christoph; Pazzini, Jacopo; Penning, Bjorn; Peskin, Michael E.; Pinna, Deborah; Procura, Massimiliano; Qazi, Shamona F.; Racco, Davide; Re, Emanuele; Riotto, Antonio; Rizzo, Thomas G.; Roehrig, Rainer; Salek, David; Sanchez Pineda, Arturo; Sarkar, Subir; Schmidt, Alexander; Schramm, Steven Randolph; Shepherd, William; Singh, Gurpreet; Soffi, Livia; Srimanobhas, Norraphat; Sung, Kevin; Tait, Tim M.P.; Theveneaux-Pelzer, Timothee; Thomas, Marc; Tosi, Mia; Trocino, Daniele; Undleeb, Sonaina; Vichi, Alessandro; Wang, Fuquan; Wang, Lian-Tao; Wang, Ren-Jie; Whallon, Nikola; Worm, Steven; Wu, Mengqing; Wu, Sau Lan; Yang, Hongtao; Yang, Yong; Yu, Shin-Shan; Zaldivar, Bryan; Zanetti, Marco; Zhang, Zhiqing; Zucchetta, Alberto

    2015-01-01

    This document is the final report of the ATLAS-CMS Dark Matter Forum, a forum organized by the ATLAS and CMS collaborations with the participation of experts on theories of Dark Matter, to select a minimal basis set of dark matter simplified models that should support the design of the early LHC Run-2 searches. A prioritized, compact set of benchmark models is proposed, accompanied by studies of the parameter space of these models and a repository of generator implementations. This report also addresses how to apply the Effective Field Theory formalism for collider searches and present the results of such interpretations.

  17. Improvements of the ALICE high level trigger for LHC Run 2 to facilitate online reconstruction, QA, and calibration

    Energy Technology Data Exchange (ETDEWEB)

    Rohr, David [Frankfurt Institute for Advanced Studies, Frankfurt (Germany); Collaboration: ALICE-Collaboration

    2016-07-01

    ALICE is one of the four major experiments at the Large Hadron Collider (LHC) at CERN. Its main goal is the study of matter under extreme pressure and temperature as produced in heavy ion collisions at LHC. The ALICE High Level Trigger (HLT) is an online compute farm of around 200 nodes that performs a real time event reconstruction of the data delivered by the ALICE detectors. The HLT employs a fast FPGA based cluster finder algorithm as well as a GPU based track reconstruction algorithm and it is designed to process the maximum data rate expected from the ALICE detectors in real time. We present new features of the HLT for LHC Run 2 that started in 2015. A new fast standalone track reconstruction algorithm for the Inner Tracking System (ITS) enables the HLT to compute and report to LHC the luminous region of the interactions in real time. We employ a new dynamically reconfigurable histogram component that allows the visualization of characteristics of the online reconstruction using the full set of events measured by the detectors. This improves our monitoring and QA capabilities. During Run 2, we plan to deploy online calibration, starting with the calibration of the TPC (Time Projection Chamber) detector's drift time. First proof of concept tests were successfully performed using data-replay on our development cluster and during the heavy ion period at the end of 2015.

  18. Heavy-ion dominance near Cluster perigees

    Science.gov (United States)

    Ferradas, C. P.; Zhang, J.-C.; Kistler, L. M.; Spence, H. E.

    2015-12-01

    Time periods in which heavy ions dominate over H+ in the energy range of 1-40 keV were observed by the Cluster Ion Spectrometry (CIS)/COmposition DIstribution Function (CODIF) instrument onboard Cluster Spacecraft 4 at L values less than 4. The characteristic feature is a narrow flux peak at around 10 keV that extends into low L values, with He+ and/or O+ dominating. In the present work we perform a statistical study of these events and examine their temporal occurrence and spatial distribution. The observed features, both the narrow energy range and the heavy-ion dominance, can be interpreted using a model of ion drift from the plasma sheet, subject to charge exchange losses. The narrow energy range corresponds to the only energy range that has direct drift access from the plasma sheet during quiet times. The drift time to these locations from the plasma sheet is > 30 h, so that charge exchange has a significant impact on the population. We show that a simple drift/loss model can explain the dependence on L shell and MLT of these heavy-ion-dominant time periods.

  19. Pushing HTCondor and glideinWMS to 200K+ Jobs in a Global Pool for CMS before Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Balcas, J. [Vilnius U.; Belforte, S. [Trieste U.; Bockelman, B. [Nebraska U.; Gutsche, O. [Fermilab; Khan, F. [Quaid-i-Azam U.; Larson, K. [Fermilab; Letts, J. [UC, San Diego; Mascheroni, M. [Milan Bicocca U.; Mason, D. [Fermilab; McCrea, A. [UC, San Diego; Saiz-Santos, M. [UC, San Diego; Sfiligoi, I. [UC, San Diego

    2015-12-23

    The CMS experiment at the LHC relies on HTCondor and glideinWMS as its primary batch and pilot-based Grid provisioning system. So far we have been running several independent resource pools, but we are working on unifying them all to reduce the operational load and more effectively share resources between various activities in CMS. The major challenge of this unification activity is scale. The combined pool size is expected to reach 200K job slots, which is significantly bigger than any other multi-user HTCondor based system currently in production. To get there we have studied scaling limitations in our existing pools, the biggest of which tops out at about 70K slots, providing valuable feedback to the development communities, who have responded by delivering improvements which have helped us reach higher and higher scales with more stability. We have also worked on improving the organization and support model for this critical service during Run 2 of the LHC. This contribution will present the results of the scale testing and experiences from the first months of running the Global Pool.

  20. Operation and Performance of a new microTCA-based CMS Calorimeter Trigger in LHC Run 2

    CERN Document Server

    Klabbers, Pamela Renee

    2016-01-01

    The Large Hadron Collider (LHC) at CERN is currently increasing the instantaneous luminosity for p-p collisions. In LHC Run 2, the center-of-mass energy has gone from 8 to 13 TeV and the instantaneous luminosity will approximately double for proton collisions. This will make it even more challenging to trigger on interesting events since the number of interactions per crossing (pileup) and the overall trigger rate will be significantly larger than in LHC Run 1. The Compact Muon Solenoid (CMS) experiment has installed the second stage of a two-stage upgrade to the Calorimeter Trigger to ensure that the trigger rates can be controlled and the thresholds kept low, so that physics data will not be compromised. The stage-1, which replaced the original CMS Global Calorimeter Trigger, operated successfully in 2015. The completely new stage-2 has replaced the entire calorimeter trigger in 2016 with AMC form-factor boards and optical links operating in a microTCA chassis. It required that updates to the calorimet...

  1. Quarkonium in ALICE: results on p-Pb and Pb-Pb collisions from LHC Run 2

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    In 1986, the modification of quarkonium production was first proposed as a signature of the formation of a Quark Gluon Plasma. While the central role of quarkonium in the understanding of the QGP is indisputable, the direct link between the expected sequential suppression, in a very hot medium, and the experimental observations is not yet completely settled. Several other mechanisms, related to either the formation of a hot medium, such as quarkonium regeneration, or to the presence of cold nuclear matter, are well-known key effects in the interpretation of the results. This talk reviews very recent LHC Run 2 results obtained with the ALICE detector, which is designed to study quarkonium in two rapidity ranges,  at mid-rapidity ($|y|<0.9$) in the dielectron decay channel and at forward rapidity ($2.5

  2. The ATLAS Production System Evolution: New Data Processing and Analysis Paradigm for the LHC Run2 and High-Luminosity

    Science.gov (United States)

    Barreiro, F. H.; Borodin, M.; De, K.; Golubkov, D.; Klimentov, A.; Maeno, T.; Mashinistov, R.; Padolski, S.; Wenaus, T.; ATLAS Collaboration

    2017-10-01

    The second generation of the ATLAS Production System called ProdSys2 is a distributed workload manager that runs daily hundreds of thousands of jobs, from dozens of different ATLAS specific workflows, across more than hundred heterogeneous sites. It achieves high utilization by combining dynamic job definition based on many criteria, such as input and output size, memory requirements and CPU consumption, with manageable scheduling policies and by supporting different kind of computational resources, such as GRID, clouds, supercomputers and volunteer-computers. The system dynamically assigns a group of jobs (task) to a group of geographically distributed computing resources. Dynamic assignment and resources utilization is one of the major features of the system, it didn’t exist in the earliest versions of the production system where Grid resources topology was predefined using national or/and geographical pattern. Production System has a sophisticated job fault-recovery mechanism, which efficiently allows to run multi-Terabyte tasks without human intervention. We have implemented “train” model and open-ended production which allow to submit tasks automatically as soon as new set of data is available and to chain physics groups data processing and analysis with central production by the experiment. We present an overview of the ATLAS Production System and its major components features and architecture: task definition, web user interface and monitoring. We describe the important design decisions and lessons learned from an operational experience during the first year of LHC Run2. We also report the performance of the designed system and how various workflows, such as data (re)processing, Monte-Carlo and physics group production, users analysis, are scheduled and executed within one production system on heterogeneous computing resources.

  3. Monte Carlo Generators for the Production of a $W$ or $Z/\\gamma^*$ Boson in Association with Jets at ATLAS in Run 2

    CERN Document Server

    The ATLAS collaboration

    2016-01-01

    This note documents the Monte Carlo generators used by the ATLAS collaboration at the start of Run 2 for processes where a $W$ or $Z/\\gamma^*$ boson is produced in association with jets. The available event generators are briefly described and comparisons are made with ATLAS measurements of $W$ or $Z/\\gamma^*$+jets performed with Run 1 data, collected at the centre-of-mass energy of 7 TeV. The model predictions are then compared at the Run 2 centre-of-mass energy of 13~TeV. A comparison is also made with an early Run 2 ATLAS $Z/\\gamma^*$+jets data measurement. Investigations into tuning the parameters of the models and evaluating systematic uncertainties on the Monte Carlo predictions are also presented.

  4. Strategies for RUN1 Deployment Using RUN2 and REN2 to Manage Grapevine Powdery Mildew Informed by Studies of Race Specificity.

    Science.gov (United States)

    Feechan, Angela; Kocsis, Marianna; Riaz, Summaira; Zhang, Wei; Gadoury, David M; Walker, M Andrew; Dry, Ian B; Reisch, Bruce; Cadle-Davidson, Lance

    2015-08-01

    The Toll/interleukin-1 receptor nucleotide-binding site leucine-rich repeat gene, "resistance to Uncinula necator 1" (RUN1), from Vitis rotundifolia was recently identified and confirmed to confer resistance to the grapevine powdery mildew fungus Erysiphe necator (syn. U. necator) in transgenic V. vinifera cultivars. However, sporulating powdery mildew colonies and cleistothecia of the heterothallic pathogen have been found on introgression lines containing the RUN1 locus growing in New York (NY). Two E. necator isolates collected from RUN1 vines were designated NY1-131 and NY1-137 and were used in this study to inform a strategy for durable RUN1 deployment. In order to achieve this, fitness parameters of NY1-131 and NY1-137 were quantified relative to powdery mildew isolates collected from V. rotundifolia and V. vinifera on vines containing alleles of the powdery mildew resistance genes RUN1, RUN2, or REN2. The results clearly demonstrate the race specificity of RUN1, RUN2, and REN2 resistance alleles, all of which exhibit programmed cell death (PCD)-mediated resistance. The NY1 isolates investigated were found to have an intermediate virulence on RUN1 vines, although this may be allele specific, while the Musc4 isolate collected from V. rotundifolia was virulent on all RUN1 vines. Another powdery mildew resistance locus, RUN2, was previously mapped in different V. rotundifolia genotypes, and two alleles (RUN2.1 and RUN2.2) were identified. The RUN2.1 allele was found to provide PCD-mediated resistance to both an NY1 isolate and Musc4. Importantly, REN2 vines were resistant to the NY1 isolates and RUN1REN2 vines combining both genes displayed additional resistance. Based on these results, RUN1-mediated resistance in grapevine may be enhanced by pyramiding with RUN2.1 or REN2; however, naturally occurring isolates in North America display some virulence on vines with these resistance genes. The characterization of additional resistance sources is needed to identify

  5. Prospects for the $\\cal{B}$$(B^0_{(s)} \\to \\mu^+ \\mu^-)$ measurements with the ATLAS detector in the Run 2 and HL-LHC data campaigns

    CERN Document Server

    The ATLAS collaboration

    2018-01-01

    This note estimates the ATLAS detector performance in measuring the branching fractions of the very rare decays $B^0_{s} \\to \\mu^+ \\mu^-$ and $B^0 \\to \\mu^+ \\mu^-$ using data collected during the whole LHC Run 2 campaign and during the whole HL-LHC campaign. The estimation is obtained by means of pseudo-MC experiments based on the measurement of the two processes performed by the ATLAS experiment using the full integrated luminosity collected during the Run 1 data taking campaign.

  6. The CMS muon system status and upgrades for LHC run-2 and performance of muon reconstruction with 13 TeV data

    CERN Document Server

    Battilana, Carlo

    2016-01-01

    The CMS muon system has played a key role for many physics results obtained from the LHC Run-1 and Run-2 data. During the Long Shutdown (2013-2014), as well as during the last year-end technical stop (2015-2016), significant consolidation and upgrades have been carried out on the muon detectors and on the L1 muon trigger. The algorithms for muon reconstruction and identification have also been improved for both the High-Level Trigger and the offline reconstruction. Results of the performance of muon detectors, reconstruction and trigger, obtained using data collected at 13 TeV center-of-mass energy during the 2015 and 2016 LHC runs, will be presented. Comparison of simulation with experimental data will also be discussed where relevant. The system's state of the art performance will be shown, and the improvements foreseen to achieve excellent overall quality of muon reconstruction in CMS, in the conditions expected during the high-luminosity phase of Run-2, will be described.

  7. Observation of $B^0_s$ to $\\mu^+\\mu^-$ and first measurement of its effective lifetime with LHCb Run-2 data

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Rare decays of beauty mesons and hadrons are sensitive probes of effects beyond the Standard Model (SM). In the SM, these decays are forbidden at tree level and are therefore strongly suppressed. For example, B(s) → ll and b → (s,d) ll processes give access to many observables where effects of New Physics can be observed. The LHCb experiment is ideally suited for beauty physics due to the optimised acceptance of the detector and a high trigger efficiency, as well as an excellent invariant mass resolution and particle identification capabilities.  Recent measurements of rare decays of beauty particles will be presented, including the status of the B → mu mu analysis with Run-2 data and future prospects.

  8. The upgraded Pixel detector and the commissioning of the Inner Detector tracking of the ATLAS experiment for Run-2 at the Large Hadron Collider

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00019188; The ATLAS collaboration

    2016-01-01

    Run-2 of the Large Hadron Collider (LHC) will provide new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). The IBL is a fourth layer of pixel detectors, and has been installed in May 2014 at a radius of 3.3 cm between the existing Pixel Detector and a new smaller radius beam-pipe. The new detector, built to cope with the high radiation and expected occupancy, is the first large scale application of 3D detectors and CMOS 130~nm technology. In addition, the Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during Run-1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. Complementing detector improvements, many improvements to Inner Detector track and vertex reconstr...

  9. Calibration of the Electromagnetic Calorimeter of the ATLAS Experiment and Application to the Measurement of (BE)H Boson Couplings in the Diphoton Channel with Run 2 Data of the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00436282

    The discovery of the Higgs boson was a major success of the run 1 of the LHC. The era of precision measurements began as any deviation from the expected Standard Model (SM) value would be an indirect hint of new physics Beyond the Standard Model (BSM). This is important since no direct evidence was found. This thesis has a first focus on the calibration of the electromagnetic calorimeter of the ATLAS experiment. The final step of this calibration uses the knowledge of the lineshape of the Z boson in order to correct the measured energy of electrons and photons. Recommendations for the beginning of run 2 have been given to provide calibration constants for early analyses. Run 2 calibration constants have been computed and the performances of run 1 have been reached and improved : the systematic uncertainty on the resolution constant term of the electromagnetic calorimeter, which was dominant for the Higgs boson couplings measurement at run 1, has been divided by a factor 3. The measurement of the H boson coupl...

  10. The CMS RPC detector performance during Run-2 data taking

    CERN Document Server

    Shah, Mehar Ali

    2017-01-01

    The CMS experiment, located at the CERN Large Hadron Collider, has a redundant muon system composed by three different detector technologies Cathode Strip Chambers (in the forward regions), Drift Tubes (in the central region), and Resistive Plate Chambers (both in the central and forward regions). The RPCs are designed mainly as a trigger detector but they contribute also to the muon reconstruction. Thus the monitoring and the analysis of the system performance are necessary and essential for the final data quality. The main detector characteristics and the hit efficiency and cluster size will be presented in the paper. The stability of the system in the conditions of high instantaneous luminosity and high number of PU events will be presented in a view of history monitoring and stable trend.

  11. Implementation of the ATLAS Run 2 event data model

    CERN Document Server

    Buckley, Andrew; Elsing, Markus; Gillberg, Dag Ingemar; Koeneke, Karsten; Krasznahorkay, Attila; Moyse, Edward; Nowak, Marcin; Snyder, Scott; van Gemmeren, Peter

    2015-01-01

    During the 2013--2014 shutdown of the Large Hadron Collider, ATLAS switched to a new event data model for analysis, called the xAOD. A key feature of this model is the separation of the object data from the objects themselves (the `auxiliary store'). Rather being stored as member variables of the analysis classes, all object data are stored separately, as vectors of simple values. Thus, the data are stored in a `structure of arrays' format, while the user still can access it as an `array of structures'. This organization allows for on-demand partial reading of objects, the selective removal of object properties, and the addition of arbitrary user-defined properties in a uniform manner. It also improves performance by increasing the locality of memory references in typical analysis code. The resulting data structures can be written to ROOT files with data properties represented as simple ROOT tree branches. This talk will focus on the design and implementation of the auxiliary store and its interaction with RO...

  12. ALICE HLT Cluster operation during ALICE Run 2

    Science.gov (United States)

    Lehrbach, J.; Krzewicki, M.; Rohr, D.; Engel, H.; Gomez Ramirez, A.; Lindenstruth, V.; Berzano, D.; ALICE Collaboration

    2017-10-01

    ALICE (A Large Ion Collider Experiment) is one of the four major detectors located at the LHC at CERN, focusing on the study of heavy-ion collisions. The ALICE High Level Trigger (HLT) is a compute cluster which reconstructs the events and compresses the data in real-time. The data compression by the HLT is a vital part of data taking especially during the heavy-ion runs in order to be able to store the data which implies that reliability of the whole cluster is an important matter. To guarantee a consistent state among all compute nodes of the HLT cluster we have automatized the operation as much as possible. For automatic deployment of the nodes we use Foreman with locally mirrored repositories and for configuration management of the nodes we use Puppet. Important parameters like temperatures, network traffic, CPU load etc. of the nodes are monitored with Zabbix. During periods without beam the HLT cluster is used for tests and as one of the WLCG Grid sites to compute offline jobs in order to maximize the usage of our cluster. To prevent interference with normal HLT operations we separate the virtual machines running the Grid jobs from the normal HLT operation via virtual networks (VLANs). In this paper we give an overview of the ALICE HLT operation in 2016.

  13. Scientific highlights from ATLAS – LHC Run 2

    CERN Document Server

    Barr, Alan; The ATLAS collaboration

    2017-01-01

    We review the recent progress made at the ATLAS experiment at the LHC, concentrating particularly in the scalar sector, and on searches for new particles. Slides for invited plenary talk at Scalars 2017, Warsaw, 30 November 2017

  14. More lepton flavor violating observables for LHCb's run 2

    Directory of Open Access Journals (Sweden)

    Diego Guadagnoli

    2016-09-01

    Full Text Available The RK measurement by LHCb suggests non-standard lepton non-universality (LNU to occur in b→sℓ+ℓ− transitions, with effects in muons rather than electrons. A number of other measurements of b→sℓ+ℓ− transitions by LHCb and B-factories display disagreement with the SM predictions and, remarkably, these discrepancies are consistent in magnitude and sign with the RK effect. Non-standard LNU suggests non-standard lepton flavor violation (LFV as well, for example in B→Kℓℓ′ and Bs→ℓℓ′. There are good reasons to expect that the new effects may be larger for generations closer to the third one. In this case, the Bs→μe decay may be the most difficult to reach experimentally. We propose and study in detail the radiative counterpart of this decay, namely Bs→μeγ, whereby the chiral-suppression factor is replaced by a factor of order α/π. A measurement of this mode would be sensitive to the same physics as the purely leptonic LFV decay and, depending on experimental efficiencies, it may be more accessible. A realistic expectation is a factor of two improvement in statistics for either of the Bd,s modes.

  15. Muon reconstruction performance in ATLAS at Run2

    CERN Document Server

    Lesage, Arthur; The ATLAS collaboration

    2015-01-01

    The ATLAS muon reconstruction performance in early 2015 data at $\\sqrt{s} = 13$ TeV is presented. The muon reconstruction and isolation efficiencies are measured using dimuon resonances ($Z\\rightarrow\\mu\\mu$ and $J\\psi\\rightarrow\\mu\\mu$) as a function of the muon transverse momentum and pseudorapidity. The muon momentum corrections are also evaluated using the same dataset.

  16. Muon reconstruction performance in ATLAS at Run 2

    CERN Document Server

    Lesage, Arthur; The ATLAS collaboration

    2015-01-01

    The ATLAS muon reconstruction performance in early 2015 data at $\\sqrt{s} = 13 \\mbox{ TeV}$ is presented. The muon reconstruction and isolation efficiencies are measured using dimuon resonances ($Z\\rightarrow\\mu^{+}\\mu^{-}$ and $J/\\psi\\rightarrow\\mu^{+}\\mu^{-}$) as a function of the muon transverse momentum and pseudorapidity. The muon momentum corrections are also evaluated using the same dataset.

  17. Run 2 Upgrades to the CMS Level-1 Calorimeter Trigger

    CERN Document Server

    Kreis, B.; Cavanaugh, R.; Mishra, K.; Rivera, R.; Uplegger, L.; Apanasevich, L.; Zhang, J.; Marrouche, J.; Wardle, N.; Aggleton, R.; Ball, F.; Brooke, J.; Newbold, D.; Paramesvaran, S.; Smith, D.; Baber, M.; Bundock, A.; Citron, M.; Elwood, A.; Hall, G.; Iles, G.; Laner, C.; Penning, B.; Rose, A.; Tapper, A.; Foudas, C.; Beaudette, F.; Cadamuro, L.; Mastrolorenzo, L.; Romanteau, T.; Sauvan, J.B.; Strebler, T.; Zabi, A.; Barbieri, R.; Cali, I.A.; Innocenti, G.M.; Lee, Y.J.; Roland, C.; Wyslouch, B.; Guilbaud, M.; Li, W.; Northup, M.; Tran, B.; Durkin, T.; Harder, K.; Harper, S.; Shepherd-Themistocleous, C.; Thea, A.; Williams, T.; Cepeda, M.; Dasu, S.; Dodd, L.; Forbes, R.; Gorski, T.; Klabbers, P.; Levine, A.; Ojalvo, I.; Ruggles, T.; Smith, N.; Smith, W.; Svetek, A.; Tikalsky, J.; Vicente, M.

    2016-01-21

    The CMS Level-1 calorimeter trigger is being upgraded in two stages to maintain performance as the LHC increases pile-up and instantaneous luminosity in its second run. In the first stage, improved algorithms including event-by-event pile-up corrections are used. New algorithms for heavy ion running have also been developed. In the second stage, higher granularity inputs and a time-multiplexed approach allow for improved position and energy resolution. Data processing in both stages of the upgrade is performed with new, Xilinx Virtex-7 based AMC cards.

  18. The Run 2 ATLAS Analysis Event Data Model

    CERN Document Server

    SNYDER, S; The ATLAS collaboration; NOWAK, M; EIFERT, T; BUCKLEY, A; ELSING, M; GILLBERG, D; MOYSE, E; KOENEKE, K; KRASZNAHORKAY, A

    2014-01-01

    During the LHC's first Long Shutdown (LS1) ATLAS set out to establish a new analysis model, based on the experience gained during Run 1. A key component of this is a new Event Data Model (EDM), called the xAOD. This format, which is now in production, provides the following features: A separation of the EDM into interface classes that the user code directly interacts with, and data storage classes that hold the payload data. The user sees an Array of Structs (AoS) interface, while the data is stored in a Struct of Arrays (SoA) format in memory, thus making it possible to efficiently auto-vectorise reconstruction code. A simple way of augmenting and reducing the information saved for different data objects. This makes it possible to easily decorate objects with new properties during data analysis, and to remove properties that the analysis does not need. A persistent file format that can be explored directly with ROOT, either with or without loading any additional libraries. This allows fast interactive naviga...

  19. Muon reconstruction performance in ATLAS at Run 2

    CERN Document Server

    Lesage, Arthur; The ATLAS collaboration

    2016-01-01

    This article documents the performance of the ATLAS muon identification and reconstruction using the first LHC dataset recorded at $\\sqrt{s} = 13$ TeV in 2015. Using a large sample of $J/\\psi\\rightarrow\\mu\\mu$ and $Z\\rightarrow\\mu\\mu$ decays, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. The reconstruction efficiency is measured to be close to $99\\%$ over most of the covered phase space ($|\\eta| 2.2$, the $p_{\\text{T}}$ resolution for a typical muon from $Z\\rightarrow\\mu\\mu$ decays is $2.9\\%$ while the precision on the momentum scale for low-$p_{\\text{T}}$ muons from $J/\\psi\\rightarrow\\mu\\mu$ decays is about $0.2\\%$.

  20. ATLAS calorimeters: Run-2 performances and Phase-II upgrades

    CERN Document Server

    Boumediene, Djamel Eddine; The ATLAS collaboration

    2017-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34} cm^{-2} s^{-1}$. A Liquid Argon-lead sampling (LAr) calorimeter is employed as electromagnetic and hadronic calorimeters, except in the barrel region, where a scintillator-steel sampling calorimeter (TileCal) is used as hadronic calorimeter. This presentation gives first an overview of the detector operation and data quality, as well as of the achieved performances of the ATLAS calorimetry system. Additionally the upgrade projects of the ATLAS calorimeter system for the high luminosity phase of the LHC (HL-LHC) are presented. For the HL-LHC, the instantaneous luminosity is expected to increase up to $L \\simeq 7.5 × 10^{34} cm^{-2} s^{-1}$ and the average pile-up up to 200 interactions per bunch crossing. The major R&D item is the upgrade of the electronics for both LAr and Tile calorimeters in order to cope with longer latenc...

  1. The ATLAS Data Flow System for Run 2

    CERN Document Server

    Kazarov, Andrei; The ATLAS collaboration

    2015-01-01

    After its first shutdown, the LHC will provide pp collisions with increased luminosity and energy. In the ATLAS experiment, the Trigger and Data Acquisition (TDAQ) system has been upgraded to deal with the increased event rates. The Data Flow (DF) element of the TDAQ is a distributed hardware and software system responsible for buffering and transporting event data from the readout system to the High Level Trigger (HLT) and to the event storage. The DF has been reshaped in order to profit from the technological progress and to maximize the flexibility and efficiency of the data selection process. The updated DF is radically different from the previous implementation both in terms of architecture and expected performance. The pre-existing two level software filtering, known as L2 and the Event Filter, and the Event Building are now merged into a single process, performing incremental data collection and analysis. This design has many advantages, among which are: the radical simplification of the architecture, ...

  2. Performance of the ATLAS muon trigger in run 2

    CERN Document Server

    Morgenstern, Marcus; The ATLAS collaboration

    2017-01-01

    Triggering on muons is a crucial ingredient to fulfill the physics program of the ATLAS experiments. The ATLAS trigger system deploys a two stage strategy, a hardware-based Level-1 trigger and a software-based high-level trigger to select events of interest at a suitable recording rate. Both stages underwent upgrades to cope with the challenges in run-II data-taking at centre-of-mass energies of 13 TeV and instantaneous luminosities up to 2x10$^{34} cm^{-2}s^{-1}$. The design of the ATLAS muon triggers and their performance in proton-proton collisions at 13 TeV are presented.

  3. Collider shot setup for Run 2 observations and suggestions

    International Nuclear Information System (INIS)

    Annala, J.; Joshel, B.

    1996-01-01

    This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This is the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb -1 /week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb -1 for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent 'components': procedures, hardware, controls, and sociology. These components don't directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components

  4. Beam Loss Monitoring for Run 2 of the LHC

    CERN Document Server

    Kalliokoski, Matti; Dehning, Bernd; Domingues Sousa, Fernando; Effinger, Ewald; Emery, Jonathan; Grishin, Viatcheslav; Holzer, Eva Barbara; Jackson, Stephen; Kolad, Blazej; Nebot Del Busto, Eduardo; Picha, Ondrej; Roderick, Chris; Sapinski, Mariusz; Sobieszek, Marcin; Zamantzas, Christos

    2015-01-01

    The Beam Loss Monitoring (BLM) system of the LHC consists of over 3600 ionization chambers. The main task of the system is to prevent the superconducting magnets from quenching and protect the machine components from damage, as a result of critical beam losses. The BLM system therefore requests a beam abort when the measured dose in the chambers exceeds a threshold value. During Long Shutdown 1 (LS1) a series of modifications were made to the system. Based on the experience from Run 1 and from improved simulation models, all the threshold settings were revised, and modified where required. This was done to improve the machine safety at 7 TeV, and to reduce beam abort requests when neither a magnet quench or damage to machine components is expected. In addition to the updates of the threshold values, about 800 monitors were relocated. This improves the response to unforeseen beam losses in the millisecond time scale due to micron size dust particles present in the vacuum chamber. This contribution will discuss...

  5. Early Run 2 Hard QCD Results from the ATLAS Collaboration

    Directory of Open Access Journals (Sweden)

    Orlando Nicola

    2016-01-01

    Full Text Available We provide an overview of hard QCD results based on data collected with the ATLAS detector in proton-proton collision at √s = 13 TeV at the Large Hadron Collider. The production of high transverse momentum jets, photons and photon-pairs were studied; the inclusive jet cross section is found to agree well with the prediction of perturbative QCD calculations performed at next-to-leading accuracy. The production cross sections for W and Z bosons in their e and μ decays was measured; in general, agreement is found with the expectation of next-to-next-to leading order QCD calculations and interesting sensitivities to the proton structure functions are already observed. The top production cross sections were measured in different top decay channels and found to agree with the state of the art QCD predictions.

  6. ATLAS LAr Calorimeter Performance and Commissioning for LHC Run-2

    CERN Document Server

    Spettel, Fabian; The ATLAS collaboration

    2015-01-01

    The ATLAS detector was designed and built to study proton-proton colli- sions produced at the LHC at centre-of-mass energies up to 14 TeV and in- stantaneous luminosities up to $10^{34} \\text{cm}^{-2} \\text{s}^{-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\\eta|<3.2$, and for hadronic calorimetry in the region from $|\\eta|=1.5$ to $|\\eta|=4.9$. In the first LHC run a total luminosity of 27 $\\text{fb}^{-1}$ as been collected at center-of-mass energies of 7-8 TeV with very high operational efficiency of the LAr Calorimeters and excellent performance. The well calibrated and highly granular detector achieved its design values both in energy measurement as well as in direction resolution, which was a main ingredient for the successul discovery of a Higgs boson in the di-photon decay channel. The talk will give an overview of the procedures applied to calibrate the 180.000 read-out channels electronically as well as from using refe...

  7. ATLAS LAr calorimeter performance and LHC Run-2 commissioning

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00366625; The ATLAS collaboration

    2016-01-01

    The ATLAS detector was built to study proton-proton collisions produced by the Large Hadron Collider (LHC) at a center of mass energy of up to 14 TeV. The Liquid Argon (LAr) calorimeters are used for all electromagnetic calorimetry as well as the hadronic calorimetry in the endcap and forward regions. They have shown excellent performance during the first LHC data taking campaign, from 2010 to 2012, so-called Run 1, at a peak luminosity of $8 \\times 10^{33} \\text{cm}^{-2}\\text{s}^{-1}$. During the next run, peak luminosities of $1.5 \\times 10^{34} \\text{cm}^{-2}\\text{s}^{-1}$ and even higher are expected at a 25ns bunch spacing. Such a high collision rate may have an impact on the quality of the energy reconstruction which is attempted to be maintained at a high level using a calibration procedure described in this contribution. It also poses major challenges to the first level of the trigger system which is constrained to a maximal rate of 100 kHz. For Run-3, scheduled to start in 2019, instantaneous luminos...

  8. Implementation of the ATLAS Run 2 event data model

    Science.gov (United States)

    Buckley, A.; Eifert, T.; Elsing, M.; Gillberg, D.; Koeneke, K.; Krasznahorkay, A.; Moyse, E.; Nowak, M.; Snyder, S.; van Gemmeren, P.

    2015-12-01

    During the 2013-2014 shutdown of the Large Hadron Collider, ATLAS switched to a new event data model for analysis, called the xAOD. A key feature of this model is the separation of the object data from the objects themselves (the ‘auxiliary store’). Rather than being stored as member variables of the analysis classes, all object data are stored separately, as vectors of simple values. Thus, the data are stored in a ‘structure of arrays’ format, while the user still can access it as an ‘array of structures’. This organization allows for on-demand partial reading of objects, the selective removal of object properties, and the addition of arbitrary user- defined properties in a uniform manner. It also improves performance by increasing the locality of memory references in typical analysis code. The resulting data structures can be written to ROOT files with data properties represented as simple ROOT tree branches. This paper focuses on the design and implementation of the auxiliary store and its interaction with ROOT.

  9. First ALICE results on quarkonium production at Run 2 energies

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Quarkonium production in hadronic collisions (either proton-proton or heavy ions) has been extensively studied in both fixed target and collider experiments. It is understood as the production of a heavy quark pair (ccbar or bbar depending on the quarkonium state) in a hard scattering process which occurs early in the collision, followed by the evolution of this quark pair into a colorless bound state. While the production of the quark pair is reasonably well described by perturbative QCD calculations, its evolution into the bound state is inherently non-perturbative and is studied experimentally in pp collisions. In heavy ion collisions on the other hand, quarkonia are used to probe the properties of the medium formed in the collision and in particular that of the quark-gluon plasma, via competing mechanisms such as color screening, thermal dissociation or recombination, as well as so-called cold nuclear matter effects such as shadowing, gluon saturation or energy loss. The first ALICE results on quarkonium...

  10. ATLAS Event Display: Run 2 Heavy Ion Collision

    CERN Multimedia

    ATLAS Collaboration

    2018-01-01

    Event display of a lead-lead collision with a large transverse momentum photon. In this event, the expected balancing jet is not visible by eye, consistent with it being degraded by its passage through the quark-gluon plasma.

  11. ATLAS Calorimeters: Run-2 performance and Phase-II upgrade

    CERN Document Server

    Boumediene, Djamel Eddine; The ATLAS collaboration

    2017-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 10^{34} cm^{−2} s^{−1}. A liquid argon (LAr)-lead sampling calorimeter is employed as electromagnetic calorimeter and hadronic calorimter, except in the barrel region, where a scintillator-steel sampling calorimeter (TileCal) is used as hadronic calorimter. This presentation will give first an overview of the detector operation and data quality, as well as the achieved performance of the ATLAS calorimetry system. Additionally, the upgrade projects of the ATLAS calorimeter system for the high luminosity phase of the LHC (HL-LHC) will be presented. For the HL-LHC, the instantaneous luminosity is expected to increase up to L ≃ 7.5 × 10^{34} cm^{−2} s^{−1} and the average pile-up up to 200 interactions per bunch crossing. The major R&D item is the upgrade of the electronics for both LAr and Tile calorimeters in order to cope wit...

  12. First Run 2 Searches for Exotica at CMS

    CERN Document Server

    Başeğmez du Pree, S

    2016-01-01

    An overview of the first results of the experimental searches for exotica at the CMS experiment with 13 TeV collision data is presented. The results cover various models with different topologies such as searches for new heavy resonances, extra space dimensions, black holes and dark matter. The analysis results with 13 TeV data are emphasized, corresponding to an integrated luminosity in the range of 2.1–2.8 fb

  13. The ATLAS Level-1 Topological Trigger performance in Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00120419; The ATLAS collaboration

    2017-01-01

    The Level-1 trigger is the first event rate reducing step in the ATLAS detector trigger system, with an output rate of up to 100 kHz and decision latency smaller than 2.5 μs. During the LHC shutdown after Run 1, the Level-1 trigger system was upgraded at hardware, firmware and software levels. In particular, a new electronics sub-system was introduced in the real-time data processing path: the Level-1 Topological trigger system. It consists of a single electronics shelf equipped with two Level-1 Topological processor blades. They receive real-time information from the Level-1 calorimeter and muon triggers, which is processed to measure angles between trigger objects, invariant masses or other kinematic variables. Complementary to other requirements, these measurements are taken into account in the final Level-1 trigger decision. The system was installed and commissioning started in 2015 and continued during 2016. As part of the commissioning, the decisions from individual algorithms were simulated and compar...

  14. Jet Mass Reconstruction with the ATLAS Detector in Run 2

    CERN Document Server

    Jansky, Roland; The ATLAS collaboration

    2016-01-01

    The details of the ATLAS jet mass reconstruction and calibration are presented. In particular, the jet mass scale is calibrated using Monte Carlo simulation for large-radius groomed jets. Corresponding uncertainties are presented. An alternative jet mass definition that incorporates tracking information called the track-assisted jet mass is introduced and its performance is compared to the traditional calorimeter-only jet mass definition. An outlook on future improvments is also given.

  15. Run 2 analysis computing for CDF and D0

    International Nuclear Information System (INIS)

    Fuess, S.

    1995-11-01

    Two large experiments at the Fermilab Tevatron collider will use upgraded of running. The associated analysis software is also expected to change, both to account for higher data rates and to embrace new computing paradigms. A discussion is given to the problems facing current and future High Energy Physics (HEP) analysis computing, and several issues explored in detail

  16. 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...

  17. 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...

  18. Higgs Tasting Workshop 2016: Higgs and flavor in the LHC Run 2 era

    CERN Document Server

    2016-01-01

    The discovery of a Higgs particle by the LHC experiments has launched the exploration of electroweak symmetry breaking and potentially opened a new window into beyond Standard Model physics. Measurements of Higgs boson properties during Run 1 of the LHC are broadly consistent with the Standard Model predictions, although they leave significant room for New Physics contributions. At the same time, a number of exciting anomalies in low-energy precision flavor observables have cumulated over the years, whose potential implications are yet to be fully gauged. One of the most pressing questions in high energy physics is the origin of flavor and it is undeniably linked in an intimate way to the physics of the Higgs boson. The Standard Model comes with definite predictions for the structure of the couplings between the Higgs boson and the fermions. Probing this structure or observing any deviation will have long-reaching implications on our understanding on how Nature works at its most fundamental level, including c...

  19. Top-squark in natural SUSY under current LHC run-2 data

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chengcheng [University of Tokyo, Kavli IPMU (WPI), UTIAS, Kashiwa (Japan); Ren, Jie [Chinese Academy of Sciences, Computer Network Information Center, Beijing (China); Wu, Lei [Nanjing Normal University, Department of Physics and Institute of Theoretical Physics, Nanjing, Jiangsu (China); The University of Sydney, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Sydney, NSW (Australia); Yang, Jin Min [Chinese Academy of Sciences, Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Beijing (China); Zhang, Mengchao [Institute for Basic Science (IBS), Center for Theoretical Physics and Universe, Taejon (Korea, Republic of)

    2017-02-15

    We utilize the recent LHC-13 TeV data to study the lower mass bound on the top-squark (stop) in natural supersymmetry. We recast the LHC sparticle inclusive search of (≥1)jets + E{sub T} with α{sub T} variable, the direct stop pair search (1-lepton channel and all-hadronic channel) and the monojet analyses. We find that these searches are complementary depending on stop and higgsino masses: for a heavy stop the all-hadronic stop pair search provides the strongest bound, for an intermediate stop the inclusive SUSY analysis with α{sub T} variable is most efficient, while for a compressed stop-higgsino scenario the monojet search plays the key role. Finally, the lower mass bound on a stop is: (1) 320 GeV for compressed stop-higgsino scenario (mass splitting less than 20 GeV); (2) 765 (860) GeV for higgsinos lighter than 300 (100) GeV. (orig.)

  20. Search for a scalar dimuon resonance with LHC Run2 data from the ATLAS detector

    Energy Technology Data Exchange (ETDEWEB)

    Hoenig, Georg Friedrich

    2017-04-21

    This analysis presents the search for a Higgs-like Boson decaying into a pair of oppositely charged muons. The invariant mass spectrum of the dimuon system is investigated for a peak above the Z-resonance arising from H→μμ decays. The two considered production mechanisms for the Higgs boson are gluon-gluon fusion (ggF) and vector boson fusion (VBF), the latter featuring two additional jets in its final state. The dominant background arises from the Z/Drell-Yan process. This thesis uses data taken by the ATLAS detector at the LHC during proton-proton collisions at a center of mass energy of 13 TeV in 2015. The amount of data analyzed corresponds to an integrated luminosity of 3.2 fb{sup -1}. Events are selected on the basis of their kinematic features into a total of seven regions with enhanced signal contribution. One of the region targets primarily VBF production, while the others are optimized to take advantage of varying mass resolution of the detector. The shape of the background spectrum is studied based on Monte Carlo simulations and a parametrized fit function is developed to describe it. In addition, the shape and normalization of the signal peak for the set of available simulated Higgs mass points is modeled by another parametrized fit function. Interpolating the associated parameters yields signal templates for arbitrary Higgs mass hypotheses. A combined fit of the signal and background model to data is performed in the seven signal regions to extract both the background estimation and the measured signal. No significant excess above the expectation from the Standard Model without the H→μμ decay has been observed in the analyzed data. A 95% confidence exclusion limit is set on the signal strength as a function of Higgs mass in the range between 115 GeV and 145 GeV. This result is re-interpreted as a limit on cross section times branching ratio for the decay of a more general scalar boson decaying into muon pairs.

  1. The CMS electron and photon trigger for the LHC Run 2

    CERN Document Server

    Beschi, Andrea

    2017-01-01

    to optimally reconstruct the electromagnetic trigger objects. The performance of the new trigger system will be presented, based on proton-proton collision data collected in Run II. The selection techniques used to trigger efficiently will be presented, along with the strategies employed to guarantee efficient triggering for new resonances and other new physics signals invo...

  2. Development, validation and integration of the ATLAS Trigger System software in Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00377077; The ATLAS collaboration

    2017-01-01

    The trigger system of the ATLAS detector at the LHC is a combination of hardware, firmware, and software, associated to various sub-detectors that must seamlessly cooperate in order to select one collision of interest out of every 40,000 delivered by the LHC every millisecond. These proceedings discuss the challenges, organization and work flow of the ongoing trigger software development, validation, and deployment. The goal of this development is to ensure that the most up-to-date algorithms are used to optimize the performance of the experiment. The goal of the validation is to ensure the reliability and predictability of the software performance. Integration tests are carried out to ensure that the software deployed to the online trigger farm during data-taking run as desired. Trigger software is validated by emulating online conditions using a benchmark run and mimicking the reconstruction that occurs during normal data-taking. This exercise is computationally demanding and thus runs on the ATLAS high per...

  3. Development, Validation and Integration of the ATLAS Trigger System Software in Run 2

    CERN Document Server

    Keyes, Robert; The ATLAS collaboration

    2016-01-01

    The trigger system of the ATLAS detector at the LHC is a combination of hardware, firmware and software, associated to various sub-detectors that must seamlessly cooperate in order to select 1 collision of interest out of every 40,000 delivered by the LHC every millisecond. This talk will discuss the challenges, workflow and organization of the ongoing trigger software development, validation and deployment. This development, from the top level integration and configuration to the individual components responsible for each sub system, is done to ensure that the most up to date algorithms are used to optimize the performance of the experiment. This optimization hinges on the reliability and predictability of the software performance, which is why validation is of the utmost importance. The software adheres to a hierarchical release structure, with newly validated releases propagating upwards. Integration tests are carried out on a daily basis to ensure that the releases deployed to the online trigger farm duri...

  4. Performance of the ATLAS Calorimeters and Commissioning for LHC Run-2

    CERN Document Server

    Rossetti, Valerio; The ATLAS collaboration

    2015-01-01

    The ATLAS general-purpose experiment at the Large Hadron Collider (LHC) is equipped with electromagnetic and hadronic liquid-argon (LAr) calorimeters and a hadronic scintillator-steel sampling calorimeter (TileCal) for measuring energy and direction of final state particles in the pseudorapidity range $|\\eta| < 4.9$. The calibration and performance of the calorimetry system was established during beam tests, cosmic ray muon measurements and in particular the first three years of pp collision data-taking. During this period, referred to as Run-1, approximately 27~fb$^{-1}$ of data have been collected at the center-of-mass energies of 7 and 8~TeV. Results on the calorimeter operation, monitoring and data quality, as well as their performance will be presented, including the calibration and stability of the electromagnetic scale, response uniformity and time resolution. These results demonstrate that the LAr and Tile calorimeters perform excellently within their design requirements. The calorimetry system thu...

  5. Search for a scalar dimuon resonance with LHC Run2 data from the ATLAS detector

    International Nuclear Information System (INIS)

    Hoenig, Georg Friedrich

    2017-01-01

    This analysis presents the search for a Higgs-like Boson decaying into a pair of oppositely charged muons. The invariant mass spectrum of the dimuon system is investigated for a peak above the Z-resonance arising from H→μμ decays. The two considered production mechanisms for the Higgs boson are gluon-gluon fusion (ggF) and vector boson fusion (VBF), the latter featuring two additional jets in its final state. The dominant background arises from the Z/Drell-Yan process. This thesis uses data taken by the ATLAS detector at the LHC during proton-proton collisions at a center of mass energy of 13 TeV in 2015. The amount of data analyzed corresponds to an integrated luminosity of 3.2 fb -1 . Events are selected on the basis of their kinematic features into a total of seven regions with enhanced signal contribution. One of the region targets primarily VBF production, while the others are optimized to take advantage of varying mass resolution of the detector. The shape of the background spectrum is studied based on Monte Carlo simulations and a parametrized fit function is developed to describe it. In addition, the shape and normalization of the signal peak for the set of available simulated Higgs mass points is modeled by another parametrized fit function. Interpolating the associated parameters yields signal templates for arbitrary Higgs mass hypotheses. A combined fit of the signal and background model to data is performed in the seven signal regions to extract both the background estimation and the measured signal. No significant excess above the expectation from the Standard Model without the H→μμ decay has been observed in the analyzed data. A 95% confidence exclusion limit is set on the signal strength as a function of Higgs mass in the range between 115 GeV and 145 GeV. This result is re-interpreted as a limit on cross section times branching ratio for the decay of a more general scalar boson decaying into muon pairs.

  6. Heavy-flavour jet identification at the CMS experiment for Run 2

    CERN Document Server

    Verzetti, Mauro

    2016-01-01

    A review of these new developments is presented, together with their performance on proton-proton collision data recorded by the CMS detector at a centre-of-mass energy of $\\sqrt{s} = 13$ TeV during 2015 and 2016.

  7. Comparison of CMS Resistive Plate Chambers performance during LHC RUN-1 and RUN-2

    CERN Document Server

    INSPIRE-00207984

    2016-01-01

    The Resistive Plate Chambers detector system at the CMS experiment at the LHC provides robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region < 1.6. The main detector parameters and environmental conditions are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC with center-of-mass energy of 13 TeV. First results of overall detector stability with 2015 data and comparisons with data from the LHC RUN-1 period at 8 TeV are presented.

  8. Comparison of CMS Resistive Plate Chambers performance during LHC RUN-1 and RUN-2

    CERN Document Server

    Shah, Mehar Ali

    2016-01-01

    The Resistive Plate Chambers detector system at the CMS experiment at the LHC provides robustness and redundancy to the muon trigger. A total of 1056 double-gap chambers cover the pseudo-rapidity region lt 1.6. The main detector parameters and environmental conditions are constantly and closely monitored to achieve operational stability and high quality data in the harsh conditions of the second run period of the LHC with center-of-mass energy of 13 TeV. First results of overall detector stability with 2015 data and comparisons with data from the LHC RUN-1 period at 8 TeV are presented.

  9. Calibration and Performance of the ATLAS Tile Calorimeter during the LHC Run 2

    CERN Document Server

    Faltova, Jana; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) covers the central part of the ATLAS experiment and provides important information for the reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling hadronic calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by charged particles in tiles is transmitted by wavelength-shifting fibres to photomultipliers, where it is converted to electric pulses and further processed by the on-detector electronics located in the outermost part of the calorimeter. The TileCal calibration system comprises Cesium radioactive sources, laser, charge injection elements and an integrator based readout system. Combined information from all systems allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitisation. The performance of the calorimeter is established with the large sample of the proton-proton collisions. Isolated hadrons a...

  10. The ATLAS Trigger Menu design for higher luminosities in Run 2

    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 large 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 the presence of energetic leptons, photons, jets or large missing energy. The trigger system exploits topological information, as well as multivariate methods to carry out the necessary physics filtering for the many analyses that are pursued by the ATLAS community. In total, the ATLAS online selection consists of nearly two thousand individual triggers. A Trigger Menu is the compilation of these triggers, it specifies the physics selection algorithms to be used during data taking and the rate and bandwidth a given trigger is allocated. Trigger menus must reflect the physics goals of the collaboration for a given run, but also take into con...

  11. Bos taurus strain:dairy beef (cattle): 1000 Bull Genomes Run 2, Bovine Whole Genome Sequence

    NARCIS (Netherlands)

    Bouwman, A.C.; Daetwyler, H.D.; Chamberlain, Amanda J.; Ponce, Carla Hurtado; Sargolzaei, Mehdi; Schenkel, Flavio S.; Sahana, Goutam; Govignon-Gion, Armelle; Boitard, Simon; Dolezal, Marlies; Pausch, Hubert; Brøndum, Rasmus F.; Bowman, Phil J.; Thomsen, Bo; Guldbrandtsen, Bernt; Lund, Mogens S.; Servin, Bertrand; Garrick, Dorian J.; Reecy, James M.; Vilkki, Johanna; Bagnato, Alessandro; Wang, Min; Hoff, Jesse L.; Schnabel, Robert D.; Taylor, Jeremy F.; Vinkhuyzen, Anna A.E.; Panitz, Frank; Bendixen, Christian; Holm, Lars-Erik; Gredler, Birgit; Hozé, Chris; Boussaha, Mekki; Sanchez, Marie Pierre; Rocha, Dominique; Capitan, Aurelien; Tribout, Thierry; Barbat, Anne; Croiseau, Pascal; Drögemüller, Cord; Jagannathan, Vidhya; Vander Jagt, Christy; Crowley, John J.; Bieber, Anna; Purfield, Deirdre C.; Berry, Donagh P.; Emmerling, Reiner; Götz, Kay Uwe; Frischknecht, Mirjam; Russ, Ingolf; Sölkner, Johann; Tassell, van Curtis P.; Fries, Ruedi; Stothard, Paul; Veerkamp, R.F.; Boichard, Didier; Goddard, Mike E.; Hayes, Ben J.

    2014-01-01

    Whole genome sequence data (BAM format) of 234 bovine individuals aligned to UMD3.1. The aim of the study was to identify genetic variants (SNPs and indels) for downstream analysis such as imputation, GWAS, and detection of lethal recessives. Additional sequences for later 1000 bull genomes runs can

  12. arXiv Simulation Study of an LWFA-based Electron Injector for AWAKE Run 2

    CERN Document Server

    Williamson, B.; Doebert, S.; Karsch, S.; Muggli, P.

    The AWAKE experiment aims to demonstrate preservation of injected electron beam quality during acceleration in proton-driven plasma waves. The short bunch duration required to correctly load the wakefield is challenging to meet with the current electron injector system, given the space available to the beamline. An LWFA readily provides short-duration electron beams with sufficient charge from a compact design, and provides a scalable option for future electron acceleration experiments at AWAKE. Simulations of a shock-front injected LWFA demonstrate a 43 TW laser system would be sufficient to produce the required charge over a range of energies beyond 100 MeV. LWFA beams typically have high peak current and large divergence on exiting their native plasmas, and optimisation of bunch parameters before injection into the proton-driven wakefields is required. Compact beam transport solutions are discussed.

  13. Development, Validation and Integration of the ATLAS Trigger System Software in Run 2

    Science.gov (United States)

    Keyes, Robert; ATLAS Collaboration

    2017-10-01

    The trigger system of the ATLAS detector at the LHC is a combination of hardware, firmware, and software, associated to various sub-detectors that must seamlessly cooperate in order to select one collision of interest out of every 40,000 delivered by the LHC every millisecond. These proceedings discuss the challenges, organization and work flow of the ongoing trigger software development, validation, and deployment. The goal of this development is to ensure that the most up-to-date algorithms are used to optimize the performance of the experiment. The goal of the validation is to ensure the reliability and predictability of the software performance. Integration tests are carried out to ensure that the software deployed to the online trigger farm during data-taking run as desired. Trigger software is validated by emulating online conditions using a benchmark run and mimicking the reconstruction that occurs during normal data-taking. This exercise is computationally demanding and thus runs on the ATLAS high performance computing grid with high priority. Performance metrics ranging from low-level memory and CPU requirements, to distributions and efficiencies of high-level physics quantities are visualized and validated by a range of experts. This is a multifaceted critical task that ties together many aspects of the experimental effort and thus directly influences the overall performance of the ATLAS experiment.

  14. Start of run2 physics at the Large Hadron Collider (LHC)

    CERN Multimedia

    Brice, Maximilien

    2015-01-01

    Images from the CERN Control Centre (CCC), where operators control the LHC, and from the control rooms of the ALICE, ATLAS, CMS and LHCb experiments, where operators control huge detectors that capture data from collisions between beams of protons in the LHC.

  15. Calibration and Performance of the ATLAS Tile Calorimeter During the LHC Run 2

    CERN Document Server

    Cerda Alberich, Leonor; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) is the hadronic sampling calorimeter of ATLAS experiment at the Large Hadron Collider (LHC). TileCal uses iron absorbers and scintillators as active material and it covers the central region |η| < 1.7. Jointly with the other calorimeters it is designed for measurements of hadrons, jets, tau-particles and missing transverse energy. It also assists in muon identification. TileCal is regularly monitored and calibrated by several different calibration systems: a Cs radioactive source that illuminates the scintillating tiles directly, a laser light system to directly test the PMT response, and a charge injection system (CIS) for the front-end electronics. These calibrations systems, in conjunction with data collected during proton-proton collisions, provide extensive monitoring of the instrument and a means for equalizing the calorimeter response at each stage of the signal propagation. The performance of the calorimeter has been established with cosmic ray muons and the large sa...

  16. Validation of Monte Carlo event generators in the ATLAS Collaboration for LHC Run 2

    CERN Document Server

    The ATLAS collaboration

    2016-01-01

    This note reviews the main steps followed by the ATLAS Collaboration to validate the properties of particle-level simulated events from Monte Carlo event generators in order to ensure the correctness of all event generator configurations and production samples used in physics analyses. A central validation procedure is adopted which permits the continual validation of the functionality and the performance of the ATLAS event simulation infrastructure. Revisions and updates of the Monte Carlo event generators are also monitored. The methodology behind the validation and tools developed for that purpose, as well as various usage cases, are presented. The strategy has proven to play an essential role in identifying possible problems or unwanted features within a restricted timescale, verifying their origin and pointing to possible bug fixes before full-scale processing is initiated.

  17. Drying results of K-Basin fuel element 3128W (run 2)

    International Nuclear Information System (INIS)

    Abrefah, J.; Klinger, G.S.; Oliver, B.M.; Marshman, S.C.; MacFarlan, P.J.; Ritter, G.A.; Flament, T.A.

    1998-07-01

    An N-Reactor outer fuel element that had been stored underwater in the Hanford 100 Area K-East Basin was subjected to a combination of low- and high-temperature vacuum drying treatments. These studies are part of a series of tests being conducted by Pacific Northwest National Laboratory on the drying behavior of N-Reactor spent nuclear fuel elements removed from both the K-West and K-East Basins. The drying test series was designed to test fuel elements that ranged from intact to severely damaged. The fuel element discussed in this report was removed from an open K-East canister (3128W) during the first fuel selection campaign conducted in 1995, and has remained in wet storage in the Postirradiation Testing Laboratory (PTL, 327 Building) since that time. Although it was judged to be breached during in-basin (i.e., K-Basin) examinations, visual inspection of this fuel element in the hot cell indicated that it was likely intact. Some scratches on the coating covering the cladding were identified before the furnace test. The drying test was conducted in the Whole Element Furnace Testing System located in G-Cell within the PTL. This test system is composed of three basic systems: the in-cell furnace equipment, the system gas loop, and the analytical instrument package. Element 3128W was subjected to the drying processes based on those proposed under the Integrated Process Strategy, which included a hot drying step. Results of the Pressure Rise and Gas Evolution Tests suggest that most of the free water in the system was released during the extended CVD cycle (68 hr versus 8 hr for the first run). An additional ∼0.34 g of water was released during the subsequent HVD phase, characterized by multiple water release peaks, with a principle peak at ∼180 C. This additional water is attributed to decomposition of a uranium hydrate (UO 4 ·4H 2 O/UO 4 ·2H 2 O) coating that was observed to be covering the surface of the fuel element to a thickness of ∼1.6 mg/cm 2 . A limited quantity of hydrogen (∼9 mg) was also released during HVD, mainly at temperatures above 300 C, likely from hydride decomposition

  18. The ATLAS Data Flow system in Run2: Design and Performance

    CERN Document Server

    Rifki, Othmane; The ATLAS collaboration

    2016-01-01

    The ATLAS detector uses a real time selective triggering system to reduce the high interaction rate from 40 MHz to its data storage capacity of 1 kHz. A hardware first level trigger limits the rate to 100 kHz and a software high level trigger selects events for offline analysis. By building on the experience gained during the successful first run of the LHC, the ATLAS Trigger and Data Acquisition system has been simplified and upgraded to take advantage of state of the art technologies. The Dataflow element of the system is composed of distributed hardware and software responsible for buffering and transporting event data from the Readout system to the High Level Trigger and to the event storage. This system has been reshaped in order to maximize the flexibility and efficiency of the data selection process. The updated dataflow is different from the previous implementation both in terms of architecture and performance. The biggest difference is within the high level trigger, where the merger of region-of-inte...

  19. Calibration and performance of the ATLAS Tile Calorimeter during the Run 2 of the LHC

    CERN Document Server

    Solovyanov, Oleg; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) is a hadronic calorimeter covering the central region of the ATLAS experiment at the LHC. It is a non-compensating sampling calorimeter comprised of steel and scintillating plastic tiles which are read-out by photomultiplier tubes (PMTs). The TileCal is regularly monitored and calibrated by several different calibration systems: a Cs radioactive source that illuminates the scintillating tiles directly, a laser light system to directly test the PMT response and a charge injection system (CIS) for the front-end electronics. These calibrations systems, in conjunction with data collected during proton-proton collisions, provide extensive monitoring of the instrument and a means for equalising the calorimeter response at each stage of the signal propagation. The performance of the calorimeter and its calibration has been established with cosmic ray muons and the large sample of the proton-proton collisions to study the energy response at the electromagnetic scale, probe of the hadron...

  20. Calibration and Performance of the ATLAS Tile Calorimeter During the Run 2 of the LHC

    CERN Document Server

    Solovyanov, Oleg; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) is a hadronic calorimeter covering the central region of the ATLAS experiment at the LHC. It is a non-compensating sampling calorimeter comprised of steel and scintillating plastic tiles which are read-out by photomultiplier tubes (PMT). The TileCal is regularly monitored and calibrated by several di erent calibration systems: a Cs radioactive source that illuminates the scintillating tiles directly, a laser light system to directly test the PMT response, and a charge injection system (CIS) for the front-end electronics. These calibrations systems, in conjunction with data collected during proton-proton collisions, provide extensive monitoring of the instrument and a means for equalizing the calorimeter response at each stage of the signal propagation. The performance of the calorimeter and its calibration has been established with cosmic ray muons and the large sample of the proton-proton collisions to study the energy response at the electromagnetic scale, probe of the hadroni...

  1. Exploiting CMS data popularity to model the evolution of data management for Run-2 and beyond

    CERN Document Server

    Bonacorsi, D; Giordano, D; Girone, M; Neri, M; Magini, N; Kuznetsov, V; Wildish, T

    2015-01-01

    During the LHC Run-1 data taking, all experiments collected large data volumes from proton-proton and heavy-ion collisions. The collisions data, together with massive volumes of simulated data, were replicated in multiple copies, transferred among various Tier levels, transformed/slimmed in format/content. These data were then accessed (both locally and remotely) by large groups of distributed analysis communities exploiting the WorldWide LHC Computing Grid infrastructure and services. While efficient data placement strategies - together with optimal data redistribution and deletions on demand - have become the core of static versus dynamic data management projects, little effort has so far been invested in understanding the detailed data-access patterns which surfaced in Run-1. These patterns, if understood, can be used as input to simulation of computing models at the LHC, to optimise existing systems by tuning their behaviour, and to explore next-generation CPU/storage/network co-scheduling solutions. This...

  2. Multi-jet event recorded by the CMS detector (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2015-01-01

    This image shows a high-multiplicity collision event observed by the CMS detector in the search for microscopic black holes, in collision data recorded in 2015. The event contains 12 jets with transverse momenta greater than 50 GeV each, and the mass of this system is 6.4 TeV. The scalar sum of the transverse energies of all energetic objects in the event (including missing transverse energy) is 5.4 TeV.

  3. The Control and Configuration Software of the ATLAS Data Acquisition System: Upgrades for LHC Run 2

    CERN Document Server

    Aleksandrov, Igor; The ATLAS collaboration; Avolio, Giuseppe; Caprini, Mihai; Corso-Radu, Alina; D'ascanio, Matteo; De Castro Vargas Fernandes, Julio; Kazarov, Andrei; Kolobara, Bernard; Lankford, Andrew; Laurent, Florian; Lehmann Miotto, Giovanna; Magnoni, Luca; Papaevgeniou, Lykourgos; Ryabov, Yury; Santos, Alejandro; Seixas, Jose; Soloviev, Igor; Unel, Gokhan; Yasu, Yoshiji

    2016-01-01

    The Trigger and Data Acquisition (TDAQ) system of the ATLAS detector at the Large Hadron Collider (LHC) at CERN is composed of a large number of distributed hardware and software components which in a coordinated manner provide the data-taking functionality of the overall system. The Controls and Configuration (CC) software offers services to configure, control and monitor the TDAQ system. It is a framework which provides essentially the glue that holds the various sub-systems together. While the overall architecture, established at the end of the 90’s, has proven to be solid and flexible, many software components (from core services, like the Run Control and the error management system, to end- user tools) have undergone a complete redesign or re-implementation during the LHC’s Long Shutdown I period. The upgrades were driven by the need to fold-in the additional requirements that appeared in the course of LHC’s Run 1, to profit from new technologies and to re-factorize and cleanup the code. This paper...

  4. ATLAS Level-1 Topological Trigger : Commissioning and Validation in Run 2

    CERN Document Server

    AUTHOR|(SzGeCERN)788741; The ATLAS collaboration; Hong, Tae Min

    2017-01-01

    The ATLAS experiment has recently commissioned a new hardware component of its first-level trigger: the topological processor (L1Topo). This innovative system, using state-of-the-art FPGA processors, selects events by applying kinematic and topological requirements on candidate objects (energy clusters, jets, and muons) measured by calorimeters and muon sub-detectors. Since the first-level trigger is a synchronous pipelined system, such requirements are applied within a latency of 200ns. We will present the first results from data recorded using the L1Topo trigger; these demonstrate a significantly improved background event rejection, thus allowing for a rate reduction without efficiency loss. This improvement has been shown for several physics processes leading to low-$P_{T}$ leptons, including $H\\to{}\\tau{}\\tau{}$ and $J/\\Psi\\to{}\\mu{}\\mu{}$. In addition, we will discuss the use of an accurate L1Topo simulation as a powerful tool to validate and optimize the performance of this new trigger system. To reach ...

  5. Performance of the ATLAS track reconstruction algorithms in dense environments in LHC Run 2

    Czech Academy of Sciences Publication Activity Database

    Aaboud, M.; Aad, G.; Abbott, B.; Chudoba, Jiří; Hejbal, Jiří; Hladík, Ondřej; Jakoubek, Tomáš; Kepka, Oldřich; Kroll, Jiří; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Penc, Ondřej; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek

    2017-01-01

    Roč. 77, č. 10 (2017), s. 1-30, č. článku 673. ISSN 1434-6044 Institutional support: RVO:68378271 Keywords : tracks * multiplicity * new physics * efficiency * pixel * data analysis method * experimental results * 13000 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 5.331, year: 2016

  6. Calibration and Performance of the ATLAS Tile Calorimeter During the LHC Run 2

    CERN Document Server

    Klimek, Pawel; The ATLAS collaboration

    2018-01-01

    The Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment and provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. It also assists in muon identification. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photomultiplier tubes (PMTs). The readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read out by two PMTs in parallel. TileCal exploits several calibration systems: a Cs radioactive source that illuminates the scintillating tiles directly, a laser light system to directly test the PMT response, and a charge injection system (CIS) for the front-end electronics. These systems together with data collected during proton-proton collisions provide extensive monitoring of the instrument and a means...

  7. Physics performances with the new ATLAS Level-1 Topological trigger in Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00414333; The ATLAS collaboration

    2016-01-01

    The ATLAS trigger system aims at reducing the 40 MHz proton-proton collision event rate to a manageable event storage rate of 1 kHz, preserving events valuable for physics analysis. The Level-1 trigger is the first rate-reducing step in the ATLAS trigger system, with an output rate of 100 kHz and decision latency of less than 2.5 micro seconds. It is composed of the calorimeter trigger, muon trigger and central trigger processor. During the last upgrade, a new electronics element was introduced to Level-1: The Topological Processor System. It will make it possible to use detailed realtime information from the Level-1 calorimeter and muon triggers, processed in individual state of the art FPGA processors to determine angles between jets and/or leptons and calculate kinematic variables based on lists of selected/sorted objects. More than one hundred VHDL algorithms are producing trigger outputs to be incorporated into the central trigger processor. This information will be essential to improve background reject...

  8. ATLAS Calorimeter system: Run-2 performance, Phase-1 and Phase-2 upgrades

    CERN Document Server

    Starz, Steffen; The ATLAS collaboration

    2018-01-01

    The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to 10^{34} cm^{−2} s^{−1}. A liquid argon-lead sampling calorimeter (LAr) is employed as electromagnetic calorimeter and hadronic calorimeter, except in the barrel region, where a scintillator-steel sampling calorimeter (TileCal) is used as hadronic calorimeter. ATLAS recorded 87 fb^{-1} of data at a center-of-mass energy of 13 TeV between 2015 and 2017. In order to achieve the level-1 acceptance rate of 100 kHz, certain adjustments have been performed. The calorimetry system performed accordingly to its design values and have played a crucial role in the ATLAS physics programme. This contribution will give an overview of the detector operation, monitoring and data quality, as well as the achieved performance, including the calibration and stability of the energy scale, noise level, response uniformity and time resolution of the ATLAS cal...

  9. ATLAS Inner Tracker Performance at the Beginning of the LHC Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00223897; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment performs studies of proton-proton collisions at the Large Hadron Collider (LHC) at CERN. The Inner Detector is a part of the ATLAS apparatus placed nearest the interaction point, designed to measure charged particles momenta and their trajectories, and to reconstruct vertices of decays of physics objects created in the collisions. During the LHC technical stop 2013-2015, the Inner Detector underwent several upgrades and improvements, most notably an additional Pixel Detector layer was installed. This document describes the improvements done in the Inner Detector and its combined performance in the first year of data taking after the LHC restart in 2015.

  10. The ATLAS Run-2 Trigger: Design, Menu, Performance and Operational Aspects

    CERN Document Server

    Martin, Tim; The ATLAS collaboration

    2016-01-01

    The LHC, at design capacity, has a bunch-crossing rate of 40 MHz whereas the ATLAS experiment at the LHC has an average recording rate of about 1000 Hz. To reduce the rate of events but still maintain a high efficiency of selecting rare events such as physics signals beyond the Standard Model, a two-level trigger system is used in ATLAS. 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 system 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 the instantaneous luminosity of the LHC, the design limits of the ATLAS detector and the o...

  11. 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...

  12. The ATLAS Run-2 Trigger: Design, Menu, Performance and Operational Aspects

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00219584; The ATLAS collaboration

    2016-01-01

    The LHC, at design capacity, has a bunch-crossing rate of 40 MHz whereas the ATLAS experiment has an average recording rate of about 1000 Hz. To reduce the rate of events but still maintain high efficiency of selecting rare events such as physics signals beyond the Standard Model, a two-level trigger system is used in ATLAS. 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 informations, 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 detecto...

  13. Performance of Top Quark and W Boson Tagging in Run 2 with ATLAS

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    The performance of hadronically-decaying top-quark and $W$-boson taggers in $pp$ collisions at $\\sqrt{s}$ = 13 TeV recorded by the ATLAS experiment at the Large Hadron Collider is presented. A set of techniques, including some new to the data recorded in 2015 and 2016, are studied to determine a set of optimal cut-based taggers for use in physics analyses. A further extension is made to study the utility of combinations of substructure observables as a multivariate tagger using boosted decision trees and deep neural networks in comparison with taggers based on two-variable combinations. The performance of these taggers is studied with the data collected during 2015 and 2016 in $t\\bar{t}$, dijet and $\\gamma$ + jet event topologies.

  14. Performance of the CMS Jets and Missing Transverse Energy Trigger at LHC Run 2

    CERN Document Server

    Nachtman, Jane; Dordevic, Milos; Kaya, Mithat; Kaya, Ozlem; Kirschenmann, Henning; Zhang, Fengwangdong

    2017-01-01

    In preparation for collecting proton-proton collisions from the LHC at a center-of-mass energy of 13 TeV and rate of 40MHz with increasing instantaneous luminosity, the CMS collaboration prepared an array of triggers utilizing jets and missing transverse energy for searches for new physics at the energy frontier as well as for SM precision measurements. The CMS trigger system must be able to sift through the collision events in order to extract events of interest at a rate of 1kHz, applying sophisticated algorithms adapted for fast and effective operation. Particularly important is the calibration of the trigger objects, as corrections to the measured energy may be substantial. Equally important is the development of improved reconstruction algorithms to mitigate negative effects due to high numbers of overlapping proton-proton collisions and increased levels of beam-related effects. Work by the CMS collaboration on upgrading the high-level trigger for jets and missing transverse energy for the upgraded LHC o...

  15. Calibration and Performance of the ATLAS Tile Calorimeter During the LHC Run 2

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00221190; The ATLAS collaboration

    2017-01-01

    The Tile Calorimeter (TileCal) covers the central part of the ATLAS experiment and provides important information for the reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling hadronic calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by charged particles in tiles is transmitted by wavelength-shifting fibres to photomultipliers, where it is converted to electric pulses and further processed by the on-detector electronics located in the outermost part of the calorimeter. The TileCal calibration system comprises Cesium radioactive sources, laser, charge injection elements and an integrator based readout system. Combined information from all systems allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitisation. The performance of the calorimeter has been established with cosmic ray muons and the large sample of the proton-proton col...

  16. Developments in the ATLAS Tracking Software ahead of LHC Run 2

    CERN Document Server

    Styles, N; The ATLAS collaboration

    2014-01-01

    After a hugely successful first run, the Large Hadron Collider (LHC) is currently in a shut-down period, during which essential maintenance and upgrades are being performed on the accelerator. The ATLAS experiment, one of the four large LHC experiments has also used this period for consolidation and further developments of the detector and of its software framework, ahead of the new challenges that will be brought by the increased centre-of-mass energy and instantaneous luminosity in the next run period. This is of particular relevance for the ATLAS Tracking software, responsible for reconstructing the trajectory of charged particles through the detector, which faces a steep increase in CPU consumption due to the additional combinatorics of the high-multiplicity environment. The steps taken to mitigate this increase and stay within the available computing resources while maintaining the excellent performance of the tracking software in terms of the information provided to the physics analyses will be presente...

  17. Developments in the ATLAS Tracking Software ahead of LHC Run 2

    International Nuclear Information System (INIS)

    Styles, Nicholas; Bellomo, Massimiliano; Salzburger, Andreas

    2015-01-01

    After a hugely successful first run, the Large Hadron Collider (LHC) is currently in a shut-down period, during which essential maintenance and upgrades are being performed on the accelerator. The ATLAS experiment, one of the four large LHC experiments has also used this period for consolidation and further developments of the detector and of its software framework, ahead of the new challenges that will be brought by the increased centre-of-mass energy and instantaneous luminosity in the next run period. This is of particular relevance for the ATLAS Tracking software, responsible for reconstructing the trajectory of charged particles through the detector, which faces a steep increase in CPU consumption due to the additional combinatorics of the high-multiplicity environment. The steps taken to mitigate this increase and stay within the available computing resources while maintaining the excellent performance of the tracking software in terms of the information provided to the physics analyses will be presented. Particular focus will be given to changes to the Event Data Model, replacement of the maths library, and adoption of a new persistent output format. The resulting CPU profiling results will be discussed, as well as the performance of the algorithms for physics processes under the expected conditions for the next LHC run. (paper)

  18. Developments in the ATLAS Tracking Software ahead of LHC Run 2

    CERN Document Server

    Styles, N; The ATLAS collaboration; Salzburger, A

    2015-01-01

    After a hugely successful first run, the Large Hadron Collider (LHC) is currently in a shut-down period, during which essential maintenance and upgrades are being performed on the accelerator. The ATLAS experiment, one of the four large LHC experiments has also used this period for consolidation and further developments of the detector and of its software framework, ahead of the new challenges that will be brought by the increased centre-of-mass energy and instantaneous luminosity in the next run period. This is of particular relevance for the ATLAS Tracking software, responsible for reconstructing the trajectory of charged particles through the detector, which faces a steep increase in CPU consumption due to the additional combinatorics of the high-multiplicity environment. The steps taken to mitigate this increase and stay within the available computing resources while maintaining the excellent performance of the tracking software in terms of the information provided to the physics analyses will be presente...

  19. Di-photon event recorded by the CMS detector (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2015-01-01

    This image shows a collision event with a photon pair observed by the CMS detector in proton-collision data collected in 2015. The mass of the di-photon system is 750 GeV. Both photon candidates, with transverse momenta of 400 GeV and 230 GeV respectively, are reconstructed in the barrel region. The candidates are consistent with the expectations that they are prompt isolated photons.

  20. Higgs and associated vector boson event recorded by CMS (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2016-01-01

    Real proton-proton collision event at 13 TeV in the CMS detector in which two high-energy electrons (green lines), two high-energy muons (red lines), and two high-energy jets (dark yellow cones) are observed. The event shows characteristics expected in the production of a Higgs boson in association with a vector boson with the decay of the Higgs boson in four leptons and the decay of the vector boson in two jets, and is also consistent with background standard model physics processes.

  1. Changes to the LHC Beam Dumping System for LHC Run 2

    CERN Document Server

    Uythoven, Jan; Borburgh, Jan; Carlier, Etienne; Gabourin, Stéphane; Goddard, Brennan; Magnin, Nicolas; Senaj, Viliam; Voumard, Nicolas; Weterings, Wim

    2014-01-01

    The LHC beam dumping system performed according to expectations during Run 1 of the LHC (2009 – 2013). A brief overview of the experience is given, including a summary of the observed performance by comparison to expectations. An important number of changes are applied to the beam dumping system during the present Long Shutdown in order to further improve its safety and performance. They include the addition of a direct link between the Beam Interlock System and the re-triggering system of the dump kickers, the modification of the uninterrupted electrical power distribution architecture, the upgrade of the HV generators, the consolidation of the trigger synchronisation system, the modifications to the triggering system of the power switches and the changes to the dump absorbers TCDQ.

  2. Di-muon event recorded by the CMS detector (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2015-01-01

    This image shows a collision event with the largest-mass muon pair so far observed by the CMS detector in proton-collision data collected in 2015. The mass of the di-muon system is 2.4 TeV. One muon, with a transverse momentum of 0.7 TeV, goes through the Drift Tubes in the central region, while the second, with a transverse momentum of 1.0 TeV, hits the Cathode Strip Chambers in the forward region. Both muons satisfy the high-transverse-momentum muon selection criteria.

  3. The ATLAS Muon Trigger Performance : Run 1 and initial Run 2.

    CERN Document Server

    Kasahara, Kota; The ATLAS collaboration

    2015-01-01

    Events with muons in the final state are an important signature for many physics topics at the Large Hadron Collider (LHC). An efficient trigger on muons and a detailed understanding of its performance are required. In 2012, the last year of Run 1, the instantaneous luminosity of the LHC reached 7.7x10^33 cm -2s-1 and the average number of events that occur in a same bunch crossing was 25. The ATLAS Muon trigger has successfully adapted to this changing environment by making use of isolation requirements, combined trigger signatures with electron and jet trigger objects, and by using so-called full-scan triggers, which make use of the full event information to search for di-lepton signatures, seeded by single lepton objects. A stable and highly efficient muon trigger was vital in the discovery of Higgs boson in 2012 and for many searches for new physics. 
The performance of muon triggers during the LHC Run 1 data-taking campaigns is presented, together with an overview and preliminary results of the new muo...

  4. Performance of the ATLAS Level-1 muon barrel trigger during the Run 2 data taking

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00404546; The ATLAS collaboration

    2018-01-01

    The Level-1 Muon Barrel Trigger is one of the main elements of the event selection of the ATLAS experiment at the Large Hadron Collider. It exploits the Resistive Plate Chambers (RPC) detectors to generate the trigger signal. The RPCs are placed in the barrel region of the ATLAS experiment: they are arranged in three concentric double layers and operate in a strong magnetic toroidal field. RPC detectors cover the pseudo-rapidity range |η| < 1.05 for a total surface of more than 4000 m 2 and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates according to their transverse momentum and associates them with the correct bunch-crossing. The trigger system is able to take a decision within a latency of about 2 μs. The measurement of the RPC detector efficiencies and the trigger performance during the ATLAS Run-II data taking are here presented.

  5. Study of the Material within the Run-2 ATLAS Inner Detector

    CERN Document Server

    Cairo, Valentina; The ATLAS collaboration

    2017-01-01

    The material in the ATLAS Inner Detector (ID) is studied with several methods, using a sample of \\sqrt{s}=13 TeV pp collisions collected in 2015 during Run II of the LHC. The material within the innermost barrel regions of the ID is studied using reconstructed secondary vertices from hadronic interactions and photon conversions. The layout of the cables, cooling p ipes and support structures (services) associated with the Pixel detector, in the region in front of the Silicon Microstrip detector (SCT), was modified in 2014. The material in this region was studied by measuring the efficiency with which tracks reconstructed only in the Pixel detector can be matched to tracks reconstructed in the full ID (track extension efficiency). The results of these studies are presented together with a comparison to previous measurements and a description of their impact on physics analyses and Monte Carlo simulation.

  6. The Upgrade of the ATLAS Electron and Photon Triggers for LHC Run 2 and their Performance

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00220717; The ATLAS collaboration

    2016-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking at $\\sqrt{s}$ = 13TeV. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. Th...

  7. The Upgrade of the ATLAS $e/\\gamma$ Triggers for Run2 and their Performance

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2016-01-01

    Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking at $\\sqrt{s} = $ 13TeV . The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. ...

  8. The New CMS DAQ System for Run 2 of the LHC

    CERN Document Server

    AUTHOR|(CDS)2087644; Behrens, Ulf; Branson, James; Chaze, Olivier; Cittolin, Sergio; Darlea, Georgiana Lavinia; Deldicque, Christian; Dobson, Marc; Dupont, Aymeric; Erhan, Samim; Forrest, Andrew Kevin; Gigi, Dominique; Glege, Frank; Gomez Ceballos, Guillelmo; Gomez-Reino Garrido, Robert; Hegeman, Jeroen Guido; Holzner, Andre Georg; Masetti, Lorenzo; Meijers, Franciscus; Meschi, Emilio; Mommsen, Remigius; Morovic, Srecko; Vivian O'Dell; Orsini, Luciano; Paus, Christoph Maria Ernst; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Sakulin, Hannes; Schwick, Christoph; Stieger, Benjamin Bastian; Sumorok, Konstanty; Veverka, Jan; Zejdl, Petr

    2015-01-01

    The data acquisition system (DAQ) of the CMS experiment at the CERN Large Hadron Collider assembles events at a rate of 100 kHz, transporting event data at an aggregate throughput of 100 GB/s to the high level trigger (HLT) farm. The HLT farm selects interesting events for storage and offline analysis at a rate of around 1 kHz. The DAQ system has been redesigned during the accelerator shutdown in 2013/14. The motivation is twofold Firstly, the current compute nodes, networking, and storage infrastructure will have reached the end of their lifetime by the time the LHC restarts. Secondly, in order to handle higher LHC luminosities and event pileup, a number of sub-detectors will be upgraded, increasing the number of readout channels and replacing the off-detector readout electronics with a micro-TCA implementation. The new DAQ architecture will take advantage of the latest developments in the computing industry. For data concentration, 10/40 Gb/s Ethernet technologies will be used, as well as an implementation...

  9. Commissioning and Validation of the ATLAS Level-1 Topological Trigger in Run 2

    CERN Document Server

    Zheng, Daniel; The ATLAS collaboration

    2017-01-01

    The ATLAS experiment has introduced and recently commissioned a completely new hardware sub-system of its first-level trigger: the topological processor (L1Topo). L1Topo consist of two AdvancedTCA blades mounting state-of-the-art FPGA processors, providing high input bandwidth (up to 4 Gb/s) and low latency data processing (200 ns). L1Topo is able to select collision events by applying kinematic and topological requirements on candidate objects (energy clusters, jets, and muons) measured by calorimeters and muon sub-detectors. Results from data recorded using the L1Topo trigger will be presented. These results demonstrate a significantly improved background event rejection, thus allowing for rate reduction with minimal efficiency loss. This improvement has been shown for several physics processes leading to low-$p_T$ leptons, including $H\\rightarrow\\tau \\tau$ and $J/\\psi \\rightarrow \\mu \\mu$. In addition to describing the L1Topo trigger system, we will discuss the use of an accurate L1Topo simulation as a pow...

  10. Jet mass reconstruction with the ATLAS Detector in early Run 2 data

    CERN Document Server

    The ATLAS collaboration

    2016-01-01

    This note presents the details of the ATLAS jet mass reconstruction for groomed large-radius jets. The jet mass scale calibrations are determined from Monte Carlo simulation. An alternative jet mass definition that incorporates tracking information called the track-assisted jet mass is introduced and its performance is compared to the traditional calorimeter-based jet mass definition. Events enriched in boosted $W$, $Z$ boson and top quark jets are used to directly compare the jet mass scale and jet mass resolution between data and simulation. This in-situ technique is also extended to constrain the jet energy scale and resolution.

  11. LHC Report: Rehearsing the LHC accelerator systems for the Run 2 start-up with beam

    CERN Multimedia

    Reyes Alemany Fernandez

    2015-01-01

    While the commissioning of the superconducting circuits is ongoing, great care is also being taken to make sure that the other key LHC accelerator systems are qualified for beam. Since spring 2014, small-scale integration tests on the accelerator systems have been scheduled and carried out successfully to exercise them fully and thoroughly debug their multiple interfaces. The LHC Operations team leads this activity in tight collaboration with the equipment experts and the essential support of the Accelerator Controls group. The tests start once individual system qualification has been performed by the equipment owners and they are ready to be handed over to operations. These tests performed by Operations are called dry runs – dry because they are performed without beam – and they are carried out from the CERN Control Centre (CCC) using the same high-level software applications that will be used during beam operation. The dry runs are the first step towards a global integration test ...

  12. Electroweak production of the top quark in the Run 2 of the D0 experiment; Production electrofaible du quark top au Run 2 de l'experience D0

    Energy Technology Data Exchange (ETDEWEB)

    Clement, B

    2006-04-15

    The work exposed in this thesis deals with the search for electroweak production of top quark (single top) in proton-antiproton collisions at {radical}s = 1.96 TeV. This production mode has not been observed yet. Analyzed data have been collected during the Run II of the D diameter experiment at the Fermilab Tevatron collider. These data correspond to an integrated luminosity of 370 pb{sup -1}. In the Standard Model, the decay of a top quark always produce a high momentum bottom quark. Therefore bottom quark jets identification plays a major role in this analysis. The large lifetime of b hadrons and the subsequent large impact parameters relative to the interaction vertex of charged particle tracks are used to tag bottom quark jets. Impact parameters of tracks attached to a jet are converted into the probability for the jet to originate from the primary vertex. This algorithm has a 45% tagging efficiency for a 0.5% mistag rate. Two processes (s and t channels) dominate single top production with slightly different final states. The searched signature consists in 2 to 4 jets with at least one bottom quark jet, one charged lepton (electron or muon) and missing energy accounting for a neutrino. This final state is background dominated and multivariate techniques are needed to separate the signal from the two main backgrounds: associated production of a W boson and jets and top quarks pair production. The achieved sensitivity is not enough to reach observation and we computed upper limits at the 95% confidence level at 5 pb (s-channel) and 4.3 pb (t-channel) on single top production cross-sections. (author)

  13. Scaling up ATLAS production system for the LHC Run 2 and beyond: project ProdSys2

    CERN Document Server

    Borodin, Mikhail; The ATLAS collaboration; García Navarro, José Enrique; Golubkov, Dmitry; Klimentov, Alexei; Maeno, Tadashi; Vaniachine, Alexandre

    2015-01-01

    The Big Data processing needs of the ATLAS experiment grow continuously, as more data and more use cases emerge. For Big Data processing the ATLAS experiment adopted the data transformation approach, where software applications transform the input data into outputs. In the ATLAS production system, each data transformation is represented by a task, a collection of many jobs, submitted by the ATLAS workload management system (PanDA) and executed on the Grid. Our experience shows that the rate of tasks submission grows exponentially over the years. To scale up the ATLAS production system for new challenges, we started the ProdSys2 project. PanDA has been upgraded with the Job Execution and Definition Interface (JEDI). Patterns in ATLAS data transformation workflows composed of many tasks, provided a scalable production system framework for template definitions of the many-tasks workflows. These workflows are being implemented in the Database Engine for Tasks (DEfT) that generates individual tasks for processing ...

  14. The opening of electricity and natural gas markets to residential clients. Yearly barometer - run 2. December 2008

    International Nuclear Information System (INIS)

    2008-12-01

    The opening of energy markets to competition became effective to individuals ('residential clients') on July 1, 2007 with the possibility to freely choose their energy supplier. This opening of energy markets to residential clients started 3 years after the opening to professionals (July 1, 2004). The Commission of energy regulation (CRE) and the national energy Ombudsman have set in place in 2007 a quantitative yearly survey ('barometer') addressed to residential clients in order to collect statistical data about the behaviour of these clients with regards to the opening of markets to competition. This document deals with the results of the fourth run of this survey carried out from November 10 to November 20, 2008 by the LH2 institute. For the 1502 households investigated, LH2 has questioned the person in charge of the energy bills management. The barometer aimed at answering the following questions: - what is the level of knowledge and information of residential clients about markets opening and the existing regulation? - What perception of this opening do they have? (pros/cons, advantages/drawbacks); - what behaviour do they have in front of the opening of markets to competition? (approach with respect to information needs, knowledge about the offer, intention to change supplier, brakes/motivations in entering the open market). (J.S.)

  15. 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...

  16. Analysis of the Dependability of the LHC Quench Detection System During LHC Run 2 and Further System Evolution

    OpenAIRE

    Podzorny, Tomasz; Calcoen, Daniel; Denz, Reiner; Siemko, Andrzej; Spasic, Jelena; Steckert, Jens

    2017-01-01

    The quench detection system (QDS) of the LHC superconducting circuits is an essential part of the LHC machine protection and ensures the integrity of key elements of the accelerator. The large amount of hardwired and software interlock channels of the QDS requires a very high system dependability in order to reduce the risk of affecting the successful operation of the LHC. This contribution will present methods and tools for systematic fault tracking and analysis, and will discuss recent resu...

  17. Search for top squark pair production in final states with two leptons at LHC Run 2 with the ATLAS detector

    CERN Document Server

    Longo, Luigi; The ATLAS collaboration

    2017-01-01

    Although no experimental evidence has been found during LHC Run1, Supersymmetry (SUSY) remains one of the most promising and motivated Standard Model (SM) extensions. Focusing the attention on models where the multiplicative quantum number R-parity is conserved, the latest results in searching for pair production of top squarks decaying to a bottom quark and the lightest chargino or to a top quark and the lightest supersymmetric particle (neutralino) in final states with 2 leptons are presented, using proton-proton collision data collected by the ATLAS experiment during 2015 and 2016 at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 36.1 fb\\$^{-1}\\$. Each of the decay modes is searched in the context of a simplified model, assuming a branching ratio of 100% for both signals

  18. Search for top squark pair production in final states with two leptons at LHC Run 2 with the ATLAS detector

    CERN Document Server

    Longo, Luigi; The ATLAS collaboration

    2017-01-01

    Although no experimental evidence has been found during LHC Run1, supersymmetry (SUSY) remains one of the most promising and motivated Standard Model extensions. Focusing the attention on its minimal formulation, the Minimal Supersymmetric Standard Model (MSSM), where the multiplicative quantum number R-parity is conserved, the latest results in searching for pair production of top squarks decaying to a bottom quark and a chargino1 or to a top quark and the lightest supersymmetric particle (neutralino) in a final state with 2 leptons are presented, using proton-proton collision data collected by the ATLAS experiment during 2015 and 2016 at the center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 36.1 fb−1. Both the decay modes are searched in the context of a simplified model where a branching ratio of 100% is assumed for both signal models.

  19. The ATLAS Trigger Core Configuration and Execution System in Light of the ATLAS Upgrade for LHC Run 2

    CERN Document Server

    Heinrich, Lukas; The ATLAS collaboration

    2015-01-01

    During the 2013/14 shutdown of the Large Hadron Collider (LHC) the ATLAS first level trigger (L1T) and the data acquisition system (DAQ) were substantially upgraded to cope with the increase in luminosity and collision multiplicity, expected to be delivered by the LHC in 2015. To name a few, the L1T was extended on the calorimeter side (L1Calo) to better cope with pile-up and apply better-tuned isolation criteria on electron, photon, and jet candidates. The central trigger (CT) was widened to analyze twice as many inputs, provide more trigger lines, and serve multiple sub-detectors in parallel during calibration periods. A new FPGA-based trigger, capable of analyzing event topologies at 40 MHz, was added to provide further input to forming the level 1 trigger decision (L1Topo). On the DAQ side the dataflow was completely remodeled, merging the two previously existing stages of the software-based high level trigger into one. Partially because of these changes, partially because of the new trigger paradigm to h...

  20. Di-photon events recorded by the CMS detector (Run 2, 13 TeV, 0 T)

    CERN Multimedia

    Mc Cauley, Thomas

    2016-01-01

    This image shows a collision event with a photon pair observed by the CMS detector in proton-collision data collected in 2015 with no magnetic field present. The energy deposits of the two photons are represented by the two large green towers. The mass of the di-photon system is between 700 and 800 GeV. The candidates are consistent with what is expected for prompt isolated photons.

  1. Highest-mass di-photon event recorded by CMS as of Dec '15 (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2015-01-01

    This image shows a collision event with the largest-mass photon pair so far observed by the CMS detector in collision data collected in 2015. The mass of the di-photon system is 1.5 TeV. One photon candidate, with a transverse momentum of 530 GeV is reconstructed in the endcap region, while a second, with a transverse momentum of 400 GeV, is reconstructed in the barrel region. Both photon candidates are consistent with the expectation that they are prompt isolated photons.

  2. Higgs boson produced via vector boson fusion event recorded by CMS (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2016-01-01

    Real proton-proton collision event at 13 TeV in the CMS detector in which two high-energy electrons (green lines), two high-energy muons (red lines), and two-high energy jets (dark yellow cones) are observed. The event shows characteristics expected from Higgs boson production via vector boson fusion with subsequent decay of the Higgs boson in four leptons, and is also consistent with background standard model physics processes.

  3. Dual-use tools and systematics-aware analysis workflows in the ATLAS Run-2 analysis model

    CERN Document Server

    FARRELL, Steven; The ATLAS collaboration; Calafiura, Paolo; Delsart, Pierre-Antoine; Elsing, Markus; Koeneke, Karsten; Krasznahorkay, Attila; Krumnack, Nils; Lancon, Eric; Lavrijsen, Wim; Laycock, Paul; Lei, Xiaowen; Strandberg, Sara Kristina; Verkerke, Wouter; Vivarelli, Iacopo; Woudstra, Martin

    2015-01-01

    The ATLAS analysis model has been overhauled for the upcoming run of data collection in 2015 at 13 TeV. One key component of this upgrade was the Event Data Model (EDM), which now allows for greater flexibility in the choice of analysis software framework and provides powerful new features that can be exploited by analysis software tools. A second key component of the upgrade is the introduction of a dual-use tool technology, which provides abstract interfaces for analysis software tools to run in either the Athena framework or a ROOT-based framework. The tool interfaces, including a new interface for handling systematic uncertainties, have been standardized for the development of improved analysis workflows and consolidation of high-level analysis tools. This paper will cover the details of the dual-use tool functionality, the systematics interface, and how these features fit into a centrally supported analysis environment.

  4. Large-mass di-jet event recorded by the CMS detector (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2015-01-01

    This image shows a collision event with the largest-mass jet pair fulfilling all analysis requirements observed so far by the CMS detector in collision data collected in 2015. The mass of the di-jet system is 6.14 TeV. Both jets are reconstructed in the barrel region and have transverse momenta of about 3 TeV each.

  5. 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...

  6. The ATLAS Production System Evolution. New Data Processing and Analysis Paradigm for the LHC Run2 and High-Luminosity

    CERN Document Server

    Borodin, Mikhail; The ATLAS collaboration

    2016-01-01

    The second generation of the ATLAS production system called ProdSys2 is a distributed workload manager that runs daily hundreds of thousands of jobs, from dozens of different ATLAS specific workflows, across a more than hundred heterogeneous sites. It achieves high utilization by combining dynamic job definition based on many criterias, such as input and output size, memory requirements and CPU consumption with manageable scheduling policies and by supporting different kind of computational resources, such as GRID, clouds, supercomputers and volunteering computers. The system dynamically assigns a group of jobs (task) to a group of geographically distributed computing resources. Dynamic assignment and resources utilization is one of the major system’s features, it didn’t exist in the earliest versions of the production system, where Grid resources topology has been predefined using national or/and geographical pattern. Production System has a sophisticated job fault-recovery mechanism, which allows effici...

  7. The ATLAS Production System Evolution: New Data Processing and Analysis Paradigm for the LHC Run2 and High-Luminosity

    CERN Document Server

    AUTHOR|(SzGeCERN)677929; The ATLAS collaboration; Barreiro Megino, Fernando Harald; De, Kaushik; Golubkov, Dmitry; Klimentov, Alexei; Maeno, Tadashi; Mashinistov, Ruslan; Padolski, Siarhei; Wenaus, Torre

    2017-01-01

    The second generation of the ATLAS Production System called ProdSys2 is a distributed workload manager that runs daily hundreds of thousands of jobs, from dozens of different ATLAS specific workflows, across more than hundred heterogeneous sites. It achieves high utilization by combining dynamic job definition based on many criteria, such as input and output size, memory requirements and CPU consumption, with manageable scheduling policies and by supporting different kind of computational resources, such as GRID, clouds, supercomputers and volunteering computers. The system dynamically assigns a group of jobs (task) to a group of geographically distributed computing resources. Dynamic assignment and resources utilization is one of the major features of the system, it didn’t exist in the earliest versions of the production system where Grid resources topology has been predefined using national or/and geographical pattern. Production System has a sophisticated job fault-recovery mechanism, which efficiently a...

  8. Large-mass di-jet event recorded by the CMS detector (Run 2, 13 TeV)

    CERN Multimedia

    Mc Cauley, Thomas

    2016-01-01

    This image shows a collision event with the largest-mass jet pair fulfilling all analysis requirements observed so far by the CMS detector in proton-proton collision data collected in 2016. The mass of the di-jet system is 7.7 TeV. Both jets are reconstructed in the barrel region and each have transverse momenta of over 3 TeV.

  9. Using MAX/MIN Transverse Regions to Study the Underlying Event in Run 2 at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, L. Alberto [Univ. of Florida, Gainesville, FL (United States)

    2005-01-01

    Elementary particle physics attempts to answer very fundamental questions of how the Universe was created and how it works. One approach to unlocking these mysteries is by «»Hiding very fast moving protons and antiprotons and studying the outcome. Most of the time these particles ooze through each other, but occasionally we get a collision that is characterized by a large amount of transverse momentum. This signals a special kind of collision that can be calculated by the theorist. The problem lies in the fact that only a portion of the collisions can he calculated, The majority of the collision is mes..~y and must be modeled. The data presented here helps to improve the current models and allows for a better understanding of the dynamics of nuclear forces.

  10. Radiation Damage of the CERN CMS HCAL Scintillator/WLS fiber readout during Run1 and Run2 of the LHC

    CERN Document Server

    de Barbaro, Pawel Jan

    2017-01-01

    We present the results of a study of radiation damage of the CERN CMS HCAL Scintillator/WLS Fiber readout. Data were obtained using the Laser calibration system of the CMS hadron endcap detector during the operation of the LHC in 2010-2017. Scintillators used in the CMS hadron endcap calorimeter (HE) were irradiated at dose rates in the range of 0.1 rad/h to 0.1 krad/h. Results indicate that the radiation damage has a strong dose rate dependence. Using data collected in 2017, we have measured the response loss in a single HE section instrumented with Silicon photomultipliers (SiPMs). The results show a much smaller signal loss for the channels read out by SiPMs compared to signal loss for the channels read out by hybrid photodetectors (HPDs). The results imply that a large fraction of the response loss in the CMS HE detector observed in 2010-2017 comes from deterioration of the HPD photodetectors and not from radiation damage of scintillators.

  11. Search for top squark pair production and decay in four bodies, with two leptons in the final state, at the ATLAS Experiment with LHC Run2 data

    CERN Document Server

    Reale, Marilea; The ATLAS collaboration

    2017-01-01

    Supersymmetry (SUSY) still remains one of the most interesting theories which are candidates to describe physics beyond the Standard Model, even if the latest Run1 results and interpretations have so far shown no experimental evidence for the existence of superparticles. If SUSY exists, the strong production of colored SUSY particles is expected to be the dominant production process at the LHC. In this work a search for the top quark supersymmetric partner (stop) pairs production is reported, using 36.1 fb$^{-1}$ of proton-proton collision data collected by the ATLAS experiment in 2015 and 2016. The analysis targets the stop decaying, with 100% branching ratio, into a b quark, a neutralino (here assumed to be the lighest supersymmetric particle), a fermion and an antifermion, with a final state including two isolated electrons or muons and missing transverse momentum. The results are interpreted in the stop and neutralino mass plane in terms of exclusion limits, since no excess in data has been found for this...

  12. Search for top squark pair production and decay in four bodies, with two leptons in the final state, at the ATLAS Experiment with LHC Run2 data

    CERN Document Server

    Reale, Marilea; The ATLAS collaboration

    2017-01-01

    Supersymmetry (SUSY) still remains one of the most interesting theories which are candidates to describe physics beyond the Standard Model, even if the latest Run1 results and interpretations have so far shown no experimental evidence for the existence of superparticles. If SUSY exists, the strong production of coloured SUSY particles is expected to be the dominant production process at the LHC. In this poster a search for the top quark Supersymmetric partner (stop) pairs production is reported, using 36.1 fb−1 of proton-proton collision data collected by the ATLAS experiment in 2015 and 2016. The analysis targets the stop decaying, with 100% branching ratio, into a b quark, a neutralino (the lighest Supersymmetric particle), a fermion and an antifermion, with a final state including two isolated electrons or muons and missing transverse momentum. The results are interpreted in the stop and neutralino mass plane in terms of exclusion limits, since no excess in data has been found for this analysis.

  13. $B_s \\rightarrow J/\\psi\\phi$ RUN-1 results and studies of $B^\\pm$ mass with RUN-2 data at ATLAS

    CERN Document Server

    Jakoubek, Tomas; The ATLAS collaboration

    2016-01-01

    We present a flavour tagged time dependent angular analysis of the $B_s \\rightarrow J/\\psi\\phi$ decay, using 14.3 fb$^{-1}$ of integrated luminosity collected by the ATLAS detector from 8 TeV LHC proton-proton collisions recorded in 2012. $CP$-violation in this channel is described by a weak phase $\\phi_s$, which is sensitive to new physics contributions. Measured parameters are statistically combined with those from 4.9 fb$^{-1}$ of 7 TeV data, leading to the final results from ATLAS in RUN 1: $\\phi_s = -0.098 \\pm 0.084 \\mathrm{(stat.)} \\pm 0.040 \\mathrm{(syst.) rad}$, which is in good agreement with Standard Model expectations. Also other measured parameters are consistent with the world average. The performance of the ATLAS detector in reconstructing $B^\\pm \\rightarrow J/\\psi K^\\pm$ candidates is also presented, using 3.2 fb$^{-1}$ of integrated luminosity of 13 TeV LHC proton-proton collisions. The $B^\\pm$ mass is used to validate the momentum calibration of the Inner Detector tracking at low-to-medium $p...

  14. Physics with photons with the ATLAS Run 2 data: calibration and identification, measurement of the Higgs boson mass and search for supersymmetry in di-photon final state.

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00436885; Carminati, Leonardo; Marchiori, Giovanni

    The work presented in this manuscript is based on the proton-proton collision data from the Large Hadron Collider at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector in 2015 and 2016. The research program of the ATLAS experiment includes the precise measurement of the parameters of the Standard Model (SM) and the search for signals of physics beyond the SM. Both these approaches are pursued in this thesis, which presents two different analyses. The first one is the measurement of the Higgs boson mass in the di-photon decay channel. The measured value of the mass is $m_H=125.11 \\pm 0.42$ GeV. Its combination with a similar measurement in the four lepton Higgs boson decay final state is presented. The value of the Higgs boson mass obtained from the combined measurement is $m_H=124.98 \\pm 0.28$ GeV. The second one is the search for production of supersymmetric particles (gluinos, squarks or winos) in a final state containing two photons and missing transverse momentum. No significant excess wit...

  15. Set up and programming of an ALICE Time-Of-Flight trigger facility and software implementation for its Quality Assurance (QA) during LHC Run 2

    CERN Document Server

    Toschi, Francesco

    2016-01-01

    The Cosmic and Topology Trigger Module (CTTM) is the main component of a trigger based on the ALICE TOF detector. Taking advantage of the TOF fast response, this VME board implements the trigger logic and delivers several L0 trigger outputs, used since Run 1, to provide cosmic triggers and rare triggers in pp, p+Pb and Pb+Pb data taking. Due to TOF DCS architectural change of the PCs controlling the CTTM (from 32 bits to 64 bits) it is mandatory to upgrade the software related to the CTTM including the code programming the FPGA firmware. A dedicated CTTM board will be installed in a CERN lab (Meyrin site), with the aim of recreating the electronics chain of the TOF trigger, to get a comfortable porting of the code to the 64 bit environment. The project proposed to the summer student is the setting up of the CTTM and the porting of the software. Moreover, in order to monitor the CTTM Trigger board during the real data taking, the implementation of a new Quality Assurance (QA) code is also crucial, together wit...

  16. Search for Additional Heavy Neutral Higgs and Gauge Bosons with LHC Run 2 data in the $\\tau\\tau$ final state with the ATLAS detector

    CERN Document Server

    Bailey, Adam; The ATLAS collaboration

    2017-01-01

    A search for heavy neutral Higgs and Z' bosons in the $\\tau\\tau$ channel is presented from data collected by the ATLAS detector in 2015 and 2016. The total data sample corresponds to an integrated luminosity of 36.1 fb$^{-1}$. The search is performed in two channels; both $\\tau$ decay hadronically, or one $\\tau$ decaying leptonically and one hadronically. Data are in good agreement with the standard model. Results are interpreted as limits on the cross section times branching fraction. Model-specific limits are presented in the $\\tan\\beta-m_{h}$ plane for two benchmark scenarios, hMSSM and $m_{h}^{mod+}$. For the Z' search results are interpreted using the Sequential Standard Model and non-universal G(221) model.

  17. Search for the Higgs boson decaying to a pair of bottom quarks and produced in association with a pair of top quarks in the LHC Run 2 data with the ATLAS detector using a likelihood technique

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00439858; Juste Rozas, Aurelio; Casado Lechuga, Maria Pilar

    Following the discovery of the Higgs boson by the ATLAS and CMS Collaborations at the Large Hadron Collider (LHC) in 2012, the attention has been focussed on studying the properties of the newly discovered particle to test the predictions of the Standard Model (SM). An object of particular interest is the top quark Yukawa coupling - the coupling of the Higgs boson to the top quark, which is predicted to be close to unity in the SM and at the same time very sensitive to the possible effects of new physics beyond the SM. The production of the Higgs boson in association with a pair of top quarks, $t \\bar{t}H$, is the mode which gives direct access to the top quark Yukawa coupling. The decay of the Higgs boson into a pair of $b$-quarks, $H \\to b \\bar{b}$, is dominant in the SM (its branching ratio is approximately 58%). This decay channel also allows measuring the $b$-quark Yukawa coupling - the second largest coupling of the Higgs boson to a fermion in the SM. In this dissertation the search for $t \\bar{t}H (H \\...

  18. The opening of electricity and natural gas markets to residential clients. Yearly barometer - run 2. December 2008; L'ouverture des marches de l'electricite et du gaz naturel pour les clients residentiels. Barometre annuel - vague 2. Decembre 2008

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-12-15

    The opening of energy markets to competition became effective to individuals ('residential clients') on July 1, 2007 with the possibility to freely choose their energy supplier. This opening of energy markets to residential clients started 3 years after the opening to professionals (July 1, 2004). The Commission of energy regulation (CRE) and the national energy Ombudsman have set in place in 2007 a quantitative yearly survey ('barometer') addressed to residential clients in order to collect statistical data about the behaviour of these clients with regards to the opening of markets to competition. This document deals with the results of the fourth run of this survey carried out from November 10 to November 20, 2008 by the LH2 institute. For the 1502 households investigated, LH2 has questioned the person in charge of the energy bills management. The barometer aimed at answering the following questions: - what is the level of knowledge and information of residential clients about markets opening and the existing regulation? - What perception of this opening do they have? (pros/cons, advantages/drawbacks); - what behaviour do they have in front of the opening of markets to competition? (approach with respect to information needs, knowledge about the offer, intention to change supplier, brakes/motivations in entering the open market). (J.S.)

  19. Nesting biology of the trap-nesting Neotropical wasp Trypoxylo n(Trypargilum) aurifrons Shuckard (Hymenoptera, Crabronidae)

    OpenAIRE

    Santoni,Mariana Marchi; Del Lama,Marco Antonio

    2007-01-01

    The present study was carried out in three localities of the state of São Paulo, Brazil: Araras (Dec/03-Dec/06), São Carlos (Nov/04-Nov/06) and Rifaina (Jul/04-Dec/06). Trap-nests were distributed among sites in the sampling areas and were collected every 35 days. Data from 295 nests indicate that T. aurifrons is a multivoltine species, with higher rates of nest building and cell production in the warm, rainy season. The trap-nests used by the females ranged from 117 to 467 mm in length and 3...

  20. Ancient shorelines of Gujarat, India, during the Indus civilization (Late Mid-Holocene): A study based on archaeological evidences

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Vora, K.H.

    or production of salt, etc. as indicators of palaeo-shorelines. As of today, these sites are located away from the present shoreline. Lothal, believed to be the oldest dockyard in the world, is located at the head of the Gulf of Khambhat, now situated about... shorelines of Gujarat, India, during the Indus civilization (Late Mid-Holocene): A study ... 16-Nov-06http://www.ias.ac.in/currsci/jul10/articles29.htm centre for acquiring and processing raw materials for manufacturing articles for export. Discovery of two...

  1. Electronic Biometric Transmission Specification. Version 1.2

    Science.gov (United States)

    2006-11-08

    Prescribed by ANSI Std Z39-18 Electronic Biometric Transmission Specification DIN: DOD_BTF_TS_EBTS_ Nov06_01.02.00 i Revision History Revision...contains: • the ORI • a Greenwich Mean (a.k.a. Zulu or UTC) date/time stamp • a code for the software used at the point of collection/transmission...long names and would generally include the tribe name. Subfield 1 Item 1 Character Type AS Characters 1 to 50 Special Characters: Any 7-bit non

  2. Spacecraft Environmental Interactions Technology 1983

    Science.gov (United States)

    1985-01-01

    recently acquired a NASA field office within the Technology Lenter; that is staffed by Mr. Wa~ne Hudson. We take our guidance from Air Force...apogee of 4.6 % geocentric and a perigee of 650 )a altitude. The DR-1 Nigh Altitude Plama instrument (DAPI) consists of five electrostatic analyzers

  3. In situ spatiotemporal measurements of the detailed azimuthal substructure of the substorm current wedge

    DEFF Research Database (Denmark)

    Forsyth, C.; Fazakerley, A. N.; Rae, I. J.

    2014-01-01

    perigee passes of the Cluster 1 and 4 spacecraft during a substorm on 15 January 2010, in conjunction with ground-based observations, to examine the spatial structuring and temporal variability of the SCW. At this time, the spacecraft traveled east-west azimuthally above the auroral region. We show...

  4. Low energy trajectories for the Moon-to-Earth space flight

    Indian Academy of Sciences (India)

    The Moon-to-Earth low energy trajectories of 'detour' type are found and studied within the frame ... km from the Earth where the Sun gravitation decreases the particle orbit perigee distance to a small value .... The solid curve in fig- ... the Moon, respectively, as is the semimajor axis .... inclination i0 = 90 .... Then, according to.

  5. Managing Space Situational Awareness Using the Space Surveillance Network

    Science.gov (United States)

    2013-11-14

    objects into Gabbard classes based on perigee and apogee height of the object’s respective orbits [3]. This simple form of sensor allocation was later...used Gabbard classes. This new method divided objects in the satellite catalog into 11 energy dissipation rate bins (each with their own suggested

  6. A new proposal for measuring the Lense-Thirring effect with a pair of supplementary satellites in the gravitational field of the Earth

    International Nuclear Information System (INIS)

    Iorio, Lorenzo

    2003-01-01

    In this Letter we propose a new observable for measuring the general relativistic Lense-Thirring effect with artificial satellites in the gravitational field of the Earth. It consists of the difference of the perigee rates of two satellites placed in identical orbits with supplementary inclinations. As in the well known LAGEOS-LARES project in which, instead, the sum of the residuals of the nodal rates would be used, the proposed observable would be able to cancel out the aliasing effect of the classical even zonal perigee precessions induced by the oblateness of the Earth. The possibility of using the already existing LAGEOS II and a twin of its, to be launched, in a supplementary orbit is briefly examined. While with the originally proposed LAGEOS-LARES mission only the sum of the nodal rates could be used because the perigee of LAGEOS is not a good observable, the implementation of the proposed mission would allow to adopt both the sum of the nodes and the difference of the perigees

  7. Dynamics of the Sun-Earth-Moon System

    Indian Academy of Sciences (India)

    The dynamics of the Sun-Earth-Moon system is discussed with special attention to the effects of. Sun's perturbations on the Moon's orbit around the Earth. Important secular effects are the re- gression of the nodes, the advance of the perigee and the increase in the Moon's mean longitude. We discuss the relationship of the ...

  8. Magnus Effect on a Spinning Satellite in Low Earth Orbit

    Science.gov (United States)

    Ramjatan, Sahadeo; Fitz-Coy, Norman; Yew, Alvin Garwai

    2016-01-01

    A spinning body in a flow field generates an aerodynamic lift or Magnus effect that displaces the body in a direction normal to the freestream flow. Earth orbiting satellites with substantial body rotation in appreciable atmospheric densities may generate a Magnus force to perturb orbital dynamics. We investigate the feasibility of using this effect for spacecraft at a perigee of 80km using the Systems Tool Kit (STK). Results show that for a satellite of reasonable properties, the Magnus effect doubles the amount of time in orbit. Orbital decay was greatly mitigated for satellites spinning at 10000 and 15000RPM. This study demonstrates that the Magnus effect has the potential to sustain a spacecraft's orbit at a low perigee altitude and could also serve as an orbital maneuver capability.

  9. NANOSAT Employment: A Theoretical Conops for Space Object Identification

    Science.gov (United States)

    2014-06-01

    was equipped with new lightweight reactor wheels , inertial measurement units, batteries, computer, and solid-state recorder. Two star tracker stellar...The communications system consisted of a VHF uplink and 100 mW S-Band downlink. A pitch-axis momentum wheel and orbit position detected via GPS...Element Value Semi-major Axis (a) 7000 km Eccentricity (e) 0 Inclination (i) 66° Right Ascension of the Ascending Node (Ω) 86.664° Argument of Perigee

  10. Low energy trajectories for the Moon-to-Earth space flight

    Indian Academy of Sciences (India)

    The Moon-to-Earth low energy trajectories of `detour'type are found and studied within the frame of the Moon –Earth –Sun-particle system. ... This results in the particle flight to a distance of about 1.5 million km from the Earth where the Sun gravitation decreases the particle orbit perigee distance to a small value that leads to ...

  11. Super Dwarf Wheat for Growth in Confined Spaces

    Science.gov (United States)

    Bugbee, Bruce

    2011-01-01

    USU-Perigee is a dwarf red spring wheat that is a hybrid of a high-yield early tall wheat (USU-Apogee) and a low-yield, extremely short wheat that has poor agronomic characteristics. USU-Perigee was selected for its extremely short height (.0.3 m) and high yield . characteristics that make it suitable for growth in confined spaces in controlled environments. Other desirable characteristics include rapid development and resistance to a leaf-tip necrosis, associated with calcium deficiency, that occurs in other wheat cultivars under rapid-growth conditions (particularly, continuous light). Heads emerge after only 21 days of growth in continuous light at a constant temperature of 25 C. In tests, USU-Perigee was found to outyield other full dwarf (defined as wheat cultivars: The yield advantage at a constant temperature of 23 C was found to be about 30 percent. Originally intended as a candidate food crop to be grown aboard spacecraft on long missions, this cultivar could also be grown in terrestrial growth chambers and could be useful for plant-physiology and -pathology studies.

  12. Frozen orbit realization using LQR analogy

    Science.gov (United States)

    Nagarajan, N.; Rayan, H. Reno

    In the case of remote sensing orbits, the Frozen Orbit concept minimizes altitude variations over a given region using passive means. This is achieved by establishing the mean eccentricity vector at the orbital poles i.e., by fixing the mean argument of perigee at 90 deg with an appropriate eccentricity to balance the perturbations due to zonal harmonics J2 and J3 of the Earth's potential. Eccentricity vector is a vector whose magnitude is the eccentricity and direction is the argument of perigee. The launcher dispersions result in an eccentricity vector which is away from the frozen orbit values. The objective is then to formulate an orbit maneuver strategy to optimize the fuel required to achieve the frozen orbit in the presence of visibility and impulse constraints. It is shown that the motion of the eccentricity vector around the frozen perigee can be approximated as a circle. Combining the circular motion of the eccentricity vector around the frozen point and the maneuver equation, the following discrete equation is obtained. X(k+1) = AX(k) + Bu(k), where X is the state (i.e. eccentricity vector components), A the state transition matrix, u the scalar control force (i.e. dV in this case) and B the control matrix which transforms dV into eccentricity vector change. Based on this, it is shown that the problem of optimizing the fuel can be treated as a Linear Quadratic Regulator (LQR) problem in which the maneuver can be solved by using control system design tools like MATLAB by deriving an analogy LQR design.

  13. The statistical study of Chorus waves using the Double star TC1 data

    Science.gov (United States)

    Yearby, K.; Aryan, H.; Balikhin, M. A.; Krasnoselskikh, V.; Agapitov, O. V.

    2013-12-01

    The Double star satellite was launched on 29 December 2003 into an equatorial elliptical orbit with a perigee of 570km and an apogee of 78970km and an inclination of 28.5°. The satellite operated until 14 October 2007. The Double star TC1 data provides extensive coverage of the inner magnetosphere regions in the range of L shells >1.1L*, and a wide range of latitudes. This study presents a detailed statistical study of the Chorus waves during 4 years of the Double star operation.

  14. NASA to launch second business communications satellite

    Science.gov (United States)

    1981-01-01

    The two stage Delta 3910 launch vehicle was chosen to place the second small business satellite (SBS-B) into a transfer orbit with an apogee of 36,619 kilometers and a perigee of 167 km, at an inclination of 27.7 degrees to Earth's equator. The firing and separation sequence and the inertial guidance system are described as well as the payload assist module. Facilities and services for tracking and control by NASA, COMSAT, Intelsat, and SBS are outlined and prelaunch operations are summarized.

  15. A numerical investigation on the eccentricity growth of GNSS disposal orbits

    Science.gov (United States)

    Alessi, E. M.; Deleflie, F.; Rosengren, A. J.; Rossi, A.; Valsecchi, G. B.; Daquin, J.; Merz, K.

    2016-05-01

    We present the results of an extensive numerical exploration performed on the eccentricity growth in MEO associated with two possible end-of-life disposal strategies for GNSS satellites. The study calls attention to the existence of values of initial inclination, longitude of ascending node, and argument of perigee that are more advantageous in terms of long-term stability of the orbit. The important role of the initial epoch and a corresponding periodicity are also shown. The present investigation is influential in view of recent analytical and numerical developments on the chaotic nature of the region due to lunisolar perturbations, but also for the upcoming Galileo and BeiDou constellations.

  16. SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe

    Science.gov (United States)

    Gamet, Philippe; Epenoy, R.; Salcedo, C.

    2007-01-01

    SIMBOL-X is a high energy new generation telescope covering by a single instrument a continuous energy range starting at classical X-rays and extending to hard X-rays, i.e. from 0.5 to 80 keV. It is using in this field a focalizing payload which until now was used for energy below 10 keV only, via the construction of a telescope distributed on two satellites flying in formation. SIMBOL-X permits a gain of two orders of magnitude in sensibility and spatial resolution in comparison to state of the art hard X-rays instruments. The mirror satellite will be in free flight on a high elliptical orbit and will target the object to observe very precisely, thus focusing the hard X-ray emission thanks to this mirror module. At the focal point area which is situated 20 meters behind the mirror satellite, the detector satellite maintains its position on a forced orbit thanks to a radio link with the mirror satellite and a lateral displacement sensor using a beam emitted onboard the mirror satellite. This configuration is said "formation flying". The location of the detector satellite shall be very finely tuned as it carries the focal plane of this distributed telescope. To provide science measurements, the Simbol-X orbit has been chosen High elliptic (HEO), which means elliptical orbit with a high perigee altitude. Preliminary studies where made with an orbit with an altitude of the perigee of 44000km and altitude of the apogee of 253000km. The orbit was seven days ground track repeated in order to maintain a perigee pass over the Malindi ground station to download scientific telemetry. But as studies went on, difficulties in mass budget, link budget, perigee maintenance and formation flying maintenance were raised. This was mainly due to the vicinity of the Moon and its disturbing effect on the satellites orbits. Alternative orbits have been proposed in order to demonstrate the feasibility of the mission. The problematic of bringing the two satellites from their injection

  17. Objective and subjective outcome 3 years after synthetic transobturator nonabsorbable anterior mesh use in symptomatic advanced pelvic organ prolapse surgery

    Directory of Open Access Journals (Sweden)

    Tsia-Shu Lo

    2015-05-01

    Conclusion: The Perigee System gave a favorable result in both anatomical and subjective success rates with a low rate of mesh-related morbidities. The strength of the study reported here is its long-term follow up of a relatively large number of patients and the use of validated questionnaires. Limitations are that it is not a RCT; hence, selection and indication bias is unavoidable. The favorable outcome and low morbidities resulting from mesh use is from a single surgeon's perspective and may not be generalized to others.

  18. Exhaustive Strategy for Optical Survey of Geosynchronous Region using TAROT Telescopes

    Science.gov (United States)

    Richard, P.; Yanez, C.; Morand, V.; Verzeni, A.; Boer, M.; Klotz, A.

    CNES and CNRS has been working on Optical Space Surveillance and Tracking for many years using the TAROT telescopes network. The goal of the study presented here is to propose an exhaustive strategy for optical survey of geosynchronous region. First, constraints will be defined on perigee and apogee of the orbits for which we are looking for exhaustiveness and then solutions will be explored making the survey in one or several nights using one or several telescopes. The last part of the study proposes solutions to help maintaining exhaustiveness if some observations failed.

  19. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Djama, Fares; The ATLAS collaboration

    2017-01-01

    Run 2 of the LHC collider sets new challenges to track and vertex reconstruction because of its higher energy, pileup and luminosity. The ATLAS tracking performance relies critically on the Pixel Detector. Therefore, in view of Run 2, the ATLAS collaboration has constructed the first 4-layer pixel detector in Particle Physics by installing a new pixel layer, called Insertable B-Layer (IBL). Operational experience and performance of the 4-layer Pixel Detector during Run 2 are presented.

  20. Characterization of the 2012-044C BRIZ-M Upper Stage Breakup

    Science.gov (United States)

    Matney, M. J.; Hamilton, J.; Horstman, M.; Papanyan, V.

    2013-08-01

    On 6 August 2012, Russia launched two commercial satellites aboard a Proton rocket, and attempted to place them in geosynchronous orbit using a Briz-M upper stage (2012-044C, SSN 38746). Unfortunately, the upper stage failed early in its burn and was left stranded in an elliptical orbit with a perigee in low Earth orbit (LEO). Because the stage failed with much of its fuel on board, it was deemed a significant breakup risk. These fears were confirmed when it broke up 16 October, creating a large cloud of debris with perigees below that of the International Space Station. The debris cloud was tracked by the U.S. Space Surveillance Network (SSN), which can reliably detect and track objects down to about 10 cm in size. Because of the unusual geometry of the breakup, there was an opportunity for the NASA Orbital Debris Program Office to use specialized radar assets to characterize the extent of the debris cloud in sizes smaller than the standard debris tracked by the SSN. This paper describes the observation campaign to measure the small particle distributions of this cloud and presents the results of the data analysis. We shall compare the data to the modelled size distribution, number, and shape of the cloud, and what implications this may have for future breakup debris models. We shall conclude the paper with a discussion about how this measurement process can be improved for future breakups.

  1. Genealogy and stability of periodic orbit families around uniformly rotating asteroids

    Science.gov (United States)

    Hou, Xiyun; Xin, Xiaosheng; Feng, Jinglang

    2018-03-01

    Resonance orbits around a uniformly rotating asteroid are studied from the approach of periodic orbits in this work. Three periodic families (denoted as I, II, and III in the paper) are fundamental in organizing the resonance families. For the planar case: (1) Genealogy and stability of Families I, II and the prograde resonance families are studied. For extremely irregular asteroids, family genealogy close to the asteroid is greatly distorted from that of the two body-problem (2BP), indicating that it is inappropriate to treat the orbital motions as perturbed Keplerian orbits. (2) Genealogy and stability of Family III are also studied. Stability of this family may be destroyed by the secular resonance between the orbital ascending node's precession and the asteroid's rotation. For the spatial case: (1) Genealogy of the near circular three-dimensional periodic families are studied. The genealogy may be broken apart by families of eccentric frozen orbits whose argument of perigee is ;frozen; in space. (2) The joint effects between the secular resonance and the orbital resonances may cause instability to three-dimensional orbital motion with orbit inclinations close to the critical values. Applying the general methodology to a case study - the asteroid Eros and also considering higher order non-spherical terms, some extraordinary orbits are found, such as the ones with orbital plane co-rotating with the asteroid, and the stable frozen orbits with argument of perigee librating around values different from 0°, 90°, 180°, 270°.

  2. High accuracy satellite drag model (HASDM)

    Science.gov (United States)

    Storz, Mark F.; Bowman, Bruce R.; Branson, Major James I.; Casali, Stephen J.; Tobiska, W. Kent

    The dominant error source in force models used to predict low-perigee satellite trajectories is atmospheric drag. Errors in operational thermospheric density models cause significant errors in predicted satellite positions, since these models do not account for dynamic changes in atmospheric drag for orbit predictions. The Air Force Space Battlelab's High Accuracy Satellite Drag Model (HASDM) estimates and predicts (out three days) a dynamically varying global density field. HASDM includes the Dynamic Calibration Atmosphere (DCA) algorithm that solves for the phases and amplitudes of the diurnal and semidiurnal variations of thermospheric density near real-time from the observed drag effects on a set of Low Earth Orbit (LEO) calibration satellites. The density correction is expressed as a function of latitude, local solar time and altitude. In HASDM, a time series prediction filter relates the extreme ultraviolet (EUV) energy index E10.7 and the geomagnetic storm index ap, to the DCA density correction parameters. The E10.7 index is generated by the SOLAR2000 model, the first full spectrum model of solar irradiance. The estimated and predicted density fields will be used operationally to significantly improve the accuracy of predicted trajectories for all low-perigee satellites.

  3. Low-energy near Earth asteroid capture using Earth flybys and aerobraking

    Science.gov (United States)

    Tan, Minghu; McInnes, Colin; Ceriotti, Matteo

    2018-04-01

    Since the Sun-Earth libration points L1 and L2 are regarded as ideal locations for space science missions and candidate gateways for future crewed interplanetary missions, capturing near-Earth asteroids (NEAs) around the Sun-Earth L1/L2 points has generated significant interest. Therefore, this paper proposes the concept of coupling together a flyby of the Earth and then capturing small NEAs onto Sun-Earth L1/L2 periodic orbits. In this capture strategy, the Sun-Earth circular restricted three-body problem (CRTBP) is used to calculate target Lypaunov orbits and their invariant manifolds. A periapsis map is then employed to determine the required perigee of the Earth flyby. Moreover, depending on the perigee distance of the flyby, Earth flybys with and without aerobraking are investigated to design a transfer trajectory capturing a small NEA from its initial orbit to the stable manifolds associated with Sun-Earth L1/L2 periodic orbits. Finally, a global optimization is carried out, based on a detailed design procedure for NEA capture using an Earth flyby. Results show that the NEA capture strategies using an Earth flyby with and without aerobraking both have the potential to be of lower cost in terms of energy requirements than a direct NEA capture strategy without the Earth flyby. Moreover, NEA capture with an Earth flyby also has the potential for a shorter flight time compared to the NEA capture strategy without the Earth flyby.

  4. On the fluctuations of density and temperature in outer space atmosphere obtained from orbital shift of TAIYO

    International Nuclear Information System (INIS)

    Kato, Yoshio; Onishi, Nobuto; Shimizu, Osamu; Enmi, Sachiko; Hirao, Kunio.

    1976-01-01

    The temperature and density in outer space atmosphere were obtained from the change of the orbital period of the artificial satellite TAIYO which was launched on February 24, 1975, from Kagoshima. An equation to calculate atmospheric density with the characteristic values of the satellite is presented in the first part together with the observed variation of the orbital elements of TAIYO. The weekly changes of temperature and density in outer space atmosphere at the altitude of 250 km, which is the perigee of the satellite, from April 1975 to May 1976 were obtained. The relations between outer space temperature and sigma KP, F10.7, and the position of the perigee were also obtained. The outer space temperature as a function of local time is presented, and it is observed that the temperature change in relation to the local time agrees with the atmospheric model, and that the ratio of maximum or minimum temperature within a day becomes nearly 1.3. It is commented that more data will be available for the further detailed analysis because TAIYO is still orbiting normally. (Aoki, K.)

  5. Observations of neutral composition and related ionospheric variations during a magnetic storm in February 1974

    International Nuclear Information System (INIS)

    Hedin, A.E.; Bauer, P.; Mayr, H.G.; Carignan, G.R.; Brace, L.H.; Brinton, H.C.; Parks, A.D.; Pelz, D.T.

    1977-01-01

    The neutral atmosphere composition experiment on Atmosphere Explorer C measured N 2 , O, Ar, and He densities during a magnetic storm in February 1974 at altitudes down to about 160 km. At latitudes above 45 0 N, N 2 , and Ar densities generally increase during the storm, while He and O densities decrease. Below 45 0 N all densities tend to increase during the storm. The density increases at perigee indicate that density or temperature profile changes are taking place below 160 km. The return to prestorm conditions is very slow, demonstrating the integrating effect of the atmospheric response. A recent theoretical model incorporating thermospheric circulation and diffusion effects reproduces the logitudinally averaged data including latitude trends and the asymmetry about the storm maximum. Comparison with the mass spectrometer and incoherent scatter empirical model shows qualitative agreement with latitude trends but not with storm asymmetry, while the earlier J71 model based on total mass density is not in agreement with observed latitudinal trends. No significant correlation is found with the short-term variations of the ap index. At any fixed altitude and for latitudes above 45 0 N (perigee) the density variations are closely correlated with invariant (or magnetic) latitude, although invariant latitude alone is not adequate to order the data completely. A close correlation is found between in situ O/N 2 measurements and in situ and ground-based ionosonde measurements of electron density

  6. Ion Outflow and Convection in the Polar Cap and Cleft as Measured by Tide, EFI, MFE and Timas

    Science.gov (United States)

    Elliott, H. A.; Craven, P. D.; Chandler, M. O.; Moore, T. E.; Maynard, N. C.; Peterson, W. K.; Lennartsson, O. W.; Shelley, E. G.; Mozer, F. S.; Russell, C. T.

    1997-01-01

    This study examines high-latitude ion outflows and velocities perpendicular to the magnetic field derived from moments of ion distributions measured by the TIDE (Thermal Ion Dynamics Experiment) instrument on the Polar satellite. Hydrogen and oxygen ions are shown to be E X B drifting in the polar cap and cleft regions with a speed of about 5-20 km/s at apogee (approximately 9 Re) and a speed of 1-2 km/s at perigee (approximately 1. 8 Re). E X B drifts are calculated from electric fields measured by EFI (Electric Field Instrument) and magnetic fields measured by MFE (Magnetic Field Experiment) both of which are also on Polar. How convection at Polar's perigee relates to potential patterns of the ionosphere will be discussed. In the cusp/cleft the distribution of hydrogen extends over a large enough range of energy to be measured by both TIDE and the Toroidal Imaging Mass-Angle Spectrograph (TIMAS). Such comparisons will be also be presented.

  7. Trajectory Design for the Transiting Exoplanet Survey Satellite (TESS)

    Science.gov (United States)

    Dichmann, Donald J.; Parker, Joel; Williams, Trevor; Mendelsohn, Chad

    2014-01-01

    The Transiting Exoplanet Survey Satellite (TESS) is a National Aeronautics and Space Administration (NASA) mission launching in 2017. TESS will travel in a highly eccentric orbit around Earth, with initial perigee radius near 17 Earth radii (Re) and apogee radius near 59 Re. The orbit period is near 2:1 resonance with the Moon, with apogee nearly 90 degrees out-of-phase with the Moon, in a configuration that has been shown to be operationally stable. TESS will execute phasing loops followed by a lunar flyby, with a final maneuver to achieve 2:1 resonance with the Moon. The goals of a resonant orbit with long-term stability, short eclipses and limited oscillations of perigee present significant challenges to the trajectory design. To rapidly assess launch opportunities, we adapted the SWM76 launch window tool to assess the TESS mission constraints. To understand the long-term dynamics of such a resonant orbit in the Earth-Moon system we employed Dynamical Systems Theory in the Circular Restricted 3-Body Problem (CR3BP). For precise trajectory analysis we use a high-fidelity model and multiple shooting in the General Mission Analysis Tool (GMAT) to optimize the maneuver delta-V and meet mission constraints. Finally we describe how the techniques we have developed can be applied to missions with similar requirements.

  8. Refilling process in the plasmasphere: a 3-D statistical characterization based on Cluster density observations

    Directory of Open Access Journals (Sweden)

    G. Lointier

    2013-02-01

    Full Text Available The Cluster mission offers an excellent opportunity to investigate the evolution of the plasma population in a large part of the inner magnetosphere, explored near its orbit's perigee, over a complete solar cycle. The WHISPER sounder, on board each satellite of the mission, is particularly suitable to study the electron density in this region, between 0.2 and 80 cm−3. Compiling WHISPER observations during 1339 perigee passes distributed over more than three years of the Cluster mission, we present first results of a statistical analysis dedicated to the study of the electron density morphology and dynamics along and across magnetic field lines between L = 2 and L = 10. In this study, we examine a specific topic: the refilling of the plasmasphere and trough regions during extended periods of quiet magnetic conditions. To do so, we survey the evolution of the ap index during the days preceding each perigee crossing and sort out electron density profiles along the orbit according to three classes, namely after respectively less than 2 days, between 2 and 4 days, and more than 4 days of quiet magnetic conditions (ap ≤ 15 nT following an active episode (ap > 15 nT. This leads to three independent data subsets. Comparisons between density distributions in the 3-D plasmasphere and trough regions at the three stages of quiet magnetosphere provide novel views about the distribution of matter inside the inner magnetosphere during several days of low activity. Clear signatures of a refilling process inside an expended plasmasphere in formation are noted. A plasmapause-like boundary, at L ~ 6 for all MLT sectors, is formed after 3 to 4 days and expends somewhat further after that. In the outer part of the plasmasphere (L ~ 8, latitudinal profiles of median density values vary essentially according to the MLT sector considered rather than according to the refilling duration. The shape of these density profiles indicates that magnetic flux tubes are not

  9. The radial and azimuthal properties of volatiles and dust in the inner coma of Comet 45P/Honda-Mrkos-Pajdušáková

    Science.gov (United States)

    Harris, Walter M.; Ryan, Erin L.; Springmann, Alessondra; Mueller, Beatrice E. A.; Samarasinha, Nalin H.; Kikwaya Elou, Jean-Baptiste; Howell, Ellen S.; Lejoly, Cassandra; Bodnarik, Julia; Fitzpatrick, Ryleigh; Maciel, Ricardo; Mitchell, Adriana; Watson, Zachary Tyler

    2017-10-01

    In February 2017 comet 45P/Honda-Mrkos-Pajdušáková (HMP) passed by the Earth at a perigee distance of 0.08 AU. Such encounters provide an important opportunity for study of the inner coma region where gas and dust production occur. We report here on wide-field (30 x 30 arcminute), high-spatial resolution (35 km/pixel) observations of HMP obtained with the 90Prime One imager on the 2.3m Bok telescope at Kitt Peak. The observations were performed on February 16 and 17, when the comet was 0.1 AU from Earth, using a combination of a wide-band Gunn r’ filter and a subset of the HB filter library (OH, CN, C2, Blue Continuum). In this presentation we will discuss the distribution and color of the dust, the relative production rates of volatiles, and the implied parent-daughter photochemical evolution from radial expansion modeling.

  10. Examining Dehydration and Hypoxic Stress in Wheat Plants Using a Porous Tube Plant Nutrient Delivery System Developed for Microgravity

    Science.gov (United States)

    Dreschel, T. W.; Hall, C. R.; Foster, T. E.; Salganic, M.; Warren, L.; Corbett, M.

    2005-01-01

    The Porous Tube Plant Nutrient Delivery System (PTPNDS) was designed for NASA to grow plants in microgravity of space. The system utilizes a controlled fluid loop to supply nutrients and water to plant roots growing on a ceramic surface moistened by capiflary action. A PTPNDS test bed was developed and utilizing remote sensing systems, spectral analyses procedures, gas-exchange, and fluorescence measurements, we examined differences in plant water status for wheat plants (Triticum aestivum, cv. Perigee) grown in a modified growth chamber during the summers of 2003 and 2004. Some differences in plant performance were detectable in the gas-exchange and fluorescence measurements. For instance, in both years the plants grown with the most available water had the lowest rates of photosynthesis and exhibited higher proportions of non-photochemical quenching particularly under low light levels. In addition, small differences in mean leaf water content between treatments were detected using spectral reflectance analyses.

  11. Scout fourth stage attitude and velocity control (AVC) system feasibility study

    Science.gov (United States)

    Byars, L. B.

    1975-01-01

    The feasibility of incorporating a guidance system in the Scout fourth stage to achieve a significant improvement in expected payload delivery accuracy is studied. The technical investigations included the determination of the AVC equipment performance requirements, establishment of qualification and acceptance test levels, generation of layouts illustrating design approaches for the upper D and payload transition sections to incorporate the hardware, and the preparation of a vendor bid package. Correction concepts, utilizing inertial velocity and attitude, were identified and evaluated. Fourth stage attitude adjustments as determined from inertial velocity variation through the first three stages and a final velocity correction based upon the measured in-plane component errors at injection were employed. Results show radical reductions in apogee-perigee deviations.

  12. Encke-Beta Predictor for Orion Burn Targeting and Guidance

    Science.gov (United States)

    Robinson, Shane; Scarritt, Sara; Goodman, John L.

    2016-01-01

    The state vector prediction algorithm selected for Orion on-board targeting and guidance is known as the Encke-Beta method. Encke-Beta uses a universal anomaly (beta) as the independent variable, valid for circular, elliptical, parabolic, and hyperbolic orbits. The variable, related to the change in eccentric anomaly, results in integration steps that cover smaller arcs of the trajectory at or near perigee, when velocity is higher. Some burns in the EM-1 and EM-2 mission plans are much longer than burns executed with the Apollo and Space Shuttle vehicles. Burn length, as well as hyperbolic trajectories, has driven the use of the Encke-Beta numerical predictor by the predictor/corrector guidance algorithm in place of legacy analytic thrust and gravity integrals.

  13. Contingency plans for the ISEE-3 libration-point mission

    Science.gov (United States)

    Dunham, D. W.

    1979-01-01

    During the planning stage of the International Sun-Earth Explorer-3 (ISEE-3) mission, a recovery strategy was developed in case the Delta rocket underperformed during the launch phase. If a large underburn had occurred, the ISEE-3 spacecraft would have been allowed to complete one revolution of its highly elliptical earth orbit. The recovery plan called for a maneuver near perigee to increase the energy of the off-nominal orbit; a relatively small second maneuver would then insert the spacecraft into a new transfer trajectory toward the desired halo orbit target, and a third maneuver would place the spacecraft in the halo orbit. Results of the study showed that a large range of underburns could be corrected for a total nominal velocity deviation cost within the ISEE-3 fuel budget.

  14. Radiation measurement on the International Space Station

    International Nuclear Information System (INIS)

    Akopova, A.B.; Manaseryan, M.M.; Melkonyan, A.A.; Tatikyan, S.Sh.; Potapov, Yu.

    2005-01-01

    The results of an investigation of radiation environment on board the ISS with apogee/perigee of 420/380km and inclination 51.6 o are presented. For measurement of important characteristics of cosmic rays (particles fluxes, LET spectrum, equivalent doses and heavy ions with Z>=2) a nuclear photographic emulsion as a controllable threshold detector was used. The use of this detector permits a registration of the LET spectrum of charged particles within wide range of dE/dx and during last years it has already been successfully used on board the MIR station, Space Shuttles and 'Kosmos' spacecrafts. An integral LET spectrum was measured in the range 0.5-2.2x103keV/μm and the value of equivalent dose 360μSv/day was estimated. The flux of biologically dangerous heavy particles with Z>=2 was measured (3.85x103particles/cm2)

  15. STS-49 ASEM activity illustrated with PLAID computer graphics

    Science.gov (United States)

    1992-01-01

    STS-49 Endeavour, Orbiter Vehicle (OV) 105, Assembly of Station by Extravehicular Activity (EVA) Methods (ASEM) activity is illustrated with PLAID computer graphics. An extravehicular mobility unit (EMU) suited crewmember, positioned on the remote manipulator system (RMS) manipulator foot restraint (MFR), grabs and maneuvers the multipurpose experiment support structure (MPESS) with truss assembly attached above OV-105's payload bay (PLB) using the steer wheel assembly. The MPESS/ASEM truss structure has been lifted out the sill-mounted payload retention latch assemblies (PRLAs) and will be repositioned in the PRLAs upon completion of handling procedures. Also seen in this illustration are the empty INTELSAT perigee stage cradle structure (aft PLB) and the capture bar grapple fixture stowed on the port side sill longeron.

  16. Nesting biology of the trap-nesting Neotropical wasp Trypoxylo n(Trypargilum aurifrons Shuckard (Hymenoptera, Crabronidae Biologia da nidificação de Trypoxylon (Trypargilum aurifrons Shuckard (Hymenoptera, Crabronidae em ninhos-armadilhas

    Directory of Open Access Journals (Sweden)

    Mariana Marchi Santoni

    2007-09-01

    Full Text Available The present study was carried out in three localities of the state of São Paulo, Brazil: Araras (Dec/03-Dec/06, São Carlos (Nov/04-Nov/06 and Rifaina (Jul/04-Dec/06. Trap-nests were distributed among sites in the sampling areas and were collected every 35 days. Data from 295 nests indicate that T. aurifrons is a multivoltine species, with higher rates of nest building and cell production in the warm, rainy season. The trap-nests used by the females ranged from 117 to 467 mm in length and 3.1 to 16.6 mm in diameter. All nests showed deep plugs and a vestibular cell was found in 37% of the complete nests. The number of cells per nest ranged from one to 12. Females were larger than males, emerged from longer cells and their cocoons were significantly larger. A secondary 1:1 sex ratio was found in Araras and Rifaina. No correlation was observed between the diameter of the trap-nest and sex ratio. Males were usually oviposited in the first brood cells. Male and female developmental time from egg to adult was longer in the cold, dry season. Trypoxylon aurifrons provisioned their nests mainly with orb-spiders from the family Araneidae. The most important mortality factor was the death of immature forms, probably due to development failure. The most important parasitoid was Melittobia sp.Este estudo foi realizado em três localidades do estado de São Paulo: Araras (dez/03-dez/06, São Carlos (nov/04-nov/06 e Rifaina (jul/04-dez/06. Ninhos-armadilhas foram distribuídos em diferentes sítios das áreas amostradas e coletados a cada 35 dias. Dados de 295 ninhos mostraram que T. aurifrons é uma espécie multivoltina, com maiores taxas de nidificação e produção de células na estação quente e chuvosa. Os ninhos-armadilhas utilizados pelas fêmeas variaram de 117 a 467 mm de comprimento e de 3,1 a 16,6 mm de diâmetro. Todos os ninhos apresentaram parede de fundo e célula vestibular foi constatada em 37% dos ninhos completos. O número de c

  17. Modeling Run Test Validity: A Meta-Analytic Approach

    National Research Council Canada - National Science Library

    Vickers, Ross

    2002-01-01

    .... This study utilized data from 166 samples (N = 5,757) to test the general hypothesis that differences in testing methods could account for the cross-situational variation in validity. Only runs >2 km...

  18. LHCb Computing Resources: 2019 requests and reassessment of 2018 requests

    CERN Document Server

    Bozzi, Concezio

    2017-01-01

    This document presents the computing resources needed by LHCb in 2019 and a reassessment of the 2018 requests, as resulting from the current experience of Run2 data taking and minor changes in the LHCb computing model parameters.

  19. LHC physics results and prospects

    CERN Document Server

    Kono, Takanori; The ATLAS collaboration

    2018-01-01

    This talk presents the latest results from LHC Run-2 as of May 2018 which include Standard Model measurements, Higgs boson properties and beyond Standard Model search results. The prospects for future LHC runs are also shown.

  20. Recent Results from the ATLAS Experiment

    CERN Document Server

    Djama, Fares; The ATLAS collaboration

    2015-01-01

    A selection of recent Run 1 ATLAS results and first preliminary results from Run 2 are shown. Overview plots on Higgs properties, top measurements and SUSY searches are presented as well as recent QCD and electroweak measurements.

  1. Designing a future Conditions Database based on LHC experience

    CERN Document Server

    Formica, Andrea; The ATLAS collaboration; Gallas, Elizabeth; Govi, Giacomo; Lehmann Miotto, Giovanna; Pfeiffer, Andreas

    2015-01-01

    The ATLAS and CMS Conditions Database infrastructures have served each of the respective experiments well through LHC Run 1, providing efficient access to a wide variety of conditions information needed in online data taking and offline processing and analysis. During the long shutdown between Run 1 and Run 2, we have taken various measures to improve our systems for Run 2. In some cases, a drastic change was not possible because of the relatively short time scale to prepare for Run 2. In this process, and in the process of comparing to the systems used by other experiments, we realized that for Run 3, we should consider more fundamental changes and possibilities. We seek changes which would streamline conditions data management, improve monitoring tools, better integrate the use of metadata, incorporate analytics to better understand conditions usage, as well as investigate fundamental changes in the storage technology, which might be more efficient while minimizing maintenance of the data as well as simplif...

  2. Conference: Gearing up for LHC13

    CERN Document Server

    2015-01-01

    2015 will be an important year for the Large Hadron Collider. With the start of Run 2 at a centre of mass energy of 13 TeV, it will be possible to probe the existence of heavier states as expected in extensions of the Standard Model motivated by e.g. naturalness and dark matter. Preliminary results from Run 2 could either confirm the Standard Model with high accuracy or provide first hints of new structures at the TeV scale. In either case, the results from Run 2 will determine much of the future of the field for decades. During the conference we are planning to discuss the most recent LHC results and their implications for physics beyond the Standard Model.

  3. BEH scalar @ 13 TeV in gamgam, ZZ, WW final states

    CERN Document Server

    Zenz, Seth

    2016-01-01

    The latest studies on the decays of the recently discovered BEH Scalar into bosons are presented to pairs of W bosons, Z bosons, and photons. These results include the latest data from the CMS and ATLAS experiments, collected from 13 TeV LHC Run 2 in 2015. Although data collected is thus far limited, the continuation and extension of these studies through the rest of Run 2 will allow detailed comparisons of the BEH Scalars properties with those predicted by the Standard Model.

  4. What is the γγ resonance at 750 GeV?

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, Roberto; Giudice, Gian F. [CERN, Theory Division,CH-1211 Geneva 23 (Switzerland); Kamenik, Jernej F. [CERN, Theory Division,CH-1211 Geneva 23 (Switzerland); Jožef Stefan Institute,Jamova 39, 1000 Ljubljana (Slovenia); Faculty of Mathematics and Physics, University of Ljubljana,Jadranska 19, 1000 Ljubljana (Slovenia); McCullough, Matthew [CERN, Theory Division,CH-1211 Geneva 23 (Switzerland); Pomarol, Alex [CERN, Theory Division,CH-1211 Geneva 23 (Switzerland); Departament de Física and IFAE-BIST, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Rattazzi, Riccardo [Institut de Théorie des Phénomènes Physiques, EPFL,Route de la Sorge, CH-1015 Lausanne (Switzerland); Redi, Michele [INFN, Sezione di Firenze,Via G. Sansone, 1, I-50019 Sesto Fiorentino (Italy); Riva, Francesco [CERN, Theory Division,CH-1211 Geneva 23 (Switzerland); Strumia, Alessandro [CERN, Theory Division,CH-1211 Geneva 23 (Switzerland); Dipartimento di Fisica dell’Università di Pisa and INFN,Largo Bruno Pontecorvo 3, 56127 Pisa (Italy); Torre, Riccardo [Institut de Théorie des Phénomènes Physiques, EPFL,Route de la Sorge, CH-1015 Lausanne (Switzerland)

    2016-03-21

    Run 2 LHC data show hints of a new resonance in the diphoton distribution at an invariant mass of 750 GeV. We analyse the data in terms of a new boson, extracting information on its properties and exploring theoretical interpretations. Scenarios covered include a narrow resonance and, as preliminary indications suggest, a wider resonance. If the width indications persist, the new particle is likely to belong to a strongly-interacting sector. We also show how compatibility between Run 1 and Run 2 data is improved by postulating the existence of an additional heavy particle, whose decays are possibly related to dark matter.

  5. Measurements at LHC and their relevance for cosmic ray physics

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Many LHC measurements are already used to improve hadronic interaction models used in cosmic ray analyses. This already had a positive effect on the model dependence of crucial data analyses. Some of the data and the model tuning is reviewed. However, the LHC still has a lot more potential to provide crucial information. Since the start of Run2 the highest accelerator beam energies are reached and no further increase can be expected for a long time. First data of Run2 are published and the fundamental performance of cosmic ray hadronic interaction models can be scrutinized. The relevance of LHC data in general for cosmic ray data analyses is demonstrated.

  6. Physics with CMS and Electronic Upgrades

    Energy Technology Data Exchange (ETDEWEB)

    Rohlf, James W. [Boston Univ., MA (United States)

    2016-08-01

    The current funding is for continued work on the Compact Muon Solenoid (CMS) at the CERN Large Hadron Collider (LHC) as part of the Energy Frontier experimental program. The current budget year covers the first year of physics running at 13 TeV (Run 2). During this period we have concentrated on commisioning of the μTCA electronics, a new standard for distribution of CMS trigger and timing control signals and high bandwidth data aquistiion as well as participating in Run 2 physics.

  7. 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.

  8. Searches for electroweak production of supersymmetric gauginos and sleptons with the ATLAS detector

    CERN Document Server

    Lorenz, Jeanette; The ATLAS collaboration

    2018-01-01

    Analyzing 36.1 fb$^{-1}$ of proton-proton collision data at $\\sqrt{s}$ = 13 TeV, delivered by the LHC and recorded by the ATLAS detector in 2015 and 2016 during Run 2, various SUSY searches for the electroweak production of gauginos and sleptons were pursued. More challenging than searches for strongly produced supersymmetric particles, many of these searches show their first results with data of Run 2. In particular, searches for higgsinos are able to reach sensitivities that surpass LEP limits for the first time using LHC data.

  9. Higgs Effective Field Theories

    CERN Document Server

    2016-01-01

    The main focus of this meeting is to present new theoretical advancements related to effective field theories, evaluate the impact of initial results from the LHC Run2, and discuss proposals for data interpretation/presentation during Run2. A crucial role of the meeting is to bring together theorists from different backgrounds and with different viewpoints and to extend bridges towards the experimental community. To this end, we would like to achieve a good balance between senior and junior speakers, enhancing the visibility of younger scientists while keeping some overview talks.

  10. TEVATRON Searches for Large Extra Dimensions and Leptoquarks

    International Nuclear Information System (INIS)

    Mattingly, S.

    2002-01-01

    This paper presents searches for large extra dimensions and leptoquarks in p(anti)p collisions from Run 1 at the Tevatron. Large extra dimensions are searched for in real graviton production with a monojet or monophoton and in virtual graviton exchange processes with electron or photon pairs. Results from leptoquark searches are presented for three generations of leptoquarks. No evidence of signal is found in any searches for large extra dimensions or leptoquarks and limits are placed. Perceptivities for these searches in the Tevatron's Run 2 are discussed and initial Run 2 data is presented. (author)

  11. Early Inner Detector Tracking Performance in the 2015 data at $\\sqrt s$ = 13 TeV

    CERN Document Server

    The ATLAS collaboration

    2015-01-01

    This note summarises the studies undertaken to recommend benchmark values and systematic uncertainties for various aspects of the ATLAS Inner Detector tracking based on $\\sqrt{s}= 13$ TeV proton-proton collisions from the Large Hadron Collider Run 2 data. The track reconstruction efficiency, fake rate, and related systematic uncertainties are presented for two different track quality selections, along with the impact parameter resolution and the alignment weak mode systematic uncertainities. These recommendations apply to physics analyses using Inner Detector tracks in Run 2 data and are important inputs for other objects based on tracks.

  12. The cosmic ray and solar flare isotope experiments in the CRRES, NOAA-I and ''Ulysses'' satellites

    International Nuclear Information System (INIS)

    Garcia-Munoz, M.

    1990-01-01

    The ONR-604 instrument has been designed to measure the energy spectra and the isotopic composition at 1 AU of the elements Hydrogen to Nickel in the energy range 40--500 MeV/n and will be carried by the Combined Release and Radiation Effects Satellite (CRRES) to be launched July, 1990 in a highly eccentric orbit between a low perigee and a synchronous orbit point. It will measure galactic cosmic rays, solar energetic particles, and trapped and pseudo-trapped particles in the Earth magnetosphere. Also at 1 AU, the Energetic Heavy Ion Composition (EHIC) instrument, designed to study mainly the elemental and isotopic composition of solar energetic particles over the charge range H to Ni, in the energy range 0.5 to 200 MeV/n, will be placed in a Sun-synchronous circular polar orbit of 833 or 870 km altitude by a NOAA-I satellite scheduled to be launched late 1990 or early 1991. The University of Chicago High Energy Telescope (HET) experiment which is part of the COSPIN consortium on the ''Ulysses'' mission will measure the energy spectra and the isotopic composition of the elments Hydrogen to Nickel in the energy interval 20--450 MeV/n in the heliosphere, both the ecliptic plane and at high heliographic latitudes in an orbit around the Sun that will have an aphelion near a Jupiter orbit point and a perhelion of about 1.4 AU. It will be launched October 1990

  13. Design, qualification and operation of nuclear rockets for safe Mars missions

    International Nuclear Information System (INIS)

    Buden, D.; Madsen, W.W.; Olson, T.S.; Redd, L.R.

    1993-01-01

    Nuclear thermal propulsion modules planned for use on crew missions to Mars improve mission reliability and overall safety of the mission. This, as well as all other systems, are greatly enhanced if the system specifications take into account safety from design initiation, and operational considerations are well thought through and applied. For instance, the use of multiple engines in the propulsion module can lead to very high system safety and reliability. Operational safety enhancements may include: the use of multiple perigee burns, thus allowing time to ensure that all systems are functioning properly prior to departure from Earth orbit; the ability to perform all other parts of the mission in a degraded mode with little or no degradation of the mission; and the safe disposal of the nuclear propulsion module in a heliocentric orbit out of the ecliptic plane. The standards used to qualify nuclear rockets are one of the main cost drivers of the program. Concepts and systems that minimize cost and risk will rely on use of the element and component levels to demonstrate technology readiness and validation. Subsystem or systems testing then is only needed for verification of performance. Also, these will be the safest concepts because they will be more thoroughly understood and the safety margins will be well established and confirmed by tests

  14. B-Identifikation im Level 2 Trigger des ATLAS Experiments

    CERN Document Server

    AUTHOR|(CDS)2072780

    Zur Zeit wird am europäischen Forschungszentrum für Teilchenphysik CERN der neue Proton-Proton-Speicherring LHC und die zugehörigen vier Experimente gebaut. Ziele der Experimente sind unter anderem der Nachweis des Higgs-Bosons sowie detaillierte Studien des top-Quarks. Um möglichst reine Datensätze zu erhalten wäre es hilfreich, diese Ereignisse bereits während der Datennahme möglichst effizient zu selektieren. Dabei würde es helfen, wenn b-Quark-Jets auf Trigger-Niveau erkannt werden könnten. Ziel der Arbeit war die Entwicklung eines Algorithmus zur Identifikation von b-Quark-Jets, welcher die Anforderungen des Level 2 Triggers erfüllt. Das erste Kapitel der Arbeit gibt einen Einblick in die wesentlichen Bestandteile des Standardmodells der Teilchenphysik. In den folgenden zwei Kapiteln wird der Beschleuniger und der ATLAS Detektor sowie das ATLAS-Triggersystem beschrieben. Kapitel vier beschreibt die Möglichkeiten der B-Jet-Identifikation sowie einen Vertexalgorithmus auf Basis der Perigee-Pa...

  15. Remote sensing of refractivity from space for global observations of atmospheric parameters

    International Nuclear Information System (INIS)

    Gorbunov, M.E.; Sokolovskiy, S.V.

    1993-01-01

    This report presents the first results of computational simulations on the retrieval of meteorological parameters from space refractometric data on the basis of the ECHAM 3 model developed at the Max Planck Institute for Meteorology (Roeckner et al. 1992). For this purpose the grid fields of temperature, geopotential and humidity available from the model were interpolated and a continuous spatial field of refractivity (together with its first derivative) was generated. This field was used for calculating the trajectories of electromagnetic rays for the given orbits of transmitting and receiving satellites and for the determination of the quantities (incident angles or Doppler frequency shifts) being measured at receiving satellite during occultation. These quantities were then used for solving the inverse problem - retrieving the distribution of refractivity in the vicinity of the ray perigees. The retrieved refractivity was used to calculate pressure and temperature (using the hydrostatic equation and the equation of state). The results were compared with initial data, and the retrieval errors were evaluated. The study shows that the refractivity can be retrieved with very high accuracy in particular if a tomographic reconstruction is applied. Effects of humidity and temperature are not separable. Stratospheric temperatures globally and upper tropospheric temperatures at middle and high latitudes can be accurately retrieved, other areas require humidity data. Alternatively humidity data can be retrieved if the temperature fields are known. (orig.)

  16. Space Radiation Environment Prediction for VLSI microelectronics devices onboard a LEO Satellite using OMERE-Trad Software

    Science.gov (United States)

    Sajid, Muhammad

    This tutorial/survey paper presents the assessment/determination of level of hazard/threat to emerging microelectronics devices in Low Earth Orbit (LEO) space radiation environment with perigee at 300 Km, apogee at 600Km altitude having different orbital inclinations to predict the reliability of onboard Bulk Built-In Current Sensor (BBICS) fabricated in 350nm technology node at OptMA Lab. UFMG Brazil. In this context, the various parameters for space radiation environment have been analyzed to characterize the ionizing radiation environment effects on proposed BBICS. The Space radiation environment has been modeled in the form of particles trapped in Van-Allen radiation belts(RBs), Energetic Solar Particles Events (ESPE) and Galactic Cosmic Rays (GCR) where as its potential effects on Device- Under-Test (DUT) has been predicted in terms of Total Ionizing Dose (TID), Single-Event Effects (SEE) and Displacement Damage Dose (DDD). Finally, the required mitigation techniques including necessary shielding requirements to avoid undesirable effects of radiation environment at device level has been estimated /determined with assumed standard thickness of Aluminum shielding. In order to evaluate space radiation environment and analyze energetic particles effects on BBICS, OMERE toolkit developed by TRAD was utilized.

  17. Pulsations of Energetic Electron Pulsations In Association With Substorm Onset

    Science.gov (United States)

    Åsnes, A.; Stadsnes, J.; Bjordal, J.; Østgaard, N.; Haaland, S.; Rosenberg, T. J.; Detrick, D. L.

    The Polar Ionospheric X-ray Imaging Experiment (PIXIE) is giving detailed images of the energetic electron precipitation when the POLAR satellite is near perigee over the Antarctica. In this area the PIXIE images have a spatial resolution of the order of 100 km, and a temporal resolution of 10 s can be obtained. In this paper we present the results of a study focusing on the onset and expansion of a substorm occuring on July 24, 1998. In this event we observe strong modulations of the energetic electron precipitation with period around 1 minute following substorm onset. The pulsations were restricted to a narrow magnetic local time sector in the pre-midnight region, about 0.5 hours wide, and showed movement towards higher latitudes and earlier lo- cal times. The event will be discussed in context of measurements from ground sta- tions and satellites in geosynchronous orbit. Precipitation of energetic electrons will be compared with VLF/ELF ground measurements. Features in the energetic elec- tron precipitation will be mapped to the magnetospheric equatorial plane by field line tracing.

  18. Global pictures of the ozone field from high altitudes from DE-I

    Science.gov (United States)

    Keating, G. M.; Frank, L.; Craven, J.; Shapiro, M.; Young, D.; Bhartia, P.

    1982-01-01

    Detailed synoptic views of the column ozone field can be obtained by the Spin-Scan Ozone Imager (SOI) (Keating et al., 1981) aboard the Dynamics Explorer I satellite. The eccentric polar orbit with an apogee altitude of 23,000 km allows high resolution global-scale images to be obtained within 12 minutes, and allows regions to be viewed for long periods of time. At perigee, a pixel size of nadir measurements of 3 km is possible, and measurements are determined using the backscattered ultraviolet technique. A wavelength measurement of 317.5 nm is used as there are limitations in filter locations and it allows comparison with Nimbus 7 SBUV/TOMS data. Consideration of the reflectivities of this data aids in checking the SOI data reduction algorithm. SOI data show short-term (less than one day) variations in the observed ozone field, and a negative correlation (greater than 0.9) between ozone and tropopause heights. It is expected, due to this correlation, that SOI data will aid in understanding the time evolution of dynamics near the tropopause.

  19. Maintaining Aura's Orbit Requirements While Performing Orbit Maintenance Maneuvers Containing an Orbit Normal Delta-V Component

    Science.gov (United States)

    Johnson, Megan R.; Petersen, Jeremy D.

    2014-01-01

    The Earth Observing System (EOS) Afternoon Constellation consists of five member missions (GCOM-W1, Aqua, CALIPSO, CloudSat, and Aura), each of which maintain a frozen, sun-synchronous orbit with a 16-day repeating ground track that follows the Worldwide Reference System-2 (WRS-2). Under nominal science operations for Aura, the propulsion system is oriented such that the resultant thrust vector is aligned 13.493 degrees away from the velocity vector along the yaw axis. When performing orbit maintenance maneuvers, the spacecraft performs a yaw slew to align the thrust vector in the appropriate direction. A new Drag Make Up (DMU) maneuver operations scheme has been implemented for Aura alleviating the need for the 13.493 degree yaw slew. The focus of this investigation is to assess the impact that no-slew DMU maneuver operations will have on Aura's Mean Local Time (MLT) which drives the required along track separation between Aura and the constellation members, as well as Aura's frozen orbit properties, eccentricity and argument of perigee. Seven maneuver strategies were analyzed to determine the best operational approach. A mirror pole strategy, with maneuvers alternating at the North and South poles, was implemented operationally to minimize impact to the MLT. Additional analysis determined that the mirror pole strategy could be further modified to include frozen orbit maneuvers and thus maintain both MLT and the frozen orbit properties under noslew operations.

  20. First results from the RAPID imaging energetic particle spectrometer on board Cluster

    Directory of Open Access Journals (Sweden)

    B. Wilken

    Full Text Available The advanced energetic particle spectrometer RAPID on board Cluster can provide a complete description of the relevant particle parameters velocity, V , and atomic mass, A, over an energy range from 30 keV up to 1.5 MeV. We present the first measurements taken by RAPID during the commissioning and the early operating phases. The orbit on 14 January 2001, when Cluster was travelling from a perigee near dawn northward across the pole towards an apogee in the solar wind, is used to demonstrate the capabilities of RAPID in investigating a wide variety of particle populations. RAPID, with its unique capability of measuring the complete angular distribution of energetic particles, allows for the simultaneous measurements of local density gradients, as reflected in the anisotropies of 90° particles and the remote sensing of changes in the distant field line topology, as manifested in the variations of loss cone properties. A detailed discussion of angle-angle plots shows considerable differences in the structure of the boundaries between the open and closed field lines on the nightside fraction of the pass and the magnetopause crossing. The 3 March 2001 encounter of Cluster with an FTE just outside the magnetosphere is used to show the first structural plasma investigations of an FTE by energetic multi-spacecraft observations.

    Key words. Magnetospheric physics (energetic particles, trapped; magnetopause, cusp and boundary layers; magnetosheath

  1. Preliminary analysis of accelerated space flight ionizing radiation testing

    Science.gov (United States)

    Wilson, J. W.; Stock, L. V.; Carter, D. J.; Chang, C. K.

    1982-01-01

    A preliminary analysis shows that radiation dose equivalent to 30 years in the geosynchronous environment can be accumulated in a typical composite material exposed to space for 2 years or less onboard a spacecraft orbiting from perigee of 300 km out to the peak of the inner electron belt (approximately 2750 km). Future work to determine spacecraft orbits better tailored to materials accelerated testing is indicated. It is predicted that a range of 10 to the 9th power to 10 to the 10th power rads would be accumulated in 3-6 mil thick epoxy/graphite exposed by a test spacecraft orbiting in the inner electron belt. This dose is equivalent to the accumulated dose that this material would be expected to have after 30 years in a geosynchronous orbit. It is anticipated that material specimens would be brought back to Earth after 2 years in the radiation environment so that space radiation effects on materials could be analyzed by laboratory methods.

  2. First results from the RAPID imaging energetic particle spectrometer on board Cluster

    Directory of Open Access Journals (Sweden)

    B. Wilken

    2001-09-01

    Full Text Available The advanced energetic particle spectrometer RAPID on board Cluster can provide a complete description of the relevant particle parameters velocity, V , and atomic mass, A, over an energy range from 30 keV up to 1.5 MeV. We present the first measurements taken by RAPID during the commissioning and the early operating phases. The orbit on 14 January 2001, when Cluster was travelling from a perigee near dawn northward across the pole towards an apogee in the solar wind, is used to demonstrate the capabilities of RAPID in investigating a wide variety of particle populations. RAPID, with its unique capability of measuring the complete angular distribution of energetic particles, allows for the simultaneous measurements of local density gradients, as reflected in the anisotropies of 90° particles and the remote sensing of changes in the distant field line topology, as manifested in the variations of loss cone properties. A detailed discussion of angle-angle plots shows considerable differences in the structure of the boundaries between the open and closed field lines on the nightside fraction of the pass and the magnetopause crossing. The 3 March 2001 encounter of Cluster with an FTE just outside the magnetosphere is used to show the first structural plasma investigations of an FTE by energetic multi-spacecraft observations.Key words. Magnetospheric physics (energetic particles, trapped; magnetopause, cusp and boundary layers; magnetosheath

  3. Possible forcing of global temperature by the oceanic tides

    Science.gov (United States)

    Keeling, Charles D.; Whorf, Timothy P.

    1997-01-01

    An approximately decadal periodicity in surface air temperature is discernable in global observations from A.D. 1855 to 1900 and since A.D. 1945, but with a periodicity of only about 6 years during the intervening period. Changes in solar irradiance related to the sunspot cycle have been proposed to account for the former, but cannot account for the latter. To explain both by a single mechanism, we propose that extreme oceanic tides may produce changes in sea surface temperature at repeat periods, which alternate between approximately one-third and one-half of the lunar nodal cycle of 18.6 years. These alternations, recurring at nearly 90-year intervals, reflect varying slight degrees of misalignment and departures from the closest approach of the Earth with the Moon and Sun at times of extreme tide raising forces. Strong forcing, consistent with observed temperature periodicities, occurred at 9-year intervals close to perihelion (solar perigee) for several decades centered on A.D. 1881 and 1974, but at 6-year intervals for several decades centered on A.D. 1923. As a physical explanation for tidal forcing of temperature we propose that the dissipation of extreme tides increases vertical mixing of sea water, thereby causing episodic cooling near the sea surface. If this mechanism correctly explains near-decadal temperature periodicities, it may also apply to variability in temperature and climate on other times-scales, even millennial and longer. PMID:11607740

  4. Chandra Snapshot Spectral Imaging of Comets C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR)

    Science.gov (United States)

    Lisse, Carey

    2003-09-01

    The highly favorable perigee passage of the very bright comets C/2001 Q4 (NEAT) and C/2002 T7 (LINEAR) in late May 2004 provides an opportunity to study cometary x-ray emission in conjunction with the new CHIPS spectroscopic mission. In 10 ksec of on-target time for each comet, ACIS-S will obtain snapshot images of the comets in the heart of the CHIPS 0.05 0.150 keV spectroscopic monitoring period in late-May 2004. The combined observations have the potential of directly detecting for the first time the ultra-soft emission due to Mg, S, Si, and Fe predicted by McCammon et al. (2002) from soft x-ray background measurements and by Kharchenko et al. (2000, 2003) from models of solar wind minor ion charge exchange emission. New work by Wegmann, Dennerl, and Lisse (2004) allows a determination of the neutral gas production rate from the spatial scale of the emission, and an independent determination of the solar wind minor ion flux density using the x-ray surface brightness.

  5. Geosynchronous inclined orbits for high-latitude communications

    Science.gov (United States)

    Fantino, E.; Flores, R. M.; Di Carlo, M.; Di Salvo, A.; Cabot, E.

    2017-11-01

    We present and discuss a solution to the growing demand for satellite telecommunication coverage in the high-latitude geographical regions (beyond 55°N), where the signal from geostationary satellites is limited or unavailable. We focus on the dynamical issues associated to the design, the coverage, the maintenance and the disposal of a set of orbits selected for the purpose. Specifically, we identify a group of highly inclined, moderately eccentric geosynchronous orbits derived from the Tundra orbit (geosynchronous, eccentric and critically inclined). Continuous coverage can be guaranteed by a constellation of three satellites in equally spaced planes and suitably phased. By means of a high-precision model of the terrestrial gravity field and the relevant environmental perturbations, we study the evolution of these orbits. The effects of the different perturbations on the ground track (which is more important for coverage than the orbital elements themselves) are isolated and analyzed. The physical model and the numerical setup are optimized with respect to computing time and accuracy. We show that, in order to maintain the ground track unchanged, the key parameters are the orbital period and the argument of perigee. Furthermore, corrections to the right ascension of the ascending node are needed in order to preserve the relative orientation of the orbital planes. A station-keeping strategy that minimizes propellant consumption is then devised, and comparisons are made between the cost of a solution based on impulsive maneuvers and one with continuous thrust. Finally, the issue of end-of-life disposal is discussed.

  6. Multipoint analysis of the spatio-temporal coherence of dayside O+ outflows with Cluster

    Directory of Open Access Journals (Sweden)

    P. Puhl-Quinn

    2004-07-01

    Full Text Available The spatial distribution of ionospheric ion outflow from the dayside cusp/cleft has previously been studied in great detail with numerous satellite missions, but only statistically. Between July and November 2001, the orbit configuration of the Cluster multi-satellite system close to its perigee (4 Earth radii allows for delay times between spacecraft of about 4 and 35min in crossing the cusp/cleft. This enables for the first time to assess the spatial and temporal coherence of O+ ion outflow on time scales of the order of the satellite time lag. After presenting two contrasting events in detail, O+ velocities and outflow intensities from three spacecraft, available on 18 events, all with a similar orbit, have been cross-correlated to quantify the degree of coherence in the outflow. The main result from the analysis is that, although dayside outflows are a permanent feature, steady-state conditions are surprisingly never achieved. In particular, a significant variability is found for convection drift and local outflow intensities on small time scales. This variability of local intensities is not found to depend on the total strenghth of the outflow, which is much more stable and increases with the dynamic solar wind pressure.

  7. Case study of inclined sporadic E layers in the Earth's ionosphere observed by CHAMP/GPS radio occultations: Coupling between the tilted plasma layers and internal waves

    Science.gov (United States)

    Gubenko, Vladimir N.; Pavelyev, A. G.; Kirillovich, I. A.; Liou, Y.-A.

    2018-04-01

    We have used the radio occultation (RO) satellite data CHAMP/GPS (Challenging Minisatellite Payload/Global Positioning System) for studying the ionosphere of the Earth. A method for deriving the parameters of ionospheric structures is based upon an analysis of the RO signal variations in the phase path and intensity. This method allows one to estimate the spatial displacement of a plasma layer with respect to the ray perigee, and to determine the layer inclination and height correction values. In this paper, we focus on the case study of inclined sporadic E (Es) layers in the high-latitude ionosphere based on available CHAMP RO data. Assuming that the internal gravity waves (IGWs) with the phase-fronts parallel to the ionization layer surfaces are responsible for the tilt angles of sporadic plasma layers, we have developed a new technique for determining the parameters of IGWs linked with the inclined Es structures. A small-scale internal wave may be modulating initially horizontal Es layer in height and causing a direction of the plasma density gradient to be rotated and aligned with that of the wave propagation vector k. The results of determination of the intrinsic wave frequency and period, vertical and horizontal wavelengths, intrinsic vertical and horizontal phase speeds, and other characteristics of IGWs under study are presented and discussed.

  8. Assimilation of GPS Refractivity from FORMOSAT-3/COSMIC Using a Nonlocal Operator with WRF 3DVAR and Its Impact on the Prediction of a Typhoon Event

    Directory of Open Access Journals (Sweden)

    Shu-Ya Chen

    2009-01-01

    Full Text Available A nonlocal observation operator has been developed to assimilate GPS radio occultation (RO refractivity with WRF 3DVAR. For simplicity, in the past GPS RO refractivity was often assimilated using a local observation operator with the assumption that the GPS RO observation was representative of amodel local point. Such an operator did not take into account the effects of horizontal inhomogeneity on the derived GPS RO refractivity. In order to more accurately model the observables, Sokolovskiy et al. (2005a developed a nonlocal observation operator, which would take into account the effects of horizontal inhomogeneity on GPS RO measurements. This nonlocal observation operator calculates the integrated amount of the model refractivity along the ray paths centered at the perigee points. For comparative purposes, the nonlocal observation operator can be simplified by limiting the length of integration near the RO point. This is called the "local operator variant", which is equivalent to the original local operator except that the original one is performed with fixed tangent points at observation levels. For computational efficiency, assimilation using both the nonlocal operator and local operator variant now is performed with smear tangent points at the mean height of each model vertical level. In this study, the statistics of observation errors using both local and nonlocal operators were estimated based on WRF simulations. The observation errors produced by the nonlocal operator are about two times smaller than those generated by the local operator and in agreement with Sokolovskiy et al. (2005b.

  9. Densities inferred from ESA's Venus Express aerobraking campaign at 130 km altitude

    Science.gov (United States)

    Bruinsma, Sean; Marty, Jean-Charles; Svedhem, Håkan; Williams, Adam; Mueller-Wodarg, Ingo

    2015-04-01

    In June-July 2014, ESA performed a planned aerobraking campaign with Venus Express to measure neutral densities above 130 km in Venus' atmosphere by means of the engineering accelerometers. To that purpose, the orbit perigee was lowered to approximately 130 km in order to enhance the atmospheric drag effect to the highest tolerable levels for the spacecraft; the accelerometer resolution and precision were not sufficient at higher altitudes. This campaign was requested as part of the Venus Express Atmospheric Drag Experiment (VExADE). A total of 18 orbits (i.e. days) were processed using the attitude quaternions to correctly orient the spacecraft bus and solar arrays in inertial space, which is necessary to accurately compute the exposed surface in the ram direction. The accelerometer data provide good measurements approximately from 130-140 km altitude; the length of the profiles is about 85 seconds, and they are on the early morning side (LST=4.5) at high northern latitude (70°N-82°N). The densities are a factor 2-3 larger than Hedin's VTS-3 thermosphere model, which is consistent with earlier results obtained via classical precise orbit determination at higher altitudes. Wavelike structures with amplitudes of 20% and more are detected, with wavelengths of about 100-500 km. We cannot entirely rule out that these waves are caused by the spacecraft or due to some unknown instrumental effect, but we estimate this probability to be very low.

  10. Development of a methodology for deriving Plasmaspheric Total Electron Content from In-Situ electron density measurements in highly eccentric equatorial orbits

    Science.gov (United States)

    Sadhique, Aliyuthuman; Buckley, Andrew; Gough, Paul; Sussex Space Science Centre Team

    2017-10-01

    The contribution of the Upper Plasmasphere (defined as the altitudes above semi-synchronous orbit height to the Plasmapause height) to the TEC has been and continues to be un-quantified. The PEACE instrument in the Chinese - ESA Double Star TC1 satellite, the mission's orbit's high eccentricity, low perigee, high apogee and the resulting smaller incident angle while in the above altitude range provide the ideal geometric opportunity to build a methodology and to utilize its empirical in-situ electron density measurements to determine the Upper Plasmaspheric TEC component. Furthermore, the variation of the Inclination Angle of TC1 makes it a suitable equatorial mission confined to the Near-Equatorial region, ie 200 - 250 on either sides of the magnetic equator. As the most pronounced absolute TEC values and variations are within this region, it offers an excellent opportunity to build a Upper Plasmaspheric TEC database. This research generates such, first-ever database along its orbital path, using a methodology of approximation equating arcs of the orbits to straight-line TEC Bars, utilizing complex mathematics, also enabling the determination of the whole Plasmaspheric TEC from any eccentric orbital probe. Presented the paper in 15th International Workshop on Technical and Scientific Aspects of MST radar (MST15/iMST2)'' and ``18th EISCAT Symposium (EISCAT18)'' in Tokyo, Japan and The Royal Astronomical Society National Astronomy Meeting 2017.

  11. Analysis of plasmaspheric plumes: CLUSTER and IMAGE observations

    Directory of Open Access Journals (Sweden)

    F. Darrouzet

    2006-07-01

    Full Text Available Plasmaspheric plumes have been routinely observed by CLUSTER and IMAGE. The CLUSTER mission provides high time resolution four-point measurements of the plasmasphere near perigee. Total electron density profiles have been derived from the electron plasma frequency identified by the WHISPER sounder supplemented, in-between soundings, by relative variations of the spacecraft potential measured by the electric field instrument EFW; ion velocity is also measured onboard these satellites. The EUV imager onboard the IMAGE spacecraft provides global images of the plasmasphere with a spatial resolution of 0.1 RE every 10 min; such images acquired near apogee from high above the pole show the geometry of plasmaspheric plumes, their evolution and motion. We present coordinated observations of three plume events and compare CLUSTER in-situ data with global images of the plasmasphere obtained by IMAGE. In particular, we study the geometry and the orientation of plasmaspheric plumes by using four-point analysis methods. We compare several aspects of plume motion as determined by different methods: (i inner and outer plume boundary velocity calculated from time delays of this boundary as observed by the wave experiment WHISPER on the four spacecraft, (ii drift velocity measured by the electron drift instrument EDI onboard CLUSTER and (iii global velocity determined from successive EUV images. These different techniques consistently indicate that plasmaspheric plumes rotate around the Earth, with their foot fully co-rotating, but with their tip rotating slower and moving farther out.

  12. Fluxes of energetic protons and electrons measured on board the Oersted satellite

    Directory of Open Access Journals (Sweden)

    J. Cabrera

    2005-11-01

    Full Text Available The Charged Particle Detector (CPD on board the Oersted satellite (649 km perigee, 865 km apogee and 96.48° inclination currently measures energetic protons and electrons. The measured peak fluxes of E>1 MeV electrons are found to confirm the predictions of AE8-MAX, though they occur at a geographical position relatively shifted in the SAA. The fluxes of protons are one order of magnitude higher than the predictions of AP8-MAX in the energy range 20-500 MeV. This huge discrepancy between AP8 and recent measurements in LEO was already noticed and modelled in SAMPEX/PSB97 and TPM-1 models. Nevertheless some other LEO measurements such as PROBA and CORONA-F result in flux values in good agreement with AP8 within a factor 2. The anisotropy of the low-altitude proton flux, combined with measurement performed on board three-axis stabilised satellites, has been suspected to be one possible source of the important discrepancies observed by different missions. In this paper, we evaluate the effect of anisotropy on flux measurements conducted using the CPD instruments. On the basis of the available data, we confirm the inaccuracy of AP8 at LEO and suggest methods to improve the analysis of data in future flux measurements of energetic protons at low altitudes.

  13. Magsat - A new satellite to survey the earth's magnetic field

    Science.gov (United States)

    Mobley, F. F.; Eckard, L. D.; Fountain, G. H.; Ousley, G. W.

    1980-01-01

    The Magsat satellite was launched on Oct. 30, 1979 into a sun-synchronous dawn-dusk orbit, of 97 deg inclination, 350 km perigee, and 550 km apogee. It contains a precision vector magnetometer and a cesium-vapor scalar magnetometer at the end of a 6-m long graphite epoxy scissors boom. The magnetometers are accurate to 2 nanotesla. A pair of star cameras are used to define the body orientation to 10 arc sec rms. An 'attitude transfer system' measures the orientation of the magnetometer sensors relative to the star cameras to approximately 5 arc sec rms. The satellite position is determined to 70 meters rms by Doppler tracking. The overall objective is to determine each component of the earth's vector magnetic field to an accuracy of 6 nanotesla rms. The Magsat satellite gathers a complete picture of the earth's magnetic field every 12 hours. The vector components are sampled 16 times per second with a resolution of 0.5 nanotesla. The data will be used by the U.S. Geological Survey to prepare 1980 world magnetic field charts and to detect large-scale magnetic anomalies in the earth's crust for use in planning resource exploration strategy.

  14. Development of the European Small Geostationary Satellite SGEO

    Science.gov (United States)

    Lübberstedt, H.; Schneider, A.; Schuff, H.; Miesner, Th.; Winkler, A.

    2008-08-01

    The SGEO product portfolio, ranging from Satellite platform delivery up to in-orbit delivery of a turnkey system including satellite and ground control station, is designed for applications ranging from TV Broadcast to multimedia applications, Internet access, mobile or fixed services in a wide range of frequency bands. Furthermore, Data Relay missions such as the European Data Relay Satellite (EDRS) as well as other institutional missions are targeted. Key design features of the SGEO platform are high flexibility and modularity in order to accommodate a very wide range of future missions, a short development time below two years and the objective to build the system based on ITAR free subsystems and components. The system will provide a long lifetime of up to 15 years in orbit operations with high reliability. SGEO is the first European satellite to perform all orbit control tasks solely by electrical propulsion (EP). This design provides high mass efficiency and the capability for direct injection into geostationary orbit without chemical propulsion (CP). Optionally, an Apogee Engine Module based on CP will provide the perigee raising manoeuvres in case of a launch into geostationary transfer orbit (GTO). This approach allows an ideal choice out of a wide range of launcher candidates in dependence of the required payload capacity. SGEO will offer to the market a versatile and high performance satellite system with low investment risk for the customer and a short development time. This paper provides an overview of the SGEO system key features and the current status of the SGEO programme.

  15. Bipolar mood cycles and lunar tidal cycles.

    Science.gov (United States)

    Wehr, T A

    2018-04-01

    In 17 patients with rapid cycling bipolar disorder, time-series analyses detected synchronies between mood cycles and three lunar cycles that modulate the amplitude of the moon's semi-diurnal gravimetric tides: the 14.8-day spring-neap cycle, the 13.7-day declination cycle and the 206-day cycle of perigee-syzygies ('supermoons'). The analyses also revealed shifts among 1:2, 1:3, 2:3 and other modes of coupling of mood cycles to the two bi-weekly lunar cycles. These shifts appear to be responses to the conflicting demands of the mood cycles' being entrained simultaneously to two different bi-weekly lunar cycles with slightly different periods. Measurements of circadian rhythms in body temperature suggest a biological mechanism through which transits of one of the moon's semi-diurnal gravimetric tides might have driven the patients' bipolar cycles, by periodically entraining the circadian pacemaker to its 24.84-h rhythm and altering the pacemaker's phase-relationship to sleep in a manner that is known to cause switches from depression to mania.

  16. Effect of NTP technology levels on engine sizing for a 2005 piloted Mars mission

    Science.gov (United States)

    Burr, Annette D.; Cross, Elden H.; Widman, Frederick W.; North, D. Michael

    1993-01-01

    Previous vehicle mass studies were performed for Mars launch windows in the 2010-2018 time frame. Within the last year, a study was performed to determine the effects of various Nuclear Thermal Propulsion (NTP) engine and mission parameters on Initial Mass in Low Earth Orbit (MLEO) for a piloted Mars mission during the 2005 opportunity. Particle Bed Reactor (PBR) and Enabler-type reactors were compared. Parameters evaluated included engine thrust, number of engines, number of Trans-Mars Injection (TMI) burns, engine thrust/weight, engine out capability, engine burn time, and Isp. Earth and Mars departure dates and outbound and return travel times were optimized for a 240-day total interplanetary transfer time (long-duration stay mission). Parameters which were seen to reduce IMLEO included a greater number of perigee burns, multiple engines, and higher Isp. Optimum engine thrust varied substantially depending on the configuration. Engine models developed jointly by Rocketdyne and Westinghouse within the last year formed the basis for the Enabler thrust optimization study.

  17. In vitro extracellular matrix model to evaluate stroma cell response to transvaginal mesh.

    Science.gov (United States)

    Wu, Ming-Ping; Huang, Kuan-Hui; Long, Cheng-Yu; Yang, Chau-Chen; Tong, Yat-Ching

    2014-04-01

    The use of surgical mesh for female pelvic floor reconstruction has increased in recent years. However, there is paucity of information about the biological responses of host stroma cells to different meshes. This study was aimed to establish an in vitro experimental model to study the micro-environment of extracellular matrix (ECM) with embedded mesh and the stroma cell behaviors to different synthetic meshes. Matrigel multi-cellular co-culture system with embedded mesh was used to evaluate the interaction of stroma cells and synthetic mesh in a simulated ECM environment. Human umbilical vein endothelial cells (HUVEC) and NIH3T3 fibroblasts were inoculated in the system. The established multi-cellular Matrigel co-culture system was used to detect stroma cell recruitment and tube formation ability for different synthetic meshes. HUVEC and NIH3T3 cells were recruited into the mesh interstices and organized into tube-like structures in type I mesh material from Perigee, Marlex and Prolift 24 hr after cell inoculation. On the contrary, there was little recruitment of HUVEC and NIH3T3 cells into the type III mesh of intra-vaginal sling (IVS). The Matrigel multi-cellular co-culture system with embedded mesh offers a useful in vitro model to study the biological behaviors of stroma cells in response to different types of synthetic meshes. The system can help to select ideal mesh candidates before actual implantation into the human body. © 2013 Wiley Periodicals, Inc.

  18. A high-fidelity N-body ephemeris generator for satellites in Earth orbit

    Science.gov (United States)

    Simmons, David R.

    1991-10-01

    A program is currently used for mission planning called the Analytic Satellite Ephemeris Program (ASEP), which produces projected data for orbits that remain fairly close to Earth. Lunar and solar perturbations are taken into account in another program called GRAVE. This project is a revision of GRAVE which incorporates more flexible means of input for initial data, provides additional kinds of output information, and makes use of structured programming techniques to make the program more understandable and reliable. The computer program ORBIT was tested against tracking data for the first 313 days of operation of the CRRES satellite. A sample graph is given comparing the semi-major axis calculated by the program with the values supplied by NORAD. When calculated for points at which CRRES passes through the ascending node, the argument of perigee, the right ascension of the ascending node, and the mean anomaly all stay within about a degree of the corresponding values from NORAD; the inclination of the orbital plane is much closer. The program value of the eccentricity is in error by no more than 0.0002.

  19. Source location of chorus emissions observed by Cluster

    Directory of Open Access Journals (Sweden)

    M. Parrot

    Full Text Available One of the objectives of the Cluster mission is to study sources of various electromagnetic waves using the four satellites. This paper describes the methods we have applied to data recorded from the STAFF spectrum analyser. This instrument provides the cross spectral matrix of three magnetic and two electric field components. This spectral matrix is analysed to determine, for each satellite, the direction of the wave normal relative to the Earth’s magnetic field as a function of frequency and of time. Due to the Cluster orbit, chorus emissions are often observed close to perigee, and the data analysis determines the direction of these waves. Three events observed during different levels of magnetic activity are reported. It is shown that the component of the Poynting vector parallel to the magnetic field changes its sense when the satellites cross the magnetic equator, which indicates that the chorus waves propagate away from the equator. Detailed analysis indicates that the source is located in close vicinity of the plane of the geomagnetic equator.

    Key words. Magnetospheric physics (plasma waves and instabilities; storms and substorms; Space plasma physics (waves and instabilities

  20. Case Studies on MHD Wave Propagation by the Exos-D Electric Field Measurements

    Directory of Open Access Journals (Sweden)

    Jeong-Seon Hwang

    1997-12-01

    Full Text Available Magnetohydrodynamic wave phenomena have been investigated in the deep plasmasphere by the electric field measurements in the EXOS-D(Akebono satellite. EXOS-D has highly eccentric orbits(the perigee: 274km, the apogee: 10,500km, which allows relatively long observational time interval near the apogee region compared to othe satellites which pass by the same region with less eccentric orbits. Case studies are peformed on one month data of October in 1989 where the apogee is located near the equator and the magnetic local time is about 9:00-12:00 a.m. in the dayside plasmasphere. The observational region ranges from L=2 to L=3 and the magnetic latitude is restricted to less than 30 degress. The power spectrum is examined for each 128 point series of 8-sec averaged data through a FFT, which covers f=0-62.3 mHz frequency bands. The results are well consistent with field line resonances(FLRs and cavity modes in the plasmasphere.

  1. NanoSail - D Orbital and Attitude Dynamics

    Science.gov (United States)

    Heaton, Andrew F.; Faller, Brent F.; Katan, Chelsea K.

    2013-01-01

    NanoSail-D unfurled January 20th, 2011 and successfully demonstrated the deployment and deorbit capability of a solar sail in low Earth orbit. The orbit was strongly perturbed by solar radiation pressure, aerodynamic drag, and oblate gravity which were modeled using STK HPOP. A comparison of the ballistic coefficient history to the orbit parameters exhibits a strong relationship between orbital lighting, the decay rate of the mean semi-major axis and mean eccentricity. A similar comparison of mean solar area using the STK HPOP solar radiation pressure model exhibits a strong correlation of solar radiation pressure to mean eccentricity and mean argument of perigee. NanoSail-D was not actively controlled and had no capability on-board for attitude or orbit determination. To estimate attitude dynamics we created a 3-DOF attitude dynamics simulation that incorporated highly realistic estimates of perturbing forces into NanoSail-D torque models. By comparing the results of this simulation to the orbital behavior and ground observations of NanoSail-D, we conclude that there is a coupling between the orbit and attitude dynamics as well as establish approximate limits on the location of the NanoSail-D solar center of pressure. Both of these observations contribute valuable data for future solar sail designs and missions.

  2. Magnetospheric Multiscale Mission Attitude Dynamics: Observations from Flight Data

    Science.gov (United States)

    Williams, Trevor; Shulman, Seth; Sedlak, Joseph; Ottenstein, Neil; Lounsbury, Brian

    2016-01-01

    Extensive flight data is being collected throughout the MMS mission that includes quantities that are of interest for attitude dynamics studies such as spin rate, spin axis orientation nutation rate, etc. One example of such data is the long-term evolution of the spin rates of the four spacecraft. Spikes in these rates are observed that are separated by the MMS orbital period (just under 24 hr) and occur around perigee due to gravity-gradient torque. Periodic discontinuities in spin rate are caused by the controller resetting the spin rate approximately to the nominal 3.1 RPM value at the time of each maneuver. In between, a slow decay in spin rate can be seen to occur. The paper will discuss various disturbance torque mechanisms that could potentially be responsible for this behavior: these include magnetic hysteresis, eddy currents, solar radiation pressure, and a possible interaction between gravity-gradient and wire boom flexibility effects. One additional disturbance mechanism is produced by the Active Spacecraft Potential Control (ASPOC) devices: these emit positive indium ions to keep the MMS spacecraft electrically neutral, so as not to corrupt the electric field observations that are made by some of the on-board instruments. The spin rate decays that could be produced by these various mechanisms will be quantified in the paper, and their signatures described. Comparing these with the observations from flight data then allow the most likely candidate to be determined.

  3. OPTIS - A satellite test of Special and General Relativity

    Science.gov (United States)

    Dittus, H.; Lämmerzahl, C.; Peters, A.; Schiller, S.

    OPTIS has been proposed as a small satellite platform in a high elliptical orbit (apogee 40,000 km, perigee 10,000 km) and is designed for high precision tests of foundations of Special and General Relativity. The experimental set-up consists of two ultrastable Nd:YAG lasers, two crossed optical resonators (monolithic cavities), an atomic clock, and an optical comb generator. OPTIS enables (1) a Michelson- Morley experiment to test the isotropy of light propagation (constancy of light speed, dc/c) with an accuracy of 1 part in 101 8 , (2) a Kennedey-Thorndike experiment to measure the independence of the light speed from the velocity of the laboratory in the order of 1 part in 101 6 , and (3) a test of the gravitational red shift by comparing the atomic clock and an optical clock on a precision level of 1 part in 104 . To avoid any influence from atmospheric drag, solar radiation, or earth albedo, the satellite needs drag free control, to depress the residual acceleration down to 10-14 m/s 2 in the frequency range between 100 to 1,000 Hz, and thermal control to stabilize the cavity temperature variation, dT/T, to 1 part in 107 during 100 s and to 1 part in 105 during 1 orbit.

  4. Measurement of b-flavoured hadron lifetimes at LHCb

    CERN Document Server

    Ilieva, Simona Ilieva

    2016-01-01

    The aim of this Student Project Note is to describe precise lifetime measurements of b-flavored hadrons at LHCb. The analysis is based on Monte Carlo data simulating Run2 2015 conditions. Decay-time biases introduced at every step of the reconstruction, trigger and selection of candidates are studied. Several methods to correct for Lower acceptance are presented.

  5. Triggering $B_s^0 \\to \\gamma\\gamma$ at LHCb

    CERN Document Server

    Benson, Sean

    2018-01-01

    The trigger strategy used in the search for the $B_s^0 \\to \\gamma\\gamma$ decay in Run 2 is described. A sample of data is also provided, corresponding to 80 pb$^{−1}$ of diphoton candidates collected in 2015.

  6. Searches for direct pair production of third generation squarks with the ATLAS detector

    CERN Document Server

    Anders, John Kenneth; The ATLAS collaboration

    2017-01-01

    An overview of the most recent searches for third generation squark production is presented for a variety of stop/sbottom decays and mass hierarchy scenarios, using either 13.3fb"^{-1}" or 36.1fb"^{-1}" of Run 2 data.

  7. LHC Beam Splash seen by the ATLAS detector - 5 Apr 2015 - run 260272 - event 6539

    CERN Multimedia

    ATLAS Collaboration

    2015-01-01

    Event display of one of the collimator "splash" events seen by the ATLAS experiment in LHC Run-2, on Tuesday April the 5th : run 260272, event 6539 . The collimator position is 140m in front of the ATLAS interaction point.

  8. Exclusive Production at CMS

    CERN Document Server

    Walczak, Marek

    2016-01-01

    I briefly introduce so-called central exclusive production. I mainly focus on the example analyses that have been performed in the CMS experiment at CERN. I conclude with ideas and perspectives for future work that will be done during Run 2 of the LHC. I pay special attention to the ultraperipheral collisions.

  9. Operational Experience and Performance with the ATLAS Pixel detector

    CERN Document Server

    Yang, Hongtao; The ATLAS collaboration

    2018-01-01

    In this presentation, I will discuss the operation of ATLAS Pixel Detector during Run 2 proton-proton data-taking at √s=13 TeV in 2017. The topics to be covered include 1) the bandwidth issue and how it is mitigated through readout upgrade and threshold adjustment; 2) the auto-corrective actions; 3) monitoring of radiation effects.

  10. SUSY Search at LHC

    CERN Document Server

    Xu, Da; The ATLAS collaboration

    2018-01-01

    Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk gives an overview of the most recent SUSY searches in ATLAS and CMS experiments using 13 TeV ATLAS Run2 data.

  11. arXiv Performance of the ALICE Time-Of-Flight detector at the LHC

    CERN Document Server

    INSPIRE-00531272

    The ALICE Time-Of-Flight (TOF) detector at LHC is based on the Multigap Resistive Plate Chambers (MRPCs). The TOF performance during LHC Run 2 is here reported. Particular attention is given to the improved time resolution reached by TOF detector of $56$ ps, with the consequently improved particle identification capabilities.

  12. Development of the Integrated Info Tech System

    Science.gov (United States)

    2007-01-01

    all ECMO patients except for the following cases: 1. Patients who have Congenital Diaphragmatic Hernias and will require a prolonged ECMO run. 2...of the uterus. Other methods, such as the use of condoms, a diaphragm or cervical cap, Platelet Rich Plasma Gel Investigational Plan PRP Gel 17 1/06

  13. JW Steed and DA Tocher

    Indian Academy of Sciences (India)

    LeBozec et al 1989), give rise to bis(cyclohexadienyl) complexes even when one of the arenes is the sterically congested 1,3,5-triisopropylbenzene ligand (Neto and ... It is also noteworthy that Boekelheide (Swann et al 1986) has demonstrated that the action of the hydride source red-Al upon Ru(n-2:2) paracyclophane)(n-.

  14. Experimental status of physics

    Indian Academy of Sciences (India)

    have finished data taking for Run 1 and now gearing up for Run 2 to begin in fall ... symmetric energies where each energy is half the §S mass, namely 5.29 ... certain quark flavor contents is equal to the same flavor contents at the quark level, ...

  15. CP violation physics in B-decays, highlights from the GPDs ( ATLAS and CMS): analysis for Bs → J/ψφ.

    CERN Document Server

    Smizanska, M; The ATLAS collaboration

    2014-01-01

    CP violation physics in B-decays - highlights from the GPDs, ATLAS and CMS are given. Details are presented for time-dependent CP violation studies in Bs → J/ψφ using 2011 data and potential for Run2 based on ATLAS simulations is presented.

  16. 40 CFR Table 4 to Subpart Uuu of... - Requirements for Performance Tests for Metal HAP Emissions From Catalytic Cracking Units Not...

    Science.gov (United States)

    2010-07-01

    ... Equation 1 or 2 of § 63.1571 as applicable. e. Wet scrubber: pressure drop (not applicable to non-venturi... test. f. If you use a wet scrubber, record the total amount (rate) of water (or scrubbing liquid) and the amount (rate) of make-up liquid to the scrubber during each test run. 2. Option 1: Elect NSPS a...

  17. Vector boson production and CMS performance at sqrt(s)=13 TeV

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    First results on W/Z inclusive cross section measurement at 13 TeV are presented. This measurement represents the ideal test bench for the physics commissioning of the electron, muon and missing energy reconstruction. The most precise knowledge of luminosity at Run2 is also used in this measurement.  

  18. Performance of the RASNIK Optical Alignment Monitoring System for the LHCb Outer Tracker Detector

    CERN Document Server

    Szczekowski, Marek; Ukleja, Artur; Pellegrino, Antonio; Hart, Robert; Syryczynski, Krzysztof

    2017-01-01

    We present the results collected by an optical system for position control of the Outer Tracker detector stations in the LHCb experiment. This system has been constructed using the RASNIK three-point alignment monitors. The measurements are based on data taken in Run 2 of LHC.

  19. Forward Top Physics at LHCb

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The first Run 2 measurement of top pair production in the dilepton channel at 13 TeV will be presented, along with previous Run 1 measurements in final states accessible to both single top and top pair production. Heavy flavour tagging strategies at LHCb will also be discussed.

  20. 40 CFR Table 7 to Subpart Ddddd of... - Establishing Operating Limits

    Science.gov (United States)

    2010-07-01

    ..., and Institutional Boilers and Process Heaters Pt. 63, Subpt. DDDDD, Table 7 Table 7 to Subpart DDDDD... the average of all the 15-minute readings taken during each test run. 2. Hydrogen Chloride a. Wet... and the hydrogen chloride performance test (a) You must collect pH, pressure drop, and liquid flow...

  1. Recent updates on the Standard Model Higgs boson measurements from the ATLAS and CMS experiments

    CERN Document Server

    Wang, Song-Ming

    2017-01-01

    This report presents the latest results from the ATLAS and CMS experiments on the measurements of the Standard Model Higgs boson by using the proton-proton collisions produced by the Large Hadron Collider during the first two years of Run 2 data taking.

  2. Validity of selected cardiovascular field-based test among Malaysian ...

    African Journals Online (AJOL)

    Based on emerge obese problem among Malaysian, this research is formulated to validate published tests among healthy female adult. Selected test namely; 20 meter multi-stage shuttle run, 2.4km run test, 1 mile walk test and Harvard Step test were correlated with laboratory test (Bruce protocol) to find the criterion validity ...

  3. Effects of preservation conditions of canine feces on in vitro gas production kinetics and fermentation end-products

    NARCIS (Netherlands)

    Bosch, G.; Wrigglesworth, D.J.; Cone, J.W.; Pellikaan, W.F.; Hendriks, W.H.

    2013-01-01

    This study investigated the effect of chilling and freezing (for 24 h) canine feces on in vitro gas production kinetics and fermentation end-product profiles from carbohydrate-rich (in vitro run 1) and protein-rich substrates (in vitro run 2). Feces were collected from 3 adult Retriever-type dogs

  4. Jagiellonian University Searches for the Standard Model Higgs boson decay to $\\tau $ lepton pairs at the CMS experiment

    CERN Document Server

    Pyskir, Andrzej

    2017-01-01

    We present results of searches for the Standard Model Higgs boson decaying to tau lepton pairs at the CMS experiment with data collected during the LHC Run 1. We also present some insight into the analysis with Run 2 data. CP sensitive variables are described and an experimental method of probing CP of the Higgs boson is presented.

  5. Improving the discovery potential of charged Higgs bosons at the ...

    Indian Academy of Sciences (India)

    The Run 2 discovery potential of H¦bosons in a general Type-II 2HDM is ... gluon and quark–antiquark pairs (hence – by definition – the attainable Higgs ... This description fails to correctly account for the production phenomenology of charged.

  6. A study of different colour reconnection settings for Pythia8 generator using underlying event observables

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    A study of the performance of various colour reconnection models included in the Pythia8 Monte Carlo event generator is performed using leading charged-particle underlying event data in three centre-of-mass energies from Run 1 and Run 2, measured in ATLAS. Each model can be tuned to describe the data reasonably well.

  7. Measurement of $H{\\to}W^\\pm W^{\\mp\\ast}{\\to}\\ell^-\\bar{\

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00423318; Köneke, Karsten

    This thesis presents and discusses measurements of the coupling of the Higgs boson to vector bosons, using data collected at $\\sqrt{s}=13$ TeV by the ATLAS detector. A full analysis of the first $5.8$ fb${}^{-1}$ of LHC Run 2 data investigating the $H{\\to}W^\\pm W^{\\mp\\ast}{\\to}\\ell^-\\bar{\

  8. Europe's latest space telescope is off to a good start

    Science.gov (United States)

    1999-12-01

    The world's most powerful observatory for X-ray astronomy, the European Space Agency's XMM satellite, set off into space from Kourou, French Guiana, at 15:32 Paris time on 10 December. The mighty Ariane 5 launcher, making its very first commercial launch, hurled the 3.9-tonne spacecraft into a far-ranging orbit. Within one hour of lift-off the European Space Operations Centre at Darmstadt, Germany, confirmed XMM was under control with electrical power available from the solar arrays. "XMM is the biggest and most innovative scientific spacecraft developed by ESA so far," said Roger Bonnet, ESA's Director of Science. "The world's space agencies now want the new technology that ESA and Europe's industries have put into XMM's amazingly sensitive X-ray telescopes. And the world's astronomers are queuing up to use XMM to explore the hottest places in the universe. We must ask them to be patient while we get XMM fully commissioned." XMM's initial orbit carries it far into space, to 114,000 kilometres from the Earth at its most distant point. On its return the satellite's closest approach, or perigee, will be at 850 kilometres. The next phase of the operation, expected to take about a week, will raise that perigee to 7000 kilometres by repeated firing of XMM's own thrusters. The spacecraft will then be on its intended path, spending 40 hours out of every 48-hour orbit clear of the radiation belts which spoil the view of the X-ray universe. Technical commissioning and verification of the performance of the telescopes and scientific instruments will then follow. XMM should be fully operational for astronomy in the spring of 2000. All of ESA's science missions present fresh technological challenges to Europe's aerospace industries. In building XMM, the prime contractor Dornier Satellitensysteme in Friedrichshafen in Germany (part of DaimlerChrysler Aerospace) has led an industrial consortium involving 46 companies from 14 European countries and one in the United States. XMM

  9. Performance Evaluation of Orbit Determination System during Initial Phase of INSAT-3 Mission

    Science.gov (United States)

    Subramanian, B.; Vighnesam, N. V.

    INSAT-3C is the second in the third generation of ISRO's INSAT series of satellites that was launched by ARIANE-SPACE on 23 January 2002 at 23 h 46 m 57 s (lift off time in U.T). The ARIANE-4 Flight Nr.147 took off from Kourou in French Guyana and injected the 2750-kg communications satellite in a geostationary transfer orbit of (571 X 35935) km with an inclination of 4.007 deg at 00 h 07 m 48 s U.T on 24 January 2002 (1252 s after lift off). The satellite was successfully guided into its intended geostationary position of 74 deg E longitude by 09 February 2002 after a series of four firings of its Liquid Apogee Motor (LAM) and four station acquisition (STAQ) maneuvers. Six distinct phases of the mission were categorized based on the orbit characteristics of the INSAT- 3C mission, namely, the pre-launch phase, the launch phase, transfer orbit phase, intermediate orbit phase, drift orbit phase and synchronous orbit phase. The orbit with a perigee height of 571 km at injection of the satellite, was gradually raised to higher orbits with perigee height increasing to 9346 km after Apogee Motor Firing #1 (AMF #1), 18335 km after AMF #2, 32448 km after AMF #3 and 35493 km after AMF #4. The North and South solar panels and the reflectors were deployed at this stage of the mission and the attitude of the satellite with respect to the three axes was stabilized. The Orbit Determination System (ODS) that was used in the initial phase of the mission played a crucial role in realizing the objectives of the mission. This system which consisted of Tracking Data Pre-Processing (TDPP) software, Ephemeris Generation (EPHGEN) software and the Orbit Determination (OD) software, performed rigorously and its results were used for planning the AMF and STAQ strategies with a greater degree of accuracy. This paper reports the results of evaluation of the performance of the apogee-motor firings employed to place the satellite in its intended position where it is collocated with INSAT-1D

  10. The RadioAstron Dedicated DiFX Distribution

    Directory of Open Access Journals (Sweden)

    Gabriele Bruni

    2016-10-01

    Full Text Available Distributed FX-architecture (DiFX is a software Very Long Baseline Interferometry (VLBI correlator currently adopted by several main correlation sites around the globe. After the launch of the RadioAstron Space-VLBI mission in 2011, an extension was necessary to handle processing of an orbiting antenna, to be correlated with supporting ground arrays. Here, we present a branch of the main DiFX distribution (2.4, uploaded on the publicly available repository during July 2016, that the Max Planck Institute for Radio Astronomy (MPIfR developed to process data of the three key active galactic nuclei (AGN-imaging RadioAstron science projects, as well as part of the AGN survey project, and General Observing Time (GOT projects proposed since Announcement of Opportunity 2 (AO-2, July 2014–July 2015. It can account for general relativistic correction of an orbiting antenna with variable position/velocity, providing a routine to convert the native RadioAstron Data Format (RDF format to the more common Mark5 B (M5B. The possibility of introducing a polynomial clock allows one to mitigate the effects of spacecraft acceleration terms in near-perigee observations. Additionally, since for the first time polarimetry on space-baselines is available thanks to RadioAstron, this DiFX branch allows one to include the spacecraft orientation information at the correlation stage, in order to perform proper polarization calibration during data reduction. Finally, a fringe-finding algorithm able to manage an arbitrarily large fringe-search window is included, allowing one to increase the search space normally adopted by common software packages like HOPS.

  11. Solar Radiation Pressure Binning for the Geosynchronous Orbit

    Science.gov (United States)

    Hejduk, M. D.; Ghrist, R. W.

    2011-01-01

    Orbital maintenance parameters for individual satellites or groups of satellites have traditionally been set by examining orbital parameters alone, such as through apogee and perigee height binning; this approach ignored the other factors that governed an individual satellite's susceptibility to non-conservative forces. In the atmospheric drag regime, this problem has been addressed by the introduction of the "energy dissipation rate," a quantity that represents the amount of energy being removed from the orbit; such an approach is able to consider both atmospheric density and satellite frontal area characteristics and thus serve as a mechanism for binning satellites of similar behavior. The geo-synchronous orbit (of broader definition than the geostationary orbit -- here taken to be from 1300 to 1800 minutes in orbital period) is not affected by drag; rather, its principal non-conservative force is that of solar radiation pressure -- the momentum imparted to the satellite by solar radiometric energy. While this perturbation is solved for as part of the orbit determination update, no binning or division scheme, analogous to the drag regime, has been developed for the geo-synchronous orbit. The present analysis has begun such an effort by examining the behavior of geosynchronous rocket bodies and non-stabilized payloads as a function of solar radiation pressure susceptibility. A preliminary examination of binning techniques used in the drag regime gives initial guidance regarding the criteria for useful bin divisions. Applying these criteria to the object type, solar radiation pressure, and resultant state vector accuracy for the analyzed dataset, a single division of "large" satellites into two bins for the purposes of setting related sensor tasking and orbit determination (OD) controls is suggested. When an accompanying analysis of high area-to-mass objects is complete, a full set of binning recommendations for the geosynchronous orbit will be available.

  12. Submillimeter Monitoring of the HCN Molecule in Fragment C of the Split Comet 73P/Schwassmann-Wachmann 3

    Science.gov (United States)

    Drahus, Michal; Kueppers, M.; Jarchow, C.; Paganini, L.; Hartogh, P.; Villanueva, G. L.

    2007-10-01

    Comet 73P/Schwassmann-Wachmann 3 is a member of the Jupiter family which broke up into several fragments in 1995. After the unfavourable return in 2000/2001, the comet passed very close to the Earth in 2006, with the perigee distance below 0.1 AU. Simultaneously, it was well situated on the sky, which resulted in several observing campaigns. We observed this comet using the SMT facility at the Mt. Graham International Observatory in Arizona. In particular, on 5 nights between 10 and 22 May 2006 the HCN molecule in fragment C was spectroscopically monitored, through the J(3-2) and J(4-3) transitions. Using a simplified model, we found the expansion velocity of the HCN coma to be equal to 0.8 ± 0.1 km/s, what is a typical value for a comet at heliocentric distance r = 1 AU. We also reconstructed the production rates Q of this molecule, finding Q(r=1AU) = 2.7 ± 0.1 × 1025 molec/s. Our result is consistent with most of the other estimates, including the CN production rate. Furthermore, taking advantage of the fairly small beam sizes during our campaign (ranging from 600 km to 1200 km in radius), we detected short-term variability of the production rate, presumably stimulated by the nucleus rotation. Although our analysis did not yield a unique rotation period, we found a limited number of possible solutions. We will discuss them in detail along with a comparison with other period claims, and propose a possible scenario that links most of the periodicities reported so far for this comet. The SMT is operated by the Arizona Radio Observatory (ARO), Steward Observatory, University of Arizona.

  13. The inner magnetosphere imager mission

    International Nuclear Information System (INIS)

    Johnson, L.; Herrmann, M.

    1993-01-01

    After 30 years of in situ measurements of the Earth's magnetosphere, scientists have assembled an incomplete picture of its global composition and dynamics. Imaging the magnetosphere from space will enable scientists to better understand the global shape of the inner magnetosphere, its components and processes. The proposed inner magnetosphere imager (IMI) mission will obtain the first simultaneous images of the component regions of the inner magnetosphere and will enable scientists to relate these global images to internal and external influences as well as local observations. To obtain simultaneous images of component regions of the inner magnetosphere, measurements will comprise: the ring current and inner plasma sheet using energetic neutral atoms; the plasmasphere using extreme ultraviolet; the electron and proton auroras using far ultraviolet (FUV) and x rays; and the geocorona using FUV. The George C. Marshall Space Flight Center (MSFC) is performing a concept definition study of the proposed mission. NASA's Office of Space Science and Applications has placed the IMI third in its queue of intermediate-class missions for launch in the 1990's. An instrument complement of approximately seven imagers will fly in an elliptical Earth orbit with a seven Earth Radii (R E ) altitude apogee and approximately 4,800-kin altitude perigee. Several spacecraft concepts were examined for the mission. The first concept utilizes a spinning spacecraft with a despun platform. The second concept splits the instruments onto a spin-stabilized spacecraft and a complementary three-axis stabilized spacecraft. Launch options being assessed for the spacecraft range from a Delta 11 for the single and dual spacecraft concepts to dual Taurus launches for the two smaller spacecraft. This paper will address the mission objectives, the spacecraft design considerations, the results of the MSFC concept definition study, and future mission plans

  14. Derivation of inner magnetospheric electric field (UNH-IMEF model using Cluster data set

    Directory of Open Access Journals (Sweden)

    H. Matsui

    2008-09-01

    Full Text Available We derive an inner magnetospheric electric field (UNH-IMEF model at L=2–10 using primarily Cluster electric field data for more than 5 years between February 2001 and October 2006. This electric field data set is divided into several ranges of the interplanetary electric field (IEF values measured by ACE. As ring current simulations which require electric field as an input parameter are often performed at L=2–6.6, we have included statistical results from ground radars and low altitude satellites inside the perigee of Cluster in our data set (L~4. Electric potential patterns are derived from the average electric fields by solving an inverse problem. The electric potential pattern for small IEF values is probably affected by the ionospheric dynamo. The magnitudes of the electric field increase around the evening local time as IEF increases, presumably due to the sub-auroral polarization stream (SAPS. Another region with enhanced electric fields during large IEF periods is located around 9 MLT at L>8, which is possibly related to solar wind-magnetosphere coupling. Our potential patterns are consistent with those derived from self-consistent simulations. As the potential patterns can be interpolated/extrapolated to any discrete IEF value within measured ranges, we thus derive an empirical electric potential model. The performance of the model is evaluated by comparing the electric field derived from the model with original one measured by Cluster and mapped to the equator. The model is open to the public through our website.

  15. Derivation of inner magnetospheric electric field (UNH-IMEF model using Cluster data set

    Directory of Open Access Journals (Sweden)

    H. Matsui

    2008-09-01

    Full Text Available We derive an inner magnetospheric electric field (UNH-IMEF model at L=2–10 using primarily Cluster electric field data for more than 5 years between February 2001 and October 2006. This electric field data set is divided into several ranges of the interplanetary electric field (IEF values measured by ACE. As ring current simulations which require electric field as an input parameter are often performed at L=2–6.6, we have included statistical results from ground radars and low altitude satellites inside the perigee of Cluster in our data set (L~4. Electric potential patterns are derived from the average electric fields by solving an inverse problem. The electric potential pattern for small IEF values is probably affected by the ionospheric dynamo. The magnitudes of the electric field increase around the evening local time as IEF increases, presumably due to the sub-auroral polarization stream (SAPS. Another region with enhanced electric fields during large IEF periods is located around 9 MLT at L>8, which is possibly related to solar wind-magnetosphere coupling. Our potential patterns are consistent with those derived from self-consistent simulations. As the potential patterns can be interpolated/extrapolated to any discrete IEF value within measured ranges, we thus derive an empirical electric potential model. The performance of the model is evaluated by comparing the electric field derived from the model with original one measured by Cluster and mapped to the equator. The model is open to the public through our website.

  16. IMF BY and the seasonal dependences of the electric field in the inner magnetosphere

    Directory of Open Access Journals (Sweden)

    H. Matsui

    2005-10-01

    Full Text Available It is known that the electric field pattern at high latitudes depends on the polarity of the Y component of the interplanetary magnetic field (IMF BY and season. In this study, we investigate the seasonal and BY dependences in the inner magnetosphere using the perigee (4

  17. Observations of EMIC Triggered Emissions off the Magnetic Equatorial Plane

    Science.gov (United States)

    Grison, B.; Breuillard, H.; Santolik, O.; Cornilleau-Wehrlin, N.

    2016-12-01

    On 19/08/2005 Cluster spacecraft had their perigee close to the dayside of the Earth magnetic equatorial plane, at about 14 hours Magnetic Local Time. The spacecraft crossed the equator from the southern hemisphere toward the northern hemisphere. In the Southern hemisphere, at about -23° magnetic latitude (MLAT) and at distance of 5.25 Earth Radii from Earth, Cluster 3 observes an EMIC triggered emission between the He+ and the proton local gyrofrequencies. The magnetic waveform (STAFF instrument data) is transformed into the Fourier space for a study based on single value decomposition (SVD) analysis. The emission lasts about 30s. The emission frequency rises from 1Hz up to 1.9Hz. The emission polarization is left-hand, its coherence value is high and the propagation angle is field aligned (lower than 30º). The Poynting flux orientation could not be established. Based on previous study results, these properties are indicative of an observation in vicinity of the source region of the triggered emission. From our knowledge this is the first time that EMIC triggered emission are observed off the magnetic equator. In order to identify the source region we study two possibilities: a source region at higher latitudes than the observations (and particles orbiting in "Shabansky" orbits) and a source region close to the magnetic equatorial plane, as reported in previous studies. We propose to identify the source region from ray tracing analysis and to compare the observed propagation angle in several frequency ranges to the ray tracing results.

  18. Chandra Observations of a Collisionally and Optically Thin Charge Exchange System - Comet 2P/Encke 2003

    Science.gov (United States)

    Christian, D. J.; Lisse, C. M.; Dennerl, K.; Wolk, S. J.; Bodewits, D.; Combi, M. R.; Hoekstra, R.; Makinen, J. T. T.; Weaver, H. A.

    2004-11-01

    The highly favorable perigee passage of the x-ray bright comet 2P/Encke in late 2003 provided an excellent opportunity to use Chandra's high spatial, spectral, and temporal resolution to study cometary x-ray emission in the low neutral target density, low x-ray flux regime. The 1997 ROSAT/EUVE observations of Encke (Lisse et al. 1999) and the nucleus rotation studies of Luu and Jewitt (1990, most likely rotation period = 15 hours) suggested a simple Chandra experiment - continuous ACIS-S observations of Encke over 15 hours during the time of its closest approach to Earth. Here we report initial results from our X-ray observations. X-ray emission from comet Encke was found only in a small, asymmetric region between 1500 km - 40,000 km from the nucleus. The Encke ACIS-S3 200 -- 1000 eV spectrum shows many of the same x-ray emission lines previously observed from comets (C+5, O+6,O+7), including confirmation of several emission lines in the 800 to 1000 eV range. However, the Encke spectrum shows very different line ratios in the 200 - 700 eV range than any previous comet. A lightcurve with peak-to-peak amplitude of 20% and period 11.7 hours was found over the 15 hour observing period. Comparing the observations to contemporaneous measurements of the coma and solar wind made by other means, we find the combination of a low density, collisionally thin (to charge exchange) coma and a post-massive X-flare, high temperature, moderate density solar wind can explain our unusual Encke x-ray observations.

  19. The Origin of Tektites

    Science.gov (United States)

    OKeefe, J. A.

    1960-01-01

    Tektites are probably extraterrestrial, rather than the result of heating some terrestrial materials, because they are a chemically homogeneous group with definite peculiarities (high silica, excess of alkaline earths over alkalis, excess of potash over soda, absence of water), and because some of them (the australites) appear to have undergone ablation in flight through the atmosphere. Since comparatively slow heating is required to explain the liquefaction of the tektite material, it is suggested that the tektites arrived along orbits which were nearly parallel to the surface of the earth, and which resulted from the decay of the orbit of a natural satellite. The great meteor procession of February 9, 1913, is an example of such an object. Comparison with the reentry phenomena of the artificial satellite 1957 Beta suggests that the 1913 shower consisted of a single large stone weighing about 400 kilograms, and a few dozen smaller bodies weighing about 40 grams each, formed by ablation from the larger body. It is shown that under the observed conditions considerable liquid flow would be expected in the stone, which would be heated to about 2100 K. Objects falling from such a shower near the perigee point of the orbit would have a considerable distribution along the orbit as a result of slight variations in height or drag coefficient. The distribution in longitude would be made wider by the turning of the earth under the orbit during the time of fall. The ultimate source of the body which produces a tektite shower is probably the moon, which appears, by virtue of its polarization and the phase distribution of the returned light, to contain high-silica materials. It is suggested that the Igast object alleged to have fallen in 1855 is in fact genuine and represents an unmelted portion of the lunar crust.

  20. Optimizing Mars Sphere of Influence Maneuvers for NASA's Evolvable Mars Campaign

    Science.gov (United States)

    Merrill, Raymond G.; Komar, D. R.; Chai, Patrick; Qu, Min

    2016-01-01

    NASA's Human Spaceflight Architecture Team is refining human exploration architectures that will extend human presence to the Martian surface. For both Mars orbital and surface missions, NASA's Evolvable Mars Campaign assumes that cargo and crew can be delivered repeatedly to the same destination. Up to this point, interplanetary trajectories have been optimized to minimize the total propulsive requirements of the in-space transportation systems, while the pre-deployed assets and surface systems are optimized to minimize their respective propulsive requirements separate from the in-space transportation system. There is a need to investigate the coupled problem of optimizing the interplanetary trajectory and optimizing the maneuvers within Mars's sphere of influence. This paper provides a description of the ongoing method development, analysis and initial results of the effort to resolve the discontinuity between the interplanetary trajectory and the Mars sphere of influence trajectories. Assessment of Phobos and Deimos orbital missions shows the in-space transportation and crew taxi allocations are adequate for missions in the 2030s. Because the surface site has yet to be selected, the transportation elements must be sized to provide enough capability to provide surface access to all landing sites under consideration. Analysis shows access to sites from elliptical parking orbits with a lander that is designed for sub-periapsis landing location is either infeasible or requires expensive orbital maneuvers for many latitude ranges. In this case the locus of potential arrival perigee vectors identifies the potential maximum north or south latitudes accessible. Higher arrival velocities can decrease reorientation costs and increase landing site availability. Utilizing hyperbolic arrival and departure vectors in the optimization scheme will increase transportation site accessibility and provide more optimal solutions.

  1. Video Observations, Atmospheric Path, Orbit and Fragmentation Record of the Fall of the Peekskill Meteorite

    Science.gov (United States)

    Ceplecha, Z.; Brown, P.; Hawkes, R. L.; Wertherill, G.; Beech, M.; Mossman, K.

    1996-02-01

    Large Near-Earth-Asteroids have played a role in modifying the character of the surface geology of the Earth over long time scales through impacts. Recent modeling of the disruption of large meteoroids during atmospheric flight has emphasized the dramatic effects that smaller objects may also have on the Earth's surface. However, comparison of these models with observations has not been possible until now. Peekskill is only the fourth meteorite to have been recovered for which detailed and precise data exist on the meteoroid atmospheric trajectory and orbit. Consequently, there are few constraints on the position of meteorites in the solar system before impact on Earth. In this paper, the preliminary analysis based on 4 from all 15 video recordings of the fireball of October 9, 1992 which resulted in the fall of a 12.4 kg ordinary chondrite (H6 monomict breccia) in Peekskill, New York, will be given. Preliminary computations revealed that the Peekskill fireball was an Earth-grazing event, the third such case with precise data available. The body with an initial mass of the order of 104 kg was in a pre-collision orbit with a = 1.5 AU, an aphelion of slightly over 2 AU and an inclination of 5‡. The no-atmosphere geocentric trajectory would have lead to a perigee of 22 km above the Earth's surface, but the body never reached this point due to tremendous fragmentation and other forms of ablation. The dark flight of the recovered meteorite started from a height of 30 km, when the velocity dropped below 3 km/s, and the body continued 50 km more without ablation, until it hit a parked car in Peekskill, New York with a velocity of about 80 m/s. Our observations are the first video records of a bright fireball and the first motion pictures of a fireball with an associated meteorite fall.

  2. Solar system anomalies: Revisiting Hubble's law

    Science.gov (United States)

    Plamondon, R.

    2017-12-01

    This paper investigates the impact of a new metric recently published [R. Plamondon and C. Ouellet-Plamondon, in On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories, edited by K. Rosquist, R. T. Jantzen, and R. Ruffini (World Scientific, Singapore, 2015), p. 1301] for studying the space-time geometry of a static symmetric massive object. This metric depends on a complementary error function (erfc) potential that characterizes the emergent gravitation field predicted by the model. This results in two types of deviations as compared to computations made on the basis of a Newtonian potential: a constant and a radial outcome. One key feature of the metric is that it postulates the existence of an intrinsic physical constant σ , the massive object-specific proper length that scales measurements in its surroundings. Although σ must be evaluated experimentally, we use a heuristic to estimate its value and point out some latent relationships between the Hubble constant, the secular increase in the astronomical unit, and the Pioneers delay. Indeed, highlighting the systematic errors that emerge when the effect of σ is neglected, one can link the Hubble constant H 0 to σ Sun and the secular increase V AU to σ Earth . The accuracy of the resulting numerical predictions, H 0 = 74 . 42 ( 0 . 02 ) ( km / s ) / Mpc and V AU ≅ 7.8 cm yr-1 , calls for more investigations of this new metric by specific experts. Moreover, we investigate the expected impacts of the new metric on the flyby anomalies, and we revisit the Pioneers delay. It is shown that both phenomena could be partly taken into account within the context of this unifying paradigm, with quite accurate numerical predictions. A correction for the osculating asymptotic velocity at the perigee of the order of 10 mm/s and an inward radial acceleration of 8 . 34 × 10 - 10 m / s 2 affecting the Pioneer ! space crafts could be explained by this new model.

  3. Shallow Lunar Seismic Activity and the Current Stress State of the Moon

    Science.gov (United States)

    Watters, Thomas R.; Weber, Renee C.; Collins, Geoffrey C.; Johnson, Catherine L.

    2017-01-01

    A vast, global network of more than 3200 lobate thrust fault scarps has been revealed in high resolution Lunar Reconnaissance Orbiter Camera (LROC) images. The fault scarps are very young, less than 50 Ma, based on their small scale and crisp appearance, crosscutting relations with small-diameter impact craters, and rates of infilling of associated small, shallow graben and may be actively forming today. The population of young thrust fault scarps provides a window into the recent stress state of the Moon and offers insight into the origin of global lunar stresses. The distribution of orientations of the fault scarps is non-random, inconsistent with isotropic stresses from late-stage global contraction as the sole source of stress. Modeling shows that tidal stresses contribute significantly to the current stress state of the lunar crust. Tidal stresses (orbital recession and diurnal tides) superimposed on stresses from global contraction result in non-isotropic compressional stress and may produce thrust faults consistent with lobate scarp orientations. At any particular point on the lunar surface, peak compressive stress will be reached at a certain time in the diurnal cycle. Coseismic slip events on currently active thrust faults are expected to be triggered when peak stresses are reached. Analysis of the timing of the 28 the shallow moonquakes recorded by the Apollo seismic network shows that 19 indeed occur when the Moon is closer to apogee, while only 9 shallow events occur when the Moon is closer to perigee. Here we report efforts to refine the model for the current stress state of the Moon by investigating the contribution of polar wander. Progress on relocating the epicentral locations of the shallow moonquakes using an algorithm designed for sparse networks is also reported.

  4. Current-State Constrained Filter Bank for Wald Testing of Spacecraft Conjunctions

    Science.gov (United States)

    Carpenter, J. Russell; Markley, F. Landis

    2012-01-01

    We propose a filter bank consisting of an ordinary current-state extended Kalman filter, and two similar but constrained filters: one is constrained by a null hypothesis that the miss distance between two conjuncting spacecraft is inside their combined hard body radius at the predicted time of closest approach, and one is constrained by an alternative complementary hypothesis. The unconstrained filter is the basis of an initial screening for close approaches of interest. Once the initial screening detects a possibly risky conjunction, the unconstrained filter also governs measurement editing for all three filters, and predicts the time of closest approach. The constrained filters operate only when conjunctions of interest occur. The computed likelihoods of the innovations of the two constrained filters form a ratio for a Wald sequential probability ratio test. The Wald test guides risk mitigation maneuver decisions based on explicit false alarm and missed detection criteria. Since only current-state Kalman filtering is required to compute the innovations for the likelihood ratio, the present approach does not require the mapping of probability density forward to the time of closest approach. Instead, the hard-body constraint manifold is mapped to the filter update time by applying a sigma-point transformation to a projection function. Although many projectors are available, we choose one based on Lambert-style differential correction of the current-state velocity. We have tested our method using a scenario based on the Magnetospheric Multi-Scale mission, scheduled for launch in late 2014. This mission involves formation flight in highly elliptical orbits of four spinning spacecraft equipped with antennas extending 120 meters tip-to-tip. Eccentricities range from 0.82 to 0.91, and close approaches generally occur in the vicinity of perigee, where rapid changes in geometry may occur. Testing the method using two 12,000-case Monte Carlo simulations, we found the

  5. Performance and development for the Inner Detector Trigger Algorithms at ATLAS

    CERN Document Server

    Penc, Ondrej; The ATLAS collaboration

    2015-01-01

    A redesign of the tracking algorithms for the ATLAS trigger for Run 2 starting in spring 2015 is in progress. The ATLAS HLT software has been restructured to run as a more flexible single stage HLT, instead of two separate stages (Level 2 and Event Filter) as in Run 1. The new tracking strategy employed for Run 2 will use a Fast Track Finder (FTF) algorithm to seed subsequent Precision Tracking, and will result in improved track parameter resolution and faster execution times than achieved during Run 1. The performance of the new algorithms has been evaluated to identify those aspects where code optimisation would be most beneficial. The performance and timing of the algorithms for electron and muon reconstruction in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves.

  6. The performance and development for the Inner Detector Trigger algorithms at ATLAS

    International Nuclear Information System (INIS)

    Penc, Ondrej

    2015-01-01

    A redesign of the tracking algorithms for the ATLAS trigger for LHC's Run 2 starting in 2015 is in progress. The ATLAS HLT software has been restructured to run as a more flexible single stage HLT, instead of two separate stages (Level 2 and Event Filter) as in Run 1. The new tracking strategy employed for Run 2 will use a Fast Track Finder (FTF) algorithm to seed subsequent Precision Tracking, and will result in improved track parameter resolution and faster execution times than achieved during Run 1. The performance of the new algorithms has been evaluated to identify those aspects where code optimisation would be most beneficial. The performance and timing of the algorithms for electron and muon reconstruction in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves. (paper)

  7. The performance and development for the Inner Detector Trigger algorithms at ATLAS

    CERN Document Server

    Penc, O; The ATLAS collaboration

    2015-01-01

    A redesign of the tracking algorithms for the ATLAS trigger for LHC's Run 2 starting in 2015 is in progress. The ATLAS HLT software has been restructured to run as a more flexible single stage HLT, instead of two separate stages (Level 2 and Event Filter) as in Run 1. The new tracking strategy employed for Run 2 will use a Fast Track Finder (FTF) algorithm to seed subsequent Precision Tracking, and will result in improved track parameter resolution and faster execution times than achieved during Run 1. The performance of the new algorithms has been evaluated to identify those aspects where code optimisation would be most beneficial. The performance and timing of the algorithms for electron and muon reconstruction in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves.

  8. Computing challenges of the CMS experiment

    International Nuclear Information System (INIS)

    Krammer, N.; Liko, D.

    2017-01-01

    The success of the LHC experiments is due to the magnificent performance of the detector systems and the excellent operating computing systems. The CMS offline software and computing system is successfully fulfilling the LHC Run 2 requirements. For the increased data rate of future LHC operation, together with high pileup interactions, improvements of the usage of the current computing facilities and new technologies became necessary. Especially for the challenge of the future HL-LHC a more flexible and sophisticated computing model is needed. In this presentation, I will discuss the current computing system used in the LHC Run 2 and future computing facilities for the HL-LHC runs using flexible computing technologies like commercial and academic computing clouds. The cloud resources are highly virtualized and can be deployed for a variety of computing tasks providing the capacities for the increasing needs of large scale scientific computing.

  9. Jets in heavy ion collisions with the ATLAS detector

    CERN Document Server

    Santos, Helena; The ATLAS collaboration

    2018-01-01

    Jets constitute a golden probe to study the quark gluon plasma produced in heavy ion collisions at the LHC. Being produced at the early stages of the collisions, they are expected to be modified as propagating through the hot and dense medium. A signature of the modification is the energy loss lowering the jet yields at a given transverse momentum. A factor of two suppression is observed in central Pb+Pb collisions with respect to pp collisions. Other signatures are the modification of the dijet momentum balance and the modification of fragmentation functions. This talk will present the currently available jet results from ATLAS in Run 2. The high statistical significance of this data sample collected by ATLAS in Run 2 allows precision measurements of these observables in a wide range of transverse momentum, centrality and rapidity intervals.

  10. Diamonds at the golden point

    CERN Multimedia

    Katarina Anthony

    2015-01-01

    Alongside the CMS Pixel Luminosity Telescope (PLT) – installed last month (see here) – lie diamond detectors. No ordinary gems, these lab-grown diamonds will be playing a vital role in Run 2: differentiating signals from collision products with those from the beam background.   The BCM detector's green "c-shaped" printed circuit board is mounted on the PLT/BCM carbon-fibre carriage ready for installation. Earlier this year, the CMS BRIL project installed beam condition monitors (BCM) at the heart of the CMS detector. Designed to measure the online luminosity and beam background as close as possible to the LHC beam pipe, the BCMs use radiation-hard diamonds to differentiate between background and collision signals. The BCM also protects the CMS silicon trackers from damaging beam losses, by aborting the beam if the signal currents measured are above an acceptable threshold. These new BCMs are designed with Run 2 bunches in mind. &ldq...

  11. ATLAS IBL operational experience

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237659; The ATLAS collaboration

    2017-01-01

    The Insertable B-Layer (IBL) is the inner most pixel layer in the ATLAS experiment, which was installed at 3.3 cm radius from the beam axis in 2014 to improve the tracking performance. To cope with the high radiation and hit occupancy due to proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed for the IBL. After the long shut-down period over 2013 and 2014, the ATLAS experiment started data-taking in May 2015 for Run-2 of the Large Hadron Collider (LHC). The IBL has been operated successfully since the beginning of Run-2 and shows excellent performance with the low dead module fraction, high data-taking efficiency and improved tracking capability. The experience and challenges in the operation of the IBL is described as well as its performance.

  12. Searches for New Physics in boosted topologies at ATLAS

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The large increase in collision energy that the LHC reached in Run 2  provides an unprecedented opportunity to search for new physics beyond the Standard Model (SM). Various extensions of the SM predict heavy resonances at the TeV scale, which couple predominantly to the Higgs and electroweak gauge bosons and to top and bottom quarks. At resonance masses well above 1 TeV, these searches face specific challenges and  employ new identification techniques to disentangle the decay products of the boson in highly boosted configurations. This talk will review recent ATLAS Run-2 searches in various possible final states as well as  the dedicated techniques related to the specificity of such event topologies.

  13. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Djama, Fares; The ATLAS collaboration

    2017-01-01

    Run-2 of the LHC is providing new challenges to track and vertex reconstruction imposed by the higher collision energy, pileup and luminosity that are being delivered. The ATLAS tracking performance relies critically on the Pixel Detector, therefore, in view of Run-2 of LHC, the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during run-1 and an additional optical link per module was added to overcome in some layers the readout bandwidth limitation when LHC will exceed the nominal peak luminosity by almost a factor of 3. The key features and challenges met during the IBL project will be presented, as well as its operational experience and Pixel Detector performance in LHC.

  14. Robustness of the ATLAS pixel clustering neural network algorithm

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00407780; The ATLAS collaboration

    2016-01-01

    Proton-proton collisions at the energy frontier puts strong constraints on track reconstruction algorithms. The algorithms depend heavily on accurate estimation of the position of particles as they traverse the inner detector elements. An artificial neural network algorithm is utilised to identify and split clusters of neighbouring read-out elements in the ATLAS pixel detector created by multiple charged particles. The method recovers otherwise lost tracks in dense environments where particles are separated by distances comparable to the size of the detector read-out elements. Such environments are highly relevant for LHC run 2, e.g. in searches for heavy resonances. Within the scope of run 2 track reconstruction performance and upgrades, the robustness of the neural network algorithm will be presented. The robustness has been studied by evaluating the stability of the algorithm’s performance under a range of variations in the pixel detector conditions.

  15. Novel strategies at Lhcb for particle identification

    CERN Document Server

    Ferrari, Fabio

    2017-01-01

    The LHCb experiment at the Large Hadron Collider (LHC) is performing high precision measurements in the avour sector. An excellent performance of the particle identication (PID) detectors as well as the development of new data taking techniques are of fundamental importance in order to cope with increasingly harder challenges posed by the LHC Run 2. The approach of data-driven calibration of particle identication performance at LHCb has changed significantly from Run 1 to Run 2 and calibration samples are now selected directly in the LHCb high-level trigger. This change of data-taking paradigm enables larger calibration samples with respect to Run 1 to be collected, giving access to low-level detector informations useful for studies of systematic effects, while retaining the same (or improving) the PID performances observed Run 1.

  16. Energy Frontier Research With ATLAS: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Butler, John [Boston Univ., MA (United States); Black, Kevin [Boston Univ., MA (United States); Ahlen, Steve [Boston Univ., MA (United States)

    2016-06-14

    The Boston University (BU) group is playing key roles across the ATLAS experiment: in detector operations, the online trigger, the upgrade, computing, and physics analysis. Our team has been critical to the maintenance and operations of the muon system since its installation. During Run 1 we led the muon trigger group and that responsibility continues into Run 2. BU maintains and operates the ATLAS Northeast Tier 2 computing center. We are actively engaged in the analysis of ATLAS data from Run 1 and Run 2. Physics analyses we have contributed to include Standard Model measurements (W and Z cross sections, t\\bar{t} differential cross sections, WWW^* production), evidence for the Higgs decaying to \\tau^+\\tau^-, and searches for new phenomena (technicolor, Z' and W', vector-like quarks, dark matter).

  17. The Fermilab computing farms in 2000

    International Nuclear Information System (INIS)

    Troy Dawson

    2001-01-01

    The year 2000 was a year of evolutionary change for the Fermilab computer farms. Additional compute capacity was acquired by the addition of PCs for the CDF, D0 and CMS farms. This was done in preparation for Run 2 production and for CMS Monte Carlo production. Additional I/O capacity was added for all the farms. This continues the trend to standardize the I/O systems on the SGI O2x00 architecture. Strong authentication was installed on the CDF and D0 farms. The farms continue to provide large CPU resources for experiments and those users whose calculations benefit from large CPU/low IO resources. The user community will change in 2001 now that the 1999 fixed-target experiments have almost finished processing and Run 2, SDSS, miniBooNE, MINOS, BTeV, and other future experiments and projects will be the major users in the future

  18. B physics with the CDF Run II upgrade

    International Nuclear Information System (INIS)

    DeJongh, F.

    1996-01-01

    During the Run 1 data taking period, from 1992 through 1995, CDF has acquired 110 pb -1 of p anti p collisions at a center of mass energy of 1,800 GeV. This data has provided many results on B physics, and provides a basis for extrapolating to Run 2, which is scheduled to start in 1999 after major upgrades to both the accelerator and detector. The authors present herein a summary of Run 1 results relevant to an analysis of the CP asymmetry in B → J/ψK s , the CDF upgrade plans for Run 2, and some of the main B physics goals related to the exploration of the origin of CP violation

  19. Support system for ATLAS distributed computing operations

    CERN Document Server

    Kishimoto, Tomoe; The ATLAS collaboration

    2018-01-01

    The ATLAS distributed computing system has allowed the experiment to successfully meet the challenges of LHC Run 2. In order for distributed computing to operate smoothly and efficiently, several support teams are organized in the ATLAS experiment. The ADCoS (ATLAS Distributed Computing Operation Shifts) is a dedicated group of shifters who follow and report failing jobs, failing data transfers between sites, degradation of ATLAS central computing services, and more. The DAST (Distributed Analysis Support Team) provides user support to resolve issues related to running distributed analysis on the grid. The CRC (Computing Run Coordinator) maintains a global view of the day-to-day operations. In this presentation, the status and operational experience of the support system for ATLAS distributed computing in LHC Run 2 will be reported. This report also includes operations experience from the grid site point of view, and an analysis of the errors that create the biggest waste of wallclock time. The report of oper...

  20. Associated production of $H(b\\bar b, c\\bar c)$ with a W or a Z in ATLAS

    CERN Document Server

    Nielsen, Jason; The ATLAS collaboration

    2018-01-01

    Results are presented from the ATLAS searches for Standard Model Higgs bosons decaying to a $b\\bar b$ or $c\\bar c$ pair, produced in association with a $W$ or $Z$ boson. The analyzed data correspond to $36.1\\,\\text{fb}^{-1}$ of $13\\,\\text{TeV}$ proton-proton collision data collected in Run 2 of the Large Hadron Collider. The combination of Run 1 and Run 2 data in the $b\\bar b$ channel yields a ratio of the measured production rate to the SM prediction equal to $0.90 \\pm 0.18\\ \\text{(stat.)}^{+0.21}_{-0.19}\\ \\text{(syst.)}$. The observed significance of $3.6\\sigma$ provides evidence for the direct $Hbb$ Yukawa coupling. A similar search for $c\\bar c$ decays results in an upper limit on the production cross section times branching ratio of $2.7\\,\\text{pb}$.

  1. ALICE common read-out receiver card status and HLT implementation

    Energy Technology Data Exchange (ETDEWEB)

    Engel, Heiko; Kebschull, Udo [IRI, Goethe-Universitaet Frankfurt am Main (Germany); Collaboration: ALICE-Collaboration

    2015-07-01

    The ALICE Common Read-Out Receiver Card (C-RORC) is an FPGA based PCIe read out board with optical interfaces primarily developed to replace the previous ALICE High-Level Trigger (HLT) and Data Acquisition (DAQ) Read-Out Receiver Cards from Run1 with a state of the art hardware platform to cope with the increased link rates and event data volume of Run2. The large scale production of the C-RORCs for Run2 has been completed in cooperation with ATLAS and the boards are installed in the productive clusters of ALICE HLT, ALICE DAQ and ATLAS TDAQ ROS. This contribution describes the hardware and firmware of the C-RORC in the ALICE HLT application and its online processing capabilities. Additionally, a high level dataflow description approach to implement hardware processing steps more efficiently is presented.

  2. Global Pressure and Temperature Surface Measurements on a NACA 0012 Airfoil in Oscillatory Compressible Flow at Low Reduced Frequencies

    Science.gov (United States)

    2012-01-01

    clc close all clear all% tic %% for looping for dateN= 1:2 %% pick a date if dateN==1 date=󈧏.21.11’ runS=2; runE =28...else date=󈧏.23.11’ runS=1; runE =32; end %% for looping for run=runS:runE %% Number of images per run ImageE...date=󈧏.21.11’ runS=2; runE =28; ImageE=[0 100 59 59 59 59 100 59 59 59 59 59 100 59 59 59 59 100 59 59 59 59 100 59 59 59 59 100 0 0 0 0

  3. Associated production of $H(b\\bar b, c \\bar c)$ with a $W$ or a $Z$ Boson in ATLAS

    CERN Document Server

    Nielsen, Jason; The ATLAS collaboration

    2018-01-01

    Results are presented from the ATLAS search for Standard Model Higgs bosons decaying to a $b\\bar b$ or $c \\bar c$ pair, produced in association with $W$ or $Z$ bosons. The analyzed data correspond to 36.1 fb$^{-1}$ of 13 TeV proton-proton collision data collected in Run 2 of the Large Hadron Collider. The combination of Run 1 and Run 2 data in the $b\\bar b$ channel yields a ratio of the measured production rate to the SM prediction equal to $0.90 \\pm 0.18 \\text{(stat.)} ^{+0.21}_{-0.19} \\text{(syst.)}$. The observed significance of $3.6\\sigma$ provides evidence for the direct $Hbb$ Yukawa coupling. A similar search for $c \\bar c$ decays results in an upper limit on the production cross section times branching ratio.

  4. How to keep the Grid full and working with ATLAS production and physics jobs

    Science.gov (United States)

    Pacheco Pagés, A.; Barreiro Megino, F. H.; Cameron, D.; Fassi, F.; Filipcic, A.; Di Girolamo, A.; González de la Hoz, S.; Glushkov, I.; Maeno, T.; Walker, R.; Yang, W.; ATLAS Collaboration

    2017-10-01

    The ATLAS production system provides the infrastructure to process millions of events collected during the LHC Run 1 and the first two years of Run 2 using grid, clouds and high performance computing. We address in this contribution the strategies and improvements that have been implemented to the production system for optimal performance and to achieve the highest efficiency of available resources from operational perspective. We focus on the recent developments.

  5. How to keep the Grid full and working with ATLAS production and physics jobs

    CERN Document Server

    Pacheco Pages, Andres; The ATLAS collaboration; Di Girolamo, Alessandro; Walker, Rodney; Filip\\v{c}i\\v{c}, Andrej; Cameron, David; Yang, Wei; Fassi, Farida; Glushkov, Ivan

    2016-01-01

    The ATLAS production system has provided the infrastructure to process of tens of thousand of events during LHC Run1 and the first years of the LHC Run2 using grid, clouds and high performance computing. We address in this contribution several strategies and improvements added to the production system to optimize its performance to get the maximum efficiency of available resources from operational perspective and focusing in detail in the recent developments

  6. How to keep the Grid full and working with ATLAS production and physics jobs

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00221495; The ATLAS collaboration; Barreiro Megino, Fernando Harald; Cameron, David; Fassi, Farida; Filipcic, Andrej; Di Girolamo, Alessandro; Gonzalez de la Hoz, Santiago; Glushkov, Ivan; Maeno, Tadashi; Walker, Rodney; Yang, Wei

    2017-01-01

    The ATLAS production system provides the infrastructure to process millions of events collected during the LHC Run 1 and the first two years of Run 2 using grid, clouds and high performance computing. We address in this contribution the strategies and improvements that have been implemented to the production system for optimal performance and to achieve the highest efficiency of available resources from operational perspective. We focus on the recent developments.

  7. LHC Beam Splash seen by the ATLAS detector, 7 Apr 2015 - Run 260466 - event 22425

    CERN Multimedia

    Adam Bourdarios, Claire

    2015-01-01

    Event display of one of the collimator "splash" event seen by the ATLAS experiment in LHC Run-2 , on Tuesday April the 7th : event 22425, run 260466. The collimator position is 140m in front of the ATLAS interaction point. The spray of particles enters ATLAS from the left hand side of the picture. The length of the yellow bars indicates the energy deposited in the ATLAS calorimeter.

  8. LHC Beam Splash seen by the ATLAS detector - 7 Apr 2015 - Run 260466 - LB 731 - Event 16848

    CERN Multimedia

    ATLAS, EXPERIMENT

    2015-01-01

    Event display of a collimator "splash" event seen by the ATLAS experiment in LHC Run-2, on Tuesday April the 7th 2015: event 16848, run 260466. The collimator position is 140m in front of the ATLAS interaction point. The figure on the left shows an axial view of the various components of the ATLAS detector. The figure on the right shows the energy deposits in the cells of the ATLAS calorimeter.

  9. Precision Physics and Searches with Top and Bottom Quarks

    International Nuclear Information System (INIS)

    Garcia-Bellido, Aran

    2016-01-01

    This report goes into detail about all of the topics that were worked on by the research group from July 2015 to July 2016. The topics are: Search for supersymmetry in the all-jets final state using @@ T , measurement of the $t\\bardifferential cross section in CMS Run 2, B-physics leadership, CMS HCAL operations, CMS HCAL detector upgrade. In addition to detailing these topics, publications are listed which came from this research group.

  10. Primary vertex reconstruction with the ATLAS detector

    International Nuclear Information System (INIS)

    Meloni, F.

    2016-01-01

    Efficient and precise reconstruction of the primary vertex in a LHC collision is essential for determining the full kinematic properties of a hard-scatter event and of soft interactions as a measure of the amount of pile-up. The reconstruction of primary vertices in the busy, high pile-up environment of Run-2 of the LHC is a challenging task. The algorithms developed by the ATLAS experiments to reconstruct multiple vertices with small spatial separation are presented.

  11. Enabling Real-Time Analysis at LHCb

    CERN Multimedia

    Govorkova, Katya

    2017-01-01

    A new streaming strategy of the LHCb experiment includes the possibility to perform the physics analysis with candidates reconstructed in the trigger, thus bypassing the offline reconstruction. In the Turbo stream the trigger writes out a compact summary of physics objects containing all information necessary for analyses. This allows an increased output rate and thus higher average efficiencies. The Turbo stream was introduced in 2015 and has allowed for and expanded physics program in Run 2 of the LHC.

  12. Performance of the ATLAS primary vertex reconstruction algorithms

    CERN Document Server

    Zhang, Matt

    2017-01-01

    The reconstruction of primary vertices in the busy, high pile up environment of the LHC is a challenging task. The challenges and novel methods developed by the ATLAS experiment to reconstruct vertices in such environments will be presented. Such advances in vertex seeding include methods taken from medical imagining, which allow for reconstruction of very nearby vertices will be highlighted. The performance of the current vertexing algorithms using early Run-2 data will be presented and compared to results from simulation.

  13. Tuning of the silicon microstrip detector (SCT) digitization parameters at ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Vishwakarma, Akanksha [Humboldt University, Unter den Linden 6, 10099 Berlin (Germany)

    2016-07-01

    The increased luminosity of LHC in RUN-2 causes high radiation exposure of the ATLAS detector. This might bring about changes in the detector responses, especially of the pixel and the silicon strip detector. To study this, several digitization parameters are varied in the simulation and are analysed by comparing with data. In particular, the impact on the reconstructed cluster and track is considered. This investigation is used to optimize data-Monte Carlo agreement.

  14. Searches for new resonances decaying into bosons with the ATLAS detector

    CERN Document Server

    Shaw, Savanna Marie; The ATLAS collaboration

    2016-01-01

    Many extensions to the Standard Model predicts new particles decaying into two bosons (WW, WZ, ZZ , W/Zgamma, W/ZH and HH) making this a smoking gun signature. Searches for such diboson resonances have been performed in final states with different numbers of leptons , photon and jets where new identification techniques to disentangle the decay products in highly boosted configuration are being used. This talk summarizes ATLAS searches for diboson resonances with LHC Run 2 data.

  15. Searches for new physics in diboson resonances with the ATLAS detector at the LHC

    CERN Document Server

    Mastrandrea, Paolo; The ATLAS collaboration

    2015-01-01

    Resonant production of two massive bosons (WW, WZ, ZZ and HH) is a smoking gun signature for physics beyond the Standard Model. Searches for diboson resonances have been performed in final states with different numbers of leptons and jets including fat-jets with jet substructure. This talk highlights ATLAS searches for diboson resonances with LHC Run 1 data. First LHC Run-2 results will be included if available.

  16. Search for New Physics in Boosted Topologies

    CERN Document Server

    Cochran, James; The ATLAS collaboration

    2014-01-01

    The presentation is expected to focus on the opportunities of discovery of new physics profiting of the latest reconstruction tools for boosted top-quark or boson (W,Z,H) reconstruction and their large effect on increasing the analysis efficiency. A summary of Run 1 results showing latest techniques for background suppression and data-driven background estimate should be included pointing out the possibilities and improvements for Run 2.

  17. ATLAS Searches
for VV/V+gamma Resonances

    CERN Document Server

    Sumida, Toshi; The ATLAS collaboration

    2018-01-01

    Many extensions to the Standard Model predicts new particles decaying into two bosons (WW, WZ, ZZ, Zgamma) making these important signatures in the search for new physics. Searches for such diboson resonances have been performed in final states with different numbers of leptons, photons and jets where new jet substructure techniques to disentangle the hadronic decay products in highly boosted configuration are being used. This talk summarizes ATLAS searches for diboson resonances with LHC Run 2 data collected in 2015 and 2016.

  18. Central Exclusive Production at LHCb

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00392425

    2017-01-01

    The LHCb detector, with its excellent momentum resolution and flexible trigger strategy, is ideally suited for measuring particles produced exclusively. In addition, a new system of forward shower counters has been installed upstream and downstream of the detector, and has been used to facilitate studies of Central Exclusive Production. Such measurements of integrated and differential cross-section in both Run 1 and Run 2 of the LHC, are summarised here.

  19. Liquid Argon Calorimeters Operation and Data Quality During the 2015 Proton Run

    CERN Document Server

    Camincher, Clement; The ATLAS collaboration

    2016-01-01

    In 2015 ATLAS operated with an excellent efficiency, recording an integrated luminosity of 3.9fb^{-1} at \\sqrt{s} = 13 TeV. The Liquid Argon (LAr) Calorimeter contributed to this effort by operating with a good data quality efficiency of 99.4% . This poster highlights the overall status, performances and data quality of the LAr Calorimeters during the first year of Run-2 operations.

  20. The B-Physics Programme of ATLAS in LHC Run-II and in HL-LHC

    CERN Document Server

    Reznicek, P; The ATLAS collaboration

    2014-01-01

    Slides for the talk to be given at Beauty 2014 conference in Edinburgh, 14-18 July 2014. The talk describes the ATLAS B-physics programme planned to future LHC runs: Run 2, 3 and HL-LHC. The relevant ATLAS detector upgrades are dicussed and a results of pilot sensitivity study of $B_{s} \\to J/\\psi \\phi$ measurement in the future runs are shown.

  1. New searches for supersymmetry in electroweak production with CMS

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The large set of proton-proton collision data recorded in 2016 at a centre-of-mass energy of 13 TeV is the basis for first results on electroweak production of supersymmetric particles in LHC Run 2. CMS results on the production of chargino / neutralino pairs are presented based on the analysis of final states with one or more leptons and interpreted under several assumptions for the decay modes of the electroweak gauginos.

  2. Searches for Dark Matter with the ATLAS detector

    CERN Document Server

    Fischer, Cora; The ATLAS collaboration

    2017-01-01

    Dark matter searches carried out with the ATLAS experiment with Run 2 data are summarised and presented. Interpretations focus on simplified models where the dark matter particles are produced via the exchange of a heavy new mediator. The results of different analyses are combined as an exclusion in the plane m_DM vs M_med. Exclusion limits are also compared with direct dark matter search experiments.

  3. Searches for electroweak Higgsino production in compressed scenarios with ATLAS

    CERN Document Server

    Swiatlowski, Maximilian; The ATLAS collaboration

    2018-01-01

    Light Higgsinos are a common feature of natural models of Supersymmetry. Cases where the other SUSY particles are heavy, or where the lightest SUSY particles are mostly Higgsino, naturally lead to compressed mass spectra. Searches sensitive to these scenarios involve difficult detector signatures, including low-momentum leptons and disappearing tracks. This talk reviews recent results from searches in the Run 2 data with the ATLAS detector that constrain these scenarios, which provide the first constraints on light Higgsinos since LEP.

  4. Assessing coal burnout

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, A. [Pacific Power, Sydney, NSW (Australia)

    1999-11-01

    Recent research has allowed a quantitative description of the basic process of burnout for pulverized coals to be made. The Cooperative Research Centre for Black Coal Utilization has built on this work to develop a coal combustion model which will allow plant engineers and coal company representatives to assess their coals for combustion performance. The paper describes the model and its validation and outlines how it is run. 2 figs.

  5. Searches for new resonances decaying into bosons with the ATLAS detector

    CERN Document Server

    Meehan, Samuel; The ATLAS collaboration

    2016-01-01

    Many extensions to the Standard Model predict new particles decaying into two bosons or jets. Searches for diboson resonances (WW, WZ, ZZ, WH, ZH, and HH) have been performed in final states with different numbers of leptons and using jets where new identification techniques to disentangle the decay products in highly boosted hadronic topologies are used. This talk summarizes ATLAS searches for such resonance signatures with LHC Run 2 data.

  6. arXiv Mixing and CPV in charm hadrons at LHCb

    CERN Document Server

    INSPIRE-00437507

    2018-05-03

    LHCb continues to expand its world-leading sample of charmed hadrons collected during LHCs Run 1 (2010-2012) and Run 2 (2015-present). This sample is yielding some of the most stringent tests of the Standard Model understanding of charm physics. This includes precise measurements of the neutral D-meson mixing parameters and some of the most sensitive searches for direct and indirect CP violation in charm interactions.

  7. Future ATLAS Higgs Studies

    CERN Document Server

    Smart, Ben; The ATLAS collaboration

    2017-01-01

    The High-Luminosity LHC will prove a challenging environment to work in, with for example $=200$ expected. It will however also provide great opportunities for advancing studies of the Higgs boson. The ATLAS detector will be upgraded, and Higgs prospects analyses have been performed to assess the reach of ATLAS Higgs studies in the HL-LHC era. These analyses are presented, as are Run-2 ATLAS di-Higgs analyses for comparison.

  8. Heavy-ion Results of the CMS Experiment

    CERN Document Server

    Boimska, B

    2016-01-01

    An overview of selected heavy-ion results of the CMS experiment is presented. Jet quenching, quarkonia suppression and two-particle angular correlation results are discussed. The measurements have been performed for lead–lead, proton–lead and proton–proton data samples recorded for Run 1 of the LHC accelerator. In the correlation analysis, low pile-up proton–proton collisions at an energy of 13 TeV (from Run 2) have been used as well

  9. Searches for Supersymmetry and Exotic phenomena with the ATLAS Detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00066029; The ATLAS collaboration

    2016-01-01

    Weak scale supersymmetry is one of the best motivated and studied extensions of the Standard Model and it is explored, together with other new physics scenarios, exploiting the recent increase in the center of mass energy of the proton-proton collisions at the Large Hadron Collider. This talk summarizes the searches performed with the ATLAS detector in the first run-2 data using 3.2 fb$^{-1}$ at 13 TeV.

  10. Besøget hos tandlægen og tandlægeskræk [The visit at the dentist and dental fear

    DEFF Research Database (Denmark)

    Moore, Rod

    2006-01-01

    English summary: This chapter contributes in simple terms to a better understanding of dental fears and provides among other things the following advice for patients: 1) Ask questions. It saves you and the dentist time in the long run. 2) Make precise deals and make sure you know that the dentist...... understands your expectations. 3) Take frequent pauses and set up handsignals if you have to stop in the middle of treatment....

  11. Electroweak measurements with the ATLAS detector

    CERN Document Server

    Krasnopevtsev, Dimitriy; The ATLAS collaboration

    2015-01-01

    Electroweak measurements with the ATLAS detector -First Run 2 measurements of electroweak processes -Run 1 measurements of SM parameters, i.e. W mass and weak mixing angle -Recent Run 1 measurements of di- and multi-boson production cross-sections as well as vector boson fusion and scattering processes at 8 TeV -Recent Run 1 measurements of exclusive di-lepton and WW production

  12. Untitled

    Indian Academy of Sciences (India)

    A source of error in runs 2 and 3 is the fact that the mean daily temperature is used to calculate A in (6). The daily mean temperature is obtained simply by taking the arithmetic mean of all the 144 values for the day. From figures 2a and 2b it is seen that most of the net radiation is received when the temperature is near its ...

  13. A model for the LHC diboson excess

    Energy Technology Data Exchange (ETDEWEB)

    Buen-Abad, Manuel; Cohen, Andrew G.; Schmaltz, Martin [Physics Department, Boston University,Boston, MA 02215 (United States)

    2016-05-18

    The first run of the LHC showed hints of a new resonance with mass near 1.9 TeV decaying into electroweak gauge boson pairs as well as into dijets. While Run 2 has neither confirmed nor ruled out such a resonance, it has yielded new constraints on models attempting to explain these decays. Additionally in W{sup ′} models where this new resonance is a charged vector boson that is a weak isospin singlet there is the potential for conflict with the electroweak precision T parameter. We construct variants of a W{sup ′} resonance model that provide an excellent fit to both Run 1 and Run 2 data, as well as electroweak precision measurements. The model also predicts a neutral vector boson, a Z{sup ′}, with mass close to 3 TeV. This Z{sup ′} is compatible with the intriguing Run 2 observation of a dielectron pair with invariant mass of 2.9 TeV at CMS.

  14. Sludge Reduction by Lumbriculus Variegatus in Ahvaz Wastewater Treatment Plant

    Directory of Open Access Journals (Sweden)

    Tim Hendrickx

    2012-08-01

    Full Text Available Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensivehealth hazards. Application of aquatic worm is an approach to decrease the amount of biological waste sludge produced in wastewater treatment plants. In the present research reduction of the amount of waste sludge from Ahvaz wastewater treatment plant was studied with the aquatic worm Lumbriculus variegatus in a reactor concept. The sludge reduction in the reactor with worm was compared to sludge reduction in a blank reactor (without worm.The effects of changes in dissolved oxygen (DO concentration up to 3 mg/L (run 1 and up to 6 mg/L (run 2 were studied in the worm and blank reactors. No meaningful relationship was found between DO concentration and the rate of total suspended solids reduction. Theaverage sludge reductions were obtained as 33% (run 2 and 32% (run 1 in worm reactor,and 16% (run 1 and 12% (run 2 in the blank reactor. These results showed that the worm reactors may reduce the waste sludge between 2 and 2.75 times higher than in the blankconditions. The obtained results showed that the worm reactor has a high potential for use in large-scale sludge processing.

  15. submitter Higgs boson production in the diphoton decay channel with CMS at the LHC: first measurement of the inclusive cross section in 13 TeV pp collisions, and study of the Higgs coupling to electroweak vector bosons

    CERN Document Server

    Machet, Martina

    In this document two analyses of the properties of the Higgs boson in the diphoton decay channel with the CMS experiment at the LHC (Large Hadron Collider) are presented. The document starts with a theoretical introduction of the Standard Model and the Higgs boson physics, followed by a detailed description of the CMS detector. Then, photon reconstruction and identication algorithms are presented, with a particular focus on the dierences between the rst and the second run of the LHC, where the rst run (Run 1) took place from 2010 to 2012 with a centre-of-mass energy of 7 and then 8 TeV, while the second run (Run 2) started in 2015 with a centre-of-mass energy of 13 TeV. Per- formances of Run 1 and Run 2 reconstructions from the photon identication point of view are compared. Then the photon identication algorithm for the H → γγ analysis optimised for Run 2 is presented. To do that a multivariate analysis method is used. Performances of the photon identication at 13 TeV are nally studied and a data-simulat...

  16. Study of the properties of the Higgs boson in the decay channel to a b-quark pair with the ATLAS experiment at the LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00388516

    This thesis focuses on two separate research axes: first, the search for the Standard Model (SM) Higgs boson $H$ in the associated production mode ($VH$) decaying to b-quark pairs, with data collected at $\\sqrt{s}=$7 TeV and 8 TeV during the LHC Run-1, and separately at $\\sqrt{s}=$13 TeV during the LHC Run-2 (until July 2016). Furthermore, the search for a high-mass CP-odd pseudoscalar $A$ boson decaying to $Zh$ pairs, with the $h$ being a SM Higgs-like boson decaying to bottom-quark pairs, with data collected at $\\sqrt{s}=$13 TeV during the LHC Run-2 (until December 2015).\\\\ The event selection, the analysis techniques, the main backgrounds and their modeling, the signal properties, and the statistical discrimination between the signal and background in data are discussed for all analyses presented in this document, as well as the interpretation of the results.\\\\ In the SM $VH(b\\bar{b})$ channel no clear excess over the background prediction is observed in the analyses of the LHC Run-1 and Run-2 datasets. F...

  17. Test of lepton flavour universality using hadronic tau decays with the LHCb detector

    CERN Document Server

    Arbouch, Emmanuel

    The goal of this internship was to realize a preliminary study on the measurement of the R(D ∗ ) parameter, defined as the ratio between the two branching frac- tions R(D ∗ ) ≡ B(B 0 → D ∗− τ + ν τ )/B(B 0 → D ∗− μ + ν μ ), using the τ + → π + π − π + ν τ hadronic decays recorded by the LHCb detector. The world average on the mea- surements done so far shows a discrepancy of 3.4 standard deviations with respect to the Standard Model prediction. This points towards Lepton Flavor Universality Violation and needs to be investigated further. So far, the Run 2 (2015-2018) data had never been exploited for the measurement of R(D ∗ ) and a first look was made during this internship. Between Run 1 (2011-2012) and Run 2, the LHC center-of- mass energy increased and the LHCb trigger was improved. Lower statistical error is expected on measurements performed on Run 2 data. The gain in performance due to the improved trigger is evaluated to be 15.3%. Finally, the gain factor...

  18. Characterization of microbial community in the two-stage process for hydrogen and methane production from food waste

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Chun-Feng [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Ebie, Yoshitaka [National Institute for Environmental Studies, Tsukuba 305-8506 (Japan); Xu, Kai-Qin [National Institute for Environmental Studies, Tsukuba 305-8506 (Japan); State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072 (China); Li, Yu-You [Department of Civil and Environmental Engineering, Tohoku University, Sendai 980-8579 (Japan); Inamori, Yuhei [Faculty of Symbiotic Systems Science, Fukushima University, Fukushima 960-1296 (Japan)

    2010-08-15

    The structure of a microbial community in the two-stage process for H{sub 2} and CH{sub 4} production from food waste was investigated by a molecular biological approach. The process was a continuous combined thermophilic acidogenic hydrogenesis and mesophilic (RUN1) or thermophilic (RUN2) methanogenesis with recirculation of the digested sludge. A two-phase process suggested in this study effectively separate H{sub 2}-producing bacteria from methanogenic archaea by optimization of design parameters such as pH, hydraulic retention time (HRT) and temperature. Galore microbial diversity was found in the thermophilic acidogenic hydrogenesis, Clostridium sp. strain Z6 and Thermoanaerobacterium thermosaccharolyticum were considered to be the dominant thermophilic H{sub 2}-producing bacteria. The hydrogenotrophic methanogens were inhibited in thermophilic methanogenesis, whereas archaeal rDNAs were higher in the thermophilic methanogenesis than those in mesophilic methanogenesis. The yields of H{sub 2} and CH{sub 4} were in equal range depending on the characteristics of food waste, whereas effluent water quality indicators were different obviously in RUN1 and RUN2. The results indicated that hydrolysis and removal of food waste were higher in RUN2 than RUN1. (author)

  19. LHCb computing in Run II and its evolution towards Run III

    CERN Document Server

    Falabella, Antonio

    2016-01-01

    his contribution reports on the experience of the LHCb computing team during LHC Run 2 and its preparation for Run 3. Furthermore a brief introduction on LHCbDIRAC, i.e. the tool to interface to the experiment distributed computing resources for its data processing and data management operations, is given. Run 2, which started in 2015, has already seen several changes in the data processing workflows of the experiment. Most notably the ability to align and calibrate the detector between two different stages of the data processing in the high level trigger farm, eliminating the need for a second pass processing of the data offline. In addition a fraction of the data is immediately reconstructed to its final physics format in the high level trigger and only this format is exported from the experiment site to the physics analysis. This concept have successfully been tested and will continue to be used for the rest of Run 2. Furthermore the distributed data processing has been improved with new concepts and techn...

  20. Bi-objective optimization of a multiple-target active debris removal mission

    Science.gov (United States)

    Bérend, Nicolas; Olive, Xavier

    2016-05-01

    The increasing number of space debris in Low-Earth Orbit (LEO) raises the question of future Active Debris Removal (ADR) operations. Typical ADR scenarios rely on an Orbital Transfer Vehicle (OTV) using one of the two following disposal strategies: the first one consists in attaching a deorbiting kit, such as a solid rocket booster, to the debris after rendezvous; with the second one, the OTV captures the debris and moves it to a low-perigee disposal orbit. For multiple-target ADR scenarios, the design of such a mission is very complex, as it involves two optimization levels: one for the space debris sequence, and a second one for the "elementary" orbit transfer strategy from a released debris to the next one in the sequence. This problem can be seen as a Time-Dependant Traveling Salesman Problem (TDTSP) with two objective functions to minimize: the total mission duration and the total propellant consumption. In order to efficiently solve this problem, ONERA has designed, under CNES contract, TOPAS (Tool for Optimal Planning of ADR Sequence), a tool that implements a Branch & Bound method developed in previous work together with a dedicated algorithm for optimizing the "elementary" orbit transfer. A single run of this tool yields an estimation of the Pareto front of the problem, which exhibits the trade-off between mission duration and propellant consumption. We first detail our solution to cope with the combinatorial explosion of complex ADR scenarios with 10 debris. The key point of this approach is to define the orbit transfer strategy through a small set of parameters, allowing an acceptable compromise between the quality of the optimum solution and the calculation cost. Then we present optimization results obtained for various 10 debris removal scenarios involving a 15-ton OTV, using either the deorbiting kit or the disposal orbit strategy. We show that the advantage of one strategy upon the other depends on the propellant margin, the maximum duration allowed

  1. Drag coefficient Variability and Thermospheric models

    Science.gov (United States)

    Moe, Kenneth

    Satellite drag coefficients depend upon a variety of factors: The shape of the satellite, its altitude, the eccentricity of its orbit, the temperature and mean molecular mass of the ambient atmosphere, and the time in the sunspot cycle. At altitudes where the mean free path of the atmospheric molecules is large compared to the dimensions of the satellite, the drag coefficients can be determined from the theory of free-molecule flow. The dependence on altitude is caused by the concentration of atomic oxygen which plays an important role by its ability to adsorb on the satellite surface and thereby affect the energy loss of molecules striking the surface. The eccentricity of the orbit determines the satellite velocity at perigee, and therefore the energy of the incident molecules relative to the energy of adsorption of atomic oxygen atoms on the surface. The temperature of the ambient atmosphere determines the extent to which the random thermal motion of the molecules influences the momentum transfer to the satellite. The time in the sunspot cycle affects the ambient temperature as well as the concentration of atomic oxygen at a particular altitude. Tables and graphs will be used to illustrate the variability of drag coefficients. Before there were any measurements of gas-surface interactions in orbit, Izakov and Cook independently made an excellent estimate that the drag coefficient of satellites of compact shape would be 2.2. That numerical value, independent of altitude, was used by Jacchia to construct his model from the early measurements of satellite drag. Consequently, there is an altitude dependent bias in the model. From the sparce orbital experiments that have been done, we know that the molecules which strike satellite surfaces rebound in a diffuse angular distribution with an energy loss given by the energy accommodation coefficient. As more evidence accumulates on the energy loss, more realistic drag coefficients are being calculated. These improved drag

  2. Field line distribution of density at L=4.8 inferred from observations by CLUSTER

    Directory of Open Access Journals (Sweden)

    S. Schäfer

    2009-02-01

    about 6% lower than the equatorial value at |MLAT|=12.5°, and then increases steeply at larger values of |MLAT|. This is to our knowledge the first evidence for a local peak in bulk electron density at the magnetic equator. Our results show that magnetoseismology can be a useful technique to determine the field line distribution of the mass density for CLUSTER at perigee and that the distribution of electron density can also be inferred from measurements by multiple spacecraft.

  3. First current density measurements in the ring current region using simultaneous multi-spacecraft CLUSTER-FGM data

    Directory of Open Access Journals (Sweden)

    C. Vallat

    2005-07-01

    Full Text Available The inner magnetosphere's current mapping is one of the key elements for current loop closure inside the entire magnetosphere. A method for directly computing the current is the multi-spacecraft curlometer technique, which is based on the application of Maxwell-Ampère's law. This requires the use of four-point magnetic field high resolution measurements. The FGM experiment on board the four Cluster spacecraft allows, for the first time, an instantaneous calculation of the magnetic field gradients and thus a measurement of the local current density. This technique requires, however, a careful study concerning all the factors that can affect the accuracy of the J estimate, such as the tetrahedral geometry of the four spacecraft, or the size and orientation of the current structure sampled. The first part of this paper is thus providing a detailed analysis of the method accuracy, and points out the limitations of this technique in the region of interest. The second part is an analysis of the ring current region, which reveals, for the first time, the large latitudinal extent of the ring current, for all magnetic activity levels, as well as the latitudinal evolution of the perpendicular (and parallel components of the current along the diffuse auroral zone. Our analysis also points out the sharp transition between two distinct plasma regions, with the existence of high diamagnetic currents at the interface, as well as the filamentation of the current inside the inner plasma sheet. A statistical study over multiple perigee passes of Cluster (at about 4 RE from the Earth reveals the azimuthal extent of the partial ring current. It also reveals that, at these distances and all along the evening sector, there isn't necessarily a strong dependence of the local current density value on the magnetic activity level. This is a direct consequence of the ring current morphology evolution, as well as the relative

  4. Spacecraft Charging Considerations and Design Efforts for the Orion Crew Module

    Science.gov (United States)

    Scully, Bob

    2017-01-01

    The Orion Crew Module (CM) is nearing completion for the next flight, designated as Exploration Mission 1 (EM-1). For the uncrewed mission, the flight path will take the CM through a Perigee Raise Maneuver (PRM) out to an altitude of approximately 1800 km, followed by a Trans-Lunar Injection burn, a pass through the Van Allen belts then out to the moon for a lunar flyby, a Distant Retrograde Insertion (DRI) burn, a Distant Retrograde Orbit (DRO), a Distant Retrograde Departure (DRD) burn, a second lunar flyby, an Earth Insertion (EI) burn, and finally entry and landing. All of this, with the exception of the DRO associated maneuvers, is similar to the previous Apollo 8 mission in late 1968. In recent discussions, it is now possible that EM-1 will be a crewed mission, and if this happens, the orbit may be quite different from that just described. In this case, the flight path may take the CM on an out and back pass through the Van Allen belts twice, then out to the moon, again passing through the Van Allen belts twice, then finally back home. Even if the current EM-1 mission doesn't end up as a crewed mission, EM-2 and subsequent missions will undoubtedly follow orbital trajectories that offer comparable exposures to heightened vehicle charging effects. Because of this, and regardless of flight path, the CM vehicle will likely experience a wide range of exposures to energetic ions and electrons, essentially covering the gamut between low earth orbit to geosynchronous orbit and beyond. National Aeronautical and Space Administration (NASA) and Lockheed Martin (LM) engineers and scientists have been working to fully understand and characterize the vehicle's immunity level with regard to surface and deep dielectric charging, and the ramifications of that immunity level pertaining to materials and impacts to operational avionics, communications, and navigational systems. This presentation attempts to chronicle these efforts in a summary fashion, and attempts to capture

  5. XMM flying beautifully

    Science.gov (United States)

    1999-12-01

    The early orbit phase came to an end on 16 December after XMM had been manoeuvred to its final orbit. This required four firings of its thrusters, on successive passages at apogee, in order to increase XMM's velocity, thus elongating its orbit and raising the perigee from 826 km to 7,365 km. One burn was then made to fine tune the apogee to around 114,000km. The spacecraft, being tracked by ground stations in Perth, Kourou and Villafranca, is now circling the Earth in this highly elliptical orbit once every 48 hours. The XMM flight operations staff have found themselves controlling a spacecraft that responds exceptionally well. During these first orbits, the satellite has been oriented several times with razor-sharp precision. On board systems have responded without incident to several thousand instructions sent by controllers. "XMM is flying so beautifully" says Dietmar Heger, XMM Spacecraft Operations Manager. "The satellite is behaving better in space than all our pre-launch simulations and we have been able to adjust our shifts to this more relaxed situation". On his return from French Guiana, Robert Lainé, XMM Project Manager immediately visited the Darmstadt Mission Control Centre, at ESOC. "The perfect behaviour of XMM at this early stage reflects the constructive cooperation of European industrial companies and top scientists. Spacecraft operations are in the hands of professionals who will endeavour to fulfill the expectations of the astronomers and astrophysicists of the world. I am very happy that ESA could provide them with such a wonderful precision tool". During the early orbit phase, controllers have activated part of XMM's science payload. The three EPIC X-ray cameras have been switched on and vented. On 17 December the telescope doors were opened allowing the spacecraft's golden X-ray Multi Mirror modules to see the sky. The Optical Monitor telescope door was opened on 18 December. During this last weekend, XMM's Radiation Monitor which records

  6. An auroral westward flow channel (AWFC and its relationship to field-aligned current, ring current, and plasmapause location determined using multiple spacecraft observations

    Directory of Open Access Journals (Sweden)

    M. L. Parkinson

    2007-02-01

    Full Text Available An auroral westward flow channel (AWFC is a latitudinally narrow channel of unstable F-region plasma with intense westward drift in the dusk-to-midnight sector ionosphere. AWFCs tend to overlap the equatorward edge of the auroral oval, and their life cycle is often synchronised to that of substorms: they commence close to substorm expansion phase onset, intensify during the expansion phase, and then decay during the recovery phase. Here we define for the first time the relationship between an AWFC, large-scale field-aligned current (FAC, the ring current, and plasmapause location. The Tasman International Geospace Environment Radar (TIGER, a Southern Hemisphere HF SuperDARN radar, observed a jet-like AWFC during ~08:35 to 13:28 UT on 7 April 2001. The initiation of the AWFC was preceded by a band of equatorward expanding ionospheric scatter (BEES which conveyed an intense poleward electric field through the inner plasma sheet. Unlike previous AWFCs, this event was not associated with a distinct substorm surge; rather it occurred during an interval of persistent, moderate magnetic activity characterised by AL~−200 nT. The four Cluster spacecraft had perigees within the dusk sector plasmasphere, and their trajectories were magnetically conjugate to the radar observations. The Waves of High frequency and Sounder for Probing Electron density by Relaxation (WHISPER instruments on board Cluster were used to identify the plasmapause location. The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE EUV experiment also provided global-scale observations of the plasmapause. The Cluster fluxgate magnetometers (FGM provided successive measurements specifying the relative location of the ring current and filamentary plasma sheet current. An analysis of Iridium spacecraft magnetometer measurements provided estimates of large-scale ionospheric FAC in relation to the AWFC evolution. Peak flows in the AWFC were located close to the peak of a Region 2

  7. Electric Field and Plasma Density Observations of Irregularities and Plasma Instabilities in the Low Latitude Ionosphere Gathered by the C/NOFS Satellite

    Science.gov (United States)

    Pfaff, Robert F.; Freudenreich, H.; Rowland, D.; Klenzing, J.; Liebrecht, C.

    2012-01-01

    The Vector Electric Field Investigation (VEFI) on the C/NOFS equatorial satellite provides a unique data set which includes detailed measurements of irregularities associated with the equatorial ionosphere and in particular with spread-F depletions. We present vector AC electric field observations gathered on C/NOFS that address a variety of key questions regarding how plasma irregularities, from meter to kilometer scales, are created and evolve. The talk focuses on occasions where the ionosphere F-peak has been elevated above the C/NOFS satellite perigee of 400 km as solar activity has increased. In particular, during the equinox periods of 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set: The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second result is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is near or below the F-peak at night. The vector electric field instrument on C/NOFS clearly shows that the electric field

  8. C/NOFS Satellite Electric Field and Plasma Density Observations of Plasma Instabilities Below the Equatorial F-Peak -- Evidence for Approximately 500 km-Scale Spread-F "Precursor" Waves Driven by Zonal Shear Flow and km-Scale, Narrow-Banded Irregularities

    Science.gov (United States)

    Pfaff, R.; Freudenreich, H.; Klenzing, J.; Liebrecht, C.; Valladares, C.

    2011-01-01

    As solar activity has increased, the ionosphere F-peak has been elevated on numerous occasions above the C/NOFS satellite perigee of 400km. In particular, during the month of April, 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set (to our knowledge): The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second new result (for C/NOFS) is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is below the F -peak at night. The vector electric field instrument on C/NOFS clearly shows that the electric field component of these waves is strongest in the zonal direction. These waves are strongly correlated with simultaneous observations of plasma density oscillations and appear both with, and without, evidence of larger-scale spread-F depletions. These km-scale, quasi-coherent waves strongly resemble the bottomside, sinusoidal irregularities reported in the Atmosphere Explorer satellite data set by Valladares et al. [JGR, 88, 8025, 1983

  9. Improved Orbit Determination and Forecasts with an Assimilative Tool for Atmospheric Density and Satellite Drag Specification

    Science.gov (United States)

    Crowley, G.; Pilinski, M.; Sutton, E. K.; Codrescu, M.; Fuller-Rowell, T. J.; Matsuo, T.; Fedrizzi, M.; Solomon, S. C.; Qian, L.; Thayer, J. P.

    2016-12-01

    operationally by the Air Force to specify neutral densities. As part of the analysis, we compare the drag observed by a variety of satellites which were not used as part of the assimilation-dataset and whose perigee altitudes span a range from 200km to 700 km.

  10. Mesoscale structure of a morning sector ionospheric shear flow region determined by conjugate Cluster II and MIRACLE ground-based observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    Full Text Available We analyse a conjunction event of the Cluster II spacecraft with the MIRACLE ground-based instrument net-work in northern Fennoscandia on 6 February 2001, between 23:00 and 00:00 UT. Shortly after the spacecraft were located at perigee, the Cluster II satellites’ magnetic footpoints move northwards over Scandinavia and Svalbard, almost perfectly aligned with the central chain of the IMAGE magnetometer network, and cross a morning sector ionospheric shear zone during this passage. In this study we focus on the mesoscale structure of the ionosphere. Ionospheric conductances, true horizontal currents, and field-aligned currents (FAC are calculated from the ground-based measurements of the IMAGE magnetometers and the STARE coherent scatter radar, using the 1-D method of characteristics. An excellent agreement between these results and the FAC observed by Cluster II is reached after averaging the Cluster measurements to mesoscales, as well as between the location of the convection reversal boundary (CRB, as observed by STARE and by the Cluster II EFW instrument. A sheet of downward FAC is observed in the vicinity of the CRB, which is mainly caused by the positive divergence of the electric field there. This FAC sheet is detached by 0.5°–2° of latitude from a more equatorward downward FAC sheet at the poleward flank of the westward electrojet. This latter FAC sheet, as well as the upward FAC at the equatorward flank of the jet, are mainly caused by meridional gradients in the ionospheric conductances, which reach up to 25 S in the electrojet region, but only ~ 5 S poleward of it, with a minimum at the CRB. Particle measurements show that the major part of the downward FAC is carried by upward flowing electrons, and only a small part by downward flowing ions. The open-closed field line boundary is found to be located 3°–4° poleward of the CRB, implying significant errors if the latter is used as a proxy of the former.

    Key words

  11. Evidence of conversion from Z-mode waves to the electromagnetic L-O mode waves at the plasmapause detected by JIKIKEN (EXOS-B)

    International Nuclear Information System (INIS)

    Oya, Hiroshi; Morioka, Akira

    1982-01-01

    JIKIKEN satellite that has the initial perigee and apogee of 250 km and 30,050 km, respectively, and has an inclination of -31 0 has passed through critical regions where the AKR spectra were carved out by the plasma surounding the satellite, at least five times during a period from January 31, 1979, to June 21, 1980. On all these occasions the usual type of AKR spectra are disclosed to show cutoff phenomena at the local Z-cutoff frequency indicating a continuation crossing over the local X-cutoff frequency from the high frequency side down to the Z mode wave frequency range rather than to be cut at the local X-cutoff frequency; i.e., the AKR waves consist of the spectra that continuously cover the frequency range corresponding to Z-mode and L-O mode waves when the observation is made near the source region. The most posible mechanism that can give cinsistent interpretations to this spectra characteristics is the mode conversion theory; i.e., the plasma waves generated in the form of the hybrid mode waves in the source regions is converted into the Z-mode wave which propagates towards dense plasma regions where the wave frequency coincides with the local plasma frequency and a part of the energy of Z-mode waves is transported to the L-O mode waves that can escape towards outer space. This conversion mechanism gives also a self-consistent interpretation of previously presented evidences reported as the cutoff phenomena of AKR near the local electron cyclotron frequency, using the mechanism of the propagation of the Z-mode waves. There is no confliction between the conversion mechanism of the AKR generation and the previous polarization observation carried out by the Voyager spacecrafts because there remains wide variety of the selection of the source region that are pertinent to give the possiblity of the LH polarization waves as the results of the conversion of the radiation waves from the Z-mode to the L-O mode in the northern polar regions. (author)

  12. The STAFF-DWP wave instrument on the DSP equatorial spacecraft: description and first results

    Directory of Open Access Journals (Sweden)

    N. Cornilleau-Wehrlin

    2005-11-01

    Full Text Available The STAFF-DWP wave instrument on board the equatorial spacecraft (TC1 of the Double Star Project consists of a combination of 2 instruments which are a heritage of the Cluster mission: the Spatio-Temporal Analysis of Field Fluctuations (STAFF experiment and the Digital Wave-Processing experiment (DWP. On DSP-TC1 STAFF consists of a three-axis search coil magnetometer, used to measure magnetic fluctuations at frequencies up to 4 kHz and a waveform unit, up to 10 Hz, plus snapshots up to 180 Hz. DWP provides several onboard analysis tools: a complex FFT to fully characterise electromagnetic waves in the frequency range 10 Hz-4 kHz, a particle correlator linked to the PEACE electron experiment, and compression of the STAFF waveform data. The complementary Cluster and TC1 orbits, together with the similarity of the instruments, permits new multi-point studies. The first results show the capabilities of the experiment, with examples in the different regions of the magnetosphere-solar wind system that have been encountered by DSP-TC1 at the beginning of its operational phase. An overview of the different kinds of electromagnetic waves observed on the dayside from perigee to apogee is given, including the different whistler mode waves (hiss, chorus, lion roars and broad-band ULF emissions. The polarisation and propagation characteristics of intense waves in the vicinity of a bow shock crossing are analysed using the dedicated PRASSADCO tool, giving results compatible with previous studies: the broad-band ULF waves consist of a superimposition of different wave modes, whereas the magnetosheath lion roars are right-handed and propagate close to the magnetic field. An example of a combined Cluster DSP-TC1 magnetopause crossing is given. This first case study shows that the ULF wave power intensity is higher at low latitude (DSP than at high latitude (Cluster. On the nightside in the tail, a first wave event comparison - in a rather quiet time interval

  13. Mesoscale structure of a morning sector ionospheric shear flow region determined by conjugate Cluster II and MIRACLE ground-based observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    2003-08-01

    Full Text Available We analyse a conjunction event of the Cluster II spacecraft with the MIRACLE ground-based instrument net-work in northern Fennoscandia on 6 February 2001, between 23:00 and 00:00 UT. Shortly after the spacecraft were located at perigee, the Cluster II satellites’ magnetic footpoints move northwards over Scandinavia and Svalbard, almost perfectly aligned with the central chain of the IMAGE magnetometer network, and cross a morning sector ionospheric shear zone during this passage. In this study we focus on the mesoscale structure of the ionosphere. Ionospheric conductances, true horizontal currents, and field-aligned currents (FAC are calculated from the ground-based measurements of the IMAGE magnetometers and the STARE coherent scatter radar, using the 1-D method of characteristics. An excellent agreement between these results and the FAC observed by Cluster II is reached after averaging the Cluster measurements to mesoscales, as well as between the location of the convection reversal boundary (CRB, as observed by STARE and by the Cluster II EFW instrument. A sheet of downward FAC is observed in the vicinity of the CRB, which is mainly caused by the positive divergence of the electric field there. This FAC sheet is detached by 0.5°–2° of latitude from a more equatorward downward FAC sheet at the poleward flank of the westward electrojet. This latter FAC sheet, as well as the upward FAC at the equatorward flank of the jet, are mainly caused by meridional gradients in the ionospheric conductances, which reach up to 25 S in the electrojet region, but only ~ 5 S poleward of it, with a minimum at the CRB. Particle measurements show that the major part of the downward FAC is carried by upward flowing electrons, and only a small part by downward flowing ions. The open-closed field line boundary is found to be located 3°–4° poleward of the CRB, implying significant errors if the latter is used as a proxy of the former.Key words. Ionosphere

  14. A revolutionary lunar space transportation system architecture using extraterrestrial LOX-augmented NTR propulsion

    Science.gov (United States)

    Borowski, Stanley K.; Corban, Robert R.; Culver, Donald W.; Bulman, Melvin J.; McIlwain, Mel C.

    1994-08-01

    The concept of a liquid oxygen (LOX)-augmented nuclear thermal rocket (NTR) engine is introduced, and its potential for revolutionizing lunar space transportation system (LTS) performance using extraterrestrial 'lunar-derived' liquid oxygen (LUNOX) is outlined. The LOX-augmented NTR (LANTR) represents the marriage of conventional liquid hydrogen (LH2)-cooled NTR and airbreathing engine technologies. The large divergent section of the NTR nozzle functions as an 'afterburner' into which oxygen is injected and supersonically combusted with nuclear preheated hydrogen emerging from the NTR's choked sonic throat: 'scramjet propulsion in reverse.' By varying the oxygen-to-fuel mixture ratio (MR), the LANTR concept can provide variable thrust and specific impulse (Isp) capability with a LH2-cooled NTR operating at relatively constant power output. For example, at a MR = 3, the thrust per engine can be increased by a factor of 2.75 while the Isp decreases by only 30 percent. With this thrust augmentation option, smaller, 'easier to develop' NTR's become more acceptable from a mission performance standpoint (e.g., earth escape gravity losses are reduced and perigee propulsion requirements are eliminated). Hydrogen mass and volume is also reduced resulting in smaller space vehicles. An evolutionary NTR-based lunar architecture requiring only Shuttle C and/or 'in-line' shuttle-derived launch vehicles (SDV's) would operate initially in an 'expandable mode' with NTR lunar transfer vehicles (LTV's) delivering 80 percent more payload on piloted missions than their LOX/LH2 chemical propulsion counterparts. With the establishment of LUNOX production facilities on the lunar surface and 'fuel/oxidizer' depot in low lunar orbit (LLO), monopropellant NTR's would be outfitted with an oxygen propellant module, feed system, and afterburner nozzle for 'bipropellant' operation. The LANTR cislunar LTV now transitions to a reusable mode with smaller vehicle and payload doubling benefits on

  15. The Precession Index and a Nonlinear Energy Balance Climate Model

    Science.gov (United States)

    Rubincam, David

    2004-01-01

    A simple nonlinear energy balance climate model yields a precession index-like term in the temperature. Despite its importance in the geologic record, the precession index e sin (Omega)S, where e is the Earth's orbital eccentricity and (Omega)S is the Sun's perigee in the geocentric frame, is not present in the insolation at the top of the atmosphere. Hence there is no one-for-one mapping of 23,000 and 19,000 year periodicities from the insolation to the paleoclimate record; a nonlinear climate model is needed to produce these long periods. A nonlinear energy balance climate model with radiative terms of form T n, where T is surface temperature and n less than 1, does produce e sin (omega)S terms in temperature; the e sin (omega)S terms are called Seversmith psychroterms. Without feedback mechanisms, the model achieves extreme values of 0.64 K at the maximum orbital eccentricity of 0.06, cooling one hemisphere while simultaneously warming the other; the hemisphere over which perihelion occurs is the cooler. In other words, the nonlinear energy balance model produces long-term cooling in the northern hemisphere when the Sun's perihelion is near northern summer solstice and long-term warming in the northern hemisphere when the aphelion is near northern summer solstice. (This behavior is similar to the inertialess gray body which radiates like T 4, but the amplitude is much lower for the energy balance model because of its thermal inertia.) This seemingly paradoxical behavior works against the standard Milankovitch model, which requires cool northern summers (Sun far from Earth in northern summer) to build up northern ice sheets, so that if the standard model is correct it must be more efficient than previously thought. Alternatively, the new mechanism could possibly be dominant and indicate southern hemisphere control of the northern ice sheets, wherein the southern oceans undergo a long-term cooling when the Sun is far from the Earth during northern summer. The cold

  16. Threshold for the destabilisation of the ion-temperature-gradient mode in magnetically confined toroidal plasmas

    Science.gov (United States)

    Zocco, A.; Xanthopoulos, P.; Doerk, H.; Connor, J. W.; Helander, P.

    2018-02-01

    The threshold for the resonant destabilisation of ion-temperature-gradient (ITG) driven instabilities that render the modes ubiquitous in both tokamaks and stellarators is investigated. We discover remarkably similar results for both confinement concepts if care is taken in the analysis of the effect of the global shear . We revisit, analytically and by means of gyrokinetic simulations, accepted tokamak results and discover inadequacies of some aspects of their theoretical interpretation. In particular, for standard tokamak configurations, we find that global shear effects on the critical gradient cannot be attributed to the wave-particle resonance destabilising mechanism of Hahm & Tang (Phys. Plasmas, vol. 1, 1989, pp. 1185-1192), but are consistent with a stabilising contribution predicted by Biglari et al. (Phys. Plasmas, vol. 1, 1989, pp. 109-118). Extensive analytical and numerical investigations show that virtually no previous tokamak theoretical predictions capture the temperature dependence of the mode frequency at marginality, thus leading to incorrect instability thresholds. In the asymptotic limit , where is the rotational transform, and such a threshold should be solely determined by the resonant toroidal branch of the ITG mode, we discover a family of unstable solutions below the previously known threshold of instability. This is true for a tokamak case described by a local local equilibrium, and for the stellarator Wendelstein 7-X, where these unstable solutions are present even for configurations with a small trapped-particle population. We conjecture they are of the Floquet type and derive their properties from the Fourier analysis of toroidal drift modes of Connor & Taylor (Phys. Fluids, vol. 30, 1987, pp. 3180-3185), and to Hill's theory of the motion of the lunar perigee (Acta Math., vol. 8, 1886, pp. 1-36). The temperature dependence of the newly determined threshold is given for both confinement concepts. In the first case, the new temperature

  17. GUMICS4 Synthetic and Dynamic Simulations of the ECLAT Project

    Science.gov (United States)

    Facsko, G.; Palmroth, M. M.; Gordeev, E.; Hakkinen, L. V.; Honkonen, I. J.; Janhunen, P.; Sergeev, V. A.; Kauristie, K.; Milan, S. E.

    2012-12-01

    The European Commission funded the European Cluster Assimilation Techniques (ECLAT) project as a collaboration of five leader European universities and research institutes. A main contribution of the Finnish Meteorological Institute (FMI) is to provide a wide range of global MHD runs with the Grand Unified Magnetosphere Ionosphere Coupling simulation (GUMICS). The runs are divided in two categories: synthetic runs investigating the extent of solar wind drivers that can influence magnetospheric dynamics, as well as dynamic runs using measured solar wind data as input. Here we consider the first set of runs with synthetic solar wind input. The solar wind density, velocity and the interplanetary magnetic field had different magnitudes and orientations; furthermore two F10.7 flux values were selected for solar radiation minimum and maximum values. The solar wind parameter values were constant such that a constant stable solution was archived. All configurations were run several times with three different (-15°, 0°, +15°) tilt angles in the GSE X-Z plane. The Cray XT supercomputer of the FMI provides a unique opportunity in global magnetohydrodynamic simulation: running the GUMICS-4 based on one year real solar wind data. Solar wind magnetic field, density, temperature and velocity data based on Advanced Composition Explorer (ACE) and WIND measurements are downloaded from the OMNIWeb open database and a special input file is created for each Cluster orbit. All data gaps are replaced with linear interpolations between the last and first valid data values before and after the data gap. Minimum variance transformation is applied for the Interplanetary Magnetic Field data to clean and avoid the code of divergence. The Cluster orbits are divided into slices allowing parallel computation and each slice has an average tilt angle value. The file timestamps start one hour before the perigee to provide time for building up a magnetosphere in the simulation space. The real

  18. Risk Management of Jettisoned Objects in LEO

    Science.gov (United States)

    Bacon, John B.; Gray, Charles

    2011-01-01

    accepted. Although ISS-related debris often presents untenable risks to the EVA crew, IVA crew, or to a departing cargo vehicle for a controlled disposal, such released objects also present a ballistic nuisance to the visiting vehicle traffic, and a potential fragmentation threat to the hundreds of other functional and debris objects whose perigees lie below the ISS orbital altitude. Thus, every such jettison decision is a conscious risk trade.

  19. Observations of 50/60 Hz Power Line Radiation in the Low Latitude Ionosphere Detected by the Electric Field Instrument on the C/NOFS Satellite

    Science.gov (United States)

    Pfaff, R. F., Jr.; Freudenreich, H. T.; Simoes, F. A.; Liebrecht, M. C.; Farrell, W.

    2017-12-01

    One of the most ubiquitous forms of EM radiation emanating from the earth's surface is that of power line radiation. Associated with AC electric power generation, such emissions are typically launched along conducting power lines that may travel hundreds, or even thousands of km, from generating stations. The fundamental frequencies of such emissions are characteristically 50 Hz or 60 Hz, depending on the regional standards for power generation/consumption. The frequency of this radiation is well below that of the plasma frequency of the ionosphere (typically several MHz) and hence is expected to reflect back to the earth and propagate in the waveguide formed by the earth's surface and the bottom ledge of the ionosphere, typically near 100 km. Given that such power lines are widespread on the exposed lithosphere, the leakage of some ELF emissions associated with electric power generation might nevertheless be expected in the ionosphere, in the same manner in which a small fraction of the power associated with ELF Schumann resonances and lightning sferics have been shown to penetrate into the ionosphere. We present direct measurements of 50/60 Hz power line radiation detected by in situ probes on an orbiting satellite in the earth's ionosphere. The data were gathered by the Vector Electric Field Investigation (VEFI) tri-axial double probe detector flown on the Communication/Navigation Outage Forecast System (C/NOFS) satellite. C/NOFS was launched in April, 2008 into a low latitude (13 deg inclination) orbit with perigee and apogee of 400 km and 850 km, respectively. The electric field wave data were gathered by ELF receivers comprised of two orthogonal broadband channels sampled at 512 s/sec each, and digitized with 16 bit A/D converters. The data show distinct 60 Hz emissions while the satellite sampled within the Brazilian sector whereas distinct 50 Hz emissions were detected over India. Other, less distinct, emissions were observed over Africa and southeast Asia

  20. Higher Trait Psychopathy Is Associated with Increased Risky Decision-Making and Less Coincident Insula and Striatal Activity

    Directory of Open Access Journals (Sweden)

    Matthew T. Sutherland

    2017-12-01

    Full Text Available Higher trait levels of psychopathy have been associated with both a tendency to maintain disadvantageous decision-making strategies and aberrant cortico-limbic neural activity. To explore the neural mechanisms associated with the psychopathy-related propensity to continue selecting risky choices, a non-forensic sample of participants completed a self-report psychopathy questionnaire and two runs of a risky decision-making task during H215O positron emission tomography (PET scanning. In this secondary data analysis study, we leveraged data previously collected to examine the impact of previous drug use on risky decision-making to explore the relations between self-reported psychopathy and behavioral and brain metrics during performance of the Cambridge Decision-Making Task (CDMT, in which volunteers chose between small/likely or large/unlikely potential reward outcomes. Behaviorally, we observed that psychopathy scores were differentially correlated with the percent of risky decisions made in run 1 vs. run 2 of the task. Specifically, higher levels of psychopathy, above and beyond that attributable to drug use or sex, were associated with greater tendencies to make risky selections only in the second half (run 2 of the task. In parallel, psychopathy scores negatively correlated with regional cerebral blood flow (rCBF in the right insula and right ventral striatum during run 2 of the CDMT. These exploratory outcomes suggest that greater levels of psychopathy may be associated with an inability to translate experience with negative outcomes into behavioral adaptations possibly due to decreased neural efficiency in regions related to somatic and/or reward feedback processes.

  1. Evaluation of efficacy of prion reduction filters using blood from an endogenously infected 263K scrapie hamster model.

    Science.gov (United States)

    McLeod, Neil P; Nugent, Philip; Dixon, Douglas; Dennis, Mike; Cornwall, Mark; Mallinson, Gary; Watkins, Nicholas; Thomas, Stephen; Sutton, J Mark

    2015-10-01

    The P-Capt prion reduction filter (MacoPharma) removes prion infectivity in model systems. This independent evaluation assesses prion removal from endogenously infected animal blood, using CE-marked P-Capt filters, and replicates the proposed use of the filter within the UK Blood Services. Two units of blood, generated from 263K scrapie-infected hamsters, were processed using leukoreduction filters (LXT-quadruple, MacoPharma). Approximately 100 mL of the removed plasma was added back to the red blood cells (RBCs) and the blood was filtered through a P-Capt filter. Samples of unfiltered whole blood, the prion filter input (RBCs plus plasma and SAGM [RBCPS]), and prion-filtered leukoreduced blood (PFB) were injected intracranially into hamsters. Clinical symptoms were monitored for 500 ± 1 day, and brains were assessed for spongiosis and prion protein deposit. In Filtration Run 1, none of the 50 challenged animals were diagnosed with scrapie after inoculation with the RBCPS fraction, while two of 190 hamsters injected with PFB were infected. In Filtration Run 2, one of 49 animals injected with RBCPS and two of 193 hamsters injected with PFB were infected. Run 1 reduced the infectious dose (ID) by 1.467 log (>1.187 log and <0.280 log for leukoreduction and prion filtration, respectively). Run 2 reduced prion infectivity by 1.424 log (1.127 and 0.297 log, respectively). Residual infectivity was estimated at 0.212 ± 0.149 IDs/mL (Run 1) and 0.208 ± 0.147 IDs/mL (Run 2). Leukoreduction removed the majority of infectivity from 263K scrapie hamster blood. The P-Capt filter removed a proportion of the remaining infectivity, but residual infectivity was observed in two independent processes. © 2015 AABB.

  2. Constraints on the CKM angle $\\gamma$ and extensions with $B^\\pm$ $\\to DK^{\\ast} {^\\pm}$ decays at LHCb

    CERN Multimedia

    Nandi, Anita Katharine

    2016-01-01

    CKM angle $\\gamma$ is the least well know of the unitary triangle angles. The most common decay modes studied to determine $\\gamma$ are of the form $B \\to DK$. These have been extensively looked at in Run 1 at LHCb. Another possibility for LHCb are decays of the type $B^{\\pm} \\to DK^{*\\pm}$. A preliminary look at this final state in the Cabibbo favoured decay of the $D$, $D \\to K\\pi$ is presented. Data from Run1 and Run2 are used. Further analysis of the other $D \\to hh$ modes will give sensitivity to the CKM angle $\\gamma$.

  3. Too much of a good thing: How to trigger in a signal-rich environment

    CERN Document Server

    CERN. Geneva

    2017-01-01

    Large beauty and charm cross-sections make the LHC an ideal place to study the physics of heavy flavour, but the rate of signals of interest to the LHCb experiment, particularly after LS2, mean that a conventional trigger design with further offline reconstruction would overwhelm the available computing resources. In this seminar I will describe the novel approaches LHCb is using in the trigger to reconstruct and select only the data required for analysis in Run 3, several of which have already been put into operation during Run 2

  4. Searches for direct pair production of third generation squarks with the ATLAS detector

    CERN Document Server

    Mitrevski, Jovan; The ATLAS collaboration

    2018-01-01

    Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Top or bottom squarks with masses less than or around one TeV can also give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents recent ATLAS results from searches for direct stop and sbottom pair production, using the data collected during the LHC Run 2.

  5. Highlights of the SM Physics at the LHC

    CERN Document Server

    Yang, Haijun; The ATLAS collaboration

    2015-01-01

    This talk shows the recent highlights of the SM physics from the ATLAS and CMS experiments at the LHC. It includes the precision measurements of diboson, triboson, vector boson scattering, and indirect search for new physics via anomalous triple/quartic gauge boson couplings etc. Some latest results from LHC Run2 @ 13 TeV will also be presented. The talk was invited to present at the 5th KIAS Workshop on Particle Physics and Cosmology in Seoul on November 9-13, 2015.

  6. Charged-particle multiplicities in pp interactions at $\\sqrt{s}$ = 13 TeV measured with the ATLAS Detector at the LHC

    CERN Document Server

    Cairo, Valentina; The ATLAS collaboration

    2016-01-01

    Measurements are presented of charged particle distributions in proton–proton collisions at a centre-of-mass energy of 13 TeV collected with the ATLAS Experiment at the LHC Run 2 and compared with lower centre-of-mass energies measurements. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity and the dependence of the mean transverse momentum on the charged-particle multiplicity are presented. The results are corrected for detector effects, presented as particle-level distributions and are compared to various Monte Carlo generator models.

  7. Operational Experience of the ATLAS SemiConductor Tracker and Pixel Detector

    CERN Document Server

    Robinson, Dave; The ATLAS collaboration

    2016-01-01

    The tracking performance of the ATLAS detector relies critically on the silicon and gaseous tracking subsystems that form the ATLAS Inner Detector. Those subsystems have undergone significant hardware and software upgrades to meet the challenges imposed by the higher collision energy, pileup and luminosity that are being delivered by the LHC during Run2. The key status and performance metrics of the Pixel Detector and the Semi Conductor Tracker are summarised, and the operational experience and requirements to ensure optimum data quality and data taking efficiency are described.

  8. Electrical production testing of the D0 Silicon microstrip tracker detector modules

    Energy Technology Data Exchange (ETDEWEB)

    D0, SMT Production Testing Group; /Fermilab

    2006-03-01

    The D0 Silicon Microstrip Tracker (SMT) is the innermost system of the D0 detector in Run 2. It consists of 912 detector units, corresponding to 5 different types of assemblies, which add up to a system with 792,576 readout channels. The task entrusted to the Production Testing group was to thoroughly debug, test and grade each detector module before its installation in the tracker. This note describes the production testing sequence and the procedures by which the detector modules were electrically tested and characterized at the various stages of their assembly.

  9. Performance of Jet reconstruction in CMS at 13 TeV

    CERN Document Server

    Strologas, John

    2016-01-01

    We report on the performance of jet reconstruction in CMS during the LHC Run 2. The jet energy scale and resolution measurements are performed on a data sample collected from proton- proton collisions at a center-of-mass energy of 13 TeV. The calibration is extracted from data and simulated events and employs combination of several channels and methods. We also report on boosted object tagging, which is particularly relevant for searches for new physics. Finally we discuss techniques to identify and reject jets originating from pileup and to discriminate between jets originating from quarks or gluons.

  10. IBL Module Loading onto Stave and Quality Check

    CERN Document Server

    The ATLAS collaboration

    2015-01-01

    During the long shutdown between Run 1 and Run 2 of the LHC, a fourth, innermost, Pixel Detector layer has been installed in the ATLAS experiment: the Insertable B-Layer, IBL. The purpose of the new layer is to add redundancy against radiation damage of the B-layer, to ensure high quality tracking and improve the flavor tagging performance. New pixel silicon detector modules have been produced and loaded onto support structures known as staves, the building blocks of IBL. A total of 20 staves have been assembled. Procedures and results of the stave loading process are presented in this note.

  11. Run-1 Searches for Beyond-SM Physics with the ATLAS Experiment

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    As excitement grows for the upcoming start of Run 2 of the LHC, we review the ATLAS searches for physics beyond the SM from Run 1 and present new analyses. These searches have covered a wide range of new physics scenarios including Supersymmetry, other top partners, new resonances, additional Higgs bosons, new Higgs boson decays, new hidden sectors, other dark-matter, and multi-charged particles - just to name a few. In addition to reviewing some of the techniques that made the analyses possible, we will summarize what we have learned from the results.

  12. Searches for direct pair production of third generation squarks with the ATLAS detector

    CERN Document Server

    Mitrevski, Jovan; The ATLAS collaboration

    2018-01-01

    Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Top or bottom squarks with masses less than or around one TeV can also give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The paper presents recent ATLAS results from searches for direct stop and sbottom pair production, using the data collected during the LHC Run 2.

  13. Summary of the RHIC Retreat 2008

    Energy Technology Data Exchange (ETDEWEB)

    Pilat,F.; Brennan, M.; Brown, K.; Fischer, W.; Montag, C.

    2008-08-01

    The main goal of the RHIC Retreat is to review last run's performance and prepare for the next. As always though we also discussed the longer term goals and plans for the facility to put the work in perspective and in the right priority. A straw-man plan for the facility was prepared for the DOE that assumes 30 cryoweek and running 2 species per year. The plan outlines RHIC operations for 2008-2012 and integrates well accelerator and detector upgrades to optimize the physics output with high luminosities. The plans includes guidance from the PAC and has been reviewed by DOE.

  14. Estimated Sensitivity for New Particle Searches at the HL-LHC

    CERN Document Server

    CMS Collaboration

    2017-01-01

    Sensitivity projections for new physics searches with 3000 $\\mathrm{fb}^{-1}$ of data anticipated at the high-luminosity LHC (HL-LHC) are presented. These results were obtained from dedicated studies performed for the ECFA 2016 upgrade workshop. Projections for heavy vector bosons (Z$'$ and W$'$) decays containing top quarks are obtained by extrapolating Run-2 results assuming scenarios with varying systematic uncertainties. Results for the dark matter and weak production of single vector-like quark searches are obtained by implementing detector performance specifications from the CMS Phase-2 technical proposal in the DELPHES simulation package.

  15. JACoW Challenges of the ALICE Detector Control System for the LHC RUN3

    CERN Document Server

    Chochula, Peter; Bond, Peter; Kurepin, Alexander; Lechman, Mateusz; Lang, John; Pinazza, Ombretta

    2018-01-01

    The ALICE Detector Control System (DCS) has provided its services to the experiment since 10 years. During this period it ensured uninterrupted operation of the experiment and guaranteed stable conditions for the data taking. The DCS has been designed to cope with the detector requirements compatible with the LHC operation during its RUN1 and RUN2 phases. The decision to extend the lifetime of the experiment beyond this horizon requires the redesign of the DCS data flow and represents a major challenge. The major challenges of the system upgrade are presented in this paper.

  16. Searches for rare top processes and decay and third generation SUSY

    CERN Document Server

    Zambito, Stefano; The ATLAS collaboration

    2018-01-01

    Many models of new physics, including natural models of Supersymmetry and vector-like quarks, predict processes that would be visible at the LHC in events with third generation quarks. These include searches for stop and sbottom particles in a variety of decay modes, as well as for flavour-changing neutral current top-quark decays. The modeling of the Standard Model backgrounds to these processes is difficult and vital to the success of the searches. This talk presents recent results from ATLAS and CMS on searches for rare top processes and stop and sbottom pair production, using the data collected during the LHC Run 2.

  17. Higgs Boson fermionic production and decay modes with the ATLAS detector

    CERN Document Server

    Piacquadio, Giacinto; The ATLAS collaboration

    2018-01-01

    The Higgs couplings to heavy quarks, top and bottom quarks, are difficult to directly access experimentally, nevertheless their measurement is crucial for a full characterization of the Higgs sector and to probe a large variety of physics scenarios beyond the Standard Model. In this talk I will discuss the results recently obtained by the ATLAS Collaboration based on Run-2 2015 and 2016 data, which led to evidence for Higgs boson decays to b-quarks and for the ttH production mode.

  18. Automated Interactive Simulation Model (AISIM) VAX Version 5.0 Training Manual.

    Science.gov (United States)

    1987-05-29

    from which the link is to run, (2) the node to which the link is to run, and (3) a user-given name of the link. To place a link called " LINKI " from...connection between NODEL and NODE2 type DELETE LINKI The result on the screen would be that the link named " LINKI " would disappear. When a node is deleted...all of the links associated with it also disappear. As an example type DELETE NODE6 The result of deleting LINKI and NODE6 is shown in figure 14. Note

  19. Pileup noise behavior and corrections in the ATLAS EMCal

    CERN Document Server

    Seneca, Jordan Anders Leo

    2017-01-01

    In this note, the pile-up influence on the energy resolution of the ATLAS LAr EMCal expected until the end of run 2 is explored, with the supercluster algorithm. The pile-up noise is extracted for various η-regions and electron energies, and found to match the expected behavior. An attempt is then made at improving the energy resolution using the ambient energy density and pileup tracks using two methods for finding correlations. The corrections yield no significant improvement to the energy resolution due to small correlations.

  20. Lepton and photon performance at ATLAS and CMS

    CERN Document Server

    Lesage, Arthur; The ATLAS collaboration

    2017-01-01

    These proceedings report on lepton and photon performance results obtained using data recorded in 2015 and 2016 at the LHC by the two experiments ATLAS and CMS. For each particle (electrons, photons and muons), the reconstruction and identification efficiencies are presented for the two experiments together with the isolation studies. Results concerning the electron and photon energy calibration as well as the muon momentum scale and resolution are also reported. Despite more challenging pile-up conditions with respect to Run 1, the two experiments achieved impressive performance in early Run 2.