WorldWideScience

Sample records for collider run ii

  1. Search for chargino and neutralino at Run II of the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Canepa, Anadi [Purdue Univ., West Lafayette, IN (United States)

    2006-08-01

    In this dissertation we present a search for the associated production of charginos and neutralinos, the supersymmetric partners of the Standard Model bosons. We analyze a data sample representing 745 pb-1 of integrated luminosity collected by the CDF experiment at the p$\\bar{p}$ Tevatron collider. We compare the Standard Model predictions with the observed data selecting events with three leptons and missing transverse energy. Finding no excess, we combine the results of our search with similar analyses carried out at CDF and set an upper limit on the chargino mass in SUSY scenarios.

  2. SDA-Based Diagnostic and Analysis Tools for Collider Run II

    CERN Document Server

    Papadimitriou, Vaia; Lebrun, Paul; Panacek, S; Slaughter, Anna Jean; Xiao, Aimin

    2005-01-01

    Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Acquisition and Analysis (SDA) has been developed to fulfill this need. Data is stored in a relational database, and is served to programs and users via Web-based tools. Summary tables are systematically generated during and after a store. These tables, the Supertable, and the Recomputed Emittances and Recomputed Intensity tables are discussed here. This information is also accesible in JAS3 (Java Analysis Studio version 3).

  3. The ATLAS Pixel Detector for Run II at the Large Hadron Collider

    CERN Document Server

    Marx, Marilyn; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the 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). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO2 based cooling system have been adopted. An overview of the refurbishing of the Pixel Detector and of the IBL project as ...

  4. The upgraded Pixel Detector of the ATLAS Experiment for Run-II at the Large Hadron Collider

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00407702

    2016-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of the LHC. Taking advantage of the detector development period 2013 – 2014, the detector was extracted from the experiment and brought to surface to equip it with new service panels and to repair modules furthermore this helped with the installation of the Insertable B-Layer (IBL), fourth layer of pixel, installed in between the existing Pixel Detector and a new beam-pipe at a radius of 3.3 cm. To cope with the high radiation and increased pixel occupancy due to the proximity to the interaction point, two different silicon sensor technologies (planar and 3D) have been used. A new readout chip has been designed with CMOS 130nm technology with larger area, smaller pixel size and faster readout capability. Dedicated design features in combination with a new composite material were considered and used in order to reduce the material budget of the support structure while keeping the optimal thermo-mechanical perfor...

  5. Emotions run high in race for collider

    CERN Multimedia

    Cartlidge, E

    2001-01-01

    The head of KEK expressed his dismay that SLAC has entered into a collaboration with 3 other US labs and proposes to build the next linear collider at Fermilab, Ilinois. KEK wants the next accelerator to be built somewhere in the Asian Pacific region (1 page).

  6. First final results from CDF RunII

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The Tevatron collider was shut down at the end of September 2011, ending a period of operation lasted ten years ("Run II"). First results are now becoming available from the analysis of the full CDF Run II sample of 10fb-1. I will cover highlights of the CDF program from charm, bottom, top and Higgs sectors.

  7. First paper from Tevatron Run II submitted by CDF collaboration

    CERN Multimedia

    2003-01-01

    "Scientists of the Collider Detector at Fermilab submitted today (March 19) the first scientific publication of Collider Run II to the science journal Physical Review D. The paper titled "Measurement of the Mass Difference m(Ds+)-m(D+) at CDF II" summarizes the results of an analysis carried out by CDF scientists Christoph Paus and Ivan Furic, MIT, describing the mass measurement of particles containing charm quarks" (1 page).

  8. The Large Hadron Collider harvest of run 1

    CERN Document Server

    2015-01-01

    This comprehensive volume summarizes and structures the multitude of results obtained at the LHC in its first running period and draws the grand picture of today’s physics at a hadron collider. Topics covered are Standard Model measurements, Higgs and top-quark physics, flavour physics, heavy-ion physics and searches for super symmetry and other extensions of the Standard Model. Emphasis is placed on overview and presentation of the lessons learned. Chapters on detectors and the LHC machine and a thorough outlook into the future complement the book. The individual chapters are written by teams of expert authors working at the forefront of LHC research, typically one from each of the two multi-purpose experiments ATLAS and CMS and one from theory.

  9. The Muon system of the run II D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M.; Acharya, B.S.; Alexeev, G.D.; Alkhazov, G.; Anosov, V.A.; Baldin, B.; Banerjee, S.; Bardon, O.; Bartlett, J.F.; Baturitsky, M.A.; Beutel, D.; Bezzubov,; Bodyagin, V.; Butler, J.M.; Cease, H.; Chi, E.; Denisov, D.; Denisov, S.P.; Diehl, H.T.; Doulas, S.; Dugad, S.R.; /Beijing, Inst. High Energy Phys. /Charles U. /Prague, Tech.

    2005-03-01

    The authors describe the design, construction and performance of the upgraded D0 muon system for Run II of the Fermilab Tevatron collider. Significant improvements have been made to the major subsystems of the D0 muon detector: trigger scintillation counters, tracking detectors, and electronics. The Run II central muon detector has a new scintillation counter system inside the iron toroid and an improved scintillation counter system outside the iron toroid. In the forward region, new scintillation counter and tracking systems have been installed. Extensive shielding has been added in the forward region. A large fraction of the muon system electronics is also new.

  10. Large Hadron particle collider may not have its run this November

    CERN Multimedia

    2007-01-01

    "The Large Hadron Collider (LHC), based at CERN in Geneva, Switzerland, will not run in November this year as scheduled. The LHC was supposed to have a test run this yera, before switching on the scientific search for the Higgs boson in 2008."(1 page)

  11. Input data to run Landis-II

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The data are input data files to run the forest simulation model Landis-II for Isle Royale National Park. Files include: a) Initial_Comm, which includes the location...

  12. ATLAS Run II Exotics Results

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2016-01-01

    While Standard Model is in a good shape especially after Higgs boson discovery, there are a lot of questions beyond SM. The ATLAS detector is performing about 50 Exotics searches addressed these questions. This talk is discussing some of them with datasets collected during the 2015-2016 LHC run from 3 fb^-1 to 18 fb^-1 of proton-proton collisions at 13 TeV centre of mass energy . Results on searches for resonances decaying into vector boson or fermions, for vector like quarks, for dark matter, and for other new phenomena using these data will be presented.

  13. COLLIDE

    CERN Multimedia

    2017-01-01

    Howie Day, Collide, Based on the original parody "Collide" by USLHC, inspired by the original song "Collide" written by Howie Day and Kevin Griffin. Re-record Produced by Mike Denneen Engineered by Patrick DiCenso -Vocals, Guitars, Keyboards- Howie Day -Guitar Patrick DiCenso -Bass- Ed Valuskas -Drums- Dave Brophy

  14. Colliders

    CERN Document Server

    Chou, Weiren

    2014-01-01

    The idea of colliding two particle beams to fully exploit the energy of accelerated particles was first proposed by Rolf Wideröe, who in 1943 applied for a patent on the collider concept and was awarded the patent in 1953. The first three colliders — AdA in Italy, CBX in the US, and VEP-1 in the then Soviet Union — came to operation about 50 years ago in the mid-1960s. A number of other colliders followed. Over the past decades, colliders defined the energy frontier in particle physics. Different types of colliers — proton–proton, proton–antiproton, electron–positron, electron–proton, electron-ion and ion-ion colliders — have played complementary roles in fully mapping out the constituents and forces in the Standard Model (SM). We are now at a point where all predicted SM constituents of matter and forces have been found, and all the latest ones were found at colliders. Colliders also play a critical role in advancing beam physics, accelerator research and technology development. It is timel...

  15. Extracting the top-quark running mass using t anti t+1-jet events produced at the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Fuster, J.; Vos, M. [Valencia Univ. and CSIC, Paterna (Spain). IFIC; Irles, A. [Paris-Sud XI Univ., CNRS/IN2P3, Orsay (France). Lab. de l' Accelerateur Lineaire; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Melini, D. [Valencia Univ. and CSIC, Paterna (Spain). IFIC; Granada Univ. (Spain). Dept. de Fisica Teorica y del Cosmos; Uwer, P. [Humboldt-Univ., Berlin (Germany)

    2017-04-04

    We present the calculation of the next-to-leading order QCD corrections for top quark pair production in association with an additional jet at hadron colliders, using the modified minimal subtraction scheme to renormalize the top-quark mass. The results are compared to measurements at the Large Hadron Collider run I. In particular, we determine the top-quark running mass from a fit of the theoretical results presented here to the LHC data.

  16. Luminosity Measurements at LHCb for Run II

    CERN Multimedia

    Coombs, George

    2018-01-01

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

  17. The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II

    CERN Document Server

    Rojo, Juan; Ball, Richard D; Cooper-Sarkar, Amanda; de Roeck, Albert; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; Huston, Joey; Glazov, Alexander; Gouzevitch, Maxime; Gwenlan, Claire; Lipka, Katerina; Lisovyi, Mykhailo; Mangano, Michelangelo; Nadolsky, Pavel; Perrozzi, Luca; Placakyte, Ringaile; Radescu, Voica; Salam, Gavin P; Thorne, Robert

    2015-01-01

    The accurate determination of the Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterisation and precision Standard Model measurements to New Physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarise the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. This document aims to provide useful input to the LHC collaborations to prioritise their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.

  18. Input data to run Landis-II

    Science.gov (United States)

    DeJager, Nathan R.

    2017-01-01

    The data are input data files to run the forest simulation model Landis-II for Isle Royale National Park. Files include: a) Initial_Comm, which includes the location of each mapcode, b) Cohort_ages, which includes the ages for each tree species-cohort within each mapcode, c) Ecoregions, which consist of different regions of soils and climate, d) Ecoregion_codes, which define the ecoregions, and e) Species_Params, which link the potential establishment and growth rates for each species with each ecoregion.

  19. The CMS Level-1 Calorimeter Trigger for LHC Run II

    CERN Document Server

    Zabi, Alexandre; Cadamuro, Luca; Davignon, Olivier; Romanteau, Thierry; Strebler, Thomas; Cepeda, Maria Luisa; Sauvan, Jean-baptiste; Wardle, Nicholas; Aggleton, Robin Cameron; Ball, Fionn Amhairghen; Brooke, James John; Newbold, David; Paramesvaran, Sudarshan; Smith, D; Taylor, Joseph Ross; Fountas, Konstantinos; Baber, Mark David John; Bundock, Aaron; Breeze, Shane Davy; Citron, Matthew; Elwood, Adam Christopher; Hall, Geoffrey; Iles, Gregory Michiel; Laner Ogilvy, Christian; Penning, Bjorn; Rose, A; Shtipliyski, Antoni; Tapper, Alexander; Durkin, Timothy John; Harder, Kristian; Harper, Sam; Shepherd-Themistocleous, Claire; Thea, Alessandro; Williams, Thomas Stephen; Dasu, Sridhara Rao; Dodd, Laura Margaret; Klabbers, Pamela Renee; Levine, Aaron; Ojalvo, Isabel Rose; Ruggles, Tyler Henry; Smith, Nicholas Charles; Smith, Wesley; Svetek, Ales; Forbes, R; Tikalsky, Jesra Lilah; Vicente, Marcelo

    2017-01-01

    Results from the completed Phase 1 Upgrade of the Compact Muon Solenoid (CMS) Level-1 Calorimeter Trigger are presented. The upgrade was completed in two stages, with the first running in 2015 for proton and Heavy Ion collisions and the final stage for 2016 data taking. The Level-1 trigger has been fully commissioned and has been used by CMS to collect over 43 fb-1 of data since the start of the Large Hadron Collider (LHC) Run II. The new trigger has been designed to improve the performance at high luminosity and large number of simultaneous inelastic collisions per crossing (pile-up). For this purpose it uses a novel design, the Time Multiplexed Trigger (TMT), which enables the data from an event to be processed by a single trigger processor at full granularity over several bunch crossings. The TMT design is a modular design based on the uTCA standard. The trigger processors are instrumented with Xilinx Virtex-7 690 FPGAs and 10 Gbps optical links. The TMT architecture is flexible and the number of trigger p...

  20. CMS Trigger Improvements towards Run II

    CERN Document Server

    AUTHOR|(CDS)2067212

    2016-01-01

    The trigger systems of the LHC detectors play a crucial role in determining the physics capabilities of the experiments. A reduction of several orders of magnitude of the event rate is needed to reach values compatible with detector readout, offline storage and analysis capability. The CMS experiment has been designed with a two-level trigger system the Level-1 Trigger (L1T), implemented on custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. Both systems need to provide an efficient and fast selection of events, to keep the average write-out rate below 450Hz. For Run II, the doubling of both the center of mass energy to 13 TeV and the collision rate to 40 MHz, will imply increased cross sections and out-of-time pile-up. We will present the improvements brought to both L1T and HLT strategies to meet those new challenges.

  1. ATLAS VH(bb) Run II Search

    CERN Document Server

    Buzatu, Adrian; The ATLAS collaboration

    2016-01-01

    The Higgs boson discovered at the LHC in 2012 has been observed coupling directly to W and Z bosons and to tau leptons, and indirectly to top quarks. In order to probe if it is indeed the particle predicted by the Standard Model, direct couplings of the Higgs boson to quarks must also be measured. The Higgs boson decays most often to a pair of bottom quarks (with a branching ratio of 58%). When the Higgs boson is produced alone in gluon-gluon fusion, the signal in this decay mode is overwhelmed by the regular multi-jet background. By requiring the Higgs boson to be produced in association with a vector boson V (W or Z), which is further required to decay leptonically, data events can be selected using charged-lepton or missing transverse energy triggers. The Tevatron experiments presented combined results showing evidence for the VH(H to bb) process at a significance level of about 3 standard deviations, while the combined LHC results from Run II data show a 2.6 standard deviation evidence for the H to bb dec...

  2. The upgraded Pixel Detector of the ATLAS Experiment for Run2 at the Large Hadron Collider

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00235789; The ATLAS collaboration

    2016-01-01

    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 includes 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 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 mechanic...

  3. Review of recent LHCb results and prospects for Run II

    CERN Document Server

    Hicheur, A

    2015-01-01

    As first Run II data acquisition has begun, it is useful to expose the pending questions by reviewing some of the most recent results obtained with Run I data analyses. Early results of the current data taking and middle-term prospects are also shown to illustrate the efficiency of the acquisition and analysis chain.

  4. Operational Experience, Improvements, and Performance of the CDF Run II Silicon Vertex Detector

    CERN Document Server

    Aaltonen, T; Boveia, A.; Brau, B.; Bolla, G; Bortoletto, D; Calancha, C; Carron, S.; Cihangir, S.; Corbo, M.; Clark, D.; Di Ruzza, B.; Eusebi, R.; Fernandez, J.P.; Freeman, J.C.; Garcia, J.E.; Garcia-Sciveres, M.; Gonzalez, O.; Grinstein, S.; Hartz, M.; Herndon, M.; Hill, C.; Hocker, A.; Husemann, U.; Incandela, J.; Issever, C.; Jindariani, S.; Junk, T.R.; Knoepfel, K.; Lewis, J.D.; Martinez-Ballarin, R.; Mathis, M.; Mattson, M.; Merkel, P; Mondragon, M.N.; Moore, R.; Mumford, J.R.; Nahn, S.; Nielsen, J.; Nelson, T.K.; Pavlicek, V.; Pursley, J.; Redondo, I.; Roser, R.; Schultz, K.; Spalding, J.; Stancari, M.; Stanitzki, M.; Stuart, D.; Sukhanov, A.; Tesarek, R.; Treptow, K.; Wallny, R.; Worm, S.

    2013-01-01

    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, an...

  5. Parton distributions for the LHC Run II

    CERN Document Server

    Ball, Richard D.; Carrazza, Stefano; Deans, Christopher S.; Del Debbio, Luigi; Forte, Stefano; Guffanti, Alberto; Hartland, Nathan P.; Latorre, José I.; Rojo, Juan; Ubiali, Maria

    2015-01-01

    We present NNPDF3.0, the first set of parton distribution functions (PDFs) determined with a methodology validated by a closure test. NNPDF3.0 uses a global dataset including HERA-II deep-inelastic inclusive cross-sections, the combined HERA charm data, jet production from ATLAS and CMS, vector boson rapidity and transverse momentum distributions from ATLAS, CMS and LHCb, W+c data from CMS and top quark pair production total cross sections from ATLAS and CMS. Results are based on LO, NLO and NNLO QCD theory and also include electroweak corrections. To validate our methodology, we show that PDFs determined from pseudo-data generated from a known underlying law correctly reproduce the statistical distributions expected on the basis of the assumed experimental uncertainties. This closure test ensures that our methodological uncertainties are negligible in comparison to the generic theoretical and experimental uncertainties of PDF determination. This enables us to determine with confidence PDFs at different pertu...

  6. Electrons and photons at High Level Trigger in CMS for Run II

    CERN Document Server

    Bin Anuar, Afiq Aizuddin

    2015-01-01

    The CMS experiment has been designed with a 2-level trigger system. The first level is implemented using custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increase in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. New approaches have been studied to keep the HLT output rate manageable while maintaining thresholds low enough to cover physics analyses. The strategy mainly relies on porting online the ingredients that have been successfully applied in the offline reconstruction, thus allowing to move HLT selection closer to offline cuts. Improvements in HLT electron and photon definitions will be presented, focusing in particular on updated clustering algorithm and the energy calibration procedure, new Particle-Flow-based isolation approach and pileup mitigation techniques, a...

  7. Radiative corrections for the LHC and linear collider era

    NARCIS (Netherlands)

    Laenen, E.; Wackeroth, D.

    2009-01-01

    We emphasize the importance of including radiative corrections when extracting physics from colliders such as the Tevatron Run II at Fermilab, the Large Hadron Collider (LHC) at CERN, and a future linear collider (LC). We review both well-tested methods and recent advances for calculating these

  8. Bounds on universal extra dimension from LHC run I and II data

    Directory of Open Access Journals (Sweden)

    Debajyoti Choudhury

    2016-12-01

    Full Text Available We discuss the collider bounds on minimal Universal Extra Dimension (mUED model from LHC Run-I and II data. The phenomenology of mUED is determined by only two parameters namely, the compactification scale (R−1 of the extra dimension and cutoff scale (Λ of the theory. The characteristic feature of mUED is the occurrence of nearly degenerate mass spectrum for the Kaluza–Klein (KK particles and hence, soft leptons, soft jets at the collider experiments. The degree of degeneracy of KK-mass spectrum crucially depends on Λ. The strongest direct bound on R−1 (∼950GeV for large Λ arises from a search for a pair of soft dimuons at the Large Hadron Collider (LHC experiment with 8 TeV center-of-mass energy and 20 fb−1 integrated luminosity. However, for small Λ and hence, small splitting within the first KK-level, the bounds from the dimuon channel are rather weak. On the other hand, the discovery of 126 GeV Higgs boson demands small Λ to prevent the scalar potential form being unbounded from below. We discuss LHC monojet searches as a probe of low Λ region of mUED parameter space. We also compute bounds on the mUED parameter space from 13 TeV multijets results.

  9. Instrument Front-Ends at Fermilab During Run II

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Thomas; Slimmer, David; Voy, Duane; /Fermilab

    2011-07-13

    The optimization of an accelerator relies on the ability to monitor the behavior of the beam in an intelligent and timely fashion. The use of processor-driven front-ends allowed for the deployment of smart systems in the field for improved data collection and analysis during Run II. This paper describes the implementation of the two main systems used: National Instruments LabVIEW running on PCs, and WindRiver's VxWorks real-time operating system running in a VME crate processor.

  10. ATLAS Jet Trigger Update for the LHC Run II

    CERN Document Server

    Tavares Delgado, Ademar; The ATLAS collaboration

    2015-01-01

    The CERN Large Hadron Collider is the biggest and most powerful particle collider ever built. It produces up to 40 million proton-proton collisions per second at unprecedented energies to explore the fundamental laws and properties of Nature. The ATLAS experiment is one of the detectors that analyses and records these collisions. It generates dozens of GB/s of data that has to be reduced before it can be permanently stored, the event selection is made by the ATLAS trigger system, which reduces the data volume by a factor of 10^5 . The trigger system has to be highly configurable in order to adapt to changing running conditions and maximize the physics output whilst keeping the output rate under control. A particularly interesting pattern generated during collisions consists of a collimated spray of particles, known as a hadronic jet. To retain the interesting jets and efficiently reject the overwhelming background, optimal jet energy resolution is needed. Therefore the Jet trigger software requires CPU-intens...

  11. The ALICE high momentum particle identification system: An overview after the first Large Hadron Collider run

    CERN Document Server

    Martinengo, P

    2011-01-01

    The ALICE High Momentum Particle Identification RICH detector (HMPID) was installed, with its 10 m(2) of Cesium Iodide (CsI) photo-cathodes, in the ALICE experiment at the Large Hadron Collider (LHC) in 2006. Since then, it has been thoroughly commissioned, together with its auxiliary systems, with cosmic rays and particles from beam dump/splash events recorded during various LHC injection tests in 2008 and 2009. Finally, the HMPID has successfully detected particles produced by the first proton-proton collisions at LHC in winter 2009. The present paper reviews the experience gained during the commissioning phase and summarizes the present status of the detector. Preliminary results concerning the detector performance are also reported. (C) 2010 Elsevier B.V. All rights reserved.

  12. PDF4LHC recommendations for LHC Run II

    NARCIS (Netherlands)

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; Roeck, Albert de; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; McNulty, Ronan; Morsch, Andreas; Nadolsky, Pavel; Radescu, Voica; Rojo, Juan; Thorne, Robert S.

    2015-01-01

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+$\\alpha_s$ uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new

  13. Improving the Compact Muon Solenoid Electromagnetic Calorimeter control and safety systems for the Large Hadron Collider Run 2

    CERN Document Server

    Da Silva Di Calafiori, Diogo Raphael; Djambazov, L; Holme, O; Lustermann, W; Adzic, P; Cirkovic, P; Jovanovic, D; Zelepoukine, S

    2015-01-01

    The first long shutdown of the Large Hadron Collider (LS1, 2013-2015) provided an opportunity for significant upgrades of the detector control and safety systems of the CMS Electromagnetic Calorimeter. A thorough evaluation was undertaken, building upon experience acquired during several years of detector operations. Substantial improvements were made to the monitoring systems in order to extend readout ranges and provide improved monitoring precision and data reliability. Additional remotely controlled hardware devices and automatic software routines were implemented to optimize the detector recovery time in the case of failures. The safety system was prepared in order to guarantee full support for both commercial off-the-shelf and custom hardware components throughout the next accelerator running period. The software applications were modified to operate on redundant host servers, to fulfil new requirements of the experiment. User interface extensions were also added to provide a more complete overview of t...

  14. Minimum Bias Trigger Scintillators in ATLAS Run II

    CERN Document Server

    Sidoti, A; The ATLAS collaboration

    2014-01-01

    The Minimum Bias Trigger Scintillators (MBTS) delivered the primary triggers for selecting events from real LHC collisions with the smallest bias for the low luminosity LHC RunI fills from 2009-2013 (proton-proton, lead-lead and lead-proton collisions). Similarly, for the next RunII of LHC (2015-2018) MBTS will provide key ingredients for the first physics measurements at the new LHC proton-proton collisions energies (charge multiplicity, proton-proton cross section, rapidity gap measurements, ...) and in general for low luminosity LHC fills. After more than $25$\\mathrm{fb}^{-1}$ of proton-proton collisions delivered during RunI of LHC, MBTS detectors have been substantially upgraded for the RunII of LHC (starting in 2015). The upgrade strategy will be presented showing the scintillator replacement, the modified read out scheme, the optical measurements on RunI scintillators assessing the degradation due to the dose received and how the new simulation is being implemented to take into accounts all the modific...

  15. LHCb detector and trigger performance in Run II

    Science.gov (United States)

    Francesca, Dordei

    2017-12-01

    The LHCb detector is a forward spectrometer at the LHC, designed to perform high precision studies of b- and c- hadrons. In Run II of the LHC, a new scheme for the software trigger at LHCb allows splitting the triggering of events into two stages, giving room to perform the alignment and calibration in real time. In the novel detector alignment and calibration strategy for Run II, data collected at the start of the fill are processed in a few minutes and used to update the alignment, while the calibration constants are evaluated for each run. This allows identical constants to be used in the online and offline reconstruction, thus improving the correlation between triggered and offline selected events. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructure for the trigger. The larger timing budget, available in the trigger, allows to perform the same track reconstruction online and offline. This enables LHCb to achieve the best reconstruction performance already in the trigger, and allows physics analyses to be performed directly on the data produced by the trigger reconstruction. The novel real-time processing strategy at LHCb is discussed from both the technical and operational point of view. The overall performance of the LHCb detector on the data of Run II is presented as well.

  16. The Pixel Detector of the ATLAS experiment for the Run 2 at the Large Hadron Collider

    CERN Document Server

    Oide, H; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run 1 of LHC. Taking advantage of the long shutdown, the 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). The IBL is the fourth layer of the Run 2 Pixel Detector, and it was installed in May 2014 between the existing Pixel Detector and the new smaller-radius beam pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO2 based cooling system have been adopted. IBL construction is now completed. An overview of the IBL project...

  17. Database usage and performance for the Fermilab Run II experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bonham, D.; Box, D.; Gallas, E.; Guo, Y.; Jetton, R.; Kovich, S.; Kowalkowski, J.; Kumar, A.; Litvintsev, D.; Lueking, L.; Stanfield, N.; Trumbo, J.; Vittone-Wiersma, M.; White, S.P.; Wicklund, E.; Yasuda, T.; /Fermilab; Maksimovic, P.; /Johns Hopkins U.

    2004-12-01

    The Run II experiments at Fermilab, CDF and D0, have extensive database needs covering many areas of their online and offline operations. Delivering data to users and processing farms worldwide has represented major challenges to both experiments. The range of applications employing databases includes, calibration (conditions), trigger information, run configuration, run quality, luminosity, data management, and others. Oracle is the primary database product being used for these applications at Fermilab and some of its advanced features have been employed, such as table partitioning and replication. There is also experience with open source database products such as MySQL for secondary databases used, for example, in monitoring. Tools employed for monitoring the operation and diagnosing problems are also described.

  18. ATLAS jet trigger update for the LHC run II

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, A. T. [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Lisbon, (Portugal)

    2015-07-01

    The CERN Large Hadron Collider is the biggest and most powerful particle collider ever built. It produces up to 40 million proton-proton collisions per second at unprecedented energies to explore the fundamental laws and properties of Nature. The ATLAS experiment is one of the detectors that analyses and records these collisions. It generates dozens of GB/s of data that has to be reduced before it can be permanently stored, the event selection is made by the ATLAS trigger system, which reduces the data volume by a factor of 105. The trigger system has to be highly configurable in order to adapt to changing running conditions and maximize the physics output whilst keeping the output rate under control. A particularly interesting pattern generated during collisions consists of a collimated spray of particles, known as a hadronic jet. To retain the interesting jets and efficiently reject the overwhelming background, optimal jet energy resolution is needed. Therefore the Jet trigger software requires CPU-intensive reconstruction algorithms. In order to reduce the resources needed for the reconstruction step, a partial detector readout scheme was developed, which effectively suppresses the low activity regions of the calorimeter. In this paper we describe the overall ATLAS trigger software, and the jet trigger in particular, along with the improvements made on the system. We then focus on detailed studies of the algorithm timing and the performance impact of the full and partial calorimeter readout schemes. We conclude with an outlook of the jet trigger plans for the next LHC data-taking period. (authors)

  19. BPM Breakdown Potential in the PEP-II B-factory Storage Ring Collider

    Energy Technology Data Exchange (ETDEWEB)

    Weathersby, Stephen; Novokhatski, Alexander; /SLAC

    2010-02-10

    High current B-Factory BPM designs incorporate a button type electrode which introduces a small gap between the button and the beam chamber. For achievable currents and bunch lengths, simulations indicate that electric potentials can be induced in this gap which are comparable to the breakdown voltage. This study characterizes beam induced voltages in the existing PEP-II storage ring collider BPM as a function of bunch length and beam current.

  20. A Final Review of the Performance of the CDF Run II Data Acquisition System

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    The CDF Collider Detector at Fermilab ceased data collection on September 30, 2011 after over twenty five years of operation. We review the performance of the CDF Run II data acquisition systems over the last ten of these years while recording nearly 10 fb-1 of proton-antiproton collisions with a high degree of efficiency. Technology choices in the online control and configuration systems and front-end embedded processing have impacted the efficiency and quality of the data accumulated by CDF, and have had to perform over a large range of instantaneous luminosity values and trigger rates. We identify significant sources of problems and successes. In particular, we present our experience computing and acquiring data in a radiation environment, and attempt to correlate system technical faults with radiation dose rate and technology choices.

  1. Operation and performance of the CMS Resistive Plate Chambers during LHC run II

    CERN Document Server

    Eysermans, Jan

    2017-01-01

    The Resitive Plate Chambers (RPC) at the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) provide redundancy to the Drift Tubes in the barrel and Cathode Strip Chambers in the endcap regions. Consisting of 1056 double gap RPC chambers, the main detector parameters and environmental conditions are carefully monitored during the data taking period. At a center of mass energy of 13 TeV, the luminosity reached record levels which was challenging from the operational and performance point of view. In this work, the main operational parameters are discussed and the overall performance of the RPC system is reported for the LHC run II data taking period. With a low amount of inactive chambers, a good and stable detector performance was achieved with high efficiency.

  2. Muon reconstruction and identification with the Run II D0 detector

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Abbott, B. [University of Oklahoma, Norman, OK 73019 (United States); Acharya, B.S. [Tata Institute of Fundamental Research, Mumbai (India); Adams, M. [University of Illinois at Chicago, Chicago, IL 60607 (United States); Adams, T. [Florida State University, Tallahassee, FL 32306 (United States); Agnew, J.P. [The University of Manchester, Manchester M13 9PL (United Kingdom); Alexeev, G.D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Alkhazov, G. [Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Alton, A. [University of Michigan, Ann Arbor, MI 48109 (United States); Arthaud, M. [CEA, Irfu, SPP, Saclay (France); Askew, A. [Florida State University, Tallahassee, FL 32306 (United States); Atkins, S. [University of Michigan, Ann Arbor, MI 48109 (United States); Augsten, K. [Czech Technical University in Prague, Prague (Czech Republic); Avila, C. [Universidad de los Andes, Bogotá (Colombia); Badaud, F. [LPC, Université Blaise Pascal, CNRS/IN2P3, Clermont (France); Bagby, L.; Baldin, B. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Bandurin, D.V. [Florida State University, Tallahassee, FL 32306 (United States); Banerjee, S. [Tata Institute of Fundamental Research, Mumbai (India); Barberis, E. [Northeastern University, Boston, MA 02115 (United States); and others

    2014-02-11

    We present an overview of the muon reconstruction and identification methods employed by the D0 collaboration to analyze the Run II (2001–2011) pp{sup ¯} data of the Fermilab Tevatron collider at √(s)=1.96TeV. We discuss the performance of these methods, how it is measured using D0 data, and how it is properly modeled by the D0 simulation program. In its pseudorapidity acceptance, |η|<2, the muon system identifies high-p{sub T} muons (p{sub T}≳10GeV) with efficiencies ranging from 72% to 89%. Muons tracks are reconstructed in the D0 central tracking system with efficiencies ranging from 85% to 92% and with a typical relative momentum resolution of 10% for p{sub T}=40GeV. Isolation criteria reject multijet background with efficiencies of 87–99%.

  3. CERN scientists take part in the Tevatron Run II performance review committee

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Tevatron Run II is under way at Fermilab, exploring the high-energy frontier with upgraded detectors that will address some of the biggest questions in particle physics.Until CERN's LHC switches on, the Tevatron proton-antiproton collider is the world's only source of top quarks. It is the only place where we can search for supersymmetry, for the Higgs boson, and for signatures of additional dimensions of space-time. The US Department of Energy (DOE) recently convened a high-level international review committee to examine Fermilab experts' first-phase plans for the accelerator complex. Pictured here with a dipole magnet in CERN's LHC magnet test facility are the four CERN scientists who took part in the DOE's Tevatron review. Left to right: Francesco Ruggiero, Massimo Placidi, Flemming Pedersen, and Karlheinz Schindl. Further information: CERN Courier 43 (1)

  4. Muon reconstruction and identification with the Run II D0 detector

    CERN Document Server

    ,

    2014-01-01

    We present an overview of the muon reconstruction and identification methods employed by the D0 Collaboration to analyze the Run II (2001-2011) ppbar data of the Fermilab Tevatron collider at sqrt s = 1.96 TeV. We discuss the performance of these methods, how it is measured using D0 data, and how it is properly modeled by the D0 simulation program. In its pseudorapidity acceptance, eta10 GeV) with efficiencies ranging from 72% to 89%. Muons tracks are reconstructed in the D0 central tracking system with efficiencies ranging from 85% to 92% and with a typical relative momentum resolution of 10% for pT = 40 GeV. Isolation criteria reject multijet background with efficiencies of 87% to 99%.

  5. Higgs Boson Measurements in CMS with Run II Data

    CERN Document Server

    Kumar, Ashok

    2017-01-01

    Latest results from the CMS experiment on studies of Higgs boson production are presented. Studies involving the 125 GeV Higgs boson using various Standard Model production and decay modes have been performed using proton proton collisions from data accumulated during the LHC Run II with center-of-mass energy of 13 TeV. Similar datasets have also been used to place constraints on physics beyond the Standard Model involving extended Higgs boson sectors.

  6. LHCb : LHCbVELO: Performance and Radiation Damage in LHC Run I and Preparationfor Run II

    CERN Multimedia

    Szumlak, Tomasz

    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. Heavy hadrons are identified through their flight distance in the Vertex Locator (VELO). The VELO comprises 42 modules made of two n+-on-n 300 um thick half-disc silicon sensors with R-measuring and Phi-measuring micro-strips. In order to allow retracting the detector, the VELO is installed as two movable halves containing 21 modules each. The detectors are operated in a secondary vacuum and are cooled by a bi-phase CO2 cooling system. During data taking in LHC Run 1 the LHCb VELO has operated with an extremely high efficiency and excellent performance. The track finding efficiency is typically greater than 98%. An impact parameter resolution of less than 35 um is achieved for particles with transverse momentum greater than 1 GeV/c. An overview of all important performance parameters will be given. The VELO sensors have received a large and non-uniform radiation dose of up to 1.2 x 10...

  7. The upgraded Pixel Detector of the ATLAS Experiment for Run2 at the Large Hadron Collider

    CERN Document Server

    Backhaus, Malte; The ATLAS collaboration

    2015-01-01

    Run-2 of the 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). 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. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, two different silicon sensor technologies (planar and 3D) have been developed as well as a new read-out chip within CMOS 130nm technology and with larger area, smaller pixel size and faster readout capability. The new detector is the first large scale application of of 3D detectors and CMOS 130nm technology. An overview of the lessons learned during the IBL project will be presented, focusing on the challenges and highlighting the issues met during the productio...

  8. The Pixel Detector of the ATLAS experiment for the Run2 at the Large Hadron Collider

    CERN Document Server

    Oide, H; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the 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). IBL is a fourth layer of pixel detectors, and will be installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO2 based cooling system have been adopted. IBL construction is now completed. An overview of the IBL project as well as the ...

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

    CERN Document Server

    Mandelli, B; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run 1 of LHC. Taking advantage of the long shutdown, the 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). The IBL is a fourth layer of pixel detectors, and has been installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO$_2$ based cooling system have been adopted. The IBL construction and installation in the ATLAS Experiment has been completed very successfu...

  10. The Pixel Detector of the ATLAS experiment for the Run2 at the Large Hadron Collider

    CERN Document Server

    Mandelli, B; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long shutdown, the 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). IBL is a fourth layer of pixel detectors, and will be installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO2 based cooling system have been adopted. IBL construction is now completed. An overview of the IBL project as well as the ...

  11. The Pixel Detector of the ATLAS experiment for the Run2 at the Large Hadron Collider

    CERN Document Server

    INSPIRE-00237659

    2015-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the 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). IBL is a fourth layer of pixel detectors, and has been installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO2 based cooling system have been adopted. An overview of the refurbishing of the Pixel Detect or and of the IBL project as...

  12. The upgraded Pixel Detector of the ATLAS Experiment for Run2 at the Large Hadron Collider

    CERN Document Server

    Mullier, Geoffrey Andre; The ATLAS collaboration

    2015-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the 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. To cope with the high radiation and increased pixel occupancy due to the proximity to the interaction point, two different silicon sensor technologies (planar and 3D) have been developed. A new readout chip has been developed within CMOS 130nm technology with larger area, smaller pixel size and faster readout capability. Dedicated design features in combination with a new composite material were considered and used in order to reduce the material budget of the support structure while keeping the optimal thermo-mechanical performan...

  13. The Pixel Detector of the ATLAS experiment for the Run2 at the Large Hadron Collider

    CERN Document Server

    Takubo, Y; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long shutdown, the detector was extracted from the experiment and brought to surface, to equip it with new service quarter panels, to repair the modules and to ease installation of the Insertable B-Layer (IBL). The IBL is a fourth layer of pixel detectors, and has been installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using light weight staves and CO$_{2}$ based cooling system have been adopted. An overview of the refurbishing of the Pixel Detector and the IBL pr...

  14. Identifying a light charged Higgs boson at the LHC Run II

    Directory of Open Access Journals (Sweden)

    Abdesslam Arhrib

    2017-11-01

    Full Text Available We analyse the phenomenological implications of a light Higgs boson, h, within the CP-conserving 2-Higgs Doublet Model (2HDM Type-I, for the detection prospects of the charged H± state at Run II of the Large Hadron Collider (LHC, assuming s=13 TeV as energy and O(100 fb−1 as luminosity. When sufficiently light, this h state can open up the bosonic decay channel H±→W±(⁎h, which may have a branching ratio significantly exceeding those of the H±→τν and H±→cs channels. We perform a broad scan of the 2HDM Type-I parameter space, assuming the heavier of the two CP-even Higgs bosons, H, to be the observed SM-like state with a mass near 125 GeV. Through these scans we highlight regions in which mH±Run II.

  15. Identifying a light charged Higgs boson at the LHC Run II

    Science.gov (United States)

    Arhrib, Abdesslam; Benbrik, Rachid; Enberg, Rikard; Klemm, William; Moretti, Stefano; Munir, Shoaib

    2017-11-01

    We analyse the phenomenological implications of a light Higgs boson, h, within the CP-conserving 2-Higgs Doublet Model (2HDM) Type-I, for the detection prospects of the charged H± state at Run II of the Large Hadron Collider (LHC), assuming √{ s } = 13 TeV as energy and O (100 fb-1) as luminosity. When sufficiently light, this h state can open up the bosonic decay channel H± →W ± (*) h, which may have a branching ratio significantly exceeding those of the H± → τν and H± → cs channels. We perform a broad scan of the 2HDM Type-I parameter space, assuming the heavier of the two CP-even Higgs bosons, H, to be the observed SM-like state with a mass near 125 GeV. Through these scans we highlight regions in which mH± Run II.

  16. The CMS Level-1 Calorimeter Trigger for the LHC Run II

    Science.gov (United States)

    Zabi, A.; Beaudette, F.; Cadamuro, L.; Davignon, O.; Romanteau, T.; Strebler, T.; Cepeda, M.; Sauvan, J. B.; Wardle, N.; Aggleton, R.; Ball, F.; Brooke, J.; Newbold, D.; Paramesvaran, S.; Smith, D.; Taylor, J.; Foudas, C.; Baber, M.; Bundock, A.; Breeze, S.; Citron, M.; Elwood, A.; Hall, G.; Iles, G.; Laner, C.; Penning, B.; Rose, A.; Shtipliyski, A.; Tapper, A.; Ojalvo, I.; Durkin, T.; Harder, K.; Harper, S.; Shepherd-Themistocleous, C.; Thea, A.; Williams, T.; Dasu, S.; Dodd, L.; Forbes, R.; Gorski, T.; Klabbers, P.; Levine, A.; Ruggles, T.; Smith, N.; Smith, W.; Svetek, A.; Tikalsky, J.; Vicente, M.

    2017-01-01

    Results from the completed Phase 1 Upgrade of the Compact Muon Solenoid (CMS) Level-1 Calorimeter Trigger are presented. The upgrade was performed in two stages, with the first running in 2015 for proton and heavy ion collisions and the final stage for 2016 data taking. The Level-1 trigger has been fully commissioned and has been used by CMS to collect over 43 fb-1 of data since the start of the Run II of the Large Hadron Collider (LHC). The new trigger has been designed to improve the performance at high luminosity and large number of simultaneous inelastic collisions per crossing (pile-up). For this purpose it uses a novel design, the Time Multiplexed Trigger (TMT), which enables the data from an event to be processed by a single trigger processor at full granularity over several bunch crossings. The TMT design is a modular design based on the μTCA standard. The trigger processors are instrumented with Xilinx Virtex-7 690 FPGAs and 10 Gbps optical links. The TMT architecture is flexible and the number of trigger processors can be expanded according to the physics needs of CMS. Sophisticated and innovative algorithms are now the core of the first decision layer of the experiment. The system has been able to adapt to the outstanding performance of the LHC, which ran with an instantaneous luminosity well above design. The performance of the system for single physics objects are presented along with the optimizations foreseen to maintain the thresholds for the harsher conditions expected during the LHC Run II and Run III periods.

  17. Top mass measurements at the Tevatron run II

    Energy Technology Data Exchange (ETDEWEB)

    Velev, Gueorgui V.; /Fermilab

    2005-10-01

    The latest top quark mass measurements by the CDF and D0 experiments are presented here. The mass has been determined in the dilepton (t{bar t} {yields} e{mu}, ee, {mu}{mu} + jets + E{sub T}) and lepton plus jets (t{bar t} {yields} e or {mu} + jets + E{sub T}) final states. The most accurate single result from lepton plus jets channel is 173.5{sub -3.6}{sup +3.7}(stat. + Jet Energy Scale Systematic) {+-} 1.3(syst.) GeV/c{sup 2}, which is better than the combined CDF and D0 Run I average. A preliminary and unofficial average of the best experimental Run II results gives M{sub top} = 172.7 {+-} 3.5 GeV/c{sup 2}.

  18. Beam instrumentation for the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  19. The CMS Level-1 Trigger system for LHC Run II

    CERN Document Server

    Tapper, Alexander

    2017-01-01

    During LHC Run II the centre-of-mass energy of pp collisions has increased up to 13 TeV and the instantaneous luminosity has progressed towards $2 \\times 10^{34} \\rm{cm}^{-2}\\rm{s}^{-1}$. In order to guarantee a successful and ambitious physics programme under these conditions, the CMS trigger system has been upgraded. The upgraded CMS Level-1 trigger is designed to improve performance at high luminosity and large number of simultaneous inelastic collisions per crossing. The trigger design, implementation and commissioning are summarised and performance results are described.

  20. Improvements to ATLAS Track Reconstruction for Run-II

    CERN Document Server

    Cairo, Valentina Maria; The ATLAS collaboration

    2015-01-01

    Run-II of the LHC will provide new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. In addition, the Insertable B-layer (IBL) is a fourth pixel layer, which has been inserted at the centre of ATLAS during the shutdown of the LHC. We will discuss improvements to track reconstruction developed during the two year shutdown of the LHC. These include novel techniques developed to improve the performance in the dense cores of jets, optimisation for the expected conditions, and a big software campaign which lead to more than a factor of three decrease in the CPU time needed to process each recorded event.

  1. VeloTT tracking for LHCb Run II

    CERN Document Server

    Bowen, Espen Eie; Tresch, Marco

    2016-01-01

    This note describes track reconstruction in the LHCb tracking system upstream of the magnet, combining VELO tracks with hits in the TT sub-detector. The implementation of the VeloTT algorithm and its performance in terms of track reconstruction efficiency, ghost rate and execution time are presented. The algorithm has been rewritten for use in the first software trigger level for LHCb Run II. The momentum and charge information obtained for the VeloTT tracks (due to a fringe magnetic field between the VELO and TT sub-detectors) can reduce the total execution time for the full tracking sequence.

  2. Electron and Photon High Level Trigger in CMS for Run II

    CERN Document Server

    AUTHOR|(CDS)2084857

    2014-01-01

    The CMS experiment has been designed with a two-level trigger system. The first level is implemented on custom-designed electronics. The second level is the so-called High Level Trigger (HLT), a streamlined version of the CMS offline reconstruction software running on a computer farm. For Run II of the Large Hadron Collider, the increase in center-of-mass energy and luminosity will raise the event rate to a level challenging for the HLT algorithms. New approaches have been studied to contain the HLT rate within the available bandwidth while keeping thresholds low enough to cover the requirements of the physics analyses. The strategy mainly relies on porting online the improvements that have been applied to the offline reconstruction, thus allowing to move HLT selection closer to offline cuts. We present such changes in the definitions of HLT electrons and photons, focusing in particular on the deployment of a new clustering algorithm allowing pileup mitigation, a new Particle-Flow based isolation replacing th...

  3. Alignment of the ATLAS Inner Detector Upgraded for the LHC Run II

    CERN Document Server

    Jimenez Pena, Javier

    2015-01-01

    ATLAS is equipped with a 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. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable Barrel Layer (IBL). An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to integration to the alignment framework of the IBL, which plays the key role in precise reconstruction of the collider luminous region, interaction vertices and identification of long-lived heavy flavour states. In order to detect as soon as possible deformations and misalignments of the tracking system that may affect the data taking, a fast alignment chain was implemented at CERN’s Tier-0. Last upgrades and tests of this fast chain will be covered. Performance from Cosmic Ray commissioning run will be discussed.

  4. The International Linear Collider Technical Design Report - Volume 3.II: Accelerator Baseline Design

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, Chris [SLAC National Accelerator Lab., Menlo Park, CA (United States); et al.

    2013-06-26

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.

  5. The International Linear Collider Technical Design Report - Volume 3.II: Accelerator Baseline Design

    CERN Document Server

    Adolphsen, Chris; Barish, Barry; Buesser, Karsten; Burrows, Philip; Carwardine, John; Clark, Jeffrey; Durand, Helene Mainaud; Dugan, Gerry; Elsen, Eckhard; Enomoto, Atsushi; Foster, Brian; Fukuda, Shigeki; Gai, Wei; Gastal, Martin; Geng, Rongli; Ginsburg, Camille; Guiducci, Susanna; Harrison, Mike; Hayano, Hitoshi; Kershaw, Keith; Kubo, Kiyoshi; Kuchler, Victor; List, Benno; Liu, Wanming; Michizono, Shinichiro; Nantista, Christopher; Osborne, John; Palmer, Mark; Paterson, James McEwan; Peterson, Thomas; Phinney, Nan; Pierini, Paolo; Ross, Marc; Rubin, David; Seryi, Andrei; Sheppard, John; Solyak, Nikolay; Stapnes, Steinar; Tauchi, Toshiaki; Toge, Nobu; Walker, Nicholas; Yamamoto, Akira; Yokoya, Kaoru

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  6. New Physics at the LHC: results and Run II perspectives

    CERN Document Server

    Kajomovitz, Enrique; The ATLAS collaboration

    2014-01-01

    The talk gives an overview of selected Run-1 results on searches for New Physics from the ATLAS and CMS experiments. A short outlook of the Run-2 schedule and some prospects for Run-2 sensitivity reach for New Physics

  7. CMS detector tracking performance in Run-II

    CERN Document Server

    Brondolin, Erica

    2016-01-01

    Since the start of Run-II in June 2015, LHC has delivered pp collisions at a center of mass energy of 13TeV and with a bunch time separation of 25 ns. On avarage, more than 25 inelastic collisions are superimposed on the event of interest. Under these new conditions, the CMS collaboration has re-calibrated and verified the performance of the whole detector. In particular, the CMS tracking performance has been measured both directly and indirectly. Direct measurements are, among others, the beam spot determination, the vertex resolution and the muon reconstruction efficiency with the tag and probe technique. An indirect assessment can be given by the pion reconstruction efficiency and the low-mass resonance parameters as a function of different single track kinematics.

  8. Boosted H­->bb Tagger In Run II

    CERN Document Server

    Sahinsoy, Merve; The ATLAS collaboration

    2016-01-01

    Several searches for Higgs bosons decaying to b­quark pairs benefit from the increased Run II centre­of­mass energy by exploiting the large transvers­momentum (boosted) Higgs boson regime, where the two b­jets are merged into one large­radius jet. ATLAS uses a boosted H­>bb tagger algorithm to separate the Higgs signal from the background processes (QCD, W and Z bosons, top quarks). The tagger takes as input a large­R=1.0 jet calibrating the pseudorapidity, energy and mass scale. The tagger employs b­tagging, Higgs candidate mass, and substructure information. The performance of several operating points in Higgs boson signal and QCD and ttbar all­hadronic backgrounds are presented. Systematic uncertainties are evaluated so that this tagger can be used in analyses.

  9. Improvements to ATLAS track reconstruction for Run II

    Energy Technology Data Exchange (ETDEWEB)

    Cairo, Valentina Maria Martina, E-mail: valentina.maria.cairo@cern.ch [University of Calabria, Arcavacata di Rende (Italy); CERN, Meyrin (Switzerland)

    2016-07-11

    Run II of the LHC will provide new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. A major change to the Inner Detector layout during the shutdown period has been the installation of the Insertable B-Layer, a fourth pixel layer located at a radius of 33 mm. This contribution discusses improvements to track reconstruction developed during the two year shutdown of the LHC. These include novel techniques developed to improve the performance in the dense cores of jets, optimisation for the expected conditions, and a big software campaign which lead to more than a factor of three decrease in the CPU time needed to process each recorded event.

  10. LHCb-The LHCb trigger in Run II

    CERN Multimedia

    Michielin, Emanuele

    2016-01-01

    The LHCb trigger system has been upgraded to exploit the real-time alignment, calibration and analysis capabilities of LHCb in Run-II. An increase in the CPU and disk capacity of the event filter farm, combined with improvements to the reconstruction software, mean that efficient, exclusive selections can be made in the first stage of the High Level Trigger (HLT1). The output of HLT1 is buffered to the 5 PB of disk on the event filter farm, while the detector is aligned and calibrated in real time. The second stage, HLT2, performs complete, offline quality, event reconstruction. Physics analyses can be performed directly on this information, and for the majority of charm physics selections, a reduced event format can be written out, which permits higher event rates.

  11. LUCID Upgrade for ATLAS Luminosity Measurement in Run II

    CERN Document Server

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

    2016-01-01

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

  12. LHCb Run II tracking performance and prospects for the Upgrade

    CERN Multimedia

    2016-01-01

    The LHCb tracking system consists of a Vertex Locator around the interaction point, a tracking station with four layers of silicon strip detectors in front of the magnet, and three tracking stations, using either straw-tubes or silicon strip detectors, behind the magnet. This system allows to reconstruct charged particles with a high efficiency (typically > 95% for particles with momentum > 5 GeV) and an excellent momentum resolution (0.5% for particles with momentum < 20 GeV). The high momentum resolution results in very narrow mass peaks, leading to a very good signal-to-background ratio in such key channels as $B_s\\to\\mu^+\\mu^-$. Furthermore an optimal decay time resolution is an essential element in the studies of time dependent CP violation. For Run II a novel reconstruction strategy was adopted, allowing to run the same track reconstruction in the software trigger as offline. This convergence was possible due to a staged approach in the track reconstruction and a large reduction in the processing tim...

  13. LHCb’s Real-Time Alignment in Run II

    CERN Document Server

    Batozskaya, Varvara

    2015-01-01

    The LHCb collaboration has introduced a novel real-time detector alignment and calibration strategy for LHC Run II. The 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. Critically, this new real-time alignment and calibration procedure allows identical constants to be used in the online and oine reconstruction, thus improving the correlation between triggered and oine selected events. This oers 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 configu...

  14. The CMS Level-1 trigger system for LHC Run II

    Science.gov (United States)

    Cadamuro, L.

    2017-03-01

    The Compact Muon Solenoid (CMS) experiment implements a sophisticated two-level online selection system that achieves a rejection factor of nearly 105. During Run II, the LHC has increased the centre-of-mass energy of proton-proton collisions up to 13 TeV and may progressively reach an instantaneous luminosity of 2×1034 cm-2 s-1 or higher. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition system has been upgraded. The upgraded CMS Level-1 (L1) trigger benefits from the recent μTCA technology and is designed to maintain the performance under high instantaneous luminosity conditions. More sophisticated, innovative algorithms are now the core of the first decision layer of CMS: this drastically reduces the trigger rate and improves the trigger efficiency for a wide variety of physics processes. In this document, we present the overall architecture of the upgraded Level-1 trigger system. The performance of single object triggers, measured on collision data recorded during the 2016 running period, are also summarised.

  15. Alignment of the ATLAS Inner Detector Upgraded for the LHC Run II

    CERN Document Server

    Butti, Pierfrancesco; The ATLAS collaboration

    2015-01-01

    ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment. ATLAS is equipped with a 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. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters. The task requires using very large data sets and represents a considerable numerical challenge in terms of both CPU time and precision. The adopted strategy uses a hierarchical approach to alignment, combining local and global least squares techniques. An o...

  16. Alignment of the ATLAS inner detector for the LHC Run II

    CERN Document Server

    Butti, Pierfrancesco; The ATLAS collaboration

    2015-01-01

    ATLAS a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment. ATLAS is equipped with a 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. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters. The task requires using very large data sets and represents a considerable numerical challenge in terms of both CPU time and precision. The adopted strategy uses a hierarchical approach to alignment, combining local and global least squares techniques. An outl...

  17. Alignment of the ATLAS Inner Detector upgraded for the LHC Run II

    CERN Document Server

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

    2015-01-01

    ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment. ATLAS is equipped with a 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. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters. The task requires using very large data sets and represents a considerable numerical challenge in terms of both CPU time and precision. The adopted strategy uses a hierarchical approach to alignment, combining local and global least squares techniques. An o...

  18. Performances of the ATLAS Level-1 Muon barrel trigger during the Run-II data taking

    CERN Document Server

    Sessa, Marco; The ATLAS collaboration

    2017-01-01

    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 $|\\eta|<1.05$ 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 with respect to their transverse momentum and associates them with the correct bunch-crossing number. The trigger system is able to take a decision within a latency of about 2 $\\mu s$. The detailed measurement of the RPC detector efficiencies and of the trigger performance during the ATLAS Run-II data taking is here presented.

  19. The Higgs and Supersymmetry at Run II of the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shih, David [Rutgers Univ., Piscataway, NJ (United States)

    2016-04-14

    Prof. David Shih was supported by DOE grant DE-SC0013678 from April 2015 to April 2016. His research during this year focused on the phenomenology of super-symmetry (SUSY) and maximizing its future discovery potential at Run II of the LHC. SUSY is one of the most well-motivated frameworks for physics beyond the Standard Model. It solves the "naturalness" or "hierarchy" problem by stabilizing the Higgs mass against otherwise uncontrolled quantum corrections, predicts "grand unification" of the fundamental forces, and provides many potential candidates for dark matter. However, after decades of null results from direct and indirect searches, the viable parameter space for SUSY is increasingly constrained. Also, the discovery of a Standard Model-like Higgs with a mass at 125 GeV places a stringent constraint on SUSY models. In the work supported on this grant, Shih has worked on four different projects motivated by these issues. He has built natural SUSY models that explain the Higgs mass and provide viable dark matter; he has studied the parameter space of "gauge mediated supersymmetry breaking" (GMSB) that satisfies the Higgs mass constraint; he has developed new tools for the precision calculation of flavor and CP observables in general SUSY models; and he has studied new techniques for discovery of supersymmetric partners of the top quark.

  20. Direct Searches for Scalar Leptoquarks at the Run II Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, Daniel Edward [Tufts Univ., Medford, MA (United States)

    2004-08-01

    This dissertation sets new limits on the mass of the scalar leptoquark from direct searches carried out at the Run II CDF detector using data from March 2001 to October 2003. The data analyzed has a total time-integrated measured luminosity of 198 pb-1 of p$\\bar{p}$ collisions with √s = 1.96 TeV. Leptoquarks are assumed to be pair-produced and to decay into a lepton and a quark of the same generation. They consider two possible leptoquark decays: (1) β = BR(LQ → μq) = 1.0, and (2) β = BR(LQ → μq) = 0.5. For the β = 1 channel, they focus on the signature represented by two isolated high-pT muons and two isolated high-pT jets. For the β = 1/2 channel, they focus on the signature represented by one isolated high-pT muon, large missing transverse energy, and two isolated high-pT jets. No leptoquark signal is experimentally detected for either signature. Using the next to leading order theoretical cross section for scalar leptoquark production in p$\\bar{p}$ collisions [1], they set new mass limits on second generation scalar leptoquarks. They exclude the existence of second generation scalar leptoquarks with masses below 221(175) GeV/c2 for the β = 1(1/2) channels.

  1. The CMS calorimeter trigger upgrade for the LHC Run II

    CERN Document Server

    Zabi, Alexandre

    2014-01-01

    The CMS experiment implements a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. The first level (L1) is based on coarse information coming from the calorimeters and the muon detectors while the High-Level Trigger combines fine-grain information from all sub-detectors. During Run II, the LHC will increase its centre of mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2e34 cm-2s-1. In order to guarantee a successful and ambitious physics program under this intense environment, the CMS Trigger and Data acquisition system must be consolidated. In particular the L1 calorimeter Trigger hardware and architecture will be modified. The goal is to maintain the current thresholds (e.g., for electrons and photons) and improve the performance for the selection of tau leptons. This can only be achieved by designing an updated trigger architecture based on the recent microTCA technology. Racks can be equipped with fast optical links and latest...

  2. Direct Searches For Scalar Leptoquarks At The Run Ii Tevatron

    CERN Document Server

    Ryan, D E

    2004-01-01

    This dissertation sets new limits on the mass of the scalar leptoquark from direct searches carried out at the Run II CDF detector using data from March 2001 to October 2003. The data analysed has a total time-integrated measured luminosity of 198 pb−1 of pp¯ collisions with s = 1.96 TeV. Leptoquarks are assumed to be pair-produced and to decay into a lepton and a quark of the same generation. We consider two possible leptoquark decays: (1) β = BR(LQ → μq ) = 1.0, and (2) β = BR(LQ → μq ) = 0.5. For the β = 1 channel, we focus on the signature represented by two isolated high- pT muons and two isolated high-pT jets. For the β = 1/2 channel, we focus on the signature represented by one isolated high-pT muon, large missing transverse energy, and two isolated high- p T jets. No leptoquark signal is experimentally detected for either signature. Using the next to leading order theoretical cross section for s...

  3. Systematic analysis of HEP collider data

    Energy Technology Data Exchange (ETDEWEB)

    Knuteson, Bruce [Massachusetts Institute of Technology (United States)]. E-mail: knuteson@fnal.gov

    2004-11-21

    These proceedings outline steps toward a systematic analysis of frontier energy collider data: specifically, those data collected at Tevatron Runs I and II, LEP Run II, HERA Runs I and II, and the future LHC. Algorithms designed to understand the gross features of the data (VISTA), to systematically and model-independently search for new physics at the electroweak scale (SLEUTH), to automate tests of specific hypotheses against those data (QUAERO), to turn an existing full detector simulation into a fast simulation (TURBOSIM), and to infer the physics underlying any hint observed in the data (BARD) are reviewed. A somewhat non-conventional viewpoint is adopted throughout.

  4. Commissioning of the nonlinear chromaticity at injection for LHC Run II

    CERN Document Server

    AUTHOR|(CDS)2080608; Tomas Garcia, Rogelio; Carlier, Felix Simon; Langner, Andy Sven; Malina, Lukas; Persson, Tobias Hakan Bjorn; Coello De Portugal - Martinez Vazquez, Jaime Maria; Skowronski, Piotr Krzysztof; Garcia-Tabares Valdivieso, Ana; CERN. Geneva. ATS Department

    2016-01-01

    For the first time, correction of nonlinear chromaticity and amplitude detuning was included in the LHC commissioning for Run II. The corrections found during the nonlinear optics commissioning have been deployed operationally at injection in the LHC. This note summarizes the relevant measurements and corrections performed during the first commissioning of the LHC in Run II

  5. Future Hadron Colliders

    CERN Document Server

    Keil, Eberhard

    1998-01-01

    Plans for future hadron colliders are presented, and accelerator physics and engineering aspects common to these machines are discussed. The Tevatron is presented first, starting with a summary of the achievements in Run IB which finished in 1995, followed by performance predictions for Run II which will start in 1999, and the TeV33 project, aiming for a peak luminosity $L ~ 1 (nbs)^-1$. The next machine is the Large Hadron Collider LHC at CERN, planned to come into operation in 2005. The last set of machines are Very Large Hadron Colliders which might be constructed after the LHC. Three variants are presented: Two machines with a beam energy of 50 TeV, and dipole fields of 1.8 and 12.6 T in the arcs, and a machine with 100 TeV and 12 T. The discussion of accelerator physics aspects includes the beam-beam effect, bunch spacing and parasitic collisions, and the crossing angle. The discussion of the engineering aspects covers synchrotron radiation and stored energy in the beams, the power in the debris of the p...

  6. $B$ physics at the Tevatron: Run II and beyond

    CERN Document Server

    Anikeev, K; Azfar, F.; Bailey, S.; Bauer, C.W.; Bell, W.; Bodwin, G.; Braaten, E.; Burdman, G.; Butler, J.N.; Byrum, K.; Cason, N.; Cerri, A.; Cheung, H.W.K.; Dighe, A.; Donati, S.; Ellis, R.K.; Falk, A.; Feild, G.; Fleming, S.; Furic, I.; Gardner, S.; Grossman, Y.; Gutierrez, G.; Hao, W; Harris, B.W.; Hewett, J.; Hiller, G.; Jesik, R.; Jones, M.; Kasper, P.A.; El-Khadra, A.; Kirk, M.; Kiselev, V.V.; Kroll, J.; Kronfeld, A.S.; Kutschke, R.; Kuznetsov, V.E.; Laenen, E.; Lee, J.; Leibovich, A.K.; Lewis, J.D.; Ligeti, Z.; Likhoded, A.K.; Logan, H.E.; Luke, M.; Maciel, A.; Majumder, G.; Maksimovic, P.; Martin, M.; Menary, S.; Nason, P.; Nierste, U.; Nir, Y.; Nogach, L.; Norrbin, E.; Oleari, C.; Papadimitriou, V.; Paulini, M.; Paus, C.; Petteni, M.; Poling, R.; Procario, M.; Punzi, G.; Quinn, H.; Rakitine, A.; Ridolfi, G.; Shestermanov, K.; Signorelli, G.; Silva, J.P.; Skwarnicki, T.; Smith, A.; Speakman, B.; Stenson, K.; Stichelbaut, F.; Stone, S.; Sumorok, K.; Tanaka, M.; Taylor, W.; Trischuk, W.; Tseng, J.; Van Kooten, R.; Vasiliev, A.; Voloshin, M.; Wang, J.C.; Wicklund, A.B.; Wurthwein, F.; Xuan, N.; Yarba, J.; Yip, K.; Zieminski, A.

    2002-01-01

    This report provides a comprehensive overview of the prospects for B physics at the Tevatron. The work was carried out during a series of workshops starting in September 1999. There were four working groups: 1) CP Violation, 2) Rare and Semileptonic Decays, 3) Mixing and Lifetimes, 4) Production, Fragmentation and Spectroscopy. The report also includes introductory chapters on theoretical and experimental tools emphasizing aspects of B physics specific to hadron colliders, as well as overviews of the CDF, D0, and BTeV detectors, and a Summary.

  7. Search for the Production of Gluinos and Squarks with the CDF II Experiment at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    De Lorenzo, Gianluca [Autonomous Univ. of Barcelona (Spain)

    2010-05-19

    This thesis reports on two searches for the production of squarks and gluinos, supersymmetric partners of the Standard Model (SM) quarks and gluons, using the CDF detector at the Tevatron √s = 1.96 TeV p$\\bar{p}$ collider. An inclusive search for squarks and gluinos pair production is performed in events with large ET and multiple jets in the final state, based on 2 fb-1 of CDF Run II data. The analysis is performed within the framework of minimal supergravity (mSUGRA) and assumes R-parity conservation where sparticles are produced in pairs. The expected signal is characterized by the production of multiple jets of hadrons from the cascade decays of squarks and gluinos and large missing transverse energy ET from the lightest supersymmetric particles (LSP). The measurements are in good agreement with SM predictions for backgrounds. The results are translated into 95% confidence level (CL) upper limits on production cross sections and squark and gluino masses in a given mSUGRA scenario. An upper limit on the production cross section is placed in the range between 1 pb and 0.1 pb, depending on the gluino and squark masses considered. The result of the search is negative for gluino and squark masses up to 392 GeV/c2 in the region where gluino and squark masses are close to each other, gluino masses up to 280 GeV/c2 regardless of the squark mass, and gluino masses up to 423 GeV=c2 for squark masses below 378 GeV/c2. These results are compatible with the latest limits on squark/gluino production obtained by the D0 Collaboration and considerably improve the previous exclusion limits from direct and indirect searches at LEP and the Tevatron. The inclusive search is then extended to a scenario where the pair production of sbottom squarks is dominant. The new search is performed in a generic MSSM scenario with R-parity conservation. A specific SUSY particle mass hierarchy is assumed such that the

  8. ATLAS Trigger Menu and Performance in Run I and Prospects for Run II

    CERN Document Server

    Igonkina, O; The ATLAS collaboration

    2013-01-01

    The ATLAS trigger system plays a key role in the collection of data for a wide range of physics analysis. The 2012 proton run had significantly larger luminosities and pile-up than 2011, while for the proton-lead run in 2013 it was critical to select samples with low biases. To address these challenges, while maintaining or even improving performance, new algorithms have been commissioned. The trigger strategy and the main algorithms and their performance are described. For the 2015 run, the combination of a luminosity increase and an energy increase will put even larger demands on the trigger system. One new tool to address the challenges will be the addition of a topological capability in the first level of the trigger, implemented in custom electronics. The L1 topological trigger hardware and software architectures and their performance will be presented.

  9. The beam energy feedback system for Beijing electron positron collider II linac

    Science.gov (United States)

    Wang, S.; Iqbal, M.; Chi, Y.; Liu, R.; Huang, X.

    2017-03-01

    A beam-energy feedback system has been developed for the injection linac to meet the beam quality needed for the Beijing electron positron collider II storage ring. This paper describes the implementation and commissioning of this system in detail. The system consists of an energy measurement unit, application software, and an actuator unit. A non-intersecting beam energy monitor was developed to allow real-time online energy adjustment. The beam energy adjustment is achieved by adjusting the output microwave phase of the RF power source station. The phase control mechanism has also been modified, and a new control method taking the return difference of the phase shifter into account is used to improve the system's performance. This system achieves the design aim and can adjust the beam center energy with a rate of 2 Hz. With the energy feedback system, the stability of the injection rate is better; the fluctuation range is reduced from 20 mA/min to 10 mA/min, while the stability of the beam center energy is maintained within ±0.1%.

  10. Search for squarks and gluinos in the D0 experiment of the Run-II-a at the Tevatron; Recherche des squarks et des gluinos dans l'experience D0 au Run-II-a du Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Verdier, P

    2007-11-15

    The D0 experiment is recording pp-bar collisions at a center-of-mass energy of 1.96 TeV since the beginning of the Run II-a of the Tevatron in 2001. The design of processor boards for the D0 level 2 trigger system is first presented. Those boards were installed in 2003, and they have been working perfectly since that date. Performances of missing transverse energy (/ ET ) reconstruction are then described. This quantity is important at hadron colliders especially for new particles searches. Finally, squarks and gluinos, supersymmetric partners of quarks and gluons, could be the most copiously produced supersymmetric particles at the Tevatron, if they are sufficiently light. Those particles were searched for in 0.96 fb{sup -1} of data recorded by D0 during the Run II-a. The final state consists of jets and missing transverse energy. The numbers of observed events are in good agreement with the Standard Model predictions. Lower mass limits at 95 % confidence level are obtained on the squark and gluino masses in the framework of the mSUGRA model. Contributions to other D0 data analyses are also shortly described. Those analyses are the search for first generation leptoquarks and the search for squarks in jets+{tau}(s)+E{sub T} events. The possibility to constrain a 'Little Higgs' model using the results of the jets+E{sub T} searches is then discussed. (author)

  11. 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...

  12. ATLAS Minimum Bias Trigger Scintillator upgrade for LHC RunII

    CERN Document Server

    Sidoti, A; The ATLAS collaboration

    2014-01-01

    The Minimum Bias Trigger Scintillators (MBTS) delivered the primary triggers for selecting events from real LHC collisions with the smallest bias for the low luminosity LHC RunI fills from 2009-2013 (proton-proton, lead-lead and lead-proton collisions). MBTS also will provide key ingredients for the first RunII physics measurements at the new LHC proton-proton collisions energies (charge multiplicity, proton-proton cross section, rapidity gap measurements, ...). After more than 25fb-1 of proton-proton collisions delivered during RunI of LHC, MBTS detectors have been substantially upgraded for the RunII of LHC (starting in 2015). The upgrade strategy will be presented showing the scintillator replacement, the modified read out scheme, the optical measurements on RunI scintillators assessing the degradation due to the dose received and how the new simulation is being implemented to take into accounts all the modifications foreseen for RunII.

  13. A New Event Builder for CMS Run II

    CERN Document Server

    Albertsson, Kim; Andronidis, Anastasios; Behrens, Ulf; Branson, James; Chaze, Olivier; Cittolin, Sergio; Darlea, Georgiana Lavinia; Deldicque, Christian; Dobson, Marc; Dupont, Aymeric; Erhan, Samim; Gigi, Dominique; Glege, Frank; Gomez Ceballos, Guillelmo; Hegeman, Jeroen Guido; Holzner, Andre Georg; Jimenez Estupinan, Raul; Masetti, Lorenzo; Meijers, Franciscus; Meschi, Emilio; Mommsen, Remigius; Morovic, Srecko; Nunez Barranco Fernandez, Carlos; O'Dell, Vivian; Orsini, Luciano; Paus, Christoph Maria Ernst; Petrucci, Andrea; Pieri, Marco; Racz, Attila; Roberts, Penelope Amelia; Sakulin, Hannes; Schwick, Christoph; Stieger, Benjamin Bastian; Sumorok, Konstanty; Veverka, Jan; Zaza, Salvatore; Zejdl, Petr

    2015-01-01

    The data acquisition system (DAQ) of the CMS experiment at the CERN Large Hadron Collider (LHC) assembles events at a rate of 100kHz, transporting event data at an aggregate throughput of 100GB/s to the high-level trigger (HLT) farm. The DAQ system has been redesigned during the LHC shutdown in 2013/14. The new DAQ architecture is based on state-of-the-art network technologies for the event building. For the data concentration, 10/40Gbps Ethernet technologies are used together with a reduced TCP/IP protocol implemented in FPGA for a reliable transport between custom electronics and commercial computing hardware. A 56Gbps Infiniband FDR CLOS network has been chosen for the event builder. This paper discusses the software design, protocols, and optimizations for exploiting the hardware capabilities. We present performance measurements from small-scale prototypes and from the full-scale production system.

  14. Electroweak production of the top quark in the Run II of the D0 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Clement, Benoit [Louis Pasteur Univ., Strasbourg (France)

    2006-04-28

    The work exposed in this thesis deals with the search for electroweak production of top quark (single top) in proton-antiproton collisions at √s = 1.96 TeV. This production mode has not been observed yet. Analyzed data have been collected during the Run II of the D0 experiment at the Fermilab Tevatron collider. These data correspond to an integrated luminosity of 370 pb-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.

  15. Performance of the ATLAS Tau Trigger in Run-II

    CERN Document Server

    Ikai, Takashi; The ATLAS collaboration

    2016-01-01

    As proton-proton collisions at the LHC reach instantaneous luminosities of over 10^{34}cm^{-2}s{-1}, tau trigger operation is more challenging. Hadronic tau trigger plays a important role and is used to measure Yukawa coupling constant and to search physics of Beyond Standard Model. This presents tau trigger system, operation, performance in Run2 and strategy in the future.

  16. 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...

  17. LHCb's Time-Real Alignment in RunII

    CERN Multimedia

    Batozskaya, Varvara

    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. 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 configur...

  18. Tevatron The Cinderella story or the art of collider

    CERN Document Server

    CERN. Geneva

    2007-01-01

    The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world's highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world's High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we'll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing" Issues; Beam Physics Issues; Luminosity Progress; Organization of Troops and Lessons for LHC.

  19. Searches for new physics in jet final states in ATLAS at LHC Run II

    CERN Document Server

    Amadio, Brian Thomas; The ATLAS collaboration

    2016-01-01

    The significant increase of the center-of-mass energy from 8 to 13 TeV at LHC Run II offers a great discovery potential for new physics at high mass, especially for strongly produced high-mass resonances, contact interactions, and TeV-gravity phenomena with high-pT jets. This talk presents the most recent Run II results from ATLAS on new physics searches in jet final states.

  20. Vector resonances at LHC Run II in composite 2HDM

    Energy Technology Data Exchange (ETDEWEB)

    Chiara, Stefano Di [National Institute of Chemical Physics and Biophysics,Rävala 10, 10143 Tallinn (Estonia); Heikinheimo, Matti; Tuominen, Kimmo [Helsinki Institute of Physics, University of Helsinki,P.O. Box 64, FI-000140, Helsinki (Finland); Department of Physics, University of Helsinki,P.O. Box 64, FI-000140, Helsinki (Finland)

    2017-03-02

    We consider a model where the electroweak symmetry breaking is driven by strong dynamics, resulting in an electroweak doublet scalar condensate, and transmitted to the standard model matter fields via another electroweak doublet scalar. At low energies the effective theory therefore shares features with a type-I two Higgs doublet model. However, important differences arise due to the rich composite spectrum expected to contain new vector resonances accessible at the LHC. We carry out a systematic analysis of the vector resonance signals at LHC and find that the model remains viable, but will be tightly constrained by direct searches as the projected integrated luminosity, around 200 fb{sup −1}, of the current run becomes available.

  1. The updated ATLAS Jet Trigger for the LHC Run II

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00359694; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and center of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High-Level Trigger, placed after a first hardware-based Level~1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

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

    CERN Document Server

    Ucchielli, Giulia; The ATLAS collaboration

    2016-01-01

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

  3. ATLAS Jet Trigger Update for the LHC Run II

    CERN Document Server

    Prince, Sebastien; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and centre of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The Jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  4. The updated ATLAS Jet Trigger for the LHC Run II

    CERN Document Server

    Prince, Sebastien; The ATLAS collaboration

    2015-01-01

    After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and center of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimen...

  5. Search for techniparticles at D0 Run II

    Energy Technology Data Exchange (ETDEWEB)

    Feligioni, Lorenzo [Univ. of Perugia (Italy)

    2006-01-01

    Technicolor theory (TC) accomplishes the necessary electroweak symmetry breaking responsible for the mass of the elementary particles. TC postulates the existence of a new SU(NTC) gauge theory. Like QCD the exchange of gauge bosons causes the existence of a non-vanishing chiral condensate which dynamically breaks the SU(NTC)L x SU(NTC)R symmetry. This gives rise to NTC2-1 Nambu-Goldstone Bosons. Three of these Goldstone Bosons become the longitudinal components of the W± and Z which therefore acquire mass; the remaining ones are new particles (technihadrons) that can be produced at the high energy colliders and detected. The Technicolor Straw Man Model (TCSM) is a version of the dynamical symmetry breaking with a large number of technifermions and a relative low value of their masses. One of the processes predicted by the TCSM is q$\\bar{q}$ → VT {yields} W{pi}T, where VT is the Technicolor equivalent of the QCD vector meson and {pi}T is the equivalent of the pion. W is the electroweak gauge boson of the Standard Model. This dissertation describes the search for WπT with the D0 detector, a multi-purpose particle detector located at one of the collision points of the Tevatron accelerator situated in Batavia, IL. The final state considered for this thesis is a W boson that decays to electron and neutrino plus a πT that decays into b$\\bar{c}$ or b$\\bar{b}$, depending on the charge of the initial technivector meson produced. In the D0 detector this process will appear as a narrow cluster of energy deposits in the electromagnetic calorimeter with an associated track reconstructed in the tracking detector. The undetected neutrino from the decay of the W boson will be seen as missing momentum. The fragmentation of the quarks from the decay of the πT will produce two jets of collimated particles. Events

  6. ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Agricola, Johannes; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; Άlvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Baca, Matthew John; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Baldin, Evgenii; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Kathrin; Becker, Maurice; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Biedermann, Dustin; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biondi, Silvia; Black, Curtis; Black, James; Black, Kevin; Blackburn, Daniel; Blair, Robert; Blanchard, Jean-Baptiste; Blanco, Jacobo Ezequiel; Blazek, Tomas; Bloch, Ingo; Blocker, Craig; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Bock, Christopher; Boehler, Michael; Bogaerts, Joannes Andreas; Bogavac, Danijela; Bogdanchikov, Alexander; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Boldyrev, Alexey; Bomben, Marco; Bona, Marcella; Boonekamp, Maarten; Borisov, Anatoly; Borissov, Guennadi; Borroni, Sara; Bortfeldt, Jonathan; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boudreau, Joseph; Bouffard, Julian; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozic, Ivan; Bracinik, Juraj; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brazzale, Simone Federico; Breaden Madden, William Dmitri; Brendlinger, Kurt; Brennan, Amelia Jean; Brenner, Lydia; Brenner, Richard; Bressler, Shikma; Bristow, Kieran; Bristow, Timothy Michael; Britton, Dave; Britzger, Daniel; Brochu, Frederic; Brock, Ian; Brock, Raymond; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, Timothy; Brooks, William; Brosamer, Jacquelyn; Brost, Elizabeth; Brown, Jonathan; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bruscino, Nello; Bryngemark, Lene; Buanes, Trygve; Buat, Quentin; Buchholz, Peter; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Buehrer, Felix; Bugge, Lars; Bugge, Magnar Kopangen; Bulekov, Oleg; Bullock, Daniel; Burckhart, Helfried; Burdin, Sergey; Burghgrave, Blake; Burke, Stephen; Burmeister, Ingo; Busato, Emmanuel; Büscher, Daniel; Büscher, Volker; Bussey, Peter; Butler, John; Butt, Aatif Imtiaz; 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; Caloba, Luiz; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarda, Stefano; Camarri, Paolo; Cameron, David; Caminal Armadans, Roger; Campana, Simone; Campanelli, Mario; Campoverde, Angel; Canale, Vincenzo; Canepa, Anadi; Cano Bret, Marc; Cantero, Josu; Cantrill, Robert; Cao, Tingting; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Cardarelli, Roberto; Cardillo, Fabio; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Sascha; Carquin, Edson; Carrillo-Montoya, German D; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Casolino, Mirkoantonio; Castaneda-Miranda, Elizabeth; Castelli, Angelantonio; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Catastini, Pierluigi; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Caudron, Julien; Cavaliere, Viviana; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerio, Benjamin; Cerny, Karel; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cerv, Matevz; Cervelli, Alberto; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chalupkova, Ina; Chang, Philip; Chapman, John Derek; Charlton, Dave; Chau, Chav Chhiv; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chegwidden, Andrew; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Karen; Chen, Liming; Chen, Shenjian; Chen, Xin; Chen, Ye; Cheng, Hok Chuen; Cheng, Yangyang; Cheplakov, Alexander; Cheremushkina, Evgenia; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Chevalier, Laurent; Chiarella, Vitaliano; Chiarelli, Giorgio; Childers, John Taylor; Chiodini, Gabriele; Chisholm, Andrew; Chislett, Rebecca Thalatta; Chitan, Adrian; Chizhov, Mihail; Choi, Kyungeon; Chouridou, Sofia; Chow, Bonnie Kar Bo; Christodoulou, Valentinos; Chromek-Burckhart, Doris; Chudoba, Jiri; Chuinard, Annabelle Julia; Chwastowski, Janusz; Chytka, Ladislav; Ciapetti, Guido; Ciftci, Abbas Kenan; Cinca, Diane; Cindro, Vladimir; Cioara, Irina Antonela; Ciocio, Alessandra; Citron, Zvi Hirsh; Ciubancan, Mihai; Clark, Allan G; Clark, Brian Lee; Clark, Philip James; Clarke, Robert; Cleland, Bill; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coffey, Laurel; Cogan, Joshua Godfrey; Colasurdo, Luca; Cole, Brian; Cole, Stephen; Colijn, Auke-Pieter; Collot, Johann; Colombo, Tommaso; Compostella, Gabriele; Conde Muiño, Patricia; Coniavitis, Elias; Connell, Simon Henry; Connelly, Ian; Consonni, Sofia Maria; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conti, Geraldine; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Côté, David; Cottin, Giovanna; Cowan, Glen; Cox, Brian; Cranmer, Kyle; Cree, Graham; Crépé-Renaudin, Sabine; Crescioli, Francesco; Cribbs, Wayne Allen; Crispin Ortuzar, Mireia; Cristinziani, Markus; Croft, Vince; Crosetti, Giovanni; Cuhadar Donszelmann, Tulay; Cummings, Jane; Curatolo, Maria; Cuthbert, Cameron; Czirr, Hendrik; Czodrowski, Patrick; D'Auria, Saverio; D'Onofrio, Monica; Da Cunha Sargedas De Sousa, Mario Jose; Da Via, Cinzia; Dabrowski, Wladyslaw; Dafinca, Alexandru; Dai, Tiesheng; Dale, Orjan; Dallaire, Frederick; Dallapiccola, Carlo; Dam, Mogens; Dandoy, Jeffrey Rogers; Dang, Nguyen Phuong; Daniells, Andrew Christopher; Danninger, Matthias; Dano Hoffmann, Maria; Dao, Valerio; Darbo, Giovanni; Darmora, Smita; Dassoulas, James; Dattagupta, Aparajita; Davey, Will; David, Claire; Davidek, Tomas; Davies, Eleanor; Davies, Merlin; Davison, Peter; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Daya-Ishmukhametova, Rozmin; 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 Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Deigaard, Ingrid; Del Peso, Jose; Del Prete, Tarcisio; Delgove, David; Deliot, Frederic; Delitzsch, Chris Malena; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Dell'Orso, Mauro; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; DeMarco, David; Demers, Sarah; Demichev, Mikhail; Demilly, Aurelien; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deterre, Cecile; Deviveiros, Pier-Olivier; Dewhurst, Alastair; Dhaliwal, Saminder; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Domenico, Antonio; Di Donato, Camilla; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Di Valentino, David; Diaconu, Cristinel; Diamond, Miriam; Dias, Flavia; Diaz, Marco Aurelio; Diehl, Edward; Dietrich, Janet; Diglio, Sara; 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; Dohmae, Takeshi; Dolejsi, Jiri; Dolezal, Zdenek; Dolgoshein, Boris; Donadelli, Marisilvia; Donati, Simone; Dondero, Paolo; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dova, Maria-Teresa; Doyle, Tony; Drechsler, Eric; Dris, Manolis; Dubreuil, Emmanuelle; Duchovni, Ehud; Duckeck, Guenter; Ducu, Otilia Anamaria; Duda, Dominik; Dudarev, Alexey; Duflot, Laurent; Duguid, Liam; Dührssen, Michael; Dunford, Monica; Duran Yildiz, Hatice; Düren, Michael; Durglishvili, Archil; Duschinger, Dirk; Dyndal, Mateusz; Eckardt, Christoph; Ecker, Katharina Maria; Edgar, Ryan Christopher; Edson, William; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Elliot, Alison; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Enari, Yuji; Endner, Oliver Chris; Endo, Masaki; Erdmann, Johannes; Ereditato, Antonio; Ernis, Gunar; Ernst, Jesse; Ernst, Michael; Errede, Steven; Ertel, Eugen; Escalier, Marc; Esch, Hendrik; Escobar, Carlos; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Ezhilov, Alexey; Fabbri, Laura; Facini, Gabriel; Fakhrutdinov, Rinat; Falciano, Speranza; Falla, Rebecca Jane; Faltova, Jana; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farooque, Trisha; Farrell, Steven; Farrington, Sinead; Farthouat, Philippe; Fassi, Farida; Fassnacht, Patrick; Fassouliotis, Dimitrios; Faucci Giannelli, Michele; Favareto, Andrea; Fayard, Louis; Federic, Pavol; Fedin, Oleg; Fedorko, Wojciech; Feigl, Simon; Feligioni, Lorenzo; Feng, Cunfeng; Feng, Eric; Feng, Haolu; 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; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filipuzzi, Marco; Filthaut, Frank; Fincke-Keeler, Margret; Finelli, Kevin Daniel; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Adam; Fischer, Cora; Fischer, Julia; Fisher, Wade Cameron; Fitzgerald, Eric Andrew; Flaschel, Nils; Fleck, Ivor; Fleischmann, Philipp; Fleischmann, Sebastian; Fletcher, Gareth Thomas; Fletcher, Gregory; Fletcher, Rob Roy MacGregor; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Formica, Andrea; Forti, Alessandra; Fournier, Daniel; Fox, Harald; Fracchia, Silvia; Francavilla, Paolo; Franchini, Matteo; Francis, David; Franconi, Laura; Franklin, Melissa; Frate, Meghan; Fraternali, Marco; Freeborn, David; French, Sky; Friedrich, Felix; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fulsom, Bryan Gregory; Fusayasu, Takahiro; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gabrielli, Alessandro; Gabrielli, Andrea; Gach, Grzegorz; Gadatsch, Stefan; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Galhardo, Bruno; Gallas, Elizabeth; Gallop, Bruce; Gallus, Petr; Galster, Gorm Aske Gram Krohn; Gan, KK; Gao, Jun; Gao, Yanyan; Gao, Yongsheng; Garay Walls, Francisca; Garberson, Ford; García, Carmen; García Navarro, José Enrique; Garcia-Sciveres, Maurice; Gardner, Robert; Garelli, Nicoletta; Garonne, Vincent; Gatti, Claudio; Gaudiello, Andrea; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gecse, Zoltan; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Geisler, Manuel Patrice; Gemme, Claudia; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerbaudo, Davide; Gershon, Avi; Ghasemi, Sara; Ghazlane, Hamid; Giacobbe, Benedetto; Giagu, Stefano; Giangiobbe, Vincent; Giannetti, Paola; Gibbard, Bruce; Gibson, Stephen; Gilchriese, Murdock; Gillam, Thomas; Gillberg, Dag; Gilles, Geoffrey; Gingrich, Douglas; Giokaris, Nikos; Giordani, MarioPaolo; Giorgi, Filippo Maria; Giorgi, Francesco Michelangelo; Giraud, Pierre-Francois; Giromini, Paolo; Giugni, Danilo; Giuliani, Claudia; Giulini, Maddalena; Gjelsten, Børge Kile; Gkaitatzis, Stamatios; Gkialas, Ioannis; Gkougkousis, Evangelos Leonidas; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glaysher, Paul; Glazov, Alexandre; Goblirsch-Kolb, Maximilian; Goddard, Jack Robert; Godlewski, Jan; Goldfarb, Steven; Golling, Tobias; Golubkov, Dmitry; Gomes, Agostinho; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez-Sevilla, Sergio; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Goshaw, Alfred; Gössling, Claus; Gostkin, Mikhail Ivanovitch; Goujdami, Driss; Goussiou, Anna; Govender, Nicolin; Gozani, Eitan; Grabas, Herve Marie Xavier; Graber, Lars; Grabowska-Bold, Iwona; Gradin, Per Olov Joakim; Grafström, Per; Grahn, Karl-Johan; Gramling, Johanna; Gramstad, Eirik; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Gray, Heather; Graziani, Enrico; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grivaz, Jean-Francois; Grohs, Johannes Philipp; Grohsjean, Alexander; Gross, Eilam; Grosse-Knetter, Joern; Grossi, Giulio Cornelio; Grout, Zara Jane; Guan, Liang; Guenther, Jaroslav; Guescini, Francesco; Guest, Daniel; Gueta, Orel; Guido, Elisa; Guillemin, Thibault; Guindon, Stefan; Gul, Umar; Gumpert, Christian; Guo, Jun; Guo, Yicheng; Gupta, Shaun; Gustavino, Giuliano; Gutierrez, Phillip; Gutierrez Ortiz, Nicolas Gilberto; Gutschow, Christian; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haber, Carl; Hadavand, Haleh Khani; Haddad, Nacim; Haefner, Petra; Hageböck, Stephan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haleem, Mahsana; Haley, Joseph; Hall, David; Halladjian, Garabed; Hallewell, Gregory David; Hamacher, Klaus; Hamal, Petr; Hamano, Kenji; Hamer, Matthias; Hamilton, Andrew; Hamity, Guillermo Nicolas; Hamnett, Phillip George; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Hanke, Paul; Hanna, Remie; 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; Hartjes, Fred; Hasegawa, Makoto; Hasegawa, Satoshi; Hasegawa, Yoji; Hasib, A; Hassani, Samira; Haug, Sigve; Hauser, Reiner; Hauswald, Lorenz; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hayashi, Takayasu; Hayden, Daniel; Hays, Chris; Hays, Jonathan Michael; Hayward, Helen; Haywood, Stephen; Head, Simon; Heck, Tobias; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heim, Timon; Heinemann, Beate; Heinrich, Lukas; Hejbal, Jiri; Helary, Louis; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, James; Henderson, Robert; Heng, Yang; Hengler, Christopher; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Herbert, Geoffrey Henry; Hernández Jiménez, Yesenia; Herrberg-Schubert, Ruth; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Hetherly, Jeffrey Wayne; Hickling, Robert; Higón-Rodriguez, Emilio; Hill, Ewan; Hill, John; Hiller, Karl Heinz; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hinman, Rachel Reisner; Hirose, Minoru; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoenig, Friedrich; Hohlfeld, Marc; Hohn, David; Holmes, Tova Ray; Homann, Michael; Hong, Tae Min; Hooft van Huysduynen, Loek; Hopkins, Walter; Horii, Yasuyuki; Horton, Arthur James; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howard, Jacob; Howarth, James; Hrabovsky, Miroslav; Hristova, Ivana; Hrivnac, Julius; Hryn'ova, Tetiana; Hrynevich, Aliaksei; Hsu, Catherine; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Hu, Diedi; Hu, Qipeng; Hu, Xueye; Huang, Yanping; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Huhtinen, Mika; Hülsing, Tobias Alexander; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Ideal, Emma; Idrissi, Zineb; Iengo, Paolo; Igonkina, Olga; Iizawa, Tomoya; Ikegami, Yoichi; Ikematsu, Katsumasa; Ikeno, Masahiro; Ilchenko, Iurii; Iliadis, Dimitrios; Ilic, Nikolina; Ince, Tayfun; Introzzi, Gianluca; Ioannou, Pavlos; Iodice, Mauro; Iordanidou, Kalliopi; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishino, Masaya; Ishitsuka, Masaki; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Iturbe Ponce, Julia Mariana; Iuppa, Roberto; Ivarsson, Jenny; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jabbar, Samina; Jackson, Brett; Jackson, Matthew; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakoubek, Tomas; Jakubek, Jan; Jamin, David Olivier; Jana, Dilip; Jansen, Eric; Jansky, Roland; Janssen, Jens; Janus, Michel; Jarlskog, Göran; Javadov, Namig; Javůrek, Tomáš; Jeanty, Laura; Jejelava, Juansher; Jeng, Geng-yuan; Jennens, David; Jenni, Peter; Jentzsch, Jennifer; Jeske, Carl; Jézéquel, Stéphane; Ji, Haoshuang; Jia, Jiangyong; Jiang, Yi; Jiggins, Stephen; Jimenez Pena, Javier; Jin, Shan; Jinaru, Adam; Jinnouchi, Osamu; Joergensen, Morten Dam; Johansson, Per; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jongmanns, Jan; Jorge, Pedro; Joshi, Kiran Daniel; Jovicevic, Jelena; Ju, Xiangyang; Jung, Christian; Jussel, Patrick; Juste Rozas, Aurelio; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kahn, Sebastien Jonathan; Kajomovitz, Enrique; Kalderon, Charles William; Kama, Sami; Kamenshchikov, Andrey; Kanaya, Naoko; Kaneti, Steven; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kaplan, Laser Seymour; Kapliy, Anton; Kar, Deepak; Karakostas, Konstantinos; Karamaoun, Andrew; Karastathis, Nikolaos; Kareem, Mohammad Jawad; Karentzos, Efstathios; Karnevskiy, Mikhail; Karpov, Sergey; Karpova, Zoya; Karthik, Krishnaiyengar; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kass, Richard; Kastanas, Alex; Kataoka, Yousuke; Katre, Akshay; Katzy, Judith; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kazama, Shingo; Kazanin, Vassili; Keeler, Richard; Kehoe, Robert; Keller, John; Kempster, Jacob Julian; Keoshkerian, Houry; Kepka, Oldrich; Kerševan, Borut Paul; Kersten, Susanne; Keyes, Robert; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharlamov, Alexey; Khoo, Teng Jian; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hee Yeun; Kim, Hyeon Jin; Kim, Shinhong; Kim, Young-Kee; Kimura, Naoki; Kind, Oliver Maria; King, Barry; King, Matthew; King, Samuel Burton; Kirk, Julie; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kiss, Florian; Kiuchi, Kenji; Kivernyk, Oleh; Kladiva, Eduard; Klein, Matthew Henry; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klioutchnikova, Tatiana; Kluge, Eike-Erik; Kluit, Peter; Kluth, Stefan; Knapik, Joanna; Kneringer, Emmerich; Knoops, Edith; Knue, Andrea; Kobayashi, Aine; Kobayashi, Dai; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohlmann, Simon; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kolanoski, Hermann; Koletsou, Iro; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kondrashova, Nataliia; Köneke, Karsten; König, Adriaan; Kono, Takanori; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kopeliansky, Revital; Koperny, Stefan; Köpke, Lutz; Kopp, Anna Katharina; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Kortner, Oliver; Kortner, Sandra; Kosek, Tomas; Kostyukhin, Vadim; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumeli-Charalampidi, Athina; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kramarenko, Viktor; Kramberger, Gregor; Krasnopevtsev, Dimitriy; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, Jana; Kravchenko, Anton; Kreiss, Sven; Kretz, Moritz; Kretzschmar, Jan; Kreutzfeldt, Kristof; Krieger, Peter; Krizka, Karol; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Krumnack, Nils; Kruse, Amanda; Kruse, Mark; Kruskal, Michael; Kubota, Takashi; Kucuk, Hilal; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuger, Fabian; Kuhl, Andrew; Kuhl, Thorsten; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kuna, Marine; Kunigo, Takuto; Kupco, Alexander; Kurashige, Hisaya; Kurochkin, Yurii; 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; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lambourne, Luke; Lammers, Sabine; Lampen, Caleb; Lampl, Walter; Lançon, Eric; Landgraf, Ulrich; Landon, Murrough; Lang, Valerie Susanne; Lange, J örn Christian; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Lasagni Manghi, Federico; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Law, Alexander; Laycock, Paul; Lazovich, Tomo; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; LeBlanc, Matthew Edgar; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Claire Alexandra; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Guillaume; Lefebvre, Michel; Legger, Federica; Leggett, Charles; Lehan, Allan; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leight, William Axel; Leisos, Antonios; Leister, Andrew Gerard; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lemmer, Boris; Leney, Katharine; Lenz, Tatjana; Lenzi, Bruno; Leone, Robert; Leone, Sandra; Leonidopoulos, Christos; Leontsinis, Stefanos; Lerner, Giuseppe; Leroy, Claude; Lester, Christopher; Levchenko, Mikhail; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levy, Mark; Lewis, Adrian; Leyko, Agnieszka; Leyton, Michael; Li, Bing; Li, Haifeng; Li, Ho Ling; Li, Lei; Li, Liang; Li, Shu; Li, Yichen; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Liblong, Aaron; Lichard, Peter; Lie, Ki; Liebal, Jessica; Liebig, Wolfgang; Limbach, Christian; Limosani, Antonio; Lin, Simon; Lin, Tai-Hua; Linde, Frank; Lindquist, Brian Edward; Linnemann, James; Lipeles, Elliot; Lipniacka, Anna; Lisovyi, Mykhailo; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Bo; Liu, Dong; Liu, Hao; Liu, Jian; Liu, Jianbei; Liu, Kun; Liu, Lulu; Liu, Miaoyuan; Liu, Minghui; Liu, Yanwen; Livan, Michele; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lo Sterzo, Francesco; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loebinger, Fred; Loevschall-Jensen, Ask Emil; Loginov, Andrey; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Brian Alexander; Long, Jonathan David; Long, Robin Eamonn; Looper, Kristina Anne; Lopes, Lourenco; Lopez Mateos, David; Lopez Paredes, Brais; Lopez Paz, Ivan; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lösel, Philipp Jonathan; Lou, XinChou; Lounis, Abdenour; Love, Jeremy; Love, Peter; Lu, Nan; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Luehring, Frederick; Lukas, Wolfgang; Luminari, Lamberto; Lundberg, Olof; Lund-Jensen, Bengt; Lynn, David; Lysak, Roman; Lytken, Else; Ma, Hong; Ma, Lian Liang; Maccarrone, Giovanni; Macchiolo, Anna; Macdonald, Calum Michael; Machado Miguens, Joana; Macina, Daniela; Madaffari, Daniele; Madar, Romain; Maddocks, Harvey Jonathan; Mader, Wolfgang; Madsen, Alexander; Maeland, Steffen; Maeno, Tadashi; Maevskiy, Artem; Magradze, Erekle; Mahboubi, Kambiz; Mahlstedt, Joern; Maiani, Camilla; Maidantchik, Carmen; Maier, Andreas Alexander; Maier, Thomas; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Malaescu, Bogdan; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mamuzic, Judita; Mancini, Giada; Mandelli, Beatrice; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Manfredini, Alessandro; Manhaes de Andrade Filho, Luciano; Manjarres Ramos, Joany; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mantifel, Rodger; Mantoani, Matteo; Mapelli, Livio; March, Luis; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marjanovic, Marija; Marley, Daniel; Marroquim, Fernando; Marsden, Stephen Philip; Marshall, Zach; Marti, Lukas Fritz; Marti-Garcia, Salvador; Martin, Brian Thomas; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martinez, Mario; Martin-Haugh, Stewart; Martoiu, Victor Sorin; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massa, Lorenzo; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mättig, Peter; Mattmann, Johannes; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; Mazini, Rachid; Mazza, Simone Michele; Mazzaferro, Luca; Mc Goldrick, Garrin; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Medinnis, Michael; Meehan, Samuel; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meineck, Christian; Meirose, Bernhard; Mellado Garcia, Bruce Rafael; Meloni, Federico; Mengarelli, Alberto; Menke, Sven; Meoni, Evelin; Mercurio, Kevin Michael; Mergelmeyer, Sebastian; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; 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; Ming, Yao; Mir, Lluisa-Maria; Mitani, Takashi; Mitrevski, Jovan; Mitsou, Vasiliki A; Miucci, Antonio; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mochizuki, Kazuya; Mohapatra, Soumya; Mohr, Wolfgang; Molander, Simon; Moles-Valls, Regina; Mönig, Klaus; Monini, Caterina; Monk, James; Monnier, Emmanuel; Montejo Berlingen, Javier; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Morange, Nicolas; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Mori, Daniel; Morii, Masahiro; Morinaga, Masahiro; Morisbak, Vanja; Moritz, Sebastian; Morley, Anthony Keith; Mornacchi, Giuseppe; Morris, John; Mortensen, Simon Stark; Morton, Alexander; Morvaj, Ljiljana; Mosidze, Maia; Moss, Josh; Motohashi, Kazuki; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Muanza, Steve; Mudd, Richard; Mueller, Felix; Mueller, James; Mueller, Ralph Soeren Peter; Mueller, Thibaut; Muenstermann, Daniel; Mullen, Paul; Mullier, Geoffrey; Murillo Quijada, Javier Alberto; Murray, Bill; Musheghyan, Haykuhi; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nachman, Benjamin Philip; Nackenhorst, Olaf; Nadal, Jordi; Nagai, Koichi; Nagai, Ryo; Nagai, Yoshikazu; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagata, Kazuki; Nagel, Martin; Nagy, Elemer; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Namasivayam, Harisankar; Naranjo Garcia, Roger Felipe; Narayan, Rohin; Naumann, Thomas; Navarro, Gabriela; Nayyar, Ruchika; Neal, Homer; Nechaeva, Polina; Neep, Thomas James; Nef, Pascal Daniel; Negri, Andrea; Negrini, Matteo; Nektarijevic, Snezana; Nellist, Clara; Nelson, Andrew; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neumann, Manuel; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen, Duong Hai; Nickerson, Richard; Nicolaidou, Rosy; Nicquevert, Bertrand; Nielsen, Jason; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Jon Kerr; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nisius, Richard; Nobe, Takuya; Nomachi, Masaharu; Nomidis, Ioannis; Nooney, Tamsin; Norberg, Scarlet; Nordberg, Markus; Novgorodova, Olga; Nowak, Sebastian; Nozaki, Mitsuaki; Nozka, Libor; Ntekas, Konstantinos; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nuti, Francesco; O'Brien, Brendan Joseph; O'grady, Fionnbarr; O'Neil, Dugan; 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; Okamura, Wataru; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olivares Pino, Sebastian Andres; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olszewski, Andrzej; Olszowska, Jolanta; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlando, Nicola; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Otero y Garzon, Gustavo; Otono, Hidetoshi; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Oussoren, Koen Pieter; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Rhys Edward; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pachal, Katherine; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagáčová, Martina; Pagan Griso, Simone; Paganis, Efstathios; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Palestini, Sandro; Palka, Marek; Pallin, Dominique; Palma, Alberto; Pan, Yibin; Panagiotopoulou, Evgenia; Pandini, Carlo Enrico; Panduro Vazquez, William; Pani, Priscilla; Panitkin, Sergey; Pantea, Dan; Paolozzi, Lorenzo; Papadopoulou, Theodora; Papageorgiou, Konstantinos; Paramonov, Alexander; Paredes Hernandez, Daniela; Parker, Michael Andrew; Parker, Kerry Ann; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Pauly, Thilo; Pearce, James; Pearson, Benjamin; Pedersen, Lars Egholm; Pedersen, Maiken; Pedraza Lopez, Sebastian; Pedro, Rute; Peleganchuk, Sergey; Pelikan, Daniel; Penc, Ondrej; Peng, Cong; Peng, Haiping; Penning, Bjoern; Penwell, John; Perepelitsa, Dennis; Perez Codina, Estel; Pérez García-Estañ, María Teresa; 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; Petrucci, Fabrizio; Pettersson, Nora Emilia; Pezoa, Raquel; Phillips, Peter William; Piacquadio, Giacinto; Pianori, Elisabetta; Picazio, Attilio; Piccaro, Elisa; Piccinini, Maurizio; Pickering, Mark Andrew; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinfold, James; Pingel, Almut; Pinto, Belmiro; Pires, Sylvestre; Pirumov, Hayk; Pitt, Michael; Pizio, Caterina; Plazak, Lukas; Pleier, Marc-Andre; Pleskot, Vojtech; Plotnikova, Elena; Plucinski, Pawel; Pluth, Daniel; Poettgen, Ruth; Poggioli, Luc; Pohl, David-leon; Polesello, Giacomo; Poley, Anne-luise; Policicchio, Antonio; Polifka, Richard; Polini, Alessandro; Pollard, Christopher Samuel; Polychronakos, Venetios; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Pospisil, Stanislav; Potamianos, Karolos; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Prell, Soeren; Price, Darren; Price, Lawrence; Primavera, Margherita; Prince, Sebastien; Proissl, Manuel; Prokofiev, Kirill; Prokoshin, Fedor; Protopapadaki, Eftychia-sofia; Protopopescu, Serban; Proudfoot, James; Przybycien, Mariusz; Ptacek, Elizabeth; Puddu, Daniele; Pueschel, Elisa; Puldon, David; Purohit, Milind; Puzo, Patrick; Qian, Jianming; Qin, Gang; Qin, Yang; Quadt, Arnulf; Quarrie, David; Quayle, William; Queitsch-Maitland, Michaela; Quilty, Donnchadha; Raddum, Silje; Radeka, Veljko; Radescu, Voica; Radhakrishnan, Sooraj Krishnan; Radloff, Peter; Rados, Pere; Ragusa, Francesco; Rahal, Ghita; Rajagopalan, Srinivasan; Rammensee, Michael; Rangel-Smith, Camila; Rauscher, Felix; Rave, Stefan; Ravenscroft, Thomas; Raymond, Michel; Read, Alexander Lincoln; Readioff, Nathan Peter; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Rehnisch, Laura; Reichert, Joseph; Reisin, Hernan; Relich, Matthew; Rembser, Christoph; Ren, Huan; Renaud, Adrien; Rescigno, Marco; Resconi, Silvia; Rezanova, Olga; Reznicek, Pavel; Rezvani, Reyhaneh; Richter, Robert; Richter, Stefan; Richter-Was, Elzbieta; Ricken, Oliver; Ridel, Melissa; Rieck, Patrick; Riegel, Christian Johann; Rieger, Julia; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Ristić, Branislav; Ritsch, Elmar; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robson, Aidan; Roda, Chiara; Roe, Shaun; Røhne, Ole; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romano Saez, Silvestre Marino; Romero Adam, Elena; Rompotis, Nikolaos; Ronzani, Manfredi; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosbach, Kilian; Rose, Peyton; Rosendahl, Peter Lundgaard; Rosenthal, Oliver; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rosten, Rachel; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexandre; Rozen, Yoram; Ruan, Xifeng; Rubbo, Francesco; Rubinskiy, Igor; Rud, Viacheslav; Rudolph, Christian; Rudolph, Matthew Scott; Rühr, Frederik; Ruiz-Martinez, Aranzazu; Rurikova, Zuzana; Rusakovich, Nikolai; Ruschke, Alexander; Russell, Heather; Rutherfoord, John; Ruthmann, Nils; Ryabov, Yury; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Saavedra, Aldo; Sabato, Gabriele; Sacerdoti, Sabrina; Saddique, Asif; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Saimpert, Matthias; Saito, Tomoyuki; Sakamoto, Hiroshi; Sakurai, Yuki; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; 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; Sanchez, Arturo; Sánchez, Javier; Sanchez Martinez, Victoria; Sandaker, Heidi; Sandbach, Ruth Laura; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandoval, Carlos; Sandstroem, Rikard; Sankey, Dave; Sannino, Mario; Sansoni, Andrea; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Santoyo Castillo, Itzebelt; Sapp, Kevin; Sapronov, Andrey; Saraiva, João; Sarrazin, Bjorn; Sasaki, Osamu; Sasaki, Yuichi; Sato, Koji; Sauvage, Gilles; Sauvan, Emmanuel; Savage, Graham; Savard, Pierre; Sawyer, Craig; Sawyer, Lee; Saxon, James; Sbarra, Carla; Sbrizzi, Antonio; Scanlon, Tim; Scannicchio, Diana; Scarcella, Mark; Scarfone, Valerio; Schaarschmidt, Jana; Schacht, Peter; Schaefer, Douglas; 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; Schillo, Christian; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitt, Sebastian; Schmitt, Stefan; Schneider, Basil; Schnellbach, Yan Jie; Schnoor, Ulrike; Schoeffel, Laurent; Schoening, Andre; Schoenrock, Bradley Daniel; Schopf, Elisabeth; Schorlemmer, Andre Lukas; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schramm, Steven; Schreyer, Manuel; Schroeder, Christian; Schuh, Natascha; Schultens, Martin Johannes; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwarz, Thomas Andrew; Schwegler, Philipp; Schweiger, Hansdieter; Schwemling, Philippe; Schwienhorst, Reinhard; Schwindling, Jerome; Schwindt, Thomas; Sciacca, Gianfranco; Scifo, Estelle; Sciolla, Gabriella; Scuri, Fabrizio; Scutti, Federico; Searcy, Jacob; Sedov, George; Sedykh, Evgeny; Seema, Pienpen; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Sekhon, Karishma; Sekula, Stephen; Seliverstov, Dmitry; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Serkin, Leonid; Serre, Thomas; Sessa, Marco; Seuster, Rolf; Severini, Horst; Sfiligoj, Tina; Sforza, Federico; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shang, Ruo-yu; Shank, James; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Shaw, Savanna Marie; Shcherbakova, Anna; Shehu, Ciwake Yusufu; Sherwood, Peter; Shi, Liaoshan; Shimizu, Shima; Shimmin, Chase Owen; Shimojima, Makoto; Shiyakova, Mariya; Shmeleva, Alevtina; Shoaleh Saadi, Diane; Shochet, Mel; Shojaii, Seyedruhollah; Shrestha, Suyog; Shulga, Evgeny; Shupe, Michael; Shushkevich, Stanislav; Sicho, Petr; Sidebo, Per Edvin; Sidiropoulou, Ourania; Sidorov, Dmitri; Sidoti, Antonio; Siegert, Frank; Sijacki, Djordje; Silva, José; Silver, Yiftah; Silverstein, Samuel; Simak, Vladislav; Simard, Olivier; Simic, Ljiljana; Simion, Stefan; Simioni, Eduard; Simmons, Brinick; Simon, Dorian; Simoniello, Rosa; Sinervo, Pekka; Sinev, Nikolai; Sioli, Maximiliano; Siragusa, Giovanni; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skinner, Malcolm Bruce; Skottowe, Hugh Philip; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Slawinska, Magdalena; Sliwa, Krzysztof; Smakhtin, Vladimir; Smart, Ben; Smestad, Lillian; Smirnov, Sergei; Smirnov, Yury; Smirnova, Lidia; Smirnova, Oxana; Smith, Matthew; Smith, Russell; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snidero, Giacomo; Snyder, Scott; Sobie, Randall; Socher, Felix; Soffer, Abner; Soh, Dart-yin; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldatov, Evgeny; Soldevila, Urmila; Solodkov, Alexander; Soloshenko, Alexei; Solovyanov, Oleg; Solovyev, Victor; Sommer, Philip; Song, Hong Ye; Soni, Nitesh; Sood, Alexander; Sopczak, Andre; Sopko, Bruno; Sopko, Vit; Sorin, Veronica; Sosa, David; Sosebee, Mark; Sotiropoulou, Calliope Louisa; Soualah, Rachik; Soukharev, Andrey; South, David; Sowden, Benjamin; Spagnolo, Stefania; Spalla, Margherita; Spanò, Francesco; Spearman, William Robert; Sperlich, Dennis; Spettel, Fabian; Spighi, Roberto; Spigo, Giancarlo; Spiller, Laurence Anthony; Spousta, Martin; Spreitzer, Teresa; St Denis, Richard Dante; Staerz, Steffen; Stahlman, Jonathan; Stamen, Rainer; Stamm, Soren; Stanecka, Ewa; Stanescu, Cristian; Stanescu-Bellu, Madalina; Stanitzki, Marcel Michael; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staszewski, Rafal; Stavina, Pavel; Steinberg, Peter; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stewart, Graeme; Stillings, Jan Andre; Stockton, Mark; Stoebe, Michael; Stoicea, Gabriel; Stolte, Philipp; Stonjek, Stefan; Stradling, Alden; Straessner, Arno; Stramaglia, Maria Elena; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strubig, Antonia; Stucci, Stefania Antonia; Stugu, Bjarne; Styles, Nicholas Adam; Su, Dong; Su, Jun; Subramaniam, Rajivalochan; Succurro, Antonella; Sugaya, Yorihito; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Siyuan; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Susinno, Giancarlo; Sutton, Mark; Suzuki, Shota; Svatos, Michal; Swedish, Stephen; Swiatlowski, Maximilian; Sykora, Ivan; Sykora, Tomas; Ta, Duc; Taccini, Cecilia; Tackmann, Kerstin; Taenzer, Joe; Taffard, Anyes; Tafirout, Reda; Taiblum, Nimrod; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Takubo, Yosuke; Talby, Mossadek; Talyshev, Alexey; Tam, Jason; Tan, Kong Guan; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Shuji; Tannenwald, Benjamin Bordy; Tannoury, Nancy; Tapprogge, Stefan; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tashiro, Takuya; Tassi, Enrico; Tavares Delgado, Ademar; Tayalati, Yahya; Taylor, Frank; Taylor, Geoffrey; Taylor, Wendy; Teischinger, Florian Alfred; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; 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, Emily; Thompson, Paul; Thompson, Ray; Thompson, Stan; Thomsen, Lotte Ansgaard; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tibbetts, Mark James; Ticse Torres, Royer Edson; Tikhomirov, Vladimir; Tikhonov, Yury; Timoshenko, Sergey; Tiouchichine, Elodie; Tipton, Paul; Tisserant, Sylvain; Todome, Kazuki; Todorov, Theodore; Todorova-Nova, Sharka; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tolley, Emma; Tomlinson, Lee; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Torrence, Eric; Torres, Heberth; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alessandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Tripiana, Martin; Trischuk, William; Trocmé, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trovatelli, Monica; True, Patrick; Truong, Loan; Trzebinski, Maciej; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsirintanis, Nikolaos; Tsiskaridze, Shota; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsuno, Soshi; Tsybychev, Dmitri; Tudorache, Alexandra; Tudorache, Valentina; Tuna, Alexander Naip; Tupputi, Salvatore; Turchikhin, Semen; Turecek, Daniel; Turra, Ruggero; Turvey, Andrew John; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Ueda, Ikuo; Ueno, Ryuichi; Ughetto, Michael; Ugland, Maren; Uhlenbrock, Mathias; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Ungaro, Francesca; Unno, Yoshinobu; Unverdorben, Christopher; Urban, Jozef; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Usanova, Anna; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Valderanis, Chrysostomos; Valencic, Nika; Valentinetti, Sara; Valero, Alberto; Valery, Loic; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Den Wollenberg, Wouter; Van Der Deijl, Pieter; van der Geer, Rogier; van der Graaf, Harry; Van Der Leeuw, Robin; van Eldik, Niels; van Gemmeren, Peter; Van Nieuwkoop, Jacobus; van Vulpen, Ivo; van Woerden, Marius Cornelis; Vanadia, Marco; Vandelli, Wainer; Vanguri, Rami; Vaniachine, Alexandre; Vannucci, Francois; Vardanyan, Gagik; Vari, Riccardo; Varnes, Erich; Varol, Tulin; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vazeille, Francois; Vazquez Schroeder, Tamara; Veatch, Jason; Veloce, Laurelle Maria; Veloso, Filipe; Velz, Thomas; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Venturini, Alessio; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Viazlo, Oleksandr; Vichou, Irene; Vickey, Trevor; Vickey Boeriu, Oana Elena; Viehhauser, Georg; Viel, Simon; Vigne, Ralph; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinogradov, Vladimir; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vladoiu, Dan; Vlasak, Michal; Vogel, Marcelo; Vokac, Petr; Volpi, Guido; Volpi, Matteo; von der Schmitt, Hans; von Radziewski, Holger; 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; Vykydal, Zdenek; Wagner, Peter; Wagner, Wolfgang; Wahlberg, Hernan; Wahrmund, Sebastian; Wakabayashi, Jun; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wang, Chao; Wang, Fuquan; Wang, Haichen; Wang, Hulin; Wang, Jike; Wang, Jin; Wang, Kuhan; Wang, Rui; Wang, Song-Ming; Wang, Tan; Wang, Tingting; Wang, Xiaoxiao; Wanotayaroj, Chaowaroj; Warburton, Andreas; Ward, Patricia; Wardrope, David Robert; Warsinsky, Markus; Washbrook, Andrew; Wasicki, Christoph; Watkins, Peter; Watson, Alan; Watson, Ian; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Ben; Webb, Samuel; Weber, Michele; Weber, Stefan Wolf; Webster, Jordan S; Weidberg, Anthony; Weinert, Benjamin; Weingarten, Jens; Weiser, Christian; Weits, Hartger; Wells, Phillippa; Wenaus, Torre; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Wessels, Martin; Wetter, Jeffrey; Whalen, Kathleen; Wharton, Andrew Mark; White, Andrew; White, Martin; White, Ryan; White, Sebastian; Whiteson, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik-Fuchs, Liv Antje Mari; Wildauer, Andreas; Wilkens, Henric George; Williams, Hugh; Williams, Sarah; Willis, Christopher; Willocq, Stephane; Wilson, Alan; Wilson, John; Wingerter-Seez, Isabelle; Winklmeier, Frank; Winter, Benedict Tobias; Wittgen, Matthias; Wittkowski, Josephine; Wollstadt, Simon Jakob; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wozniak, Krzysztof; Wu, Mengqing; Wu, Miles; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wyatt, Terry Richard; Wynne, Benjamin; Xella, Stefania; Xu, Da; Xu, Lailin; Yabsley, Bruce; Yacoob, Sahal; Yakabe, Ryota; Yamada, Miho; Yamaguchi, Yohei; Yamamoto, Akira; Yamamoto, Shimpei; Yamanaka, Takashi; Yamauchi, Katsuya; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Hongtao; Yang, Yi; Yao, Weiming; Yasu, Yoshiji; Yatsenko, Elena; Yau Wong, Kaven Henry; Ye, Jingbo; Ye, Shuwei; Yeletskikh, Ivan; Yen, Andy L; Yildirim, Eda; Yorita, Kohei; Yoshida, Rikutaro; Yoshihara, Keisuke; Young, Charles; Young, Christopher John; Youssef, Saul; Yu, David Ren-Hwa; Yu, Jaehoon; Yu, Jiaming; Yu, Jie; Yuan, Li; Yuen, Stephanie P; Yurkewicz, Adam; Yusuff, Imran; Zabinski, Bartlomiej; Zaidan, Remi; Zaitsev, Alexander; Zalieckas, Justas; Zaman, Aungshuman; Zambito, Stefano; Zanello, Lucia; Zanzi, Daniele; Zeitnitz, Christian; Zeman, Martin; Zemla, Andrzej; Zengel, Keith; Zenin, Oleg; Ženiš, Tibor; Zerwas, Dirk; Zhang, Dongliang; Zhang, Fangzhou; Zhang, Huijun; Zhang, Jinlong; Zhang, Lei; Zhang, Ruiqi; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Xiandong; Zhao, Yongke; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Chen; Zhou, Lei; Zhou, Li; 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; zur Nedden, Martin; Zurzolo, Giovanni; Zwalinski, Lukasz

    2015-10-29

    This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton--proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 fb$^{-1}$ of collisions at a centre-of-mass energy of $\\sqrt{s} = 8$ TeV, although in some case an additional 4.7 fb$^{-1}$ of collision data at $\\sqrt{s}= 7$ TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models.

  7. ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider.

    Science.gov (United States)

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Suzuki, S; Svatos, M; Swedish, S; Swiatlowski, M; Sykora, I; Sykora, T; Ta, D; Taccini, C; Tackmann, K; Taenzer, J; Taffard, A; Tafirout, R; Taiblum, N; Takai, H; Takashima, R; Takeda, H; Takeshita, T; Takubo, Y; Talby, M; Talyshev, A A; Tam, J Y C; Tan, K G; Tanaka, J; Tanaka, R; Tanaka, S; Tannenwald, B B; Tannoury, N; Tapprogge, S; Tarem, S; Tarrade, F; Tartarelli, G F; Tas, P; Tasevsky, M; Tashiro, T; Tassi, E; Tavares Delgado, A; Tayalati, Y; Taylor, F E; Taylor, G N; Taylor, W; Teischinger, F A; Teixeira Dias Castanheira, M; Teixeira-Dias, P; Temming, K K; 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, E N; Thompson, P D; Thompson, R J; Thompson, A S; Thomsen, L A; Thomson, E; Thomson, M; Thun, R P; Tibbetts, M J; Ticse Torres, R E; Tikhomirov, V O; Tikhonov, Yu A; Timoshenko, S; Tiouchichine, E; Tipton, P; Tisserant, S; Todome, K; Todorov, T; Todorova-Nova, S; Tojo, J; Tokár, S; Tokushuku, K; Tollefson, K; Tolley, E; Tomlinson, L; Tomoto, M; Tompkins, L; Toms, K; Torrence, E; Torres, H; Torró Pastor, E; Toth, J; Touchard, F; Tovey, D R; Trefzger, T; Tremblet, L; Tricoli, A; Trigger, I M; Trincaz-Duvoid, S; Tripiana, M F; Trischuk, W; Trocmé, B; Troncon, C; Trottier-McDonald, M; Trovatelli, M; True, P; Truong, L; Trzebinski, M; Trzupek, A; Tsarouchas, C; Tseng, J C-L; Tsiareshka, P V; Tsionou, D; Tsipolitis, G; Tsirintanis, N; Tsiskaridze, S; Tsiskaridze, V; Tskhadadze, E G; Tsukerman, I I; Tsulaia, V; Tsuno, S; Tsybychev, D; Tudorache, A; Tudorache, V; Tuna, A N; Tupputi, S A; Turchikhin, S; Turecek, D; Turra, R; Turvey, A J; Tuts, P M; Tykhonov, A; Tylmad, M; Tyndel, M; Ueda, I; Ueno, R; Ughetto, M; Ugland, M; Uhlenbrock, M; Ukegawa, F; Unal, G; Undrus, A; Unel, G; Ungaro, F C; Unno, Y; Unverdorben, C; Urban, J; Urquijo, P; Urrejola, P; Usai, G; Usanova, A; Vacavant, L; Vacek, V; Vachon, B; Valderanis, C; Valencic, N; Valentinetti, S; Valero, A; Valery, L; Valkar, S; Valladolid Gallego, E; Vallecorsa, S; Valls Ferrer, J A; Van Den Wollenberg, W; Van Der Deijl, P C; van der Geer, R; van der Graaf, H; Van Der Leeuw, R; van Eldik, N; van Gemmeren, P; Van Nieuwkoop, J; van Vulpen, I; van Woerden, M C; Vanadia, M; Vandelli, W; Vanguri, R; Vaniachine, A; Vannucci, F; Vardanyan, G; Vari, R; Varnes, E W; Varol, T; Varouchas, D; Vartapetian, A; Varvell, K E; Vazeille, F; Vazquez Schroeder, T; Veatch, J; Veloce, L M; Veloso, F; Velz, T; Veneziano, S; Ventura, A; Ventura, D; Venturi, M; Venturi, N; Venturini, A; Vercesi, V; Verducci, M; Verkerke, W; Vermeulen, J C; Vest, A; Vetterli, M C; Viazlo, O; Vichou, I; Vickey, T; Vickey Boeriu, O E; Viehhauser, G H A; Viel, S; Vigne, R; Villa, M; Villaplana Perez, M; Vilucchi, E; Vincter, M G; Vinogradov, V B; Vivarelli, I; Vives Vaque, F; Vlachos, S; Vladoiu, D; Vlasak, M; Vogel, M; Vokac, P; Volpi, G; Volpi, M; von der Schmitt, H; von Radziewski, 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; Vykydal, Z; Wagner, P; Wagner, W; Wahlberg, H; Wahrmund, S; Wakabayashi, J; Walder, J; Walker, R; Walkowiak, W; Wang, C; Wang, F; Wang, H; Wang, H; Wang, J; Wang, J; Wang, K; Wang, R; Wang, S M; Wang, T; Wang, T; Wang, X; Wanotayaroj, C; Warburton, A; Ward, C P; Wardrope, D R; Warsinsky, M; Washbrook, A; Wasicki, C; Watkins, P M; Watson, A T; Watson, I J; Watson, M F; Watts, G; Watts, S; Waugh, B M; Webb, S; Weber, M S; Weber, S W; Webster, J S; Weidberg, A R; Weinert, B; Weingarten, J; Weiser, C; Weits, H; Wells, P S; Wenaus, T; Wengler, T; Wenig, S; Wermes, N; Werner, M; Werner, P; Wessels, M; Wetter, J; Whalen, K; Wharton, A M; White, A; White, M J; White, R; White, S; Whiteson, D; Wickens, F J; Wiedenmann, W; Wielers, M; Wienemann, P; Wiglesworth, C; Wiik-Fuchs, L A M; Wildauer, A; Wilkens, H G; Williams, H H; Williams, S; Willis, C; Willocq, S; Wilson, A; Wilson, J A; Wingerter-Seez, I; Winklmeier, F; Winter, B T; Wittgen, M; Wittkowski, J; Wollstadt, S J; Wolter, M W; Wolters, H; Wosiek, B K; Wotschack, J; Woudstra, M J; Wozniak, K W; Wu, M; Wu, M; Wu, S L; Wu, X; Wu, Y; Wyatt, T R; Wynne, B M; Xella, S; Xu, D; Xu, L; Yabsley, B; Yacoob, S; Yakabe, R; Yamada, M; Yamaguchi, Y; Yamamoto, A; Yamamoto, S; Yamanaka, T; Yamauchi, K; Yamazaki, Y; Yan, Z; Yang, H; Yang, H; Yang, Y; Yao, W-M; Yasu, Y; Yatsenko, E; Yau Wong, K H; Ye, J; Ye, S; Yeletskikh, I; Yen, A L; Yildirim, E; Yorita, K; Yoshida, R; Yoshihara, K; Young, C; Young, C J S; Youssef, S; Yu, D R; Yu, J; Yu, J M; Yu, J; Yuan, L; Yuen, S P Y; Yurkewicz, A; Yusuff, I; Zabinski, B; Zaidan, R; Zaitsev, A M; Zalieckas, J; Zaman, A; Zambito, S; Zanello, L; Zanzi, D; Zeitnitz, C; Zeman, M; Zemla, A; Zengel, K; Zenin, O; Ženiš, T; Zerwas, D; Zhang, D; Zhang, F; Zhang, H; Zhang, J; Zhang, L; Zhang, R; Zhang, X; Zhang, Z; Zhao, X; Zhao, Y; Zhao, Z; Zhemchugov, A; Zhong, J; Zhou, B; Zhou, C; Zhou, L; Zhou, L; 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; Zur Nedden, M; Zurzolo, G; Zwalinski, L

    This paper reviews and extends searches for the direct pair production of the scalar supersymmetric partners of the top and bottom quarks in proton-proton collisions collected by the ATLAS collaboration during the LHC Run 1. Most of the analyses use 20 [Formula: see text] of collisions at a centre-of-mass energy of [Formula: see text] TeV, although in some case an additional [Formula: see text] of collision data at [Formula: see text] TeV are used. New analyses are introduced to improve the sensitivity to specific regions of the model parameter space. Since no evidence of third-generation squarks is found, exclusion limits are derived by combining several analyses and are presented in both a simplified model framework, assuming simple decay chains, as well as within the context of more elaborate phenomenological supersymmetric models.

  8. The CMS Level-1 Calorimeter Trigger for LHC Run II

    Science.gov (United States)

    Sinthuprasith, Tutanon

    2017-01-01

    The phase-1 upgrades of the CMS Level-1 calorimeter trigger have been completed. The Level-1 trigger has been fully commissioned and it will be used by CMS to collect data starting from the 2016 data run. The new trigger has been designed to improve the performance at high luminosity and large number of simultaneous inelastic collisions per crossing (pile-up). For this purpose it uses a novel design, the Time Multiplexed Design, which enables the data from an event to be processed by a single trigger processor at full granularity over several bunch crossings. The TMT design is a modular design based on the uTCA standard. The architecture is flexible and the number of trigger processors can be expanded according to the physics needs of CMS. Intelligent, more complex, and innovative algorithms are now the core of the first decision layer of CMS: the upgraded trigger system implements pattern recognition and MVA (Boosted Decision Tree) regression techniques in the trigger processors for pT assignment, pile up subtraction, and isolation requirements for electrons, and taus. The performance of the TMT design and the latency measurements and the algorithm performance which has been measured using data is also presented here.

  9. First Run II Measurement of the W Boson Mass

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; /Helsinki Inst. of Phys.; Abulencia, A.; /Illinois U., Urbana; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Albrow, Michael G.; /Fermilab; Alvarez Gonzalez, B.; /CSIC, Catalunya; Amerio, S.; /Padua U.; Amidei, Dante E.; /Michigan U.; Anastassov, A.; /Rutgers U., Piscataway; Annovi, A.; /Frascati; Antos, J.; /Comenius U. /Fermilab

    2007-08-01

    We describe a measurement of the W boson mass m{sub W} using 200 pb{sup -1} of {radical}s = 1.96 TeV p{bar p} collision data taken with the CDF II detector. With a sample of 63,964 W {yields} e{nu} candidates and 51,128 W {yields} {mu}{nu} candidates, we measure m{sub W} = [80.413 {+-} 0.034(stat.) {+-} 0.034 (sys.) = 80.413 {+-} 0.048] GeV/c{sup 2}. This is the single most precise m{sub W} measurement to date. When combined with other measured electroweak parameters, this result further constrains the properties of new unobserved particles coupling to W and Z bosons.

  10. Test runs of a Belle II PXD prototype readout system

    Energy Technology Data Exchange (ETDEWEB)

    Getzkow, Dennis; Kuehn, Wolfgang; Lange, Soeren; Lautenbach, Klemens [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut (Germany); Gessler, Thomas [KEK, Tsukuba (Japan); Collaboration: Belle II-Collaboration

    2016-07-01

    The Belle II PXD readout system (called ONSEN for Online Selection Nodes) uses ATCA (Advanced Telecommunications Architecture) boards with Xilinx Virtex-5 FX70T FPGAs and high speed optical links (6.5 Gbit/s each). The full system consists of 9 carrier boards and 33 daughter cards. The ONSEN system has several interfaces: (a) it receives PXD data from the DHH (Data Handling Hybrid) system, (b) it receives ROI (Regions-of-Interest) data for online data reduction from the HLT (High Level Trigger) system by GbE, and (c) it features data ports to two event builders: EVB1 combines data from all detectors except PXD (in order to generate the ROIs) and EVB2 combines the reduced PXD data with all other data. One of the critical issues is the matching of trigger numbers in the data (received by DHH from the timing distribution system) and trigger numbers in the ROIs (received by the HLT). In order to test the interfaces, in particular for a high HLT rate up to 30 kHz, a prototype system with 3 daughter cards was installed at KEK and tested with DHH, HLT and EVB2. Test results are presented.

  11. Preparation and commissioning of LHCb for the Run II of LHC

    CERN Document Server

    AUTHOR|(CDS)2070171

    2016-01-01

    The LHCb experiment has performed very well during the Run I of the LHC, producing a large number of relevant physics results on a wide range of topics. The preparation and commissioning of the LHCb experiment for Run II is discussed here, with special emphasis on the changes in the trigger strategy and the addition of a new subdetector to improve the physics reach of the experiment. An overview of the commissioning with the first collisions delivered by the LHC is also included.

  12. Technical design report for the upgrade of the ICD for D-Zero Run II

    Energy Technology Data Exchange (ETDEWEB)

    Sawyer, L. [Louisiana Tech Univ., Ruston, LA (United States); De, K. [Texas Univ., Arlington, TX (United States)], Draper, P. [Texas Univ., Arlington, TX (United States)], Gallas, E. [Texas Univ., Arlington, TX (United States)], Li, J. [Texas Univ., Arlington, TX (United States)], Sosebee, M. [Texas Univ., Arlington, TX (United States)], Stephens, R.W. [Texas Univ., Arlington, TX (United States)], White, A. [Texas Univ., Arlington, TX (United States)

    1998-01-01

    The Inter Cryostat Detector (ICD) used in Run I of the D0 Experiment will be inoperable in the central, high magnetic field planned for Run II. In Run I, the ICD enhanced the hermeticity and uniformity of the D0 calorimeter system, improving both missing transverse energy and jet energy resolution. The goals for the Run II ICD are the same. In this document, the physics arguments for maintaining the ICD are presented, followed by a detailed description of the planned design changes, prototype tests, construction, installation, and commissioning of the device for the Run II D0 detector. Estimates of costs and schedule can be found on //DOSERVER2/Operations/Upgrade Project/ subareas available via DZERO`s WinFrame Program Manager. This detector is not intended to provide any ``L0`` capabilities (for luminosity monitoring), or to provide any EM coverage in the intermediate region, or to provide additional coverage in the intermediate regions, unlike previous upgrades proposed in this detector region. The ICD upgrade described here maintains most of the Run I capabilities in a high magnetic field environment.

  13. A Silicon Strip Detector for the Phase II High Luminosity Upgrade of the ATLAS Detector at the Large Hadron Collider

    CERN Document Server

    INSPIRE-00425747; McMahon, Stephen J

    2015-01-01

    ATLAS is a particle physics experiment at the Large Hadron Collider (LHC) that detects proton-proton collisions at a centre of mass energy of 14 TeV. The Semiconductor Tracker is part of the Inner Detector, implemented using silicon microstrip detectors with binary read-out, providing momentum measurement of charged particles with excellent resolution. The operation of the LHC and the ATLAS experiment started in 2010, with ten years of operation expected until major upgrades are needed in the accelerator and the experiments. The ATLAS tracker will need to be completely replaced due to the radiation damage and occupancy of some detector elements and the data links at high luminosities. These upgrades after the first ten years of operation are named the Phase-II Upgrade and involve a re-design of the LHC, resulting in the High Luminosity Large Hadron Collider (HL-LHC). This thesis presents the work carried out in the testing of the ATLAS Phase-II Upgrade electronic systems in the future strips tracker a...

  14. Forward tracking at the next $e^{+}e^{-}$ collider part II: experimental challenges and detector design

    CERN Document Server

    Aplin, S.; Dannheim, D.; Duarte, J.; Gaede, F.; Ruiz-Jimeno, A.; Sailer, A.; Valentan, M.; Vila, I.; Vos, M.

    2013-06-01

    We present the second in a series of studies into the forward tracking system for a future linear e+e− collider with a center-of-mass energy in the range from 250 GeV to 3 TeV. In this note a number of specific challenges are investigated, which have caused a degradation of the tracking and vertexing performance in the forward region in previous experiments. We perform a quantitative analysis of the dependence of the tracking performance on detector design parameters and identify several ways to mitigate the performance loss for charged particles emitted at shallow angle.

  15. Measurement of the t$\\bar{t}$ cross section at the Run II Tevatron using Support Vector Machines

    Energy Technology Data Exchange (ETDEWEB)

    Whitehouse, Benjamin Eric [Tufts Univ., Medford, MA (United States)

    2010-08-01

    This dissertation measures the t$\\bar{t}$ production cross section at the Run II CDF detector using data from early 2001 through March 2007. The Tevatron at Fermilab is a p$\\bar{p}$ collider with center of mass energy √s = 1.96 TeV. This data composes a sample with a time-integrated luminosity measured at 2.2 ± 0.1 fb-1. A system of learning machines is developed to recognize t$\\bar{t}$ events in the 'lepton plus jets' decay channel. Support Vector Machines are described, and their ability to cope with a multi-class discrimination problem is provided. The t$\\bar{t}$ production cross section is then measured in this framework, and found to be σt$\\bar{t}$ = 7.14 ± 0.25 (stat)-0.86+0.61(sys) pb.

  16. Online monitoring for the CDF Run II experiment and the remote operation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Arisawa, T.; /Waseda U.; Fabiani, D.; /INFN, Pisa; Hirschbuehl, D.; /Karlsruhe U.; Ikado, K.; /Waseda U.; Kubo, T.; /KEK, Tsukuba; Kusakabe, Y.; /Waseda U.; Maeshima, K.; /UCLA; Naganoma, J.; Nakamura, K.; /Waseda U.; Plager, C.; /UCLA; Schmidt, E.; /Fermilab /INFN, Pisa /Karlsruhe U.

    2007-01-01

    The foundation of the CDF Run II online event monitoring framework, placed well before the physics runs start, allowed to develop coherent monitoring software across all the different subsystems which consequently made maintenance and operation simple and efficient. Only one shift person is needed to monitor the entire CDF detector, including the trigger system. High data quality check is assured in real time and well defined monitoring results are propagated coherently to offline datasets used for physics analyzes. We describe the CDF Run II online event monitoring system and operation, with emphasis on the remote monitoring shift operation started since November 2006 with Pisa-INFN as pilot Institution and exploiting the WEB based access to the data.

  17. ATLAS strategy for primary vertex reconstruction during Run-II of the LHC

    CERN Document Server

    ATLAS Collaboration; The ATLAS collaboration

    2015-01-01

    Based on experience gained from run-I of the LHC, the ATLAS vertex reconstruction group has developed a refined primary vertex reconstruction strategy for run-II.  With instantaneous luminosity exceeding 10^34 cm-2 s-1, an average of 40 to 50 pp collisions per bunch crossing are expected. Together with the increase of the center-of-mass collision energy from 8 TeV to 13 TeV, this will create a challenging environment for primary vertex pattern recognition. This contribution explains the ATLAS strategy for primary vertex reconstruction in high pile-up conditions.  The new approach is based on vertex seeding with a medical-imaging algorithm, adaptive reconstruction of vertex positions, and iterative recombination of occasional split vertices. The mathematical foundation and software implementation of the method are described in detail. Monte Carlo-based estimates of vertex reconstruction performance for LHC run-II are presented.

  18. Operation of the DC current transformer intensity monitors at FNAL during run II

    Energy Technology Data Exchange (ETDEWEB)

    Crisp, J.; Fellenz, B.; Heikkinen, D.; Ibrahim, M.A.; Meyer, T.; Vogel, G.; /Fermilab

    2012-01-01

    Circulating beam intensity measurements at FNAL are provided by five DC current transformers (DCCT), one per machine. With the exception of the DCCT in the Recycler, all DCCT systems were designed and built at FNAL. This paper presents an overview of both DCCT systems, including the sensor, the electronics, and the front-end instrumentation software, as well as their performance during Run II.

  19. Theory Motivation For Exotic Signatures: Prospects and Wishlist for Run II

    CERN Document Server

    Stolarski, Daniel

    2015-01-01

    Here I give some motivations for exotic signatures to search for at Run II of the LHC, focusing on displaced phenomena. I will discuss signatures arising from various different kinds of models including theories of dark matter and those with exotic decays of the Higgs.

  20. Overview of Energy Reconstruction, and Electron and Photon Performances with the CMS ECAL in Run II

    Science.gov (United States)

    Teixeira de Lima, Rafael; CMS Collaboration

    2017-11-01

    The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid (CMS) Experiment is crucial for achieving high resolution measurements of electrons and photons. Maintaining and possibly improving the excellent performance achieved in Run I is vital for measurements of the Standard Model Higgs boson and searches for new higher mass resonances in final states with electrons and photons. Since spring 2015, the ECAL has operated with proton-proton collisions at 13 TeV center-of-mass energy and at a reduced bunch spacing of 25 ns. The instantaneous luminosity delivered by the LHC during Run II is expected to exceed the levels previously attained. The average number of concurrent proton-proton collisions per bunch-crossing (pileup) is expected to reach up to 40 interactions. In this summary we present new crystal energy reconstruction algorithms and clustering techniques that have been developed to maintain the excellent performance of the CMS ECAL throughout Run II. We will show first performance results from 2015 data, achieved through energy calibrations using electrons from W and Z boson decays, photons from π 0/η decays, and the azimuthally symmetric energy distribution of minimum bias events. Lastly, we present an outlook on the expected Run II performance in the next years.

  1. CTEQ-TEA parton distribution functions and HERA Run I and II combined data

    Science.gov (United States)

    Hou, Tie-Jiun; Dulat, Sayipjamal; Gao, Jun; Guzzi, Marco; Huston, Joey; Nadolsky, Pavel; Pumplin, Jon; Schmidt, Carl; Stump, Daniel; Yuan, C.-P.

    2017-02-01

    We analyze the impact of the recent HERA Run I +II combination of inclusive deep inelastic scattering cross-section data on the CT14 global analysis of parton distribution functions (PDFs). New PDFs at next-to-leading order and next-to-next-to-leading order, called CT14 HERA 2 , are obtained by a refit of the CT14 data ensembles, in which the HERA Run I combined measurements are replaced by the new HERA Run I +II combination. The CT14 functional parametrization of PDFs is flexible enough to allow good descriptions of different flavor combinations, so we use the same parametrization for CT14 HERA 2 but with an additional shape parameter for describing the strange quark PDF. We find that the HERA I +II data can be fit reasonably well, and both CT14 and CT14 HERA 2 PDFs can describe equally well the non-HERA data included in our global analysis. Because the CT14 and CT14 HERA 2 PDFs agree well within the PDF errors, we continue to recommend CT14 PDFs for the analysis of LHC Run 2 experiments.

  2. The PDF4LHC report on PDFs and LHC data : Results from Run I and preparation for Run II

    NARCIS (Netherlands)

    Rojo, Juan; Accardi, Alberto; Ball, Richard D.; Cooper-Sarkar, Amanda; Roeck, Albert de; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; Huston, Joey; Glazov, Alexander; Gouzevitch, Maxime; Gwenlan, Claire; Lipka, Katerina; Lisovyi, Mykhailo; Mangano, Michelangelo L.; Nadolsky, Pavel; Perrozzi, Luca; Placakyte, Ringaile; Radescu, Voica; Salam, Gavin P.; Thorne, Robert S.

    2015-01-01

    The accurate determination of the Parton Distribution Functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterisation and precision Standard Model measurements to New Physics

  3. Improvement of the Jet Calibration Techniques for the ATLAS Experiment in LHC Run II

    CERN Document Server

    AUTHOR|(CDS)2097636; Di Simone, Andrea; Consorti, Valerio; Rúriková, Zuzana

    Many analyses in particle physics need jets, clustered with different parameters or even with different algorithms. But it is not feasible to provide in-situ correction factors for each case. In this thesis a new calibration method is tested which is called "R-scan calibration". This calibration uses only one fully calibrated jet collection. By building ratios between the fully calibrated jets and partially calibrated jets, it is possible to derive in-situ correction factors for the probe jet. Especially for the new run of the LHC a quick inter-calibration like the R-scan is very useful. Therefore, during this thesis the R-scan method is designed and improved with the data acquired during Run I. After a validation of this method it is applied to the new data format of Run II.

  4. Measurement of B(t→Wb)/B(t→Wq) in Top-Quark-Pair Decays Using Dilepton Events and the Full CDF Run II Data Set

    Science.gov (United States)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2014-06-01

    We present a measurement of the ratio of the top-quark branching fractions R=B(t→Wb)/B(t→Wq), where q represents any quark flavor, in events with two charged leptons, imbalance in total transverse energy, and at least two jets. The measurement uses proton-antiproton collision data at center-of-mass energy 1.96 TeV, corresponding to an integrated luminosity of 8.7 fb-1 collected with the Collider Detector at Fermilab during Run II of the Tevatron. We measure R to be 0.87±0.07, and extract the magnitude of the top-bottom quark coupling to be |Vtb|=0.93±0.04, assuming three generations of quarks. Under these assumptions, a lower limit of |Vtb|>0.85(0.87) at 95% (90%) credibility level is set.

  5. Measurement of R=B(t→Wb)/B(t→Wq) in top-quark-pair decays using lepton+jets events and the full CDF run II dataset

    Science.gov (United States)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M. A.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; De Barbaro, P.; Demortier, L.; Deninno, M.; d'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; Stancari, M.; Denis, R. St.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Wester, W. C., III; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2013-06-01

    We present a measurement of the ratio of the top-quark branching fractions R=B(t→Wb)/B(t→Wq), where q represents quarks of type b, s, or d, in the final state with a lepton and hadronic jets. The measurement uses s=1.96TeV proton-antiproton collision data from 8.7fb-1 of integrated luminosity collected with the Collider Detector at Fermilab during Run II of the Tevatron. We simultaneously measure R=0.94±0.09 (stat+syst) and the tt¯ production cross section σtt¯=7.5±1.0(stat+syst)pb. The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element, |Vtb|=0.97±0.05 (stat+syst) is extracted assuming three generations of quarks, and a lower limit of |Vtb|>0.89 at 95% credibility level is set.

  6. Physics performance and fast turn around: the challenge of calibration and alignment at the CMS experiment during the LHC Run-II

    CERN Document Server

    Di Guida, Salvatore; Franzoni, Giovanni; Govi, Giacomo; Musich, Marco; Pfeiffer, Andreas

    2017-01-01

    The CMS detector at the Large Hadron Collider (LHC) is a very complex apparatus with more than 70 million acquisition channels. To exploit its full physics potential, a very careful calibra- tion of the various components, together with an optimal knowledge of their position in space, is essential. The CMS Collaboration has set up a powerful infrastructure to allow for the best knowledge of these conditions at any given moment. The quick turnaround of these workflows was proven crucial both for the algorithms performing the online event selection and for the ul- timate resolution of the offline reconstruction of the physics objects. The contribution will report about the design and performance of these workflows during the operations of the 13TeV LHC RunII.

  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. Alignment of the ATLAS Inner Detector in the LHC Run II

    CERN Document Server

    Barranco Navarro, Laura; The ATLAS collaboration

    2015-01-01

    ATLAS physics goals require excellent resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system and on the quality of its offline alignment. ATLAS is equipped with a 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. For the Run II of the LHC, the system was upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to integration of the IBL into the alignment framework, techniques allowing to identify and eliminate tracking systematics as well as strategies to deal with time-dependent alignment. Performance from the commissioning of Cosmic data and potentially early LHC Run II proton-proton collisions will be discussed.

  9. Performance of the LHCb RICH detectors during the LHC Run II

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00261218; D'Ambrosio, Carmelo

    2017-01-01

    The LHCb RICH system provides hadron identification over a wide momentum range $(2–100 ~\\text{GeV}/c)$. This detector system is key to LHCb’s precision flavour physics programme, which has unique sensitivity to physics beyond the standard model. This paper reports on the performance of the LHCb RICH in Run II, following significant changes in the detector and operating conditions. The changes include the refurbishment of significant number of photon detectors, assembled using new vacuum technologies, and the removal of the aerogel radiator. The start of Run II of the LHC saw the beam energy increase to $6.5 ~\\text{TeV}$ per beam and a new trigger strategy for LHCb with full online detector calibration. The RICH information has also been made available for all trigger streams in the High Level Trigger for the first time.

  10. First measurement of the W boson mass in run II of the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; Abulencia, A.; /Helsinki Inst. of Phys.; Adelman, J.; /Illinois U., Urbana; Affolder, Anthony Allen; /Chicago U., EFI; Akimoto, T.; /UC, Santa Barbara; Albrow, Michael G.; /Tsukuba U.; Amerio, S.; /Fermilab; Amidei, Dante E.; /Padua U.; Anastassov, A.; /Michigan U.; Anikeev, K.; /Rutgers U., Piscataway; Annovi, A.; /Fermilab /Frascati /Comenius U.

    2007-07-01

    We present a measurement of the W boson mass using 200 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV by the CDF II detector at Run II of the Fermilab Tevatron. With a sample of 63964 W {yields} ev candidates and 51128 W W {yields} {mu}v candidates, we measure M{sub W} = (80413 {+-} 34{sub stat} {+-}34{sub syst} = 80413 {+-} 48) MeV/c{sup 2}. This is the most precise single measurement of the W boson mass to date.

  11. Beauty and charm rare decays at the LHC: prospects for Run II

    CERN Document Server

    Fiorendi, Sara; De Sanctis, Umberto

    2016-01-01

    The main results on the searches for rare decays of B and D mesons from ATLAS, CMS and LHCb experiments are summarised in this report. Particular attention will be given to the measurements performed by at least two of the three experiments, where common aspects and differences are highlighted. Detector improvements and perspectives of the three experiments for Run II ongoing data campaign are also discussed.

  12. Measurements of $\\sigma(V+D^{*})/\\sigma(V)$ in $9.7$ fb$^{-1}$ at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Matera, Keith [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2014-01-01

    The Standard Model of particle physics has been remarkably successful, but the non-perturbative features of quantum chromodynamics must be tested and modeled with data. There have been many such tests, focused primarily on the use of jet-based probes of heavy flavor (bottom and charm quark) production at hadron colliders. In this thesis, we propose and test a strategy for identifying heavy flavor in events containing a W or Z vector boson (a V boson); this technique probes a much lower energy regime than can be explored by jet-based methods. In a sample of W and Z events skimmed from 9.7 fb-1 of high- pT electron and muon data from CDF Run II p p collisions at center of mass energy √s = 1:96 GeV , we identify charm by fully reconstructing D* (2010) → D0(→ Kπ )π s decays at the track level. Using a binned fit of Δm=m(Kππ s) m(Kπ ) to count reconstructed D* candidates, we then unfold these raw counts with acceptance values derived from Monte Carlo, and present measurements of σ(W + D* )/ σ(W) and σ(Z + D* )/ σ(Z) in the W/Z leptonic decay channels. All measurements are found to be in agreement with the predictions of Pythia 6.2 (PDF set CTEQ5L). These results include the first measurement of W/Z + c production in events with zero jet objects at the Tevatron, and the first measurement of W/Z +c production with pT (c) < 15 GeV at the Tevatron.

  13. Jet reclustering and close-by effects in ATLAS run II

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    The reconstruction of hadronically-decaying, high-$p_{T}$ $W$, $Z$ and Higgs bosons and top quarks is instrumental to exploit the physics potential of the ATLAS detector in $pp$ collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider (LHC). The jet reclustering procedure reconstructs such objects by using calibrated anti-$k_{t}$ jets as inputs to the anti-$k_{t}$ algorithm with a larger distance parameter. The performance of these reclustered large-radius jets during LHC Run 2 is studied, and compared with that of trimmed anti-$k_{t}$ large-radius jets directly constructed from locally calibrated topological clusters. The propagation of calibrations to reclustered jets is found to be sufficient to restore their average energy and mass scales to particle level. The modelling of small-radius anti-$k_{t}$ jets in each other's vicinity is studied using methods which combine tracking and calorimeter information. Systematic uncertainties resulting from the propagation of the uncertainties on th...

  14. One-family walking technicolor in light of LHC Run II

    Science.gov (United States)

    Matsuzaki, Shinya

    2017-12-01

    The LHC Higgs can be identified as the technidilaton, a composite scalar, arising as a pseudo Nambu-Goldstone boson for the spontaneous breaking of scale symmetry in walking technicolor. One interesting candidate for the walking technicolor is the QCD with the large number of fermion flavors, involving the one-family model having the eight-fermion flavors. The smallness of the technidilaton mass can be ensured by the generic walking feature, Miransky scaling, and the presence of the “anti-Veneziano limit” characteristic to the large-flavor walking scenario. To tell the standard-model Higgs from the technidilaton, one needs to wait for the precise estimate of the Higgs couplings to the standard model particles, which is expected at the ongoing LHC Run II. In this talk the technidilaton phenomenology in comparison with the LHC Run-I data is summarized with the special emphasis placed on the presence of the anti-Veneziano limit supporting the lightness of technidilaton. Besides the technidilaton, the walking technicolor predicts the rich particle spectrum such as technipions and technirho mesons, arising as composite particles formed by technifermions. The LHC phenomenology of those technihadrons and the discovery channels are also discussed, which are smoking-guns of the walking technicolor, to be accessible at the LHC Run II.

  15. Time-integrated luminosity recorded by the BABAR detector at the PEP-II e{sup +}e{sup -} collider

    Energy Technology Data Exchange (ETDEWEB)

    Lees, J.P.; Poireau, V.; Tisserand, V. [Laboratoire d’a-le-Vieux de Physique des Particules (LAPP), Université de Savoie, CNRS/IN2P3, F-74941 a-Le-Vieux (France); Grauges, E. [Universitat de Barcelona, Facultat de Fisica, Departament ECM, E-08028 Barcelona (Spain); Palano, A. [Humboldt-Universität zu Berlin, Institut für Physik, Newtonstr. 15, D-12489 Berlin (Germany); INFN Sezione di Bari, Dipartimento di Fisica, Università di Bari, I-70126 Bari (Italy); Eigen, G.; Stugu, B. [University of Bergen, Institute of Physics, N-5007 Bergen (Norway); Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G. [Lawrence Berkeley National Laboratory and University of California, Berkeley, California 94720 (United States); Koch, H.; Schroeder, T. [Ruhr Universität Bochum, Institut für Experimentalphysik 1, D-44780 Bochum (Germany); Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; So, R.Y. [University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 (Canada); Khan, A. [Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom); Blinov, V.E. [Budker Institute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); and others

    2013-10-21

    We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e{sup +}e{sup -}→e{sup +}e{sup -} and (for the ϒ(4S) only) e{sup +}e{sup -}→μ{sup +}μ{sup -} candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e{sup +}e{sup -}→e{sup +}e{sup -} and e{sup +}e{sup -}→μ{sup +}μ{sup -}, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e{sup +}e{sup -}X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S)

  16. Magnet trouble likely to complicate start of large hadron collider Repairs may preclude a test run before the particle smasher starts tackling the Higgs boson

    CERN Multimedia

    2007-01-01

    "Researchers building the world's next top particle accelerator, the Large Hadron Collider (LHC) that straddles the Franco-Swiss border, may not get a chance to work out the bugs before they fire up the machine in earnest." (1/2 page)

  17. The CMS Level-1 tau lepton and Vector Boson Fusion triggers for the LHC Run II

    CERN Document Server

    Amendola, Chiara

    2017-01-01

    The CMS experiment implements a sophisticated two-level triggering system composed of Level-1, instrumented by custom-design hardware boards, and a software High-Level-Trigger. A new Level-1 trigger architecture with improved performance is now being used to maintain the thresholds that were used in LHC Run I for the more challenging luminosity conditions experienced during Run II. The upgrades to the calorimetry trigger will be described along with performance data. The algorithms for the selection of final states with tau leptons, both for precision measurements and for searches of new physics beyond the Standard Model, will be described in detail. The implementation of the first dedicated Vector Boson Fusion trigger algorithm will be presented as well, along with its performance on benchmark physics signals.

  18. Novel Real-time Calibration and Alignment Procedure for LHCb Run II

    CERN Multimedia

    Prouve, Claire

    2016-01-01

    In order to achieve optimal detector performance the LHCb experiment has introduced a novel real-time detector alignment and calibration strategy for Run II of the LHC. For the alignment tasks, data is collected and processed at the beginning of each fill while the calibrations are performed for each run. This real time alignment and calibration allows the same constants being used in both the online and offline reconstruction, thus improving the correlation between triggered and offline selected events. Additionally the newly computed alignment and calibration constants can be instantly used in the trigger, making it more efficient. The online alignment and calibration of the RICH detectors also enable the use of hadronic particle identification in the trigger. The computing time constraints are met through the use of a new dedicated framework using the multi-core farm infrastructure for the LHCb trigger. An overview of all alignment and calibration tasks is presented and their performance is shown.

  19. Measurement of \\boldmath $R = {\\mathcal{B}\\left(t \\rightarrow Wb \\right)/\\mathcal{B}\\left(t \\rightarrow Wq \\right)} $ in Top--Quark--Pair Decays using Dilepton Events and the Full CDF Run II Data Set

    OpenAIRE

    Aaltonen, Timo Antero; Amerio, Silvia; Amidei, Dante E; Anastassov, Anton Iankov; Annovi, Alberto; Antos, Jaroslav; Apollinari, Giorgio; Appel, Jeffrey A; Arisawa, Tetsuo; Artikov, Akram Muzafarovich; Asaadi, Jonathan A; Ashmanskas, William Joseph; Auerbach, Benjamin; Aurisano, Adam J; Azfar, Farrukh A

    2014-01-01

    We present a measurement of the ratio of the top-quark branching fractions $R=\\mathcal{B}(t\\rightarrow Wb)/\\mathcal{B}(t\\rightarrow $ $q$ represents quarks of flavors $b$, $s$, or $d$, in the final state, in events with two charged leptons, missing transverse energy and at least two jets. The measurement uses $\\sqrt{s}$ = 1.96 TeV proton--antiproton collision data corresponding to an integrated luminosity of 8.7 fb$^{-1}$ and collected with the Collider Detector at Fermilab during Run II of t...

  20. Measurement of the inclusive jet cross section using the midpoint algorithm in Run II at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Group, Robert Craig [Univ. of Florida, Gainesville, FL (United States)

    2006-01-01

    A measurement is presented of the inclusive jet cross section using the Midpoint jet clustering algorithm in five different rapidity regions. This is the first analysis which measures the inclusive jet cross section using the Midpoint algorithm in the forward region of the detector. The measurement is based on more than 1 fb-1 of integrated luminosity of Run II data taken by the CDF experiment at the Fermi National Accelerator Laboratory. The results are consistent with the predictions of perturbative quantum chromodynamics.

  1. Measurement of the inclusive jet cross section at D0 Run II

    Energy Technology Data Exchange (ETDEWEB)

    Agram, Jean-Laurent [Univ. of Upper Alsace, Mulhouse (France)

    2004-12-17

    This work describes the measurement of inclusive jets cross section in the DØ experiment. This cross section is computed as a function of jet transverse momentum, in several rapidity intervals. This quantity is sensitive to the proton structure and is crucial for the determination of parton distribution functions (PDF), essentially for the gluon at high proton momentum fraction. The measurement presented here gives the first values obtained for Tevatron Run II for the cross section in several rapidity intervals, for an integrated luminosity of 143 pb-1. The results are in agreement, within the uncertainties, with theoretical Standard Model predictions, showing no evidence for new physics.

  2. Dark Matter Search Results from the Commissioning Run of PandaX-II

    CERN Document Server

    Tan, Andi; Cui, Xiangyi; Chen, Xun; Chen, Yunhua; Fang, Deqing; Fu, Changbo; Giboni, Karl; Giuliani, Franco; Gong, Haowei; Hu, Shouyang; Huang, Xingtao; Ji, Xiangdong; Ju, Yonglin; Lei, Siao; Li, Shaoli; Li, Xiaomei; Li, Xinglong; Liang, Hao; Lin, Qing; Liu, Huaxuan; Liu, Jianglai; Lorenzon, Wolfgang; Ma, Yugang; Mao, Yajun; Ni, Kaixuan; Pushkin, Kirill; Ren, Xiangxiang; Schubnell, Michael; Shen, Manbin; Shi, Fang; Stephenson, Scott; Wang, Hongwei; Wang, Jiming; Wang, Meng; Wang, Qiuhong; Wang, Siguang; Wang, Xuming; Wang, Zhou; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; Yang, Yong; Yue, Jianfeng; Zeng, Xionghui; Zhang, Hongguang; Zhang, Hua; Zhang, Huanqiao; Zhang, Tao; Zhao, Li; Zhou, Jing; Zhou, Xiaopeng

    2016-01-01

    We present the results of a search for WIMPs from the commissioning run of the PandaX-II experiment located at the China Jinping underground Laboratory. A WIMP search data set with an exposure of 306$\\times$19.1 kg-day was taken, while its dominant $^{85}$Kr background was used as the electron recoil calibration. No WIMP candidates are identified, and a 90\\% upper limit is set on the spin-independent elastic WIMP-nucleon cross section with a lowest excluded cross section of 2.97$\\times$10$^{-45}$~cm$^2$ at a WIMP mass of 44.7~GeV/c$^2$.

  3. Constraining top quark effective theory in the LHC Run II era

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Andy; Englert, Christoph; Ferrando, James; Miller, David J.; Moore, Liam; Russell, Michael; White, Chris D. [School of Physics and Astronomy, Scottish Universities Physics Alliance, University of Glasgow,Glasgow G12 8QQ, Scotland (United Kingdom); Collaboration: The TopFitter collaboration

    2016-04-04

    We perform an up-to-date global fit of top quark effective theory to experimental data from the Tevatron, and from LHC Runs I and II. Experimental data includes total cross-sections up to 13 TeV, as well as differential distributions, for both single top and pair production. We also include the top quark width, charge asymmetries, and polarisation information from top decay products. We present bounds on the coefficients of dimension six operators, and examine the interplay between inclusive and differential measurements, and Tevatron/LHC data. All results are currently in good agreement with the Standard Model.

  4. Polishing optical fibers for the D0 ICD in Run II

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth Gallas and Jia Li

    1998-12-01

    The active element in the Run II D0 Inter Cryostat Detector (ICD) is an array of scintil- lator tiles. Charged and neutral particles produce light in the tiles which is transported to the photodetection system along optical fiber pathways. In general, building a tile/fiber detector requires very conscientious technical support and a high degree of quality control. Polishing fibers is one of the most delicate of tasks involved. This note describes methods used by the ICD group to polish the ends of fibers. These methods may be used in the ICD production as well as in prototype development.

  5. Performance of the CMS electromagnetic calorimeter in Run II and its role in the measurement of the Higgs boson properties

    CERN Document Server

    Organtini, Giovanni

    2017-01-01

    The characterisation of the Higgs boson discovered in 2012 around 125 GeV, and confirmed with the data collected in Run II, requires the precise determination of its mass, width and couplings. The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid Experiment (CMS) is crucial for measurements in the highest resolution channels, $H\\to \\gamma \\gamma$ and $H\\to 4$ leptons. In particular the energy resolution, the scale uncertainty and the position resolution for electrons and photons are required to be as good as possible.During Run II the LHC is continuously operating with 25 ns bunch spacing and increasing instantaneous luminosity. The calorimeter reconstruction algorithm has been adapted to cope with increasing levels of pile-up and the calibration and monitoring strategy have been optimised to maintain the excellent performance of the CMS ECAL throughout Run II. We show first performance results from the Run II data taking periods, achieved through energy calibrations using physics events, with...

  6. Proton-antiproton collider physics

    CERN Document Server

    Altarelli, Guido

    1989-01-01

    This volume reviews the physics studied at the CERN proton-antiproton collider during its first phase of operation, from the first physics run in 1981 to the last one at the end of 1985. The volume consists of a series of review articles written by physicists who are actively involved with the collider research program. The first article describes the proton-antiproton collider facility itself, including the antiproton source and its principle of operation based on stochastic cooling. The subsequent six articles deal with the various physics subjects studied at the collider. Each article descr

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

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Jessica Lynn [DESY, Hamburg (Germany)

    2016-07-01

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

  8. An investigation of triply heavy baryon production at hadron colliders

    CERN Document Server

    Gomshi Nobary, M A

    2006-01-01

    The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the Ωccc and Ωbbb baryons as the prototypes of triply heavy baryons at the hadron colliders with different . We present and compare the transverse momentum distributions of the differential cross sections, distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

  9. Using Drell-Yan to probe the underlying event in Run II at Collider Detector at Fermilab (CDF)

    Energy Technology Data Exchange (ETDEWEB)

    Kar, Deepak [Univ. of Florida, Gainesville, FL (United States)

    2008-12-01

    We study the behavior of charged particles produced in association with Drell-Yan lepton-pairs in the region of the Z-boson in proton-antiproton collisions at 1.96 TeV. We use the direction of the Z-boson in each event to define 'toward', 'away', and 'transverse' regions. For Drell-Yan production (excluding the leptons) both the 'toward' and 'transverse' regions are very sensitive to the 'underlying event', which is defined as everything except the two hard scattered components. The data are corrected to the particle level and are then compared with several PYTHIA models (with multiple parton interactions) and HERWIG (without multiple parton interactions) at the particle level (i.e. generator level). The data are also compared with a previous analysis on the behavior of the 'underlying event' in high transverse momentum jet production. The goal is to produce data that can be used by the theorists to tune and improve the QCD Monte-Carlo models of the 'underlying event' that are used to simulate hadron-hadron collisions.

  10. From the LHC to Future Colliders

    DEFF Research Database (Denmark)

    De Roeck, A.; Ellis, J.; Grojean, C.

    2010-01-01

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300/fb of integrated luminosity, of the proposed sLHC luminosity...... upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10/fb of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because...... harvest of new physics from multi-TeV collisions....

  11. From the LHC to Future Colliders

    Energy Technology Data Exchange (ETDEWEB)

    De Roeck, A.; Ellis, J.; /CERN; Grojean, C.; Heinemeyer, S.; /Cantabria Inst. of Phys.; Jakobs, K.; /Freiburg U.; Weiglein, G.; /Durham U., IPPP; Azuelos, G.; /TRIUMF; Dawson, S.; /Brookhaven; Gripaios, B.; /CERN; Han, T.; /Wisconsin U., Madison; Hewett, J.; /SLAC; Lancaster, M.; /University Coll. London; Mariotti, C.; /INFN, Turin; Moortgat, F.; /Zurich, ETH; Moortgat-Pick, G.; /Durham U., IPPP; Polesello, G.; /INFN, Pavia; Riemann, S.; /DESY; Assamagan, K.; /Brookhaven; Bechtle, P.; /DESY; Carena, M.; /Fermilab; Chachamis, G.; /PSI, Villigen /Taiwan, Natl. Taiwan U. /INFN, Florence /Bonn U. /CERN /Bonn U. /Freiburg U. /Oxford U. /Louvain U., CP3 /Bangalore, Indian Inst. Sci. /INFN, Milan Bicocca /Munich, Max Planck Inst. /Taiwan, Natl. Taiwan U. /Frascati /Fermilab /Warsaw U. /Florida U. /Orsay, LAL /LPSC, Grenoble /Warsaw U. /Yale U. /Stockholm U., Math. Dept. /Durham U., IPPP /DESY /Rome U. /University Coll. London /UC, San Diego /Heidelberg U. /Florida State U. /SLAC /Durham U., IPPP /Southern Denmark U., CP3-Origins /McGill U. /Durham U., IPPP; /more authors..

    2010-06-11

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb{sup -1} of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, theWorking Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.

  12. B-Physics at CMS with LHC Run-II and Beyond

    CERN Document Server

    Chen, Kai-Feng

    2015-01-01

    The LHC is entering into operation with an increased centre-of-mass energy of 13~TeV, and within the next 3 years of operations (Run-II) the foreseen integrated luminosity delivered to CMS will be about 100 fb$^{-1}$. The B hadron production cross section is expected to nearly double at this energy, thus potentially increasing by almost one order of magnitude the collected statistics relative to the previous operation period. This will enable CMS to perform enhanced measurements in the B-physics sector. A further increase in integrated luminosity is expected to occur in two more steps after the second LHC long shutdown (LS) in 2018 and the third LS in 2021, thus enabling to significantly improve the precision of several B-physics measurements, including $B_s(B_d)\\to\\mu^+\\mu^-$, and search for rarer decays. This proceeding reports on the prospects for B-physics measurements with high statistics data at CMS.

  13. CMS operations for Run II preparation and commissioning of the offline infrastructure

    CERN Document Server

    Cerminara, Gianluca

    2016-01-01

    The restart of the LHC coincided with an intense activity for the CMS experiment. Both at the beginning of Run II in 2015 and the restart of operations in 2016, the collaboration was engaged in an extensive re-commissioning of the CMS data-taking operations. After the long stop, the detector was fully aligned and calibrated. Data streams were redesigned, to fit the priorities dictated by the physics program for 2015 and 2016. A new reconstruction software (both online and offline) was commissioned with early collisions and further developed during the year. A massive campaign of Monte Carlo production was launched, to assist physics analyses. This presentation reviews the main event of this commissioning journey and describes the status of CMS physics performances for 2016.

  14. Novel methods and expected run II performance of ATLAS track reconstruction in dense environments

    CERN Document Server

    Jansky, Roland Wolfgang; The ATLAS collaboration

    2015-01-01

    Detailed understanding and optimal track reconstruction performance of ATLAS in the core of high pT objects is paramount for a number of techniques such as jet energy and mass calibration, jet flavour tagging, and hadronic tau identification as well as measurements of physics quantities like jet fragmentation functions. These dense environments are characterized by charged particle separations on the order of the granularity of ATLAS’s inner detector. With the insertion of a new innermost layer in this tracking detector, which allows measurements closer to the interaction point, and an increase in the centre of mass energy, these difficult environments will become even more relevant in Run II, such as in searches for heavy resonances. Novel algorithmic developments to the ATLAS track reconstruction software targeting these topologies as well as the expected improved performance will be presented.

  15. Search for the neutral MSSM Higgs bosons in the ditau decay channels at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Almenar, Cristobal Cuenca [Univ. of Valencia (Spain)

    2008-04-01

    This thesis presents the results on a search for the neutral MSSM Higgs bosons decaying to tau pairs, with least one of these taus decays leptonically. The search was performed with a sample of 1.8 fb-1 of proton-antiproton collisions at √s = 1.96 TeV provided by the Tevatron and collected by CDF Run II. No significant excess over the Standard Model prediction was found and a 95% confidence level exclusion limit have been set on the cross section times branching ratio as a function of the Higgs boson mass. This limit has been translated into the MSSM Higgs sector parameter plane, tanβ vs. MA, for the four different benchmark scenarios.

  16. COLLIDE Pro Helvetia Award

    CERN Multimedia

    2016-01-01

    The COLLIDE Pro Helvetia Award is run in partnership with Pro Helvetia, giving the opportunity to Swiss artists to do research at CERN for three months.   From left to right: Laura Perrenoud, Marc Dubois and Simon de Diesbach. The photo shows their VR Project, +2199. Fragment.In are the winning artists of COLLIDE Pro Helvetia. They came to CERN for two months in 2015, and will now continue their last month in the laboratory. Fragment.In is a Swiss based interaction design studio. They create innovative projects, interactive installations, video and game design. Read more about COLLIDE here.

  17. A Measurement of the Lifetime of the Λb Baryon with the CDF Detector at the Tevatron Run II

    Energy Technology Data Exchange (ETDEWEB)

    Unverhau, Tatjana Alberta Hanna [Univ. of Glasgow, Scotland (United Kingdom)

    2004-12-01

    In March 2001 the Tevatron accelerator entered its Run II phase, providing colliding proton and anti-proton beams with an unprecedented center-of-mass energy of 1.96 TeV. The Tevatron is currently the only accelerator to produce Λb baryons, which provides a unique opportunity to measure the properties of these particles. This thesis presents a measurement of the mean lifetime of the Λb baryon in the semileptonic channel Λ$0\\atop{b}$ → Λ$+\\atop{c}$ μ- $\\bar{v}$μ. In total 186 pb-1 of data were used for this analysis, collected with the CDF detector between February 2002 and September 2003. To select the long-lived events from b-decays, the secondary vertex trigger was utilized. This significant addition to the trigger for Run II allows, for the first time, the selection of events with tracks displaced from the primary interaction vertex at the second trigger level. After the application of selection cuts this trigger sample contains approximately 991 Λb candidates. To extract the mean lifetime of Λb baryons from this sample, they transverse decay length of the candidates is fitted with an unbinned maximum likelihood fit under the consideration of the missing neutrino momentum and the bias introduced by the secondary vertex trigger. The mean lifetime of the Λb is measured to be τ = 1.29 ± 0.11(stat.) ± 0.07(syst.) ps equivalent to a mean decay length of cτ = 387 ± 33(stat.) ± 21 (syst.) μm.

  18. Measurement of the Top Quark Mass with the Collider Detector at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Koji [Univ. of Tsukuba (Japan)

    2005-02-01

    We present a measurement of the top quark mass using tt pair creation events decaying into the lepton+jets channel in pp collisions at √s = 1.96 TeV. The data sample used in this analysis was collected with the Collider Detector at Fermilab (CDF) in Tevatron Run II during the period from March 2002 through August 2003.

  19. Muon colliders

    CERN Document Server

    AUTHOR|(CDS)2108556; Blondel, Alain; CERN. Geneva. Audiovisual Unit

    1999-01-01

    Muon Colliders - Prospective Physics (J. Ellis). Muon storage rings can address fundamental issues in neutrino physics, enable precision Higgs physics, and advance the high-energy frontier in lepton-antilepton collisions. In this lecture, the principa with particular emphasis on neutrino and Higgs factories. Muon Colliders (D. Neuffer). In these lectures the concept of a high-energy high-luminosity µ+ - µ- collider is developed. A µ+ - µ- colliderwould provide heavy lepton collisions, with uniqu of Higgs bosons at 100-180 GeV energies, and it could be extended to multi-TeV energies.A µ+-µ- collider requires a high-intensity proton source for ¼-production, a high-acceptance decay channel to collect µ?s from ¼-decay, a µ-cooling system, a r system, and a high-luminosity collider ring for the collisions of short, intense µ+-µ- bunches. Critical problems exist in each of the collider concept components, and in the interaction-region detectors needed to analyze the collisions. These pro within the curr...

  20. Search for non-standard model signatures in the WZ/ZZ final state at CDF run II

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Matthew [Univ. of California, San Diego, CA (United States)

    2009-01-01

    This thesis discusses a search for non-Standard Model physics in heavy diboson production in the dilepton-dijet final state, using 1.9 fb -1 of data from the CDF Run II detector. New limits are set on the anomalous coupling parameters for ZZ and WZ production based on limiting the production cross-section at high š. Additionally limits are set on the direct decay of new physics to ZZ andWZ diboson pairs. The nature and parameters of the CDF Run II detector are discussed, as are the influences that it has on the methods of our analysis.

  1. Physics at Hadronic Colliders course

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    Present and future hadron colliders play an important role in the investigation of fundamental questions of particle physics. After an introductory lecture, tests of the Standard Model and measurements of its parameters (like the mass of the top quark) at hadron colliders are presented. In addition, it will be discussed how the Higgs boson can be searched for at hadron colliders and how "New Physics", i.e. physics beyond the Standard Model, can be explored. Results are presented from the currently ongoing run at the Tevatron proton antiproton collider at the US research lab Fermilab. In addition, the rich physics potential of the experiments at the CERN Large Hadron Collider is discussed. Note: Prerequisite Knowledge: - The Standard Model (Lecture by A. Pich) - Beyond The Standard Model (Lecture by E. Kiritsis)

  2. ALICE Diffractive Detector Control System for RUN-II in the ALICE Experiment

    CERN Document Server

    INSPIRE-00522336; Martinez, M.I.; Monzon, I. Leon

    2016-01-01

    This paper describes general characteristics of the deployment and commissioned of the Detector Control System (DCS) AD0 for the second phase of the Large Hadron Collider (LHC). The AD0 detector is installed in the ALICE experiment to provide a better selection of diffractive events.

  3. Alignment of the ATLAS inner detector for the LHC Run II

    NARCIS (Netherlands)

    Butti, P.

    2015-01-01

    ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, quality of its offline alignment. ATLAS is

  4. Search for electroweak production of supersymmetric particles with photonic final states using the first LHC Run II data recorded with the CMS detector

    CERN Document Server

    Lange, Johannes

    2016-01-01

    A search for supersymmetry in final states with photons is presented in this thesis. Datacollected in Run II of the Large Hadron Collider at a center-of-mass energy of 13 TeV isused. The proton-proton collision dataset recorded with the CMS experiment in 2015corresponds to an integrated luminosity of 2.3 fb−1 .The analysis is designed to be sensitive to electroweak production of supersymmetric particles and compressed mass spectra. All considered models are motivated bygauge-mediated supersymmetry breaking. A cut-and-count experiment is performedusing three exclusive search bins. No sign for physics beyond the standard model isobserved.Exclusion limits are set for a general gauge mediation scenario and a simplifiedmodel assuming electroweak gaugino production. A similar sensitivity is reached as inthe search performed at s = 8 TeV.Additionally, two simplified models of gluino pair production are considered. Thecurrently best limits set by CMS can be improved for these scenarios at large neutralinoand cha...

  5. Alignment of the CMS Tracker: Latest results from LHC Run-II

    CERN Document Server

    Mittag, Gregor

    2017-01-01

    The all-silicon design of the tracking system of the CMS experiment provides excellent measurements of charged-particle tracks and an efficient tagging of jets. Conditions of the CMS tracker changed repeatedly during the 2015/2016 shutdown and the 2016 data-taking period. Still the true position and orientation of each of the 15 148 silicon strip and 1440 silicon pixel modules need to be known with high precision for all intervals. The alignment constants also need to be promptly re-adjusted each time the state of the CMS magnet is changed between 0T and 3.8 T. Latest Run-II results of the CMS tracker alignment and resolution performance are presented, which are obtained using several millions of reconstructed tracks from collision and cosmic-ray data of 2016. The geometries and the resulting performance of physics observables are carefully validated. In addition to the offline alignment, an online procedure has been put in place which continuously monitors movements of the pixel high-level structures and tri...

  6. The CMS Level-1 electron and photon trigger: for Run II of LHC

    Science.gov (United States)

    Dev, N.; Jessop, C.; Meng, F.; Marinelli, N.; Taroni, S.; Beaudette, F.; Cadamuro, L.; Davignon, O.; Romanteau, T.; Strebler, T.; Zabi, A.; Sauvan, J. B.; Marrouche, J.; Wardle, N.; Aggleton, R.; Ball, F.; Brooke, J.; Newbold, D.; Paramesvaran, S.; Smith, D.; Taylor, J.; Baber, M.; Bundock, A.; Citron, M.; Elwood, A.; Hall, G.; Iles, G.; Laner, C.; Penning, B.; Rose, A.; Shtipliyski, A.; Tapper, A.; Durkin, T.; Harder, K.; Harper, S.; Shepherd-Themistocleous, C.; Thea, A.; Williams, T.; Neu, C.; Sinthuprasith, T.; Xia, F.

    2017-02-01

    The Compact Muon Solenoid (CMS) employs a sophisticated two-level online triggering system that has a rejection factor of up to 105. Since the beginning of Run II of LHC, the conditions that CMS operates in have become increasingly challenging. The centre-of-mass energy is now 13 TeV and the instantaneous luminosity currently peaks at 1.5 ×1034 cm-2s-1. In order to keep low physics thresholds and to trigger efficiently in such conditions, the CMS trigger system has been upgraded. A new trigger architecture, the Time Multiplexed Trigger (TMT) has been introduced which allows the full granularity of the calorimeters to be exploited at the first level of the online trigger. The new trigger has also benefited immensely from technological improvements in hardware. Sophisticated algorithms, developed to fully exploit the advantages provided by the new hardware architecture, have been implemented. The new trigger system started taking physics data in 2016 following a commissioning period in 2015, and since then has performed extremely well. The hardware and firmware developments, electron and photon algorithms together with their performance in challenging 2016 conditions is presented.

  7. Level-1 trigger selection of electrons and photons with CMS for LHC Run-II.

    CERN Document Server

    AUTHOR|(CDS)2088114

    2016-01-01

    The CMS experiment has a sophisticated two-level online selection system that achieves a rejection factor of nearly $10^5$. The first, hardware-level trigger (L1) is based on coarse information coming from the calorimeters and the muon detectors while the High-Level Trigger combines fine-grain information from all subdetectors. During Run II, the LHC will increase its center of mass energy to 13 or 14 TeV, and progressively reach an instantaneous luminosity of $2\\times10^{34} \\mathrm{cm}^{-2}\\mathrm{s}^{-1}$. In order to guarantee a successful and ambitious physics programme in this intense environment, the CMS trigger and data acquisition system must be upgraded. The L1 calorimeter trigger hardware and architecture in particular has been redesigned to maintain the current thresholds even in presence of more demanding conditions (e.g., for electrons and photons) and improve the performance for the selection of $\\tau$ leptons. This design benefits from recent $\\mu$TCA technology, allowing sophisticated algorit...

  8. The CMS Level-1 Tau identification algorithm for the LHC Run II

    CERN Document Server

    AUTHOR|(CDS)2083962

    2016-01-01

    The CMS experiment implements a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. The first level (L1) is based on coarse information coming from the calorimeters and the muon detectors while the High Level Trigger combines fine-grain information from all sub-detectors. During Run II, the centre of mass energy of the LHC collisions will be increased up to 13/14 TeV and the instantaneous luminosity will eventually reach 2e34 cm-2s-1. To guarantee a successful and ambitious physics program under this intense environment, the CMS Trigger and Data acquisition system must be consolidated. In particular, the L1 calorimeter Trigger hardware and architecture will be upgraded, benefiting from the recent microTCA technology allowing sophisticated algorithms to be deployed, better exploiting the calorimeter granularity and opening the possibility of making correlations between different parts of the detector. Given the enhanced granularity provided by the new system, an opt...

  9. Study of Long-range Collisions and Wire Compensation for Tevatron Run-II

    CERN Document Server

    Zimmermann, Frank; Erdelyi, B; Boocha, V

    2004-01-01

    This report summarizes studies of long-range collisions and their compensation by current carrying wires for the Tevatron Run-II, which were performed during a two-week stay at Fermilab, February 22 to March 8, 2004. The weak-strong code WSDIFF was significantly extended to simulate the actual long-range encounters at the Tevatron for different antiproton bunches in the train at injection and in collision. Tune footprints and diffusive apertures simulated by this code are presented for various cases, differing in the bunch position, the energy, the number of long-range and head-on collisions, the presence of additional compensating wires and the momentum deviation. It is confirmed that the solution of 4 wires for injection, previously found by B. Erdelyi, raises the dynamic aperture, by about 1.0-1.5sigma. For both injection and collision an ideal compensation of the 6 or 3 closest long-range encounters was modeled, by removing these collisions altogether. At collision, an improvement in the dynamic aperture ...

  10. Invited talk at SM@LHC2016 titled "Higgs Prospects for Run-II and HL-LHC"

    CERN Document Server

    Neubauer, Mark; The ATLAS collaboration

    2016-01-01

    Summary of the expectations for Higgs precision measurements of couplings and properties at Run II and the HL-LHC phase. The talk should also cover the increased potential for new searches and measurements with limited sensitivity until now, including BSM Higgs boson searches.

  11. The Physics Case for Extended Tevatron Running

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Darien R.

    2010-11-01

    Run II of the Tevatron collider at Fermilab is currently scheduled to end late in 2011. Given the current performance of the collider and of the CDF and D0 detectors, it is estimated that the current data set could be approximately doubled with a run extended into 2014. A few examples are presented of the physics potential of these additional statistics. These are discussed in the context of the expected reach of the LHC 7 TeV data and the existing Tevatron data. In particular, an extraordinary opportunity is described which could probe the existence of a standard model Higgs boson with mass in the currently preferred region between 115 GeV and 150 GeV.

  12. 2007 2008 ACADEMIC TRAINING PROGRAMME: Tevatron: The Cinderella Story or The Art Of Collider Commissioning

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 01, 03, 04, 05 October 2007 Main Auditorium, bldg. 500 Tevatron: The Cinderella Story or The Art Of Collider Commissioning V. SHILTSEV / Fermi National Accelerator Laboraty, Batavia IL, USA The Tevatron Collider at Fermilab (Batavia, IL, USA) is the world’s highest energy particle collider at 1.8TeV c.m.e. The machine was a centerpiece of the US and world’s High Energy Physics for many years. Currently, the Tevatron is in the last years of its operation in so-called Run II which started 2001 and is tentatively scheduled to end in 2010. In this lecture series, we’ll try to learn from the exciting story of the Tevatron Collider Run II: the story of long preparations, great expectations, initial difficulties, years of "blood and sweat", continuous upgrades, exceeding its goals, high emotions, tune-up of accelerator organization for "combat fighting". The lectures will cover Introduction to the Tevatron, its history and Run II; "Plumbing"...

  13. Measurement of the W Plus N Inclusive Jets Cross-Section at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Stentz, Dale James [Northwestern Univ., Evanston, IL (United States)

    2012-01-01

    In this thesis we present the study of the production of the W boson in association with hadronic jets at the Collider Detector at Fermilab (CDF). Along with the electroweak properties the W boson, we examine jet kinematic variables with the aim of studying predictions of perturbative quantum chromodynamics. We derive several di erential crosssections as a function of the inclusive jet multiplicity and the transverse momenta of each jet. In this analysis, we are using 2.8 fb-1 of data and consider both the electron and muon lepton nal states for the W boson decay.

  14. Measurement of \\boldmath $R = {\\mathcal{B}\\left(t \\rightarrow Wb \\right)/\\mathcal{B}\\left(t \\rightarrow Wq \\right)} $ in Top--Quark--Pair Decays using Dilepton Events and the Full CDF Run II Data Set

    CERN Document Server

    Aaltonen, Timo Antero; Amidei, Dante E; Anastassov, Anton Iankov; Annovi, Alberto; Antos, Jaroslav; Apollinari, Giorgio; Appel, Jeffrey A; Arisawa, Tetsuo; Artikov, Akram Muzafarovich; Asaadi, Jonathan A; Ashmanskas, William Joseph; Auerbach, Benjamin; Aurisano, Adam J; Azfar, Farrukh A; Badgett, William Farris; Bae, Taegil; Barbaro-Galtieri, Angela; Barnes, Virgil E; Barnett, Bruce Arnold; Barria, Patrizia; Bartos, Pavol; Bauce, Matteo; Bedeschi, Franco; Behari, Satyajit; Bellettini, Giorgio; Bellinger, James Nugent; Benjamin, Douglas P; Beretvas, Andrew F; Bhatti, Anwar Ahmad; Bland, Karen Renee; Blumenfeld, Barry J; Bocci, Andrea; Bodek, Arie; Bortoletto, Daniela; Boudreau, Joseph Francis; Boveia, Antonio; Brigliadori, Luca; Bromberg, Carl Michael; Brucken, Erik; Budagov, Ioulian A; Budd, Howard Scott; Burkett, Kevin Alan; Busetto, Giovanni; Bussey, Peter John; Butti, Pierfrancesco; Buzatu, Adrian; Calamba, Aristotle; Camarda, Stefano; Campanelli, Mario; Canelli, Florencia; Carls, Benjamin; Carlsmith, Duncan L; Carosi, Roberto; Carrillo Moreno, Salvador; Casal Larana, Bruno; Casarsa, Massimo; Castro, Andrea; Catastini, Pierluigi; Cauz, Diego; Cavaliere, Viviana; Cavalli-Sforza, Matteo; Cerri, Alessandro; Cerrito, Lucio; Chen, Yen-Chu; Chertok, Maxwell Benjamin; Chiarelli, Giorgio; Chlachidze, Gouram; Cho, Kihyeon; Chokheli, Davit; Clark, Allan Geoffrey; Clarke, Christopher Joseph; Convery, Mary Elizabeth; Conway, John Stephen; Corbo, Matteo; Cordelli, Marco; Cox, Charles Alexander; Cox, David Jeremy; Cremonesi, Matteo; Cruz Alonso, Daniel; Cuevas Maestro, Javier; Culbertson, Raymond Lloyd; D'Ascenzo, Nicola; Datta, Mousumi; de Barbaro, Pawel; Demortier, Luc M; Deninno, Maria Maddalena; D'Errico, Maria; Devoto, Francesco; Di Canto, Angelo; Di Ruzza, Benedetto; Dittmann, Jay Richard; Donati, Simone; D'Onofrio, Monica; Dorigo, Mirco; Driutti, Anna; Ebina, Koji; Edgar, Ryan Christopher; Elagin, Andrey L; Erbacher, Robin D; Errede, Steven Michael; Esham, Benjamin; Farrington, Sinead Marie; Fernández Ramos, Juan Pablo; Field, Richard D; Flanagan, Gene U; Forrest, Robert David; Franklin, Melissa EB; Freeman, John Christian; Frisch, Henry J; Funakoshi, Yujiro; Galloni, Camilla; Garfinkel, Arthur F; Garosi, Paola; Gerberich, Heather Kay; Gerchtein, Elena A; Giagu, Stefano; Giakoumopoulou, Viktoria Athina; Gibson, Karen Ruth; Ginsburg, Camille Marie; Giokaris, Nikos D; Giromini, Paolo; Giurgiu, Gavril A; Glagolev, Vladimir; Glenzinski, Douglas Andrew; Gold, Michael S; Goldin, Daniel; Golossanov, Alexander; Gomez, Gervasio; Gomez-Ceballos, Guillelmo; Goncharov, Maxim T; González López, Oscar; Gorelov, Igor V; Goshaw, Alfred T; Goulianos, Konstantin A; Gramellini, Elena; Grinstein, Sebastian; Grosso-Pilcher, Carla; Group, Robert Craig; Guimaraes da Costa, Joao; Hahn, Stephen R; Han, Ji-Yeon; Happacher, Fabio; Hara, Kazuhiko; Hare, Matthew Frederick; Harr, Robert Francis; Harrington-Taber, Timothy; Hatakeyama, Kenichi; Hays, Christopher Paul; Heinrich, Joel G; Herndon, Matthew Fairbanks; Hocker, James Andrew; Hong, Ziqing; Hopkins, Walter Howard; Hou, Suen Ray; Hughes, Richard Edward; Husemann, Ulrich; Hussein, Mohammad; Huston, Joey Walter; Introzzi, Gianluca; Iori, Maurizio; Ivanov, Andrew Gennadievich; James, Eric B; Jang, Dongwook; Jayatilaka, Bodhitha Anjalike; Jeon, Eun-Ju; Jindariani, Sergo Robert; Jones, Matthew T; Joo, Kyung Kwang; Jun, Soon Yung; Junk, Thomas R; Kambeitz, Manuel; Kamon, Teruki; Karchin, Paul Edmund; Kasmi, Azeddine; Kato, Yukihiro; Ketchum, Wesley Robert; Keung, Justin Kien; Kilminster, Benjamin John; Kim, DongHee; Kim, Hyunsoo; Kim, Jieun; Kim, Min Jeong; Kim, Shin-Hong; Kim, Soo Bong; Kim, Young-Jin; Kim, Young-Kee; Kimura, Naoki; Kirby, Michael H; Knoepfel, Kyle James; Kondo, Kunitaka; Kong, Dae Jung; Konigsberg, Jacobo; Kotwal, Ashutosh Vijay; Kreps, Michal; Kroll, IJoseph; Kruse, Mark Charles; Kuhr, Thomas; Kurata, Masakazu; Laasanen, Alvin Toivo; Lammel, Stephan; Lancaster, Mark; Lannon, Kevin Patrick; Latino, Giuseppe; Lee, Hyun Su; Lee, Jaison; Leo, Sabato; Leone, Sandra; Lewis, Jonathan D; Limosani, Antonio; Lipeles, Elliot David; Lister, Alison; Liu, Hao; Liu, Qiuguang; Liu, Tiehui Ted; Lockwitz, Sarah E; Loginov, Andrey Borisovich; Lucchesi, Donatella; Lucà, Alessandra; Lueck, Jan; Lujan, Paul Joseph; Lukens, Patrick Thomas; Lungu, Gheorghe; Lys, Jeremy E; Lysak, Roman; Madrak, Robyn Leigh; Maestro, Paolo; Malik, Sarah Alam; Manca, Giulia; Manousakis-Katsikakis, Arkadios; Marchese, Luigi; Margaroli, Fabrizio; Marino, Christopher Phillip; Martínez-Perez, Mario; Matera, Keith; Mattson, Mark Edward; Mazzacane, Anna; Mazzanti, Paolo; McNulty, Ronan; Mehta, Andrew; Mehtala, Petteri; Mesropian, Christina; Miao, Ting; Mietlicki, David John; Mitra, Ankush; Miyake, Hideki; Moed, Shulamit; Moggi, Niccolo; Moon, Chang-Seong; Moore, Ronald Scott; Morello, Michael Joseph; Mukherjee, Aseet; Muller, Thomas; Murat, Pavel A; Mussini, Manuel; Nachtman, Jane Marie; Nagai, Yoshikazu; Naganoma, Junji; Nakano, Itsuo; Napier, Austin; Nett, Jason Michael; Neu, Christopher Carl; Nigmanov, Turgun S; Nodulman, Lawrence J; Noh, Seoyoung; Norniella Francisco, Olga; Oakes, Louise Beth; Oh, Seog Hwan; Oh, Young-do; Oksuzian, Iuri Artur; Okusawa, Toru; Orava, Risto Olavi; Ortolan, Lorenzo; Pagliarone, Carmine Elvezio; Palencia, Jose Enrique; Palni, Prabhakar; Papadimitriou, Vaia; Parker, William Chesluk; Pauletta, Giovanni; Paulini, Manfred; Paus, Christoph Maria Ernst; Phillips, Thomas J; Piacentino, Giovanni M; Pianori, Elisabetta; Pilot, Justin Robert; Pitts, Kevin T; Plager, Charles; Pondrom, Lee G; Poprocki, Stephen; Potamianos, Karolos Jozef; Pranko, Aliaksandr Pavlovich; Prokoshin, Fedor; Ptohos, Fotios K; Punzi, Giovanni; Ranjan, Niharika; Redondo Fernández, Ignacio; Renton, Peter B; Rescigno, Marco; Rimondi, Franco; Ristori, Luciano; Robson, Aidan; Rodriguez, Tatiana Isabel; Rolli, Simona; Ronzani, Manfredi; Roser, Robert Martin; Rosner, Jonathan L; Ruffini, Fabrizio; Ruiz Jimeno, Alberto; Russ, James S; Rusu, Vadim Liviu; Sakumoto, Willis Kazuo; Sakurai, Yuki; Santi, Lorenzo; Sato, Koji; Saveliev, Valeri; Savoy-Navarro, Aurore; Schlabach, Philip; Schmidt, Eugene E; Schwarz, Thomas A; Scodellaro, Luca; Scuri, Fabrizio; Seidel, Sally C; Seiya, Yoshihiro; Semenov, Alexei; Sforza, Federico; Shalhout, Shalhout Zaki; Shears, Tara G; Shepard, Paul F; Shimojima, Makoto; Shochet, Melvyn J; Shreyber-Tecker, Irina; Simonenko, Alexander V; Sliwa, Krzysztof Jan; Smith, John Rodgers; Snider, Frederick Douglas; Song, Hao; Sorin, Maria Veronica; St Denis, Richard Dante; Stancari, Michelle Dawn; Stentz, Dale James; Strologas, John; Sudo, Yuji; Sukhanov, Alexander I; Suslov, Igor M; Takemasa, Ken-ichi; Takeuchi, Yuji; Tang, Jian; Tecchio, Monica; Teng, Ping-Kun; Thom, Julia; Thomson, Evelyn Jean; Thukral, Vaikunth; Toback, David A; Tokar, Stanislav; Tollefson, Kirsten Anne; Tomura, Tomonobu; Tonelli, Diego; Torre, Stefano; Torretta, Donatella; Totaro, Pierluigi; Trovato, Marco; Ukegawa, Fumihiko; Uozumi, Satoru; Velev, Gueorgui; Vellidis, Konstantinos; Vernieri, Caterina; Vidal Marono, Miguel; Vilar Cortabitarte, Rocio; Vizán Garcia, Jesus Manuel; Vogel, Marcelo; Volpi, Guido; Vázquez-Valencia, Elsa Fabiola; Wagner, Peter; Wallny, Rainer S; Wang, Song-Ming; Waters, David S; Wester, William Carl; Whiteson, Daniel O; Wicklund, Arthur Barry; Wilbur, Scott; Williams, Hugh H; Wilson, Jonathan Samuel; Wilson, Peter James; Winer, Brian L; Wittich, Peter; Wolbers, Stephen A; Wolfe, Homer; Wright, Thomas Roland; Wu, Xin; Wu, Zhenbin; Yamamoto, Kazuhiro; Yamato, Daisuke; Yang, Tingjun; Yang, Un-Ki; Yang, Yu Chul; Yao, Wei-Ming; Yeh, Gong Ping; Yi, Kai; Yoh, John; Yorita, Kohei; Yoshida, Takuo; Yu, Geum Bong; Yu, Intae; Zanetti, Anna Maria; Zeng, Yu; Zhou, Chen; Zucchelli, Stefano

    2014-06-02

    We present a measurement of the ratio of the top-quark branching fractions $R=\\mathcal{B}(t\\rightarrow Wb)/\\mathcal{B}(t\\rightarrow $ $q$ represents quarks of flavors $b$, $s$, or $d$, in the final state, in events with two charged leptons, missing transverse energy and at least two jets. The measurement uses $\\sqrt{s}$ = 1.96 TeV proton--antiproton collision data corresponding to an integrated luminosity of 8.7 fb$^{-1}$ and collected with the Collider Detector at Fermilab during Run II of the Tevatron. We measure $R=0.87 \\pm 0.07$ (stat+syst), and extract the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element, $\\left|V_{tb}\\right| = 0.93 \\pm 0.04$ (stat+syst) assuming three generations of quarks. Under these assumptions, a lower limit of $|V_{tb}|>0.85$ at 95% credibility level is set.

  15. Differential satellite cell density of type I and II fibres with lifelong endurance running in old men

    DEFF Research Database (Denmark)

    Mackey, Abigail; Karlsen, A; Couppé, C

    2014-01-01

    AIM: To investigate the influence of lifelong endurance running on the satellite cell pool of type I and type II fibres in healthy human skeletal muscle. METHODS: Muscle biopsies were collected from 15 healthy old trained men (O-Tr) who had been running 43 ± 16 (mean ± SD) kilometres a week for 28...... ± 9 years. Twelve age-matched untrained men (O-Un) and a group of young trained and young untrained men were recruited for comparison. Frozen sections were immunohistochemically stained for Pax7, type I myosin and laminin, from which fibre area, the number of satellite cells, and the relationship...... between these variables were determined. RESULTS: In O-Un and O-Tr, type II fibres were smaller and contained fewer satellite cells than type I fibres. However, when expressed relative to fibre area, the difference in satellite cell content between fibre types was eliminated in O-Tr, but not O...

  16. Novel real-time alignment and calibration of LHCb detector for Run II and tracking for the upgrade.

    CERN Document Server

    AUTHOR|(CDS)2091576

    2016-01-01

    LHCb has introduced a novel real-time detector alignment and calibration strategy for LHC Run II. Data collected at the start of the fill is processed in a few minutes and used to update the alignment, while the calibration constants are evaluated for each run. The procedure aims to improve the quality of the online selection and performance stability. The required computing time constraints are met thanks to a new dedicated framework using the multi-core farm infrastructure for the trigger. A similar scheme is planned to be used for Run III foreseen to start in 2020. At that time LHCb will run at an instantaneous luminosity of $2 \\times 10^{33}$ cm$^2$ s$^1$ and a fully software based trigger strategy will be used. The new running conditions and the tighter timing constraints in the software trigger (only 13 ms per event are available) represent a big challenge for track reconstruction. The new software based trigger strategy implies a full detector read-out at the collision rate of 40 MHz. High performance ...

  17. Measurement of the forward-backward asymmetry of top-quark and antiquark pairs using the full CDF Run II data set

    Science.gov (United States)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2016-06-01

    We measure the forward-backward asymmetry of the production of top-quark and antiquark pairs in proton-antiproton collisions at center-of-mass energy √{s }=1.96 TeV using the full data set collected by the Collider Detector at Fermilab (CDF) in Tevatron Run II corresponding to an integrated luminosity of 9.1 fb-1 . The asymmetry is characterized by the rapidity difference between top quarks and antiquarks (Δ y ) and measured in the final state with two charged leptons (electrons and muons). The inclusive asymmetry, corrected to the entire phase space at parton level, is measured to be AFBt t ¯=0.12 ±0.13 , consistent with the expectations from the standard model (SM) and previous CDF results in the final state with a single charged lepton. The combination of the CDF measurements of the inclusive AFBt t ¯ in both final states yields AFBt t ¯=0.160 ±0.045 , which is consistent with the SM predictions. We also measure the differential asymmetry as a function of Δ y . A linear fit to AFBt t ¯(|Δ y |), assuming zero asymmetry at Δ y =0 , yields a slope of α =0.14 ±0.15 , consistent with the SM prediction and the previous CDF determination in the final state with a single charged lepton. The combined slope of AFBt t ¯(|Δ y |) in the two final states is α =0.227 ±0.057 , which is 2.0 σ larger than the SM prediction.

  18. Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets. II. Dynamic field changes and scaling laws

    Directory of Open Access Journals (Sweden)

    Nicholas J. Sammut

    2007-08-01

    Full Text Available A superconducting particle accelerator like the LHC (Large Hadron Collider at CERN, can only be controlled well if the effects of the magnetic field multipoles on the beam are compensated. The demands on a control system solely based on beam feedback may be too high for the requirements to be reached at the specified bandwidth and accuracy. Therefore, we designed a suitable field description for the LHC (FIDEL as part of the machine control baseline to act as a feed-forward magnetic field prediction system. FIDEL consists of a physical and empirical parametric field model based on magnetic measurements at warm and in cryogenic conditions. The performance of FIDEL is particularly critical at injection when the field decays, and in the initial part of the acceleration when the field snaps back. These dynamic components are both current and time dependent and are not reproducible from cycle to cycle since they also depend on the magnet powering history. In this paper a qualitative and quantitative description of the dynamic field behavior substantiated by a set of scaling laws is presented.

  19. Les Houches 2015: Physics at TeV Colliders Standard Model Working Group Report

    CERN Document Server

    Andersen, J.R.; Becker, K.; Bell, M.; Bellm, J.; Bendavid, J.; Bothmann, E.; Boughezal, R.; Butterworth, J.; Carrazza, S.; Chiesa, M.; Cieri, L.; Ciulli, V.; Denner, A.; Duehrssen-Debling, M.; Falmagne, G.; Forte, S.; Francavilla, P.; Frederix, R.; Freytsis, M.; Gao, J.; Gras, P.; Grazzini, M.; Greiner, N.; Grellscheid, D.; Heinrich, G.; Hesketh, G.; Hoche, S.; Hofer, L.; Hou, T.J.; Huss, A.; Huston, J.; Isaacson, J.; Jueid, A.; Kallweit, S.; Kar, D.; Kassabov, Z.; Konstantinides, V.; Krauss, F.; Kuttimalai, S.; Lazapoulos, A.; Lenzi, P.; Li, Y.; Lindert, J.M.; Liu, X.; Luisoni, G.; Lonnblad, L.; Maierhofer, P.; Maître, D.; Marini, A.C.; Montagna, G.; Moretti, M.; Nadolsky, P.M.; Nail, G.; Napoletano, D.; Nicrosini, O.; Oleari, C.; Pagani, D.; Pandini, C.; Perrozzi, L.; Petriello, F.; Piccinini, F.; Platzer, S.; Pogrebnyak, I.; Pozzorini, S.; Prestel, S.; Reuschle, C.; Rojo, J.; Russo, L.; Schichtel, P.; Schonherr, M.; Schumann, S.; Siodmok, A.; Skands, P.; Soper, D.; Soyez, G.; Sun, P.; Tackmann, F.J.; Tackmann, K.; Takasugi, E.; Thaler, J.; Uccirati, S.; Utku, U.; Viliani, L.; Vryonidou, E.; Wang, B.T.; Waugh, B.; Weber, M.A.; Williams, C.; Winter, J.; Xie, K.P.; Yuan, C.P.; Yuan, F.; Zapp, K.; Zaro, M.

    2016-01-01

    This Report summarizes the proceedings of the 2015 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) the new PDF4LHC parton distributions, (III) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (IV) a host of phenomenological studies essential for comparing LHC data from Run I with theoretical predictions and projections for future measurements in Run II, and (V) new developments in Monte Carlo event generators.

  20. Les Houches 2015: Physics at TeV Colliders Standard Model Working Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, J.R.; et al.

    2016-05-16

    This Report summarizes the proceedings of the 2015 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments relevant for high precision Standard Model calculations, (II) the new PDF4LHC parton distributions, (III) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, (IV) a host of phenomenological studies essential for comparing LHC data from Run I with theoretical predictions and projections for future measurements in Run II, and (V) new developments in Monte Carlo event generators.

  1. Performances of the ATLAS RPC Level-1 Muon trigger during the Run-II data taking

    CERN Document Server

    Alberghi, Gian Luigi; 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. Its input stage consists of an array of processors receiving the full granularity of data from Resistive Plate Chambers in the central area of the ATLAS detector ("Barrel"). The RPCs, placed in the barrel region of the ATLAS detector, 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 m2 and about 3600 gas volumes. The Level-1 Muon Trigger in the barrel region allows to select muon candidates with respect to their transverse momentum and associates them with the correct bunch-crossing number. The trigger system is able to take a decision within a latency of about 2 μs. We illustrate the selections, strategy and validation for an unbiased determination of the efficiency and timing of the RPC and the L1 from data; and show the results w...

  2. 14th Topical Conference on Hadron Collider Physics

    CERN Document Server

    Müller, T

    2003-01-01

    Hadron colliders probe physics at new energy frontiers and search for new particles and forces. In addition, hadron colliders now provide also an environment for precision physics. The present volume collects the results from recently completed runs at major colliders as well as new ideas about collider physics and techniques. It will serve as the main source of reference in the field for many years to come.

  3. Measurement of W-Boson Polarization in Top-quark Decay using the Full CDF Run II Data Set

    CERN Document Server

    Aaltonen, T.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K.R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H.S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y.C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M.A.; Clark, A.; Clarke, C.; Convery, M.E.; Conway, J.; Corbo, M..; Cordelli, M.; Cox, C.A.; Cox, D.J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; Devoto, F.; d'Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J.R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernandez Ramos, J.P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J.C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A.F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C.M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzalez Lopez, O.; Gorelov, I.; Goshaw, A.T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R.C.; Guimaraes da Costa, J.; Hahn, S.R.; Han, J.Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R.F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R.E.; Husemann, U.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E.J.; Jindariani, S.; Jones, M.; Joo, K.K.; Jun, S.Y.; Junk, T.R.; Kambeitz, M.; Kamon, T.; Karchin, P.E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D.H.; Kim, H.S.; Kim, J.E.; Kim, M.J.; Kim, S.B.; Kim, S.H.; Kim, Y.K.; Kim, Y.J.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D.J.; Konigsberg, J.; Kotwal, A.V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A.T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H.S.; Lee, J.S.; Leo, S.; Leone, S.; Lewis, J.D.; Limosani, A.; Lipeles, E.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martinez, M.; Matera, K.; Mattson, M.E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C.S.; Moore, R.; Morello, M.J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S.Y.; Norniella, O.; Oakes, L.; Oh, S.H.; Oh, Y.D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T.J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernandez, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J.L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W.K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E.E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S.Z.; Shears, T.; Shepard, P.F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J.R.; Snider, F.D.; Sorin, V.; Song, H.; Stancari, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P.K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vazquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizan, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Walsh, K.; Wang, S.M.; Warburton, A.; Waters, D.; Wester, W.C., III; Whiteson, D.; Wicklund, A.B.; Wilbur, S.; Williams, H.H.; Wilson, J.S.; Wilson, P.; Winer, B.L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U.K.; Yang, Y.C.; Yao, W.M.; Yeh, G.P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G.B.; Yu, I.; Zanetti, A.M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2013-02-21

    We measure the polarization of W bosons from top-quark (t) decays into final states with a charged lepton and jets, tt --> WbWb --> lvbqqb, using the full Run II data set collected by the CDF II detector. A model-independent method simultaneously determines the fraction of longitudinal (f_0) and right-handed (f_+) W bosons to yield f_0 = 0.726 +/- 0.066 (stat) +/- 0.067 (syst) and f_+ = -0.045 +/- 0.044 (stat) +/- 0.058 (syst) with a correlation coefficient of -0.69. Additional results are presented under various standard model assumptions. No significant discrepencies with the standard model are observed.

  4. Report of Snowmass 2001 Working Group E2: Electron-Positron Colliders from the Phi to the Z

    Energy Technology Data Exchange (ETDEWEB)

    Decker, Franz-Josef

    2002-08-07

    We report on the status and plans of experiments now running or proposed for electron-positron colliders at energies between the {phi} and the Z. The e{sup +}e{sup -} B and charm factories we considered were PEP-II/BABAR, KEKB/Belle, superKEK, SuperBABAR, and CESR-c/CLEO-c. We reviewed the programs at the {phi} factory at Frascati and the proposed PEP-N facility at Stanford Linear Accelerator Center. We studied the prospects for B physics with a dedicated linear collider Z factory, associated with the TESLA high energy linear collider. In all cases, we compared the physics reach of these facilities with that of alternative experiments at hadron colliders or fixed target facilities.

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

    CERN Document Server

    Zhang, Zhicai

    2017-01-01

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

  6. Modelling Energy Loss Mechanisms and a Determination of the Electron Energy Scale for the CDF Run II W Mass Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Riddick, Thomas [Univ. College London, Bloomsbury (United Kingdom)

    2012-06-15

    The calibration of the calorimeter energy scale is vital to measuring the mass of the W boson at CDF Run II. For the second measurement of the W boson mass at CDF Run II, two independent simulations were developed. This thesis presents a detailed description of the modification and validation of Bremsstrahlung and pair production modelling in one of these simulations, UCL Fast Simulation, comparing to both geant4 and real data where appropriate. The total systematic uncertainty on the measurement of the W boson mass in the W → eve channel from residual inaccuracies in Bremsstrahlung modelling is estimated as 6.2 ±3.2 MeV/c2 and the total systematic uncertainty from residual inaccuracies in pair production modelling is estimated as 2.8± 2.7 MeV=c2. Two independent methods are used to calibrate the calorimeter energy scale in UCL Fast Simulation; the results of these two methods are compared to produce a measurement of the Z boson mass as a cross-check on the accuracy of the simulation.

  7. Real-time alignment and calibration of the LHCb Detector in Run II

    CERN Multimedia

    Dujany, Giulio

    2015-01-01

    Stable, precise spatial alignment and PID calibration are necessary to achieve optimal detector performance. During Run2, LHCb will have a new real-time detector alignment and calibration to allow equivalent performance in the online and offline reconstruction to be reached. This offers the opportunity to optimise the event selection by applying stronger constraints, and to use hadronic particle identification at the trigger level. The computing time constraints are met through the use of 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 the operative and physics performance point of view. Specific challenges of this configuration are discussed, as well as the designed framework and its performance.

  8. Real-time alignment and calibration of the LHCb Detector in Run II

    CERN Multimedia

    Dujany, Giulio

    2016-01-01

    Stable, precise spatial alignment and PID calibration are necessary to achieve optimal detector performance. During Run2, LHCb has a new real-time detector alignment and calibration to allow equivalent performance in the online and offline reconstruction to be reached. This offers the opportunity to optimise the event selection by applying stronger constraints, and to use hadronic particle identification at the trigger level. The computing time constraints are met through the use of 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 the operative and physics performance point of view. Specific challenges of this configuration are discussed, as well as the designed framework and its performance.

  9. Performance of the CASTOR calorimeter at CMS during Run II of LHC

    CERN Document Server

    Van De Klundert, Merijn H F

    2016-01-01

    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 systematic uncerta...

  10. RUN COORDINATION

    CERN Multimedia

    Christophe Delaere

    2012-01-01

      On Wednesday 14 March, the machine group successfully injected beams into LHC for the first time this year. Within 48 hours they managed to ramp the beams to 4 TeV and proceeded to squeeze to β*=0.6m, settings that are used routinely since then. This brought to an end the CMS Cosmic Run at ~Four Tesla (CRAFT), during which we collected 800k cosmic ray events with a track crossing the central Tracker. That sample has been since then topped up to two million, allowing further refinements of the Tracker Alignment. The LHC started delivering the first collisions on 5 April with two bunches colliding in CMS, giving a pile-up of ~27 interactions per crossing at the beginning of the fill. Since then the machine has increased the number of colliding bunches to reach 1380 bunches and peak instantaneous luminosities around 6.5E33 at the beginning of fills. The average bunch charges reached ~1.5E11 protons per bunch which results in an initial pile-up of ~30 interactions per crossing. During the ...

  11. Search for Supersymmetry in the Dilepton Final State with Taus at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Robert David [Univ. of California, Davis, CA (United States)

    2011-01-01

    This thesis presents the results a search for chargino and neutralino supersymmetric particles yielding same signed dilepton final states including one hadronically decaying tau lepton using 6.0 fb-1 of data collected by the the CDF II detector. This signature is important in SUSY models where, at high tan β, the branching ratio of charginos and neutralinos to tau leptons becomes dominant. We study event acceptance, lepton identification cuts, and efficiencies. We set limits on the production cross section as a function of SUSY particle mass for certain generic models.

  12. Measurement of the W W and W Z production cross section using final states with a charged lepton and heavy-flavor jets in the full CDF Run II data set

    Science.gov (United States)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; De Barbaro, P.; Demortier, L.; Deninno, M.; Devoto, F.; d'Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Sorin, V.; Song, H.; Stancari, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2016-08-01

    We present a measurement of the total W W and W Z production cross sections in p p ¯ collision at √{s }=1.96 TeV , in a final state consistent with leptonic W boson decay and jets originating from heavy-flavor quarks from either a W or a Z boson decay. This analysis uses the full data set collected with the CDF II detector during Run II of the Tevatron collider, corresponding to an integrated luminosity of 9.4 fb-1 . An analysis of the dijet mass spectrum provides 3.7 σ evidence of the summed production processes of either W W or W Z bosons with a measured total cross section of σW W +W Z=13.7 ±3.9 pb . Independent measurements of the W W and W Z production cross sections are allowed by the different heavy-flavor decay patterns of the W and Z bosons and by the analysis of secondary-decay vertices reconstructed within heavy-flavor jets. The productions of W W and of W Z dibosons are independently seen with significances of 2.9 σ and 2.1 σ , respectively, with total cross sections of σW W=9.4 ±4.2 pb and σW Z=3. 7-2.2+2.5 pb . The measurements are consistent with standard-model predictions.

  13. Measurement of the $WW$ and $WZ$ production cross section using final states with a charged lepton and heavy-flavor jets in the full CDF Run II data set

    CERN Document Server

    Aaltonen, Timo Antero

    2016-08-23

    We present a measurement of the $WW$ and $WZ$ diboson production cross-sections in a final state consistent with leptonic $W$ boson decay and jets originating from heavy-flavor quarks from either a $W$ or a $Z$ boson decay. This analysis uses the full data set collected with the CDF II detector during Run II of the Tevatron proton-antiproton collider, corresponding to an integrated luminosity of 9.4 fb$^{-1}$ at $\\sqrt{s}=1.96$ TeV. An analysis of the dijet mass spectrum provides $3.7\\sigma$ evidence of the summed production processes of either $WW$ or $WZ$ bosons with a measured cross section of $\\sigma_{WW+WZ} = 13.7\\pm 3.9$ pb. Independent measurements of the $WW$ and $WZ$ production cross-sections are allowed by the different heavy-flavor decay-patterns of the $W$ and $Z$ bosons and by the analysis of secondary-decay vertices reconstructed within heavy-flavor jets. The productions of $WW$ and of $WZ$ dibosons are independently seen with significances of $2.9\\sigma$ and $2.1\\sigma$, respectively, with cros...

  14. Measurement of the W Boson Mass with the D0 Run II Detector using the Electron P(T) Spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Andeen, Jr., Timothy R. [Northwestern Univ., Evanston, IL (United States)

    2008-06-01

    This thesis is a description of the measurement of the W boson mass using the D0 Run II detector with 770 pb-1 of p$\\bar{p}$ collision data. These collisions were produced by the Tevatron at √s = 1.96 TeV between 2002 and 2006. We use a sample of W → ev and Z → ee decays to determine the W boson mass with the transverse momentum distribution of the electron and the transverse mass distribution of the boson. We measure MW = 80340 ± 37 (stat.) ± 26 (sys. theo.) ± 51 (sys. exp.) MeV = 80340 ± 68 MeV with the transverse momentum distribution of the electron and MW = 80361 ± 28 (stat.) ± 17 (sys. theo.) ± 51 (sys. exp.) MeV = 80361 ± 61 MeV with the transverse mass distribution.

  15. Study of the $H^0/A^0 \\to \\tau \\mu$ signal at the hadronic colliders and intercalibration of the D0 calorimeter at Tevatron Run II

    Energy Technology Data Exchange (ETDEWEB)

    Delsart, Pierre Antoine [Claude Bernard Univ. Lyon (France)

    2003-10-13

    This thesis was realized in collaboration with the "theory'' group and the "D0" group of IPNL. Within D0 we have worked on a component of the calibration of the detector's calorimeter : the intercalibration. Using the fact the physics is $\\phi$-symmetric in D0, we created and applied statistical methods for a relative calibration of the $\\phi$-symmetric parts of the calorimeter. Work on particle physics concerned the two Higgs doublet model. In such models leptonic number violation is possible : we have simulated the $H^0/A^0 \\to \\tau \\mu$ signal in order to study the discovery potential and the constraints on the coupling responsible for this decay.

  16. Search for The Standard Model Higgs Boson in the four lepton final state by the D0 experiment at Run II of the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Diego [Northern Illinois Univ., DeKalb, IL (United States)

    2013-01-01

    This dissertation presents a measurement of Z boson pair production in p¯p collisions at 1.96 TeV with 9.6 fb-1 to 9.8 fb-1 of D0 data. We examine the final states eeee, eeμμ, and μμμμ. Based on selected data, the measured cross section in the mass region M(Z/γ*) > 30 GeV is σ(p¯p → Z/γ* Z/γ*) = 1.26+0.44 -0.36 (stat)+0.17 -0.15 (syst) ± 0.08 (lumi) pb.

  17. Measurement of R = \\boldmath${\\mathcal{B}(t \\rightarrow Wb)/\\mathcal{B}(t \\rightarrow Wq)} $ in Top--quark--pair Decays using Lepton+jets Events and the Full CDF Run II Data set

    CERN Document Server

    Aaltonen, T.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K.R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H.S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y.C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M.A.; Clark, A.; Clarke, C.; Convery, M.E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C.A.; Cox, D.J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; d'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J.R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernandez Ramos, J.P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J.C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A.F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C.M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzalez Lopez, O.; Gorelov, I.; Goshaw, A.T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R.C.; Guimaraes da Costa, J.; Hahn, S.R.; Han, J.Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R.F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R.E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E.J.; Jindariani, S.; Jones, M.; Joo, K.K.; Jun, S.Y.; Junk, T.R.; Kambeitz, M.; Kamon, T.; Karchin, P.E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D.H.; Kim, H.S.; Kim, J.E.; Kim, M.J.; Kim, S.B.; Kim, S.H.; Kim, Y.J.; Kim, Y.K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D.J.; Konigsberg, J.; Kotwal, A.V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A.T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H.S.; Lee, J.S.; Leo, S.; Leone, S.; Lewis, J.D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martinez, M.; Matera, K.; Mattson, M.E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C.S.; Moore, R.; Morello, M.J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S.Y.; Norniella, O.; Oakes, L.; Oh, S.H.; Oh, Y.D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T.J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernandez, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J.L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W.K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E.E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S.Z.; Shears, T.; Shepard, P.F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J.R.; Snider, F.D.; Song, H.; Sorin, V.; Stancari, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P.K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vazquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizan, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S.M.; Warburton, A.; Waters, D.; Wester, W.C., III; Whiteson, D.; Wicklund, A.B.; Wilbur, S.; Williams, H.H.; Wilson, J.S.; Wilson, P.; Winer, B.L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U.K.; Yang, Y.C.; Yao, W.M.; Yeh, G.P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G.B.; Yu, I.; Zanetti, A.M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2013-06-03

    We present a measurement of the ratio of the top-quark branching fractions $R=\\mathcal{B}(t\\rightarrow Wb)/\\mathcal{B}(t\\rightarrow Wq)$, where $q$ represents quarks of type $b$, $s$, or $d$, in the final state with a lepton and hadronic jets. The measurement uses $\\sqrt{s}$ = 1.96 TeV proton--antiproton collision data from 8.7 fb$^{-1}$ of integrated luminosity collected with the Collider Detector at Fermilab during Run II of the Tevatron. We simultaneously measure $R=0.94 \\pm 0.09$ (stat+syst), the $t\\bar{t}$ production cross section $\\sigma_{t \\bar t} = 7.5 \\pm 1.0$ (stat+syst) pb. The magnitude of the Cabibbo-Kobayashi-Maskawa matrix element, $|V_{tb}| = 0.97 \\pm 0.05$ (stat+syst) is extracted assuming three generations of quarks, and a lower limit of $|V_{tb}|>0.89$ at 95% credibility level is set.

  18. Triggering on electrons, jets and tau leptons with the CMS upgraded calorimeter trigger for the LHC RUN II

    CERN Document Server

    AUTHOR|(CDS)2068461; Cadamuro, L.; Mastrolorenzo, L.; Romanteau, T.; Sauvan, J.B.; Strebler, T.; 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.; Durkin, T.; Harder, K.; Harper, S.; Shepherd-Themistocleous, C.; Thea, A.; Williams, T.

    2016-01-01

    The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. During Run II, the LHC will increase its centre-of-mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2e34cm-2s-1. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition (DAQ) system has been upgraded. A novel concept for the L1 calorimeter trigger is introduced the Time Multiplexed Trigger (TMT). In this design, nine main receive each all of the calorimeter data from an entire event provided by 18 preprocessors. This design is not different from that of the CMS DAQ and HLT systems. The advantage of the TMT architecture is that a global view and full granularity of the calorimeters can be exploited by sophisticated algortihms. The goal is to maintain the current thresholds for calorimeter objects and improve the performance for their selection. T...

  19. Summary of the half-day internal review of LHC performance limitations (linked to transverse collective effects) during run II (CERN, 29/11/2016)

    CERN Document Server

    Metral, Elias; Biancacci, Nicolo; Buffat, Xavier; Carver, Lee Robert; Iadarola, Giovanni; Li, Kevin Shing Bruce; Persson, Tobias Hakan Bjorn; Romano, Annalisa; Schenk, Michael; Tambasco, Claudia; CERN. Geneva. ATS Department

    2017-01-01

    In this note the half-day internal review of LHC performance limitations (linked to transverse collective effects) during run II (2015-2016), which took place at CERN on 29/11/2016 (https://indico.cern.ch/event/589625/), is summarised and the next steps are discussed.

  20. NICADD scientists develop detector technology for International Linear Collider

    CERN Multimedia

    2006-01-01

    "Scientist at the Northern Illinois Center for Accelerator and Detector Development (NICADD) are celebrating the successful run of a prototype subdetector for the proposed International Linear Collider (ILC)." (1 page)

  1. State of hadron collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Grannis, P.D. [State Univ. of New York, Stony Brook, NY (United States)]|[Fermi National Accelerator Lab., Batavia, IL (United States)

    1993-12-01

    The 9th Topical Workshop on Proton-Antiproton Collider Physics in Tsukuba Japan demonstrated clearly the enormous breadth of physics accessible in hadron cowders. Although no significant chinks were reported in the armor of the Standard Model, new results presented in this meeting have expanded our knowledge of the electroweak and strong interactions and have extended the searches for non-standard phenomena significantly. Much of the new data reported came from the CDF and D0 experiments at the Fermilab cowder. Superb operation of the Tevatron during the 1992-1993 Run and significant advances on the detector fronts -- in particular, the emergence of the new D0 detector as a productive physics instrument in its first outing and the addition of the CDF silicon vertex detector -- enabled much of this advance. It is noteworthy however that physics from the CERN collider experiments UA1 and UA4 continued to make a large impact at this meeting. In addition, very interesting summary talks were given on new results from HERA, cosmic ray experiments, on super-hadron collider physics, and on e{sup +}e{sup {minus}} experiments at LEP and TRISTAN. These summaries are reported in elsewhere in this volume.

  2. Study of the heavy flavour fractions in z+jets events from $p\\bar{p}$ collisions at energy √s = 1.96 TeV with the CDF II detector at the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Mastrandrea, Paolo [Univ. of Siena (Italy)

    2008-06-01

    to provide collisions for the experiments at the end of 2008. In the meanwhile the only running accelerator able to provide collisions suitable for the search of the Higgs boson is the Tevatron at Fermilab, a proton-antiproton collider with a center of mass energy of 1.96 TeV working at 3 • 1032cm-2s-1 peak luminosity. These features make the Tevatron able for the direct search of the Higgs boson in the 115-200 GeV mass range. Since the coupling of the Higgs boson is proportional to the masses of the particles involved, the decay in b{bar b} has the largest branching ratio for Higgs mass < 135 GeV and thus the events Z/W + $b\\bar{b}$ are the main background to the Higgs signal in the most range favored by Standard Model fits. In this thesis a new technique to identify Heavy Flavour quarks inside high - PT jets is applied to events with a reconstructed Z boson to provide a measurement of the Z+b and Z+c inclusive cross sections. The study of these channels represent also a test of QCD in high transferred momentum regime, and can provide information on proton pdf. This new Heavy Flavour identication technique (tagger) provides an increased statistical separation between b, c and light flavours, using a new vertexing algorithm and a chain of artificial Neural Networks to exploit as much information as possible in each event. For this work I collaborated with the Universita di Roma 'La Sapienza' group working in the CDF II experiment at Tevatron, that has at first developed this tagger. After a brief theoretical introduction (chapter 1) and a description of the experimental apparatus (chapter 2), the tagger itself and its calibration procedure are described in chapter 3 and 4. The chapter 5 is dedicated to the event selection and the chapter 6 contains the results of the measurement and the study of the systematic errors.

  3. Muon Collider Design

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Pisin

    2003-06-02

    Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. Parameters are given of 4 TeV and 0.5 TeV high luminosity {mu}{sup +}{mu}{sup -} colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are discussed.

  4. Running Away

    Science.gov (United States)

    ... Dieting OK for Kids? Your Teeth Heart Murmurs Running Away KidsHealth > For Kids > Running Away Print A ... life on the streets. continue The Reality of Running Away When you think about running away, you ...

  5. When Moons Collide

    Science.gov (United States)

    Rufu, Raluca; Aharonson, Oded

    2017-10-01

    Impacts between two orbiting satellites is a natural consequence of Moon formation. Mergers between moonlets are especially important for the newly proposed multiple-impact hypothesis as these moonlets formed from different debris disks merge together to form the final Moon. However, this process is relevant also for the canonical giant impact, as previous work shows that multiple moonlets are formed from the same debris disk.The dynamics of impacts between two orbiting bodies is substantially different from previously heavily studied planetary-sized impacts. Firstly, the impact velocities are smaller and limited to, thus heating is limited. Secondly, both fragments have similar mass therefore, they would contribute similarly and substantially to the final satellite. Thirdly, this process can be more erosive than planetary impacts as the velocity of ejected material required to reach the mutual Hill sphere is smaller than the escape velocity, altering the merger efficiency. Previous simulations show that moonlets inherit different isotopic signatures from their primordial debris disk, depending on the parameters of the collision with the planet. We therefore, evaluate the degree of mixing in moonlet-moonlet collisions in the presence of a planetary gravitational field, using Smooth Particle Hydrodynamics (SPH). Preliminary results show that the initial thermal state of the colliding moonlets has only a minor influence on the amount of mixing, compared to the effects of velocity and impact angle over their likely ranges. For equal mass bodies in accretionary collisions, impact angular momentum enhances mixing. In the hit-and-run regime, only small amounts of material are transferred between the bodies therefore mixing is limited. Overall, these impacts can impart enough energy to melt ~15-30% of the mantle extending the magma ocean phase of the final Moon.

  6. Higgs Sector of Non-minimal Supersymmetric Models at Future Hadron Colliders

    CERN Document Server

    Hugonie, Cyril

    2001-01-01

    We investigate the potential of current and planned hadron colliders operating at the TeV scale in disentangling the structure of the Higgs sector of non-minimal Supersymmetric extensions of the Standard Model with an extra gauge singlet. We assume universality of the soft Supersymmetry breaking terms at the GUT scale as well as a CP-even Higgs boson with mass around 115 GeV, as suggested by LEP. We find that mixing angles between the doublet and singlet Higgs states are always small. However, concrete prospects exist at both the Tevatron (Run II) and the Large Hadron Collider of detecting at least one neutral Higgs state with a dominant singlet component, in addition to those available from a doublet Higgs sector which is similar to the one of the Minimal Supersymmetric Standard Model.

  7. Extra dimensions at particle colliders

    Energy Technology Data Exchange (ETDEWEB)

    Dvergsnes, Erik Wolden

    2004-08-01

    This thesis consists of an introduction where we consider different aspects of theories involving extra dimensions, together with four research publications (Papers I-IV) attached at the end. The introductional chapters should serve as background material for better understanding the models on which the articles are based. In Chap. 4 we also present some plots not included in the papers. The topic of Papers I-III is graviton induced Bremsstrahlung. In Paper I we consider the contribution to this process from graviton exchange through gluon-gluon fusion at the LHC, compared to the QED background. Only final-state radiation is considered in Paper I, whereas in Paper II we extend this work to include also the quark-antiquark annihilation with graviton exchange, as well as initial-state radiation for both graviton and Standard Model exchange. Paper III is a study of graviton-induced Bremsstrahlung at e{sup +}e{sup -} colliders, including both initial- and final-state radiation. Paper IV is devoted to a study of the center-edge asymmetry at hadron colliders, an asymmetry which previously had been studied for e{sup +}e{sup -} colliders. The center-edge asymmetry can be used as a method of distinguishing between spin-1 and spin-2 exchange, something which will be of major importance if a signal is observed.

  8. Setup and performance of RHIC for the 2008 run with deuteron-gold collisions.

    Energy Technology Data Exchange (ETDEWEB)

    Gardner,C.; Abreu, N.P.; Ahren, L.; Alessi, J.; Bai, M.; et al.

    2008-06-23

    This year (2008) deuterons and gold ions were collided in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) for the first time since 2003. The setup and performance of the collider for the 2008 run is reviewed with a focus on improvements that have led to an order of magnitude increase in luminosity over that achieved in the 2003 run.

  9. Towards future circular colliders

    Science.gov (United States)

    Benedikt, Michael; Zimmermann, Frank

    2016-09-01

    The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) presently provides proton-proton collisions at a center-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics program will extend through the second half of the 2030's. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ˜100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCCee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3 S n superconductor, for the FCC-hh hadron collider, and a highly-efficient superconducting radiofrequency system for the FCC-ee lepton collider. Following the FCC concept, the Institute of High Energy Physics (IHEP) in Beijing has initiated a parallel design study for an e + e - Higgs factory in China (CEPC), which is to be succeeded by a high-energy hadron collider (SPPC). At present a tunnel circumference of 54 km and a hadron collider c.m. energy of about 70 TeV are being considered. After a brief look at the LHC, this article reports the motivation and the present status of the FCC study, some of the primary design challenges and R&D subjects, as well as the emerging global collaboration.

  10. Combined search for the standard model Higgs boson decaying to bb using the D0 run II data set.

    Science.gov (United States)

    Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Askew, A; Atkins, S; Augsten, K; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Bartlett, J F; Bassler, U; Bazterra, V; Bean, A; Begalli, M; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Bross, A; Brown, D; Brown, J; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Buszello, C P; Camacho-Pérez, E; Casey, B C K; Castilla-Valdez, H; Caughron, S; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chapon, E; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Das, A; Davies, G; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; Devaughan, K; Diehl, H T; Diesburg, M; Ding, P F; Dominguez, A; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Feng, L; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garcia-Bellido, A; García-González, J A; García-Guerra, G A; Gavrilov, V; Gay, P; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Gutierrez, G; Gutierrez, P; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hogan, J; Hohlfeld, M; Howley, I; Hubacek, Z; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jayasinghe, A; Jeong, M S; Jesik, R; Jiang, P; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kiselevich, I; Kohli, J M; Kozelov, A V; Kraus, J; Kulikov, S; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, H; Liu, Y; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Nguyen, H T; Nunnemann, T; Orduna, J; Osman, N; Osta, J; Padilla, M; Pal, A; Parashar, N; Parihar, V; Park, S K; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Salcido, P; Sánchez-Hernández, A; Sanders, M P; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shaw, S; Shchukin, A A; Shivpuri, R K; Simak, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stoyanova, D A; Strauss, M; Suter, L; Svoisky, P; Takahashi, M; Titov, M; Tokmenin, V V; Tsai, Y-T; Tschann-Grimm, K; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Verkheev, A Y; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Wang, R-J; Warchol, J; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yamada, R; Yang, S; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J M; Zennamo, J; Zhao, T; Zhao, T G; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2012-09-21

    We present the results of the combination of searches for the standard model Higgs boson produced in association with a W or Z boson and decaying into bb using the data sample collected with the D0 detector in pp collisions at √s = 1.96 TeV at the Fermilab Tevatron Collider. We derive 95% C.L. upper limits on the Higgs boson cross section relative to the standard model prediction in the mass range 100 GeV ≤ M(H) ≤ 150 GeV, and we exclude Higgs bosons with masses smaller than 102 GeV at the 95% C.L. In the mass range 120 GeV ≤ M(H) ≤145 GeV, the data exhibit an excess above the background prediction with a global significance of 1.5 standard deviations, consistent with the expectation in the presence of a standard model Higgs boson.

  11. CERN to start Large Hadron Collider november 2007

    CERN Multimedia

    2006-01-01

    "The Large Hadron Collider (LHC) is expected to provide its first collisions in November 2007, CERN has announced. A two-month run at 0.9 TeV is planned for 2007 to test the accelerating and detecting equipment, and a full power run at 14 TeV is expected in the spring of 2008."

  12. Resonant production of sleptons in the run I of the DO experiment and identification of electrons in the run II; Recherche de production resonante de sleptons au Run I de D zero et identification et mesure des electrons au Run 2

    Energy Technology Data Exchange (ETDEWEB)

    Abdesselam, A

    2001-10-01

    This work deals with the resonant production of supersymmetric particles smuons and muon sneutrinos. The theoretical framework of this study rests on the model mSUGRA in which 5 parameters are considered: m{sub 0}, m{sub 1/2}, tan({beta}), A{sub 0}, sign({mu}) and one parameter for the violation of the R-parity. 2 analysis methods have been used: the traditional sequential analysis and the neuron network analysis that begins to be largely used in particle physics. This work is based on the experimental data collected during the run I of the experiment DO at the Tevatron (Fermilab, Usa). The value of luminosity is 94 pb{sup -1}. The general result is that no more events were detected than predicted by the standard model, so these results can be interpreted as a mean to draw limits for the values of the parameters. For instance values up to 230 GeV and 260 GeV are excluded for m{sub 0} and m{sub 1/2} respectively if the coupling constant {lambda}{sub 211} is worth 0.09, tan({beta}) = 2, sign({mu}) =-1 and A{sub 0} = 0. The interpretation can be made in terms of mass and the study shows that relative masses for {nu}-tilde{sub {mu}} and {chi}{sup 0}{sub 1} of 280 GeV and 112 GeV respectively are excluded with a 95% probability. Another part of this work deals with the identification of electron in the run II, different tools can be used, here the author chose the covariance matrix ( H matrix). (A.C.)

  13. Characterising the Decays of High-pt Top Quarks and Addressing Naturalness with Jet Substructure in ATLAS Runs I and II

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00397460

    The coupling of the Standard Model top quark to the Higgs boson is O(1), which leads to large quantum corrections in the perturbative expansion of the Higgs boson mass. Possible solutions to this so-called naturalness problem include supersymmetric models with gluinos and stop squarks whose masses are at the electroweak scale, O(1 TeV). If supersymmetry is realised in nature at this scale, these particles are expected to be accessible with the Large Hadron Collider at CERN. A search for gluino pair production with decays mediated by stop- and sbottom-squark loops in the initial 14.8 ifb of the ATLAS run 2 dataset is presented in terms of a pair of simplified models, which targets extreme regions of phase space using jet substructure techniques. No excess is observed and limits are set which greatly extend the previous exclusion region of this search, up to 1.9 TeV (1.95 TeV) for gluinos decaying through light stop (sbottom) squarks to the lightest neutralinos. A performance study of top tagging algorithms in ...

  14. Muon collider progress

    Energy Technology Data Exchange (ETDEWEB)

    Noble, Robert J. FNAL

    1998-08-01

    Recent progress in the study of muon colliders is presented. An international collaboration consisting of over 100 individuals is involved in calculations and experiments to demonstrate the feasibility of this new type of lepton collider. Theoretical efforts are now concentrated on low-energy colliders in the 100 to 500 GeV center-of-mass energy range. Credible machine designs are emerging for much of a hypothetical complex from proton source to the final collider. Ionization cooling has been the most difficult part of the concept, and more powerful simulation tools are now in place to develop workable schemes. A collaboration proposal for a muon cooling experiment has been presented to the Fermilab Physics Advisory Committee, and a proposal for a targetry and pion collection channel experiment at Brookhaven National Laboratory is in preparation. Initial proton bunching and space-charge compensation experiments at existing hadron facilities have occurred to demonstrate proton driver feasibility.

  15. Majorana Higgses at colliders

    National Research Council Canada - National Science Library

    Nemevšek, Miha; Nesti, Fabrizio; Vasquez, Juan Carlos

    2017-01-01

    Collider signals of heavy Majorana neutrino mass origin are studied in the minimal Left-Right symmetric model, where their mass is generated spontaneously together with the breaking of lepton number...

  16. Linear collider: a preview

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, H.

    1981-11-01

    Since no linear colliders have been built yet it is difficult to know at what energy the linear cost scaling of linear colliders drops below the quadratic scaling of storage rings. There is, however, no doubt that a linear collider facility for a center of mass energy above say 500 GeV is significantly cheaper than an equivalent storage ring. In order to make the linear collider principle feasible at very high energies a number of problems have to be solved. There are two kinds of problems: one which is related to the feasibility of the principle and the other kind of problems is associated with minimizing the cost of constructing and operating such a facility. This lecture series describes the problems and possible solutions. Since the real test of a principle requires the construction of a prototype I will in the last chapter describe the SLC project at the Stanford Linear Accelerator Center.

  17. Tutorial on Linear Colliders

    CERN Document Server

    Zimmermann, Frank

    2001-01-01

    Proceeding from the collision point towards the source, we discuss purpose and design concepts of the various linear-collider subsystems, as well as important mechanisms of emittance dilution, beam diagnostics, and advanced tuning methods. In particular, we address beamstrahlung, linac emittance degradation due to dispersion and wake fields, scaling of damping-ring parameters with collider energy, fast beam-ion and electron-cloud instabilities, coherent synchrotron radiation, and rf guns. Five case studies are examined in detail.

  18. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The internat...

  19. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The interna...

  20. Towards Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...

  1. Forward Tracking with the silicon vertex detector at the CDF experiment in RUN II. Spurrekonstruktion in Vorwärtsrichtung mit dem Silizium-Vertexdetektor des CDF-Experiments in RUN II

    Energy Technology Data Exchange (ETDEWEB)

    Scheidle, Thorsten [Univ. of Karlsruhe (TH) (Germany)

    2007-02-01

    The Standard Model of particle physics describes the fundamental particles of matter and their interactions. In order to test the Standard Model, determine free parameters and search for new particles beyond the Standard Model, large accelerator complexes produce particle collisions which are recorded by large detectors. Until the start of the Large Hadron Collider at CERN, the Tevatron accelerator at Fermilab provides particle collisions with the highest center-of-mass energy of √s = 1.96 TeV. The two multipurpose detector systems CDF and DØ record the collisions. A multipurpose detector system is built of several specialized sub-detectors to measure different particle properties. A particle which passes the detector deposits energy by interacting with the detector material. A silicon strip detector and a wire drift chamber detect charged particles close to the collision point. The energy loss in these systems is relatively small, instead many different small energy depositions are produced by one passing particle. These so-called hits can be combined to a track, indicating the path of the particle. A homogeneous magnetic field surrounding the tracking system forces a charged particle to a helix path which allows a momentum measurement by measuring the curvature. The reconstruction of particle tracks is a non-trivial task. First all position measurements belonging to a particle along a hypothetical helix have to be found and then all position information has to be combined to a reconstructed track and its parameters. I focused my work on the track reconstruction in the silicon detector which provides a good position resolution of the measurements.

  2. Collide@CERN: sharing inspiration

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    Late last year, Julius von Bismarck was appointed to be CERN's first "artist in residence" after winning the Collide@CERN Digital Arts award. He’ll be spending two months at CERN starting this March but, to get a flavour of what’s in store, he visited the Organization last week for a crash course in its inspiring activities.   Julius von Bismarck, taking a closer look... When we arrive to interview German artist Julius von Bismarck, he’s being given a presentation about antiprotons’ ability to kill cancer cells. The whiteboard in the room contains graphs and equations that might easily send a non-scientist running, yet as Julius puts it, “if I weren’t interested, I’d be asleep”. Given his numerous questions, he must have been fascinated. “This ‘introduction’ week has been exhilarating,” says Julius. “I’ve been able to interact ...

  3. Optical Isolation of Scintillating Tiles Using TiO{subscript 2} Doped Epoxy for the D-Zero ICD in Run II

    Energy Technology Data Exchange (ETDEWEB)

    Elizabeth Gallas

    1999-02-16

    A Run II D0 Inter Cryostat Detector tile array will be composed of 16 identical modules. Each module contains 12 optically isolated scintillating tile elements, each with dimension of 0.1 x 0.1 in {eta} and {phi} in the pseudora-pidity region from 1.1 to 1.4. The 12 tiles in a module are formed by routing grooves in a single piece of scintillator - optical isolation is achieved by fill-ing the grooves with a white re ective epoxy. The procedure for filling these isolation grooves is described here.

  4. GRID Computing at Belle II

    CERN Document Server

    Bansal, Vikas

    2015-01-01

    The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, will start physics data taking in 2018 and will accumulate 50 ab$^{-1}$ of e$^{+}$e$^{-}$ collision data, about 50 times larger than the data set of the earlier Belle experiment. The computing requirements of Belle II are comparable to those of a run I high-p$_T$ LHC experiment. Computing will make full use of such grids in North America, Asia, Europe, and Australia, and high speed networking. Results of an initial MC simulation campaign with 3 ab$^{-1}$ equivalent luminosity will be described

  5. Photon-photon colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, A.M.

    1995-04-01

    Since the seminal work by Ginsburg, et at., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention. A 1990 article by V.I. Teinov describes the situation at that time. In March 1994, the first workshop on this subject was held. This report briefly reviews the physics that can be achieved through the photon-photon channel and then focuses on the means of achieving such a collider. Also reviewed is the spectrum of backscattered Compton photons -- the best way of obtaining photons. We emphasize the spectrum actually obtained in a collider with both polarized electrons and photons (peaked at high energy and very different from a Compton spectrum). Luminosity is estimated for the presently considered colliders, and interaction and conversion-point geometries are described. Also specified are laser requirements (such as wavelength, peak power, and average power) and the lasers that might be employed. These include conventional and free-electron lasers. Finally, we describe the R&D necessary to make either of these approaches viable and explore the use of the SLC as a test bed for a photon-photon collider of very high energy.

  6. Search for Excited or Exotic Electron Production Using the Dielectron + Photon Signature at CDF in Run II

    Energy Technology Data Exchange (ETDEWEB)

    Gerberich, Heather Kay [Duke Univ., Durham, NC (United States)

    2004-01-01

    The author presents a search for excited or exotic electrons decaying to an electron and a photon with high transverse momentum. An oppositely charged electron is produced in association with the excited electron, yielding a final state dielectron + photon signature. The discovery of excited electrons would be a first indication of lepton compositeness. They use ~ 202 pb-1 of data collected in p$\\bar{p}$ collisions at √s = 1.96 TeV with the Collider Detector at Fermilab during March 2001 through September 2003. The data are consistent with standard model expectations. Upper limits are set on the experimental cross-section σ($\\bar{p}$p → ee* → eeγ) at the 95% confidence level in a contact-interaction model and a gauge-mediated interaction model. Limits are also presented as exclusion regions in the parameter space of the excited electron mass (Me*) and the compositeness energy scale (Λ). In the contact-interaction model, for which there are no previously published limits, they find Me* < 906 GeV is excluded for Me* = Λ. In the gauge-mediated model, the exclusion region in the Me* versus the phenomenological coupling f/Λ parameter space is extended to M{sub e*} < 430 GeV for f/Λ ~ 10-2 GeV-1. In comparison, other experiments have excluded Me* < 280 GeV for f/Λ ~ 10-2 GeV-1.

  7. Determination of the effective inelastic p anti-p cross-section for the D0 Run II luminosity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.; /Manchester U.; Yacoob, S.; Andeen, T.; /Northwestern U.; Begel, M.; /Rochester U.; Casey, B.C.K.; Partridge, R.; /Brown U.; Schellman, H.; /Northwestern U.; Sznajder, A.; /Rio de Janeiro State U.

    2004-11-01

    The authors determine the effective inelastic p{bar p} cross-section into the D0 Luminosity Monitor for all run periods prior to September 2004. This number is used to relate the measured inelastic collision rate to the delivered luminosity. The key ingredients are the inelastic p{bar p} cross-section, the Luminosity Monitor efficiency, and the modeling of kinematic distributions for various inelastic processes used to determine the detector acceptance. The resulting value is {sigma}{sub p{bar p},eff} = 46 {+-} 3 mb.

  8. Search for Supersymmetry using rare B$0\\atop{s(d)}$ → μ+μ- decays at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Krutelyov, Vyacheslav E. [Texas A & M Univ., College Station, TX (United States)

    2005-12-01

    A search for rare B$0\\atop{s}$ → μ+μ- and B$0\\atop{d}$ → μ+μ- decays has been performed in pp collisions at √s = 1.96 TeV using 364 pb-1 of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The rate of each decay is sensitive to contributions from physics beyond the Standard Model (SM). No events pass the optimized selection requirements, consistent with the SM expectation. The resulting upper limits on the branching ratios are B(B$0\\atop{s}$ → μ+μ-) < 1.5 × 10-7 and B(B$0\\atop{d}$ → μ+μ-) < 3.8 × 10-8 at the 90% confidence level. The limits are used to exclude some parameter space for several supersymmetric models.

  9. The Large Hadron Collider

    CERN Document Server

    Evans, Lyndon

    2012-01-01

    The construction of the Large Hadron Collider (LHC) has been a massive endeavour spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing large electron–positron (LEP) collider tunnel of 27 km circumference and with a tunnel diameter of only 3.8 m has required considerable innovation. The first was the development of a two-in-one magnet, where the two rings are integrated into a single magnetic structure. This compact two-in-one structure was essential for the LHC owing to the limited space available in the existing LEP collider tunnel and the cost. The second was a bold move to the use of superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor.

  10. The Large Hadron Collider.

    Science.gov (United States)

    Evans, Lyndon

    2012-02-28

    The construction of the Large Hadron Collider (LHC) has been a massive endeavour spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing large electron-positron (LEP) collider tunnel of 27 km circumference and with a tunnel diameter of only 3.8 m has required considerable innovation. The first was the development of a two-in-one magnet, where the two rings are integrated into a single magnetic structure. This compact two-in-one structure was essential for the LHC owing to the limited space available in the existing LEP collider tunnel and the cost. The second was a bold move to the use of superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor.

  11. On extracting design principles from biology: II. Case study-the effect of knee direction on bipedal robot running efficiency.

    Science.gov (United States)

    Haberland, M; Kim, S

    2015-02-02

    Comparing the leg of an ostrich to that of a human suggests an important question to legged robot designers: should a robot's leg joint bend in the direction of running ('forwards') or opposite ('backwards')? Biological studies cannot answer this question for engineers due to significant differences between the biological and engineering domains. Instead, we investigated the inherent effect of joint bending direction on bipedal robot running efficiency by comparing energetically optimal gaits of a wide variety of robot designs sampled at random from a design space. We found that the great majority of robot designs have several locally optimal gaits with the knee bending backwards that are more efficient than the most efficient gait with the knee bending forwards. The most efficient backwards gaits do not exhibit lower touchdown losses than the most efficient forward gaits; rather, the improved efficiency of backwards gaits stems from lower torque and reduced motion at the hip. The reduced hip use of backwards gaits is enabled by the ability of the backwards knee, acting alone, to (1) propel the robot upwards and forwards simultaneously and (2) lift and protract the foot simultaneously. In the absence of other information, designers interested in building efficient bipedal robots with two-segment legs driven by electric motors should design the knee to bend backwards rather than forwards. Compared to common practices for choosing robot knee direction, application of this principle would have a strong tendency to improve robot efficiency and save design resources.

  12. The Pixel Detector of the ATLAS experiment for the Run2 at the Large Hadron Collider -- Plot Approval (Pixel, IBL) : This is a submission of plot approval request for Pixel+IBL, facing on a talk at ICHEP 2014 conference

    CERN Document Server

    Mandelli, B; The ATLAS collaboration

    2014-01-01

    The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long showdown, the 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). IBL is a fourth layer of pixel detectors, and will be installed in May 2014 between the existing Pixel Detector and a new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy due to the proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed. Furthermore, the physics performance will be improved through the reduction of pixel size while, targeting for a low material budget, a new mechanical support using lightweight staves and a CO2 based cooling system have been adopted. IBL construction is now completed. An overview of the IBL project as well as the ...

  13. Collide@CERN Geneva

    CERN Multimedia

    CERN. Geneva; Kieffer, Robert; Blas Temino, Diego; Bertolucci, Sergio; Mr. Decelière, Rudy; Mr. Hänni, Vincent

    2014-01-01

    CERN, the Republic and Canton of Geneva, and the City of Geneva are delighted to invite you to “Collide@CERN Geneva Music”. Come to the public lecture about collisions between music and particle physics by the third winners of Collide@CERN Geneva, Vincent Hänni & Rudy Decelière, and their scientific inspiration partners, Diego Blas and Robert Kieffer. The event marks the beginning of their residency at CERN, and will be held at the CERN Globe of Science and Innovation on 16 October 2014 at 19.00. Doors will open at 18.30.

  14. The Large Hadron Collider

    CERN Multimedia

    't Hooft, Gerardus; Llewellyn Smith, Christopher Hubert; Brüning, Oliver Sim; Collier, Paul; Stapnes, Steinar; Ellis, Jonathan Richard; Braun-Munzinger, Peter; Stachel, Johanna; Lederman, Leon Max

    2007-01-01

    Several articles about the LHC: The Making of the standard model; high-energy colliders and the rise of the standard model; How the LHC came to be; Building a behemoth; Detector challenges at the LHC; Beyond the standard model with the LHC; The quest for the quark-gluon plasma; The God particle et al. (42 pages

  15. The Large Hadron Collider

    CERN Multimedia

    Wright, Alison

    2007-01-01

    "We are on the threshold of a new era in particle-physics research. In 2008, the Large Hadron Collider (LHC) - the hightest-energy accelerator ever built - will come into operation at CERN, the European labortory that straddles the French-Swiss border near Geneva." (1/2 page)

  16. Hadron collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Pondrom, L.

    1991-10-03

    An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.

  17. Tevatron's complex collider cousins

    CERN Multimedia

    Fischer, W

    2004-01-01

    Letter referring to Schwarzschild's story "Disappointing performance and tight budgets confront Fermilab with tough decisions" and contesting that the Tevatron is not the most complex accelerator operating. They use the examples of CERN's SPS collider, HERA at DESY and the RHIC at Brookhaven (1/4 page)

  18. Large Hadron Collider

    CERN Multimedia

    2007-01-01

    "In the spring 2008, the Large Hadron Collider (LHC) machine at CERN (the European Particle Physics laboratory) will be switched on for the first time. The huge machine is housed in a circular tunnel, 27 km long, excavated deep under the French-Swiss border near Geneva." (1,5 page)

  19. Why Large Hadron Collider?

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... ... I discuss the high energy colliders leading up to LHC and their role in the discovery of these SM particles. Then I discuss the two main physics issues of LHC, i.e. Higgs mechanism and supersymmetry. I briefly touch upon Higgs and SUSY searches at LHC along with their cosmological implications.

  20. When stars collide

    NARCIS (Netherlands)

    Glebbeek, E.; Pols, O.R.

    2007-01-01

    When two stars collide and merge they form a new star that can stand out against the background population in a star cluster as a blue straggler. In so called collision runaways many stars can merge and may form a very massive star that eventually forms an intermediate mass blackhole. We have

  1. arXiv Proceedings of the Sixth International Workshop on Multiple Partonic Interactions at the Large Hadron Collider

    CERN Document Server

    Astalos, R.; Bartalini, P.; Belyaev, I.; Bierlich, Ch.; Blok, B.; Buckley, A.; Ceccopieri, F.A.; Cherednikov, I.; Christiansen, J.R.; Ciangottini, D.; Deak, M.; Ducloue, B.; Field, R.; Gaunt, J.R.; Golec-Biernat, K.; Goerlich, L.; Grebenyuk, A.; Gueta, O.; Gunnellini, P.; Helenius, I.; Jung, H.; Kar, D.; Kepka, O.; Klusek-Gawenda, M.; Knutsson, A.; Kotko, P.; Krasny, M.W.; Kutak, K.; Lewandowska, E.; Lykasov, G.; Maciula, R.; Moraes, A.M.; Martin, T.; Mitsuka, G.; Motyka, L.; Myska, M.; Otwinowski, J.; Pierog, T.; Pleskot, V.; Rinaldi, M.; Schafer, W.; Siodmok, A.; Sjostrand, T.; Snigirev, A.; Stasto, A.; Staszewski, R.; Stebel, T.; Strikman, M.; Szczurek, A.; Treleani, D.; Trzebinski, M.; van Haevermaet, H.; van Hameren, A.; van Mechelen, P.; Waalewijn, W.; Wang, W.Y.; MPI@LHC 2014

    2014-01-01

    Multiple Partonic Interactions are often crucial for interpreting results obtained at the Large Hadron Collider (LHC). The quest for a sound understanding of the dynamics behind MPI - particularly at this time when the LHC is due to start its "Run II" operations - has focused the aim of this workshop. MPI@LHC2014 concentrated mainly on the phenomenology of LHC measurements whilst keeping in perspective those results obtained at previous hadron colliders. The workshop has also debated some of the state-of-the-art theoretical considerations and the modeling of MPI in Monte Carlo event generators. The topics debated in the workshop included: Phenomenology of MPI processes and multiparton distributions; Considerations for the description of MPI in Quantum Chromodynamics (QCD); Measuring multiple partonic interactions; Experimental results on inelastic hadronic collisions: underlying event, minimum bias, forward energy flow; Monte Carlo generator development and tuning; Connections with low-x phenomena, diffractio...

  2. Study of Beam-Beam Effects at PEP-II

    Energy Technology Data Exchange (ETDEWEB)

    Narsky, I

    2004-06-29

    Using a self-consistent three-dimensional simulation running on parallel supercomputers, we have modeled the beam-beam interaction at the PEP-II asymmetric e{sup +}e{sup -}collider. To provide guidance for luminosity improvement, we scanned the tunes and currents in both rings and computed their impact on the luminosity and transverse beam sizes. We also studied the effects of colliding the beams with a small crossing angle. Where possible, the code was benchmarked against experimental measurements of luminosity and beam sizes, yielding an acceptable agreement.

  3. Measurement of the Top Quark Mass at D0 Run II with the Matrix Element Method in the Lepton+Jets Final State

    Energy Technology Data Exchange (ETDEWEB)

    Schieferdecker, Philipp [Ludwig Maximilian Univ. of Munich (Germany)

    2005-08-05

    The mass of the top quark is a fundamental parameter of the Standard Model. Its precise knowledge yields valuable insights into unresolved phenomena in and beyond the Standard Model. A measurement of the top quark mass with the matrix element method in the lepton+jets final state in D0 Run II is presented. Events are selected requiring an isolated energetic charged lepton (electron or muon), significant missing transverse energy, and exactly four calorimeter jets. For each event, the probabilities to originate from the signal and background processes are calculated based on the measured kinematics, the object resolutions and the respective matrix elements. The jet energy scale is known to be the dominant source of systematic uncertainty. The reference scale for the mass measurement is derived from Monte Carlo events. The matrix element likelihood is defined as a function of both, m{sub top} and jet energy scale JES, where the latter represents a scale factor with respect to the reference scale. The top mass is obtained from a two-dimensional correlated fit, and the likelihood yields both the statistical and jet energy scale uncertainty. Using a dataset of 320 pb-1 of D0 Run II data, the mass of the top quark is measured to be: m$ℓ+jets\\atop{top}$ = 169.5 ± 4.4(stat. + JES)$+1.7\\atop{-1.6}$(syst.) GeV; m$e+jets\\atop{top}$ = 168.8 ± 6.0(stat. + JES)$+1.9\\atop{-1.9}$(syst.) GeV; m$μ+jets\\atop{top}$ = 172.3 ± 9.6(stat.+JES)$+3.4\\atop{-3.3}$(syst.) GeV. The jet energy scale measurement in the ℓ+jets sample yields JES = 1.034 ± 0.034, suggesting good consistency of the data with the simulation. The measurement forecasts significant improvements to the total top mass uncertainty during Run II before the startup of the LHC, as the data sample will grow by a factor of ten and D0's tracking capabilities will be employed in jet energy reconstruction and flavor identification.

  4. From the LHC to Future Colliders CERN Theory Institute Summary Report

    CERN Document Server

    de Roeck, A; Grojean, C; Heinemeyer, S; Jakobs, K; Weiglein, G; Wells, J; Azuelos, Georges; Dawson, S; Gripaios, B; Han, T; Hewett, J; Lancaster, M; Mariotti, C; Moortgat, F; Moortgat-Pick, G; Polesello, G; Riemann, S; Schumacher, M; Assamagan, K; Bechtle, P; Carena, M S; Chachamis, G; Chen, K F; De Curtis, S; Desch, K; Dittmar, M; Dreiner, H; Dührssen, M; Frandsen, M T; Giammanco, A; Godbole, R; Govoni, P; Gunion, J F; Hollik, W; Hou, W S; Isidori, G; Juste, A; Kalinowski, J; Korytov, A; Kou, E; Kraml, S; Krawczyk, M; Martin, A; Milstead, D; Morton-Thurtle, V; Mönig, K; Melé, B; Pieri, M; Plehn, T; Reina, L; Richter-Was, E; Rizzo, T; Rolbiecki, K; Sannino, F; Schram, M; Smillie, J; Sultansoy, S; Uwer, P

    2010-01-01

    Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300/fb of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10/fb of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, the Working Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discover...

  5. Search for Third Generation Squarks in the Missing Transverse Energy plus Jet Sample at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Marono, Miguel Vidal [Complutense Univ. of Madrid (Spain)

    2010-03-01

    lightest SUSY particle (LSP) which would provide a candidate for cold dark matter, that account for 23% of the universe content, as strongly suggested by recent astrophysical data [1]. The Tevatron is a hadron collider operating at Fermilab, USA. This accelerator provides proton-antiproton (p$\\bar{p}$) collisions with a center of mass energy of √s = 1.96 TeV. CDF and D0 are the detectors built to analyse the products of the collisions provided by the Tevatron. Both experiments have produced a very significant scientific output in the last few years, like the discovery of the top quark or the measurement of the Bs mixing. The Tevatron experiments are also reaching sensitivity to the SM Higgs boson. The scientific program of CDF includes a broad spectrum on searches for physics signatures beyond the Standard Model. Tevatron is still the energy frontier, what means an unique opportunity to produce a discovery in physic beyond the Standard Model. The analyses presented in this thesis focus on the search for third generation squarks in the missing transverse energy plus jets final state. The production of sbottom ($\\tilde{b}$) and stop ($\\tilde{t}$) quarks could be highly enhanced at the Tevatron, giving the possibility of discovering new physics or limiting the parameter space available in the theory. No signal is found over the predicted Standard Model background in both searches. Instead, 95% confidence level limits are set on the production cross section, and then translated into the mass plane of the hypothetical particles. This thesis sketches the basic theory concepts of the Standard Model and the Minimal Supersymmetric Extension in Chapter 2. Chapter 3, describes the Tevatron and CDF. Based on the CDF subsystems information, Chapter 4 and 5 describe the analysis objet reconstruction and the heavy flavor tagging tools. The development of the analyses is shown in Chapter 6 and Chapter 7. Finally, Chapter 8 is devoted to discuss the results and conclusions

  6. Measurement of the top-quark mass in the t t xAF dilepton channel using the full CDF Run II data set

    Science.gov (United States)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2015-08-01

    We present a measurement of the top-quark mass in events containing two leptons (electrons or muons) with a large transverse momentum, two or more energetic jets, and a transverse-momentum imbalance. We use the full proton-antiproton collision data set collected by the CDF experiment during the Fermilab Tevatron Run II at center-of-mass energy √{s }=1.96 TeV , corresponding to an integrated luminosity of 9.1 fb-1 . A special observable is exploited for an optimal reduction of the dominant systematic uncertainty, associated with the knowledge of the absolute energy of the hadronic jets. The distribution of this observable in the selected events is compared to simulated distributions of t t ¯ dilepton signal and background. We measure a value for the top-quark mass of 171.5 ±1.9 (stat)±2.5 (syst) GeV /c2 .

  7. Measuring the CP asymmetry in the decay $D^0 \\rightarrow K^0_SK^0_S$ using Run II data at LHCb.

    CERN Document Server

    Fischer, Kamil Leszek

    2017-01-01

    A sensitivity study for the measurement of $CP$ asymmetry in the decay $D^0 \\rightarrow K^0_{S}K^0_{S}$ has been performed using $pp$ collision data collected by the LHCb experiment during Run II at center-of-mass energy $\\sqrt{s} =13 \\ TeV$. The results indicate that an improvement of a factor of at least three in efficiency is necessary to achieve a world's best precision on $\\mathcal{A}_{CP}$. A proposed set of changes to the trigger selection for this channel is presented. If implemented these changes would increase the signal yield per unit of integrated luminosity by a factor of six, and therefore place LHCb in the position to perform the world's most precise measurement of $\\mathcal{A}_{CP}$($D^0 \\rightarrow K^0_{S}K^0_{S}$).

  8. Search for singly-produced vector-like quarks in lepton and jets final state with the ATLAS detector in Run-II

    Energy Technology Data Exchange (ETDEWEB)

    Biedermann, Dustin; Dietrich, Janet; Grancagnolo, Sergio; Lacker, Heiko; Sperlich, Dennis [Humboldt-Universitaet zu Berlin (Germany)

    2016-07-01

    Vector-like quarks are predicted by many extensions of the Standard Model of particle physics. They provide the possibility to solve some long-standing problems such as the hierarchy problem and also might help to explain the b-quark forward-backward asymmetry in e{sup +}e{sup -} collisions measured at LEP. Candidates for these vector-like quarks are the top-like T and the Y quark. The Y quarks decay exclusively into a W-boson and a b-quark, which appears also to be the dominant decay channel of the T quarks. We present the search strategy for singly-produced T/Y quarks and the expected sensitivity using the first LHC run-II data recorded by the ATLAS detector in 2015.

  9. Large Hadron Collider manual

    CERN Document Server

    Lavender, Gemma

    2018-01-01

    What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the world’s largest particle smasher – the Large Hadron Collider – at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerator’s greatest discoveries – from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.

  10. The International Linear Collider

    Directory of Open Access Journals (Sweden)

    List Benno

    2014-04-01

    Full Text Available The International Linear Collider (ILC is a proposed e+e− linear collider with a centre-of-mass energy of 200–500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.

  11. An Electromagnetic Sensor for the Autonomous Running of Visually Impaired and Blind Athletes (Part II: The Wearable Device).

    Science.gov (United States)

    Pieralisi, Marco; Di Mattia, Valentina; Petrini, Valerio; De Leo, Alfredo; Manfredi, Giovanni; Russo, Paola; Scalise, Lorenzo; Cerri, Graziano

    2017-02-16

    Currently, the availability of technology developed to increase the autonomy of visually impaired athletes during sports is limited. The research proposed in this paper (Part I and Part II) focuses on the realization of an electromagnetic system that can guide a blind runner along a race track without the need for a sighted guide. In general, the system is composed of a transmitting unit (widely described in Part I) and a receiving unit, whose components and main features are described in this paper. Special attention is paid to the definition of an electromagnetic model able to faithfully represent the physical mechanisms of interaction between the two units, as well as between the receiving magnetic sensor and the body of the user wearing the device. This theoretical approach allows for an estimation of the signals to be detected, and guides the design of a suitable signal processing board. This technology has been realized, patented, and tested with a blind volunteer with successful results and this paper presents interesting suggestions for further improvements.

  12. Heavy neutral MSSM Higgs bosons at the photon linear collider – a ...

    Indian Academy of Sciences (India)

    spectra for the PLC at the TESLA collider [6,7]. One-year run of PLC was as- sumed with the center-of-mass energy of the colliding electron beams optimized for the production of the pseudoscalar Higgs bosons. The distribution of the primary vertex and the beam crossing angle were taken into account. The total widths.

  13. Measurement of the s dependence of jet production at the CERN pp collider

    DEFF Research Database (Denmark)

    Appel, J.A.; Bagnaia, P.; Banner, M.

    1985-01-01

    The production of very large transverse momentum (pT) hadron jets has been measured in the UA2 experiment at the CERN pp Collider for s=630 GeV. The inclusive jet production cross sections exhibit a pT-dependent increase with respect to the s=546 GeV data from previous Collider runs. This increase...

  14. Promise of Higgs fails to save CERN collider

    CERN Document Server

    Abbott, A

    2000-01-01

    After eleven years and a three-month reprieve, the death knell for LEP has finally been sounded. Luciano Maiani, director-general of CERN, rejected requests to keep the collider running for another year, ruling it shoud be dismantled in the new year (1/2 page).

  15. String Resonances at Hadron Colliders

    CERN Document Server

    Anchordoqui, Luis A; Dai, De-Chang; Feng, Wan-Zhe; Goldberg, Haim; Huang, Xing; Lust, Dieter; Stojkovic, Dejan; Taylor, Tomasz R

    2014-01-01

    [Abridged] We consider extensions of the standard model based on open strings ending on D-branes. Assuming that the fundamental string mass scale M_s is in the TeV range and that the theory is weakly coupled, we discuss possible signals of string physics at the upcoming HL-LHC run (3000 fb^{-1}) with \\sqrt{s} = 14 TeV, and at potential future pp colliders, HE-LHC and VLHC, operating at \\sqrt{s} = 33 and 100 TeV, respectively. In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets and \\gamma + jet are completely independent of the details of compactification, and can be evaluated in a parameter-free manner. We make use of these amplitudes evaluated near the first (n=1) and second (n=2) resonant poles to determine the discovery potential for Regge excitations of the quark, the gluon, and the color singlet living on the QCD stack. We show that for string scales as large as 7.1 TeV (6.1 TeV), lowest massive Regge exc...

  16. The Big Collider

    CERN Multimedia

    Barna-Alper Productions Inc. Toronto

    2005-01-01

    The Large Hadron Collider is a gigantic particle-smasher, designed to discover the origins of the universe. Awe-inspiring in vision and scope, it’s also the most expensive physics experiment in history with a price-tag of 4 billion dollars.Documentary series "Mega builders" : a fast-paced, character-driven show that focuses on the world’s biggest and most intriguing engineering challenges – the projects that are making history, and the people who are making it happen.

  17. CASY: a dynamic simulation of the gas-cooled fast breeder reactor core auxiliary cooling system. Volume II. Example computer run

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    A listing of a CASY computer run is presented. It was initiated from a demand terminal and, therefore, contains the identification ST0952. This run also contains an INDEX listing of the subroutine UPDATE. The run includes a simulated scram transient at 30 seconds.

  18. RHIC polarized proton performance in run-8.

    Energy Technology Data Exchange (ETDEWEB)

    Montag,C.; Abreu, N.; Ahrens, L.; Bai, M.; Barton, D.; et al.

    2008-06-23

    During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8.

  19. R&D for Collider Beauty Physics at the LHC

    CERN Multimedia

    2002-01-01

    We propose an R&D program for the development of a Beauty trigger and innovative elements of the associated spectrometer. The program builds on the success of the recent S$\\bar{p}$pS collider run of the P238 Collaboration, in which clean signals from beam-beam interactions were observed in a large silicon strip microvertex detector running 1.5~mm from the circulating beams. A continuing successful R&D program of the type proposed could ultimately lead to a collider experiment at the LHC to study CP-violation and rare B decays. \\\\ \\\\ We request a fixed target run during late 1992 in order to demonstrate the effectiveness of a heavy flavour trigger which uses real time digital calculations on silicon strip data, implemented with a data driven processor.

  20. Measurement of the top-quark mass in the ${t\\bar{t}}$ dilepton channel using the full CDF Run II data set

    CERN Document Server

    Aaltonen, T; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Butti, P; Buzatu, A; Calamba, A; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Chokheli, D; Clark, A; Clarke, C; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; d'Ascenzo, N; Datta, M; de Barbaro, P; Demortier, L; Marchese, L; Deninno, M; Devoto, F; D'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dorigo, M; Driutti, A; Ebina, K; Edgar, R; Elagin, A; Erbacher, R; Errede, S; Esham, B; Farrington, S; Ramos, J P Fernández; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Frisch, H; Funakoshi, Y; Galloni, C; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; López, O González; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grosso-Pilcher, C; Group, R C; da Costa, J Guimaraes; Hahn, S R; Han, J Y; Happacher, F; Hara, K; Hare, M; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hays, C; Heinrich, J; Herndon, M; Hocker, A; Hong, Z; Hopkins, W; Hou, S; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kambeitz, M; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kurata, M; Laasanen, A T; Lammel, S; Lancaster, M; Lannon, K; Latino, G; Lee, H S; Lee, J S; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lipeles, E; Lister, A; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucà, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, P; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagliarone, C; Palencia, E; Palni, P; Papadimitriou, V; Parker, W; Pauletta, G; Paulini, M; Paus, C; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Fernández, I Redondo; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodriguez, T; Rolli, S; Ronzani, M; Roser, R; Rosner, J L; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schwarz, T; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sliwa, K; Smith, J R; Snider, F D; Sorin, V; Song, H; Stancari, M; Denis, R St; Stentz, D; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Vázquez, F; Velev, G; Vellidis, C; Vernieri, C; Vidal, M; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wallny, R; Wang, S M; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Zanetti, A M; Zeng, Y; Zhou, C; Zucchelli, S

    2015-01-01

    We present a measurement of the top-quark mass in events containing two leptons (electrons or muons) with a large transverse momentum, two or more energetic jets, and a transverse-momentum imbalance. We use the full proton-antiproton collision data set collected by the CDF experiment during the Fermilab Tevatron Run~II at center-of-mass energy $\\sqrt{s} = 1.96$ TeV, corresponding to an integrated luminosity of 9.1 fb$^{-1}$. A special observable is exploited for an optimal reduction of the dominant systematic uncertainty, associated with the knowledge of the absolute energy of the hadronic jets. The distribution of this observable in the selected events is compared to simulated distributions of ${t\\bar{t}}$ dilepton signal and background.We measure a value for the top-quark mass of $171.5\\pm 1.9~{\\rm (stat)}\\pm 2.5~{\\rm (syst)}$ GeV/$c^2$.

  1. The collider phenomenology of supersymmetric models

    Science.gov (United States)

    Muller, David J.

    Scope and method of study. The purpose of this study is to investigate the phenomenology of various supersymmetric models. First, the Minimal Supersymmetric Standard Model (MSSM) is investigated. This model contains an extended Higgs sector that includes a charged boson. The effect that this charged Higgs boson has on the signatures for top quark pair production at the Tevatron is investigated. The rest of the work is devoted to the phenomenology of models with gauge mediated supersymmetry breaking (GMSB). In GMSB models, the lighter stau can be the next to lightest supersymmetric particle. The signals at hadronic colliders for GMSB models with minimal visible sector content are explored for this case. A GMSB model with non-minimal visible sector content is also explored. This is the left-right symmetric GMSB model which contains doubly charged bosons and fermions that could be light enough in mass to be produced at Run II of the Tevatron. Findings and conclusions. The presence of a charged Higgs boson that is lighter than the top quark is found to have a significant impact on the expected signatures for top quark pair production at the Tevatron. This is marked by an overall decrease in high pT electrons and muons in the final states. In addition, for tan beta less than about one, the three-body decay H+→bbW leads to final states that are not present in the Standard Model. For GMSB models with the lighter stau as the next to lightest supersymmetric particle, the signature at the Tevatron typically involves two or three tau-jets plus large missing transverse energy. This tau-jet signature can be even more pronounced in left-right symmetric GMSB models due to the production of light doubly charged fermions that may couple preferentially to the third generation of leptons. The left-right models can be distinguished from GMSB models with minimal visible sector content by the distribution in angle between the highest ET tau-jets when they come from same sign tau

  2. FUTURE VERY HIGH LUMINOSITY OPTIONS FOR PEP-II

    Energy Technology Data Exchange (ETDEWEB)

    Seeman, J

    2004-03-08

    A Super B Factory, an asymmetric e{sup +}e{sup -} collider with a luminosity of 10{sup 36} cm{sup -2}s{sup -1}, can provide a sensitive probe of new physics in the flavor sector of the Standard Model. The success of PEP-II and KEKB in producing unprecedented luminosity with unprecedented short commissioning time has taught us about the accelerator physics of asymmetric e{sup +}e{sup -} colliders in a new parameter regime. It appears to be possible to build on this success to advance the state of the accelerator art by building a collider at a luminosity approaching 10{sup 36} cm{sup -2}s{sup -1}. Such a collider would produce an integrated luminosity up to 10,000 fb{sup -1} (10 ab{sup -1}) in a running year. Design studies are underway to arrive at a complete parameter set based on a collider in the PEP-II tunnel but with an upgraded RF system (perhaps a higher frequency) and an upgraded interaction region [1-6].

  3. Supersymmetric Higgs pair discovery prospects at hadron colliders

    CERN Document Server

    Belyaev, A; Éboli, Oscar J P; Mizukoshi, J K; Novaes, S F

    2000-01-01

    We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is emphasised. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously.

  4. The Large Hadron Collider

    Science.gov (United States)

    Evans, Lyndon

    2011-11-01

    The Large Hadron Collider (LHC) is the most complex instrument ever built for particle physics research. It will, for the first time, provide access to the TeV-energy scale. Numerous technological innovations are necessary to achieve this goal. For example, two counterrotating proton beams are guided and focused by superconducting magnets whose novel two-in-one structure saves cost and allowed the machine to be installed in an existing tunnel. The very high (>8-T) field in the dipoles can be achieved only by cooling them below the transition temperature of liquid helium to the superfluid state. More than 80 tons of superfluid helium are needed to cool the whole machine. So far, the LHC has behaved reliably and predictably. Single-bunch currents 30% above the design value have been achieved, and the luminosity has increased by five orders of magnitude. In this review, I briefly describe the design principles of the major systems and discuss some initial results.

  5. CERN balances linear collider studies

    CERN Multimedia

    ILC Newsline

    2011-01-01

    The forces behind the two most mature proposals for a next-generation collider, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) study, have been steadily coming together, with scientists from both communities sharing ideas and information across the technology divide. In a support of cooperation between the two, CERN in Switzerland, where most CLIC research takes place, recently converted the project-specific position of CLIC Study Leader to the concept-based Linear Collider Study Leader.   The scientist who now holds this position, Steinar Stapnes, is charged with making the linear collider a viable option for CERN’s future, one that could include either CLIC or the ILC. The transition to more involve the ILC must be gradual, he said, and the redefinition of his post is a good start. Though not very much involved with superconducting radiofrequency (SRF) technology, where ILC researchers have made significant advances, CERN participates in many aspect...

  6. Soviet Hadron Collider

    Science.gov (United States)

    Kotchetkov, Dmitri

    2017-01-01

    Rapid growth of the high energy physics program in the USSR during 1960s-1970s culminated with a decision to build the Accelerating and Storage Complex (UNK) to carry out fixed target and colliding beam experiments. The UNK was to have three rings. One ring was to be built with conventional magnets to accelerate protons up to the energy of 600 GeV. The other two rings were to be made from superconducting magnets, each ring was supposed to accelerate protons up to the energy of 3 TeV. The accelerating rings were to be placed in an underground tunnel with a circumference of 21 km. As a 3 x 3 TeV collider, the UNK would make proton-proton collisions with a luminosity of 4 x 1034 cm-1s-1. Institute for High Energy Physics in Protvino was a project leading institution and a site of the UNK. Accelerator and detector research and development studies were commenced in the second half of 1970s. State Committee for Utilization of Atomic Energy of the USSR approved the project in 1980, and the construction of the UNK started in 1983. Political turmoil in the Soviet Union during late 1980s and early 1990s resulted in disintegration of the USSR and subsequent collapse of the Russian economy. As a result of drastic reduction of funding for the UNK, in 1993 the project was restructured to be a 600 GeV fixed target accelerator only. While the ring tunnel and proton injection line were completed by 1995, and 70% of all magnets and associated accelerator equipment were fabricated, lack of Russian federal funding for high energy physics halted the project at the end of 1990s.

  7. Running Linux

    CERN Document Server

    Dalheimer, Matthias Kalle

    2006-01-01

    The fifth edition of Running Linux is greatly expanded, reflecting the maturity of the operating system and the teeming wealth of software available for it. Hot consumer topics such as audio and video playback applications, groupware functionality, and spam filtering are covered, along with the basics in configuration and management that always made the book popular.

  8. RUN COORDINATION

    CERN Multimedia

    C. Delaere

    2013-01-01

    Since the LHC ceased operations in February, a lot has been going on at Point 5, and Run Coordination continues to monitor closely the advance of maintenance and upgrade activities. In the last months, the Pixel detector was extracted and is now stored in the pixel lab in SX5; the beam pipe has been removed and ME1/1 removal has started. We regained access to the vactank and some work on the RBX of HB has started. Since mid-June, electricity and cooling are back in S1 and S2, allowing us to turn equipment back on, at least during the day. 24/7 shifts are not foreseen in the next weeks, and safety tours are mandatory to keep equipment on overnight, but re-commissioning activities are slowly being resumed. Given the (slight) delays accumulated in LS1, it was decided to merge the two global runs initially foreseen into a single exercise during the week of 4 November 2013. The aim of the global run is to check that we can run (parts of) CMS after several months switched off, with the new VME PCs installed, th...

  9. A Search for Supersymmetry via Chargino-Neutralino Production in Low-$p_T$ Dimuon with the Collider Detector at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Rekovic, Vladimir [Univ. of New Mexico, Albuquerque, NM (United States)

    2007-05-01

    We have searched for evidence of supersymmetry with 1 $fb^-1$ with collected with low-$p_T$ dimuon triggers of the Collider Detector on Tevatron Run II, at Fermilab. We looked for trilepton events in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV. In the Minimal Supersymmetric Standard Model (MSSM) we expect chargino-neutralino pair production, with subsequent decay into three isolated leptons. We observe one event of three isolated muons, a possible hint of supersymmetry.

  10. Update on the MEIC electron collider ring design

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Fangei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Harwood, Leigh [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Hutton, Andrew [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Pilat, Fulvia [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Cai, Y. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nosochkov, Y. M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Sullivan, Michael [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wang, M.-H [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wienands, Uli [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-09-01

    The electron collider ring of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab is designed to accumulate and store a high-current polarized electron beam for collisions with an ion beam. We consider a design of the electron collider ring based on reusing PEP-II components, such as magnets, power supplies, vacuum system, etc. This has the potential to significantly reduce the cost and engineering effort needed to bring the project to fruition. This paper reports on an electron ring optics design considering the balance of PEP-II hardware parameters (such as dipole sagitta, magnet field strengths and acceptable synchrotron radiation power) and electron beam quality in terms of equilibrium emittances.

  11. A precise measurement of the top quark mass in dilepton final states using 9.7 fb$^{-1}$ of D{Ø} Run II data

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huanzhao [Southern Methodist Univ., Dallas, TX (United States)

    2015-05-16

    The top quark is a very special fundamental particle in the Standard Model (SM) mainly due to its heavy mass. The top quark has extremely short lifetime and decays before hadronization. This reduces the complexity for the measurement of its mass. The top quark couples very strongly to the Higgs boson since the fermion-Higgs Yukawa coupling linearly depends on the fermion’s mass. Therefore, the top quark is also heavily involved in Higgs production and related study. A precise measurement of the top quark mass is very important, as it allows for self-consistency check of the SM, and also gives a insight about the stability of our universe in the SM context. This dissertation presents my work on the measurement of the top quark mass in dilepton final states of t$\\bar{t}$ events in p$\\bar{p}$ collisions at √s = 1.96 TeV, using the full DØ Run II data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron. I extracted the top quark mass by reconstructing event kinematics, and integrating over expected neutrino rapidity distributions to obtain solutions over a scanned range of top quark mass hypotheses. The analysis features a comprehensive optimization that I made to minimize the expected statistical uncertainty. I also improve the calibration of jets in dilepton events by using the calibration determined in t$\\bar{t}$ → lepton+jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured mass is 173.11 ± 1.34(stat)+0.83 -0.72(sys) GeV .

  12. Topics in Collider Physics

    Energy Technology Data Exchange (ETDEWEB)

    Petriello, Frank J

    2003-08-27

    It is an exciting time for high energy physics. Several experiments are currently exploring uncharted terrain; the next generation of colliders will begin operation in the coming decade. These experiments will together help us understand some of the most puzzling issues in particle physics: the mechanism of electroweak symmetry breaking and the generation of flavor physics. It is clear that the primary goal of theoretical particle physics in the near future is to support and guide this experimental program. These tasks can be accomplished in two ways: by developing experimental signatures for new models which address outstanding problems, and by improving Standard Model predictions for precision observables. We present here several results which advance both of these goals. We begin with a study of non-commutative field theories. It has been suggested that TeV-scale non-commutativity could explain the origin of CP violation in the SM. We identify several distinct signatures of non-commutativity in high energy processes. We also demonstrate the one-loop quantum consistency of a simple spontaneously broken non-commutative U(1) theory; this result is an important preface to any attempt to embed the SM within a non-commutative framework. We then investigate the phenomenology of extra-dimensional theories, which have been suggested recently as solutions to the hierarchy problem of particle physics. We first examine the implications of allowing SM fields to propagate in the full five-dimensional spacetime of the Randall-Sundrum model, which solves the hierarchy problem via an exponential ''warping'' of the Planck scale induced by a five-dimensional anti de-Sitter geometry. In an alternative extra-dimensional theory, in which all SM fields are permitted to propagate in flat extra dimensions, we show that properties of the Higgs boson are significantly modified. Finally, we discuss the next-to-next-to leading order QCD corrections to the dilepton

  13. Hadron collider physics at UCR

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, A.; Shen, B.C.

    1997-07-01

    This paper describes the research work in high energy physics by the group at the University of California, Riverside. Work has been divided between hadron collider physics and e{sup +}-e{sup {minus}} collider physics, and theoretical work. The hadron effort has been heavily involved in the startup activities of the D-Zero detector, commissioning and ongoing redesign. The lepton collider work has included work on TPC/2{gamma} at PEP and the OPAL detector at LEP, as well as efforts on hadron machines.

  14. Physics at Future Hadron Colliders

    CERN Document Server

    Baur, U.; Parsons, J.; Albrow, M.; Denisov, D.; Han, T.; Kotwal, A.; Olness, F.; Qian, J.; Belyaev, S.; Bosman, M.; Brooijmans, G.; Gaines, I.; Godfrey, S.; Hansen, J.B.; Hauser, J.; Heintz, U.; Hinchliffe, I.; Kao, C.; Landsberg, G.; Maltoni, F.; Oleari, C.; Pagliarone, C.; Paige, F.; Plehn, T.; Rainwater, D.; Reina, L.; Rizzo, T.; Su, S.; Tait, T.; Wackeroth, D.; Vataga, E.; Zeppenfeld, D.

    2001-01-01

    We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.

  15. When Black Holes Collide

    Science.gov (United States)

    Baker, John

    2010-01-01

    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  16. RUN COORDINATION

    CERN Multimedia

    M. Chamizo

    2012-01-01

      On 17th January, as soon as the services were restored after the technical stop, sub-systems started powering on. Since then, we have been running 24/7 with reduced shift crew — Shift Leader and DCS shifter — to allow sub-detectors to perform calibration, noise studies, test software upgrades, etc. On 15th and 16th February, we had the first Mid-Week Global Run (MWGR) with the participation of most sub-systems. The aim was to bring CMS back to operation and to ensure that we could run after the winter shutdown. All sub-systems participated in the readout and the trigger was provided by a fraction of the muon systems (CSC and the central RPC wheel). The calorimeter triggers were not available due to work on the optical link system. Initial checks of different distributions from Pixels, Strips, and CSC confirmed things look all right (signal/noise, number of tracks, phi distribution…). High-rate tests were done to test the new CSC firmware to cure the low efficiency ...

  17. Running Club

    CERN Document Server

    Running Club

    2011-01-01

    The cross country running season has started well this autumn with two events: the traditional CERN Road Race organized by the Running Club, which took place on Tuesday 5th October, followed by the ‘Cross Interentreprises’, a team event at the Evaux Sports Center, which took place on Saturday 8th October. The participation at the CERN Road Race was slightly down on last year, with 65 runners, however the participants maintained the tradition of a competitive yet friendly atmosphere. An ample supply of refreshments before the prize giving was appreciated by all after the race. Many thanks to all the runners and volunteers who ensured another successful race. The results can be found here: https://espace.cern.ch/Running-Club/default.aspx CERN participated successfully at the cross interentreprises with very good results. The teams succeeded in obtaining 2nd and 6th place in the Mens category, and 2nd place in the Mixed category. Congratulations to all. See results here: http://www.c...

  18. RUN COORDINATION

    CERN Multimedia

    Christophe Delaere

    2013-01-01

    The focus of Run Coordination during LS1 is to monitor closely the advance of maintenance and upgrade activities, to smooth interactions between subsystems and to ensure that all are ready in time to resume operations in 2015 with a fully calibrated and understood detector. After electricity and cooling were restored to all equipment, at about the time of the last CMS week, recommissioning activities were resumed for all subsystems. On 7 October, DCS shifts began 24/7 to allow subsystems to remain on to facilitate operations. That culminated with the Global Run in November (GriN), which   took place as scheduled during the week of 4 November. The GriN has been the first centrally managed operation since the beginning of LS1, and involved all subdetectors but the Pixel Tracker presently in a lab upstairs. All nights were therefore dedicated to long stable runs with as many subdetectors as possible. Among the many achievements in that week, three items may be highlighted. First, the Strip...

  19. [New technology for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, P.M.

    1992-08-12

    This report discusses the following topics on research of microwave amplifiers for linear colliders: Context in current microwave technology development; gated field emission for microwave cathodes; cathode fabrication and tests; microwave cathode design using field emitters; and microwave localization.

  20. Bottomonium production in hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Brenner Mariotto, C. [Universidade de Caxias do Sul, RS (Brazil). Centro de Ciencias Exatas e Tecnologia]. E-mail: mariotto@if.ufrgs.br; Gay Ducati, M.B. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica. Grupo de Fenomenologia de Particulas em Altas Energias; Ingelman, G. [Uppsala Univ. (Sweden). High Energy Physics

    2004-07-01

    Production of bottomonium in hadronic collisions is studied in the framework of the soft colour approach. We report some results for production of {upsilon} in the Tevatron and predictions for the future Large Hadron Collider (LHC). (author)

  1. US panel backs linear collider

    CERN Multimedia

    2001-01-01

    A draft report from a working group examining the future of American particle physics has stated that the US should give top priority to a high energy e-p collider, wherever it is built (2 paragraphs).

  2. Lare Hadron Collider faces today

    CERN Multimedia

    Cartwright, Jon

    2007-01-01

    "The start-up of the Large Hadron Collider (LHC) at CERN could be delayed after three of the magnets used to focus and manipulate the accelerator's proton beams failed premilinary tests at CERN earlier this week." (1 page)

  3. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  4. CLIC: developing a linear collider

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    Compact Linear Collider (CLIC) is a CERN project to provide high-energy electron-positron collisions. Instead of conventional radio-frequency klystrons, CLIC will use a low-energy, high-intensity primary beam to produce acceleration.

  5. Beam collimation at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Nikolai V. Mokhov

    2003-08-12

    Operational and accidental beam losses in hadron colliders can have a serious impact on machine and detector performance, resulting in effects ranging from minor to catastrophic. Principles and realization are described for a reliable beam collimation system required to sustain favorable background conditions in the collider detectors, provide quench stability of superconducting magnets, minimize irradiation of accelerator equipment, maintain operational reliability over the life of the machine, and reduce the impact of radiation on personnel and the environment. Based on detailed Monte-Carlo simulations, such a system has been designed and incorporated in the Tevatron collider. Its performance, comparison to measurements and possible ways to further improve the collimation efficiency are described in detail. Specifics of the collimation systems designed for the SSC, LHC, VLHC, and HERA colliders are discussed.

  6. Large Hadron Collider nears completion

    CERN Multimedia

    2008-01-01

    Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument.

  7. A 233 km tunnel for lepton and hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T. [Dept. of Physics and Astronomy, University of Mississippi-Oxford, University, MS 38677 (United States)

    2012-12-21

    A decade ago, a cost analysis was conducted to bore a 233 km circumference Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we outline implementations of e{sup +}e{sup -}, pp-bar , and {mu}{sup +}{mu}{sup -} collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV e{sup +}e{sup -} colliders employ Crab Waist Crossings, ultra low emittance damped bunches, short vertical IP focal lengths, superconducting RF, and low coercivity, grain oriented silicon steel/concrete dipoles. Some details are also provided for a high luminosity 240 GeV e{sup +}e{sup -} collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV pp-bar collider uses the high intensity Fermilab p-bar source, exploits high cross sections for pp-bar production of high mass states, and uses 2 Tesla ultra low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds, uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in 63 orbits with 71% survival, and mitigates neutrino radiation with phase shifting, roller coaster motion in a FODO lattice.

  8. Observation of Exclusive Dijet Production at the Fermilab Tevatron p-pbar Collider

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Albrow, M.G.; /Fermilab; Gonzalez, B.Alvarez; /Cantabria U., Santander; Amerio, S.; /Padua U.; Amidei, D.; /Michigan U.; Anastassov, A.; /Rutgers U., Piscataway; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Aoki, M.; /Illinois U., Urbana /Fermilab

    2007-12-01

    The authors present the first observation and cross section measurement of exclusive dijet production in {bar p}p interactions, {bar p}p {yields} {bar p} + dijet + p. Using a data sample of 310 pb{sup -1} collected by the Run II Collider Detector at Fermilab at {radical}s = 1.96 TeV, exclusive cross sections for events with two jets of transverse energy E{sub T}{sup jet} {ge} 10 GeV have been measured as a function of minimum E{sub T}{sup jet}. The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of 200 pb{sup -1} of b-tagged jet events, where exclusive dijet production is expected to be suppressed by the J{sub z} = 0 total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the pp Large Hadron Collider at {radical}s = 14 TeV are discussed.

  9. CDF II integrated calorimetry environment

    CERN Document Server

    Dell'Agnello, S

    2002-01-01

    The Run IIa integrated calorimetry environment of CDF II comprises: sampling scintillator calorimeters, e.m. preshower and shower-maximum detectors (gas based in the central, scintillator based in the forward), crack-filler detectors, radioactive source calibration systems, light pulse calibration systems, dedicated triggers for critical low energy calibrations, new FEE, a Windows NT slow control system, the master online-offline Oracle Database and an online data validation framework, distilled over the previous years of CDF data taking (now based on the CERN Root). The preexisting central calorimeters are the bridge between the energy and time measurement of the past and current physics runs. New forward calorimeters (the "plugs"), built with the modern scintillating tile-fiber technique, replaced the old gas calorimeters. Together they form an integrated, general-purpose calorimetry system which has been successfully commissioned with the 2000-2001 collider data. The time measurement, before present only i...

  10. Muon muon collider: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-18

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup {minus}2} s{sup {minus}1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice--the authors believe--to allow them to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring which has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design.

  11. A Large Hadron Electron Collider at CERN

    CERN Document Server

    Abelleira Fernandez, J L; Adzic, P; Akay, A N; Aksakal, H; Albacete, J L; Allanach, B; Alekhin, S; Allport, P; Andreev, V; Appleby, R B; Arikan, E; Armesto, N; Azuelos, G; Bai, M; Barber, D; Bartels, J; Behnke, O; Behr, J; Belyaev, A S; Ben-Zvi, I; Bernard, N; Bertolucci, S; Bettoni, S; Biswal, S; Blumlein, J; Bottcher, H; Bogacz, A; Bracco, C; Bracinik, J; Brandt, G; Braun, H; Brodsky, S; Bruning, O; Bulyak, E; Buniatyan, A; Burkhardt, H; Cakir, I T; Cakir, O; Calaga, R; Caldwell, A; Cetinkaya, V; Chekelian, V; Ciapala, E; Ciftci, R; Ciftci, A K; Cole, B A; Collins, J C; Dadoun, O; Dainton, J; Roeck, A.De; d'Enterria, D; DiNezza, P; Dudarev, A; Eide, A; Enberg, R; Eroglu, E; Eskola, K J; Favart, L; Fitterer, M; Forte, S; Gaddi, A; Gambino, P; Garcia Morales, H; Gehrmann, T; Gladkikh, P; Glasman, C; Glazov, A; Godbole, R; Goddard, B; Greenshaw, T; Guffanti, A; Guzey, V; Gwenlan, C; Han, T; Hao, Y; Haug, F; Herr, W; Herve, A; Holzer, B J; Ishitsuka, M; Jacquet, M; Jeanneret, B; Jensen, E; Jimenez, J M; Jowett, J M; Jung, H; Karadeniz, H; Kayran, D; Kilic, A; Kimura, K; Klees, R; Klein, M; Klein, U; Kluge, T; Kocak, F; Korostelev, M; Kosmicki, A; Kostka, P; Kowalski, H; Kraemer, M; Kramer, G; Kuchler, D; Kuze, M; Lappi, T; Laycock, P; Levichev, E; Levonian, S; Litvinenko, V N; Lombardi, A; Maeda, J; Marquet, C; Mellado, B; Mess, K H; Milanese, A; Milhano, J G; Moch, S; Morozov, I I; Muttoni, Y; Myers, S; Nandi, S; Nergiz, Z; Newman, P R; Omori, T; Osborne, J; Paoloni, E; Papaphilippou, Y; Pascaud, C; Paukkunen, H; Perez, E; Pieloni, T; Pilicer, E; Pire, B; Placakyte, R; Polini, A; Ptitsyn, V; Pupkov, Y; Radescu, V; Raychaudhuri, S; Rinolfi, L; Rizvi, E; Rohini, R; Rojo, J; Russenschuck, S; Sahin, M; Salgado, C A; Sampei, K; Sassot, R; Sauvan, E; Schaefer, M; Schneekloth, U; Schorner-Sadenius, T; Schulte, D; Senol, A; Seryi, A; Sievers, P; Skrinsky, A N; Smith, W; South, D; Spiesberger, H; Stasto, A M; Strikman, M; Sullivan, M; Sultansoy, S; Sun, Y P; Surrow, B; Szymanowski, L; Taels, P; Tapan, I; Tasci, T; Tassi, E; Kate, H.Ten; Terron, J; Thiesen, H; Thompson, L; Thompson, P; Tokushuku, K; Tomas Garcia, R; Tommasini, D; Trbojevic, D; Tsoupas, N; Tuckmantel, J; Turkoz, S; Trinh, T N; Tywoniuk, K; Unel, G; Ullrich, T; Urakawa, J; VanMechelen, P; Variola, A; Veness, R; Vivoli, A; Vobly, P; Wagner, J; Wallny, R; Wallon, S; Watt, G; Weiss, C; Wiedemann, U A; Wienands, U; Willeke, F; Xiao, B W; Yakimenko, V; Zarnecki, A F; Zhang, Z; Zimmermann, F; Zlebcik, R; Zomer, F; CERN. Geneva. LHeC Department

    2012-01-01

    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100) fb$^{-1}$. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC.

  12. RUN COORDINATION

    CERN Multimedia

    G. Rakness.

    2013-01-01

    After three years of running, in February 2013 the era of sub-10-TeV LHC collisions drew to an end. Recall, the 2012 run had been extended by about three months to achieve the full complement of high-energy and heavy-ion physics goals prior to the start of Long Shutdown 1 (LS1), which is now underway. The LHC performance during these exciting years was excellent, delivering a total of 23.3 fb–1 of proton-proton collisions at a centre-of-mass energy of 8 TeV, 6.2 fb–1 at 7 TeV, and 5.5 pb–1 at 2.76 TeV. They also delivered 170 μb–1 lead-lead collisions at 2.76 TeV/nucleon and 32 nb–1 proton-lead collisions at 5 TeV/nucleon. During these years the CMS operations teams and shift crews made tremendous strides to commission the detector, repeatedly stepping up to meet the challenges at every increase of instantaneous luminosity and energy. Although it does not fully cover the achievements of the teams, a way to quantify their success is the fact that that...

  13. String resonances at hadron colliders

    Science.gov (United States)

    Anchordoqui, Luis A.; Antoniadis, Ignatios; Dai, De-Chang; Feng, Wan-Zhe; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Stojkovic, Dejan; Taylor, Tomasz R.

    2014-09-01

    We consider extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. Assuming that the fundamental string mass scale Ms is in the TeV range and that the theory is weakly coupled, we discuss possible signals of string physics at the upcoming HL-LHC run (integrated luminosity =3000 fb-1) with a center-of-mass energy of √s =14 TeV and at potential future pp colliders, HE-LHC and VLHC, operating at √s =33 and 100 TeV, respectively (with the same integrated luminosity). In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets and γ +jet are completely independent of the details of compactification and can be evaluated in a parameter-free manner. We make use of these amplitudes evaluated near the first (n=1) and second (n=2) resonant poles to determine the discovery potential for Regge excitations of the quark, the gluon, and the color singlet living on the QCD stack. We show that for string scales as large as 7.1 TeV (6.1 TeV) lowest massive Regge excitations are open to discovery at the ≥5σ in dijet (γ +jet) HL-LHC data. We also show that for n=1 the dijet discovery potential at HE-LHC and VLHC exceedingly improves: up to 15 TeV and 41 TeV, respectively. To compute the signal-to-noise ratio for n=2 resonances, we first carry out a complete calculation of all relevant decay widths of the second massive level string states (including decays into massless particles and a massive n=1 and a massless particle), where we rely on factorization and conformal field theory techniques. Helicity wave functions of arbitrary higher spin massive bosons are also constructed. We demonstrate that for string scales Ms≲10.5 TeV (Ms≲28 TeV) detection of n =2 Regge recurrences at HE-LHC (VLHC) would become the smoking gun for D

  14. PEP-II Operations Report

    Energy Technology Data Exchange (ETDEWEB)

    Zisman, Michael S.

    2000-11-01

    PEP-II is a two-ring asymmetric B factory operating at the Upsilon(4S) resonance. It was constructed by a SLAC-LBNL-LLNL collaboration. The collider comprises two rings, a High-Energy Ring (HER) storing 9 GeV electrons, and a Low-Energy Ring (LER) storing 3.1 GeV positrons. Commissioning of the HER began in mid-1997 and commissioning of the LER began in mid-1998. First evidence for collisions was obtained on July 23, 1998. The BaBar detector was installed in early 1999, and commissioning with the detector commenced in May 1999. By September 1999, PEP-II had reached a peak luminosity of 1.35 x 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. In the present run, which began in October 1999, the peak luminosity has reached 3.1 x 10{sup 33} cm{sup {minus}2} s{sup {minus}1} and the integrated luminosity delivered is 25 fb{sup {minus}1}. At present, PEP-II is the world's highest luminosity collider. In this paper we describe the startup experience and summarize the operational experience during fiscal year 2000 (from October 1999 through September 2000). Plan s for luminosity upgrades are briefly described.

  15. Is there really an eccentric action of the hamstrings during the swing phase of high-speed running? Part II: Implications for exercise.

    Science.gov (United States)

    Van Hooren, Bas; Bosch, Frans

    2017-12-01

    We have previously argued that there may actually be no significant eccentric, but rather predominantly an isometric action of the hamstring muscle fibres during the swing phase of high-speed running when the attachment points of the hamstrings are moving apart. Based on this we suggested that isometric rather than eccentric exercises are a more specific way of conditioning the hamstrings for high-speed running. In this review we argue that some of the presumed beneficial adaptations following eccentric training may actually not be related to the eccentric muscle fibre action, but to other factors such as exercise intensity. Furthermore, we discuss several disadvantages associated with commonly used eccentric hamstring exercises. Subsequently, we argue that high-intensity isometric exercises in which the series elastic element stretches and recoils may be equally or even more effective at conditioning the hamstrings for high-speed running, since they also avoid some of the negative side effects associated with eccentric training. We provide several criteria that exercises should fulfil to effectively condition the hamstrings for high-speed running. Adherence to these criteria will guarantee specificity with regards to hamstrings functioning during running. Practical examples of isometric exercises that likely meet several criteria are provided.

  16. The collider of the future?

    CERN Multimedia

    CERN Audiovisual Service

    2009-01-01

    Why are two studies for one linear collider being conducted in parallel? This is far from a duplication of effort or a waste of resources, since the two studies reflect a complementary strategy aimed at providing the best technology for future physics. On Friday 12 June CERN hosted the first joint meeting between CLIC and ILC, which led to a host of good results and important decisions. The International Linear Collider (ILC) and Compact Linear Collider (CLIC) studies both call for cutting-edge technologies. At first glance they may appear to be in competition, but they are in fact complementary and have a common objective – namely to propose a design , as soon as possible and at the lowest possible cost, for the linear accelerator best suited to taking over the baton of physics research at the high-energy frontier after the LHC.

  17. A prototype of the LHC dipole magnet, with the two beampipes running through the centre.

    CERN Multimedia

    Laurent Guiraud

    1997-01-01

    CERN scientists conceived of their next collider as a "high-luminosity" machine that would excel at producing a high number of collisions. But since making a strong antiproton beam is laborious, this collider would have to smash together two proton beams. Since the LHC would use two proton beams running in opposite directions, it required two sets of magnets-a "two-in-one" collider.

  18. Running Club

    CERN Document Server

    Running Club

    2010-01-01

    The 2010 edition of the annual CERN Road Race will be held on Wednesday 29th September at 18h. The 5.5km race takes place over 3 laps of a 1.8 km circuit in the West Area of the Meyrin site, and is open to everyone working at CERN and their families. There are runners of all speeds, with times ranging from under 17 to over 34 minutes, and the race is run on a handicap basis, by staggering the starting times so that (in theory) all runners finish together. Children (< 15 years) have their own race over 1 lap of 1.8km. As usual, there will be a “best family” challenge (judged on best parent + best child). Trophies are awarded in the usual men’s, women’s and veterans’ categories, and there is a challenge for the best age/performance. Every adult will receive a souvenir prize, financed by a registration fee of 10 CHF. Children enter free (each child will receive a medal). More information, and the online entry form, can be found at http://cern.ch/club...

  19. RUN COORDINATION

    CERN Multimedia

    C. Delaere

    2012-01-01

      With the analysis of the first 5 fb–1 culminating in the announcement of the observation of a new particle with mass of around 126 GeV/c2, the CERN directorate decided to extend the LHC run until February 2013. This adds three months to the original schedule. Since then the LHC has continued to perform extremely well, and the total luminosity delivered so far this year is 22 fb–1. CMS also continues to perform excellently, recording data with efficiency higher than 95% for fills with the magnetic field at nominal value. The highest instantaneous luminosity achieved by LHC to date is 7.6x1033 cm–2s–1, which translates into 35 interactions per crossing. On the CMS side there has been a lot of work to handle these extreme conditions, such as a new DAQ computer farm and trigger menus to handle the pile-up, automation of recovery procedures to minimise the lost luminosity, better training for the shift crews, etc. We did suffer from a couple of infrastructure ...

  20. Muon Muon Collider: Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo, J.C.; Palmer, R.B.; /Brookhaven; Tollestrup, A.V.; /Fermilab; Sessler, A.M.; /LBL, Berkeley; Skrinsky, A.N.; /Novosibirsk, IYF; Ankenbrandt, C.; Geer, S.; Griffin, J.; Johnstone, C.; Lebrun, P.; McInturff, A.; Mills, Frederick E.; Mokhov, N.; Moretti, A.; Neuffer, D.; Ng, K.Y.; Noble, R.; Novitski, I.; Popovic, M.; Qian, C.; Van Ginneken, A. /Fermilab /Brookhaven /Wisconsin U., Madison /Tel Aviv U. /Indiana U. /UCLA /LBL, Berkeley /SLAC /Argonne /Sobolev IM, Novosibirsk /UC, Davis /Munich, Tech. U. /Virginia U. /KEK, Tsukuba /DESY /Novosibirsk, IYF /Jefferson Lab /Mississippi U. /SUNY, Stony Brook /MIT /Columbia U. /Fairfield U. /UC, Berkeley

    2012-04-05

    A feasibility study is presented of a 2 + 2 TeV muon collider with a luminosity of L = 10{sup 35} cm{sup -2}s{sup -1}. The resulting design is not optimized for performance, and certainly not for cost; however, it does suffice - we believe - to allow us to make a credible case, that a muon collider is a serious possibility for particle physics and, therefore, worthy of R and D support so that the reality of, and interest in, a muon collider can be better assayed. The goal of this support would be to completely assess the physics potential and to evaluate the cost and development of the necessary technology. The muon collider complex consists of components which first produce copious pions, then capture the pions and the resulting muons from their decay; this is followed by an ionization cooling channel to reduce the longitudinal and transverse emittance of the muon beam. The next stage is to accelerate the muons and, finally, inject them into a collider ring wich has a small beta function at the colliding point. This is the first attempt at a point design and it will require further study and optimization. Experimental work will be needed to verify the validity of diverse crucial elements in the design. Muons because of their large mass compared to an electron, do not produce significant synchrotron radiation. As a result there is negligible beamstrahlung and high energy collisions are not limited by this phenomena. In addition, muons can be accelerated in circular devices which will be considerably smaller than two full-energy linacs as required in an e{sup +} - e{sup -} collider. A hadron collider would require a CM energy 5 to 10 times higher than 4 TeV to have an equivalent energy reach. Since the accelerator size is limited by the strength of bending magnets, the hadron collider for the same physics reach would have to be much larger than the muon collider. In addition, muon collisions should be cleaner than hadron collisions. There are many detailed particle

  1. Muon Physics at Run-I and its upgrade plan

    Science.gov (United States)

    Benekos, Nektarios Chr.

    2015-05-01

    The Large Hadron Collider (LHC) and its multi-purpose Detector, ATLAS, has been operated successfully at record centre-of-mass energies of 7 and TeV. After this successful LHC Run-1, plans are actively advancing for a series of upgrades, culminating roughly 10 years from now in the high luminosity LHC (HL-LHC) project, delivering of order five times the LHC nominal instantaneous luminosity along with luminosity leveling. The final goal is to extend the data set from about few hundred fb-1 expected for LHC running to 3000 fb-1 by around 2030. To cope with the corresponding rate increase, the ATLAS detector needs to be upgraded. The upgrade will proceed in two steps: Phase I in the LHC shutdown 2018/19 and Phase II in 2023-25. The largest of the ATLAS Phase-1 upgrades concerns the replacement of the first muon station of the highrapidity region, the so called New Small Wheel. This configuration copes with the highest rates expected in Phase II and considerably enhances the performance of the forward muon system by adding triggering functionality to the first muon station. Prospects for the ongoing and future data taking are presented. This article presents the main muon physics results from LHC Run-1 based on a total luminosity of 30 fb^-1. Prospects for the ongoing and future data taking are also presented. We will conclude with an update of the status of the project and the steps towards a complete operational system, ready to be installed in ATLAS in 2018/19.

  2. Muon Physics at Run-I and its upgrade plan

    Directory of Open Access Journals (Sweden)

    Benekos Nektarios Chr.

    2015-01-01

    Full Text Available The Large Hadron Collider (LHC and its multi-purpose Detector, ATLAS, has been operated successfully at record centre-of-mass energies of 7 and TeV. After this successful LHC Run-1, plans are actively advancing for a series of upgrades, culminating roughly 10 years from now in the high luminosity LHC (HL-LHC project, delivering of order five times the LHC nominal instantaneous luminosity along with luminosity leveling. The final goal is to extend the data set from about few hundred fb−1 expected for LHC running to 3000 fb−1 by around 2030. To cope with the corresponding rate increase, the ATLAS detector needs to be upgraded. The upgrade will proceed in two steps: Phase I in the LHC shutdown 2018/19 and Phase II in 2023-25. The largest of the ATLAS Phase-1 upgrades concerns the replacement of the first muon station of the highrapidity region, the so called New Small Wheel. This configuration copes with the highest rates expected in Phase II and considerably enhances the performance of the forward muon system by adding triggering functionality to the first muon station. Prospects for the ongoing and future data taking are presented. This article presents the main muon physics results from LHC Run-1 based on a total luminosity of 30 fb^-1. Prospects for the ongoing and future data taking are also presented. We will conclude with an update of the status of the project and the steps towards a complete operational system, ready to be installed in ATLAS in 2018/19.

  3. The collider of the future?

    CERN Multimedia

    2009-01-01

    Why are two studies for one linear collider being conducted in parallel? This is far from a duplication of effort or a waste of resources, since the two studies reflect a complementary strategy aimed at providing the best technology for future physics. On Friday 12 June CERN hosted the first joint meeting between CLIC, ILC and the CERN management.

  4. Working group report: Collider Physics

    Indian Academy of Sciences (India)

    This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is ...

  5. Fast Timing for Collider Detectors

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Advancements in fast timing particle detectors have opened up new possibilities to design collider detectors that fully reconstruct and separate event vertices and individual particles in the time domain. The applications of these techniques are considered for the physics at HL-LHC.

  6. Top production at hadron colliders

    Indian Academy of Sciences (India)

    New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including ...

  7. Design flaw could delay collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "A magnet for the Large Hadron Collider (LHC) failed during a key test at the European particle physics laboratory CERN last week. Physicists and engineers will have to repair the damaged magnet and retrofit others to correct the underlynig design flaw, which could delay the start-up of the mammouth subterranean machine." (1,5 page)

  8. Unraveling supersymmetry at future colliders

    Indian Academy of Sciences (India)

    After a quick review of the current limits on sparticle masses, we outline the prospects for their discovery at future colliders. We then proceed to discuss how precision measurements of sparticle masses can provide information about how SM suprpartners acquire their masses. Finally, we examine how we can proceed to ...

  9. B physics at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Butler, J.N.; /Fermilab

    2005-09-01

    This paper discusses the physics opportunity and challenges for doing high precision B physics experiments at hadron colliders. It describes how these challenges have been addressed by the two currently operating experiments, CDF and D0, and how they are addressed by three experiments, ATLAS, CMS, and LHCb, at the LHC.

  10. Hard QCD at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Moch, S.

    2008-02-15

    We review the status of QCD at hadron colliders with emphasis on precision predictions and the latest theoretical developments for cross sections calculations to higher orders. We include an overview of our current information on parton distributions and discuss various Standard Model reactions such as W{sup {+-}}/Z-boson, Higgs boson or top quark production. (orig.)

  11. Large Hadron Collider nears completion

    CERN Multimedia

    2008-01-01

    Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument. It is being constructed by the European Organization for Nuclear Research, one of the world's largest particle physics laboratories.

  12. The very large hadron collider

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    This paper reviews the purposes to be served by a very large hadron collider and the organization and coordination of efforts to bring it about. There is some discussion of magnet requirements and R&D and the suitability of the Fermilab site.

  13. Search for supersymmetric particles decaying into tri-leptons through R-parity violation, with D0 Run-II experiment at Fermilab; Recherche de particules supersymetriques se desintegrant en R-parite violee (couplage {lambda}(121)) dans un etat final a trois leptons, avec les donnees du Run-II de l'experience D0 au TeVatron

    Energy Technology Data Exchange (ETDEWEB)

    Magnan, A.M

    2005-07-15

    This thesis is dedicated to the study of the first data taken by the D0 detector during the Run II of the Tevatron. Supersymmetric particles have been search for in proton-antiproton collisions, with a center of mass energy of 1.96 TeV. In the framework of supersymmetry with R-parity violation, I have studied the pair production of Gauginos, leading to a pair of LSP (0,{chi}{sub 1}), each one decaying into ee{nu}{sub {mu}} or e{mu}{nu}{sub e} with a {lambda}(121) coupling. The final state contains at least two electrons: I have thus paid special attention in this work to the methods concerning identification and mis-identification of electromagnetic particles, as well as reconstruction, triggering, and correction (of the reconstructed energy). In a selection of tri-leptons, with at least two electrons, and some transverse missing energy, we observed 0 event in the 350 pb{sup -1} of analyzed data, for 0.4 + 0.35 - 0.05 (sta) {+-} 0.16 (sys) expected from the Standard Model contributions. In the signal considered in this analysis, the selection efficiency is around 12 per cent. Results have been studied in two models: mSUGRA and MSSM. In mSUGRA model, limits on m(1/2) and lightest gauginos's masses have been obtained, with tan({beta}) = 5, A{sub 0} = 0, m{sub 0} = 100 and 1000 GeV.c{sup -2} and both signs of {mu}. In MSSM, with the hypothesis of massive sfermions (1000 GeV.c{sup -2}), we can exclude, at 95% Confidence Level, the region m({chi}{sub 1}{sup {+-}}) < 200 GeV.c{sup -2} for all masses of {chi}{sub 1}{sup 0} LSP. (author)

  14. Optimising charged Higgs boson searches at the Large Hadron Collider across bb¯W± final states

    Directory of Open Access Journals (Sweden)

    Stefano Moretti

    2016-09-01

    Full Text Available In the light of the most recent data from Higgs boson searches and analyses, we re-assess the scope of the Large Hadron Collider in accessing heavy charged Higgs boson signals in bb¯W± final states, wherein the contributing channels can be H+→tb¯, hW±, HW± and AW±. We consider a 2-Higgs Doublet Model Type-II and we assume as production mode bg→tH−+c.c., the dominant one over the range MH±≥480 GeV, as dictated by b→sγ constraints. Prospects of detection are found to be significant for various Run 2 energy and luminosity options.

  15. A group exercise programme for people at risk from type II diabetes run as a physiotherapy student clinical placement is beneficial: a qualitative study

    National Research Council Canada - National Science Library

    van Bysterveldt, Erin; Davey, Simon; Douglas, Naomi; Liu, Robert; Robertson, Linda; Conroy, Jenny; Higgs, Chris; Hale, Leigh

    2014-01-01

    ... for undergraduate physiotherapy students. Class participants included 10 adults with, or at high risk of developing, type II diabetes and 3 family members attending a 12-week group exercise programme and 20 supervised undergraduate physio...

  16. From Neutrino Factory to Muon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Geer, S.; /Fermilab

    2010-01-01

    Both Muon Colliders and Neutrino Factories require a muon source capable of producing and capturing {Omicron}(10{sup 21}) muons/year. This paper reviews the similarities and differences between Neutrino Factory and Muon Collider accelerator complexes, the ongoing R&D needed for a Muon Collider that goes beyond Neutrino Factory R&D, and some thoughts about how a Neutrino Factory on the CERN site might eventually be upgraded to a Muon Collider.

  17. Measurement of the top quark mass using dilepton events and a neutrino weighting algorithm with the DOe experiment at the Tevatron (Run II)

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.

    2007-07-01

    Several measurements of the top quark mass in the dilepton final states with the DOe experiment are presented. The theoretical and experimental properties of the top quark are described together with a brief introduction of the Standard Model of particle physics and the physics of hadron collisions. An overview over the experimental setup is given. The Tevatron at Fermilab is presently the highest-energy hadron collider in the world with a center-of-mass energy of 1.96 TeV. There are two main experiments called CDF and DOe, A description of the components of the multipurpose DOe detector is given. The reconstruction of simulated events and data events is explained and the criteria for the identification of electrons, muons, jets, and missing transverse energy is given. The kinematics in the dilepton final state is underconstraint. Therefore, the top quark mass is extracted by the so-called Neutrino Weighting method. This method is introduced and several different approaches are described, compared, and enhanced. Results for the international summer conferences 2006 and winter 2007 are presented. The top quark mass measurement for the combination of all three dilepton channels with a dataset of 1.05 1/fb yields: mtop=172.5{+-}5.5 (stat.) {+-} 5.8 (syst.) GeV. This result is presently the most precise top quark mass measurement of the DOe experiment in the dilepton chann el. It entered the top quark mass wold average from March 2007. (orig.)

  18. Search for $B_s \\rightarrow \\mu^{+}\\mu^{-}$ and $B_d \\rightarrow \\mu^{+}\\mu^{-}$ decays with the full CDF Run II data set

    CERN Document Server

    Aaltonen, T.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K.R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H.S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y.C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M.A.; Clark, A.; Clarke, C.; Convery, M.E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C.A.; Cox, D.J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; Devoto, F.; d'Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J.R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernandez Ramos, J.P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J.C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A.F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C.M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzalez Lopez, O.; Gorelov, I.; Goshaw, A.T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R.C.; Guimaraes da Costa, J.; Hahn, S.R.; Han, J.Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R.F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R.E.; Husemann, U.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E.J.; Jindariani, S.; Jones, M.; Joo, K.K.; Jun, S.Y.; Junk, T.R.; Kambeitz, M.; Kamon, T.; Karchin, P.E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D.H.; Kim, H.S.; Kim, J.E.; Kim, M.J.; Kim, S.B.; Kim, S.H.; Kim, Y.K.; Kim, Y.J.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D.J.; Konigsberg, J.; Kotwal, A.V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A.T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H.S.; Lee, J.S.; Leo, S.; Leone, S.; Lewis, J.D.; Limosani, A.; Lipeles, E.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martinez, M.; Matera, K.; Mattson, M.E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C.S.; Moore, R.; Morello, M.J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S.Y.; Norniella, O.; Oakes, L.; Oh, S.H.; Oh, Y.D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T.J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernandez, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J.L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W.K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E.E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S.Z.; Shears, T.; Shepard, P.F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J.R.; Snider, F.D.; Sorin, V.; Song, H.; Sperka, D.; Stancari, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P.K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vazquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizan, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S.M.; Warburton, A.; Waters, D.; Wester, W.C., III; Whiteson, D.; Wicklund, A.B.; Wilbur, S.; Williams, H.H.; Wilson, J.S.; Wilson, P.; Winer, B.L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U.K.; Yang, Y.C.; Yao, W.M.; Yeh, G.P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G.B.; Yu, I.; Zanetti, A.M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2013-04-04

    We report on a search for \\bsmm\\ and \\bdmm\\ decays using proton-antiproton collision data at $\\sqrt{s}=1.96$~TeV corresponding to $10~\\fb$ of integrated luminosity collected by the CDF detector at the Fermilab Tevatron collider. The observed number of \\bd\\ candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of $\\brbdmm < 4.6\\times 10^{-9}$ at 95\\% confidence level. We observe an excess of \\bs\\ candidates. The probability that the background processes alone could produce such an excess or larger is $0.94\\%$. The probability that the combination of background and the expected standard model rate of \\bsmm\\ could produce such an excess or larger is $6.8\\%$. These data are used to determine a branching fraction $\\brbsmm = (1.3^{+0.9}_{-0.7}) \\times 10^{-8} $ and provide an upper limit of $\\brbsmm < 3.1\\times 10^{-8}$ at 95\\% confidence level.

  19. and collider physics: Working group report

    Indian Academy of Sciences (India)

    This report summarises [1] the activities of the working group on ' and collider physics'. Presented are the results of investigations relating to various scenarios of su- persymmetry breaking and their collider signatures and the consequences of violation of. К-parity for both collider signals as well as various -meson decay ...

  20. Shedding Light on Dark Matter at Colliders

    CERN Document Server

    Mitsou, Vasiliki A

    2013-01-01

    Dark matter remains one of the most puzzling mysteries in Fundamental Physics of our times. Experiments at high-energy physics colliders are expected to shed light to its nature and determine its properties. This review focuses on recent searches for dark-matter signatures at the Large Hadron Collider, also discussing related prospects in future e+e- colliders.

  1. Higgs and SUSY searches at future colliders

    Indian Academy of Sciences (India)

    http://www.ias.ac.in/article/fulltext/pram/054/04/0499-0518. Keywords. Higgs; supersymmetry; colliders. Abstract. In this talk, I discuss some aspects of Higgs searches at future colliders, particularly comparing and contrasting the capabilities of LHC and next linear collider (NLC), including the aspects of Higgs searches in ...

  2. The technical challenges of the Large Hadron Collider.

    Science.gov (United States)

    Collier, Paul

    2015-01-13

    The Large Hadron Collider (LHC) is a 27km circumference hadron collider, built at CERN to explore the energy frontier of particle physics. Approved in 1994, it was commissioned and began operation for data taking in 2009. The design and construction of the LHC presented many design, engineering and logistical challenges which involved pushing a number of technologies well beyond their level at the time. Since the start-up of the machine, there has been a very successful 3-year run with an impressive amount of data delivered to the LHC experiments. With an increasingly large stored energy in the beam, the operation of the machine itself presented many challenges and some of these will be discussed. Finally, the planning for the next 20 years has been outlined with progressive upgrades of the machine, first to nominal energy, then to progressively higher collision rates. At each stage the technical challenges are illustrated with a few examples.

  3. Electron-cloud effects in high-luminosity colliders

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, F.

    1998-01-01

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

  4. Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider

    Directory of Open Access Journals (Sweden)

    R. Bruce

    2010-09-01

    Full Text Available We have studied the time evolution of the heavy-ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC at BNL, and in the Large Hadron Collider (LHC at CERN. First, we present measurements from a large number of RHIC stores (from run-7, colliding 100  GeV/nucleon ^{197}Au^{79+} beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multiparticle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the rf bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future ^{208}Pb^{82+} beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

  5. Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider

    Science.gov (United States)

    Bruce, R.; Jowett, J. M.; Blaskiewicz, M.; Fischer, W.

    2010-09-01

    We have studied the time evolution of the heavy-ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC) at BNL, and in the Large Hadron Collider (LHC) at CERN. First, we present measurements from a large number of RHIC stores (from run-7), colliding 100GeV/nucleon Au79+197 beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multiparticle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the rf bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future Pb82+208 beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

  6. A search for particle dark matter using cryogenic germanium and silicon detectors in the one- and two- tower runs of CDMS-II at Soudan

    Energy Technology Data Exchange (ETDEWEB)

    Ogburn, IV, Reuben Walter [Stanford Univ., CA (United States)

    2008-06-01

    Images of the Bullet Cluster of galaxies in visible light, X-rays, and through gravitational lensing confirm that most of the matter in the universe is not composed of any known form of matter. The combined evidence from the dynamics of galaxies and clusters of galaxies, the cosmic microwave background, big bang nucleosynthesis, and other observations indicates that 80% of the universe's matter is dark, nearly collisionless, and cold. The identify of the dar, matter remains unknown, but weakly interacting massive particles (WIMPs) are a very good candidate. They are a natural part of many supersymmetric extensions to the standard model, and could be produced as a nonrelativistic, thermal relic in the early universe with about the right density to account for the missing mass. The dark matter of a galaxy should exist as a spherical or ellipsoidal cloud, called a 'halo' because it extends well past the edge of the visible galaxy. The Cryogenic Dark Matter Search (CDMS) seeks to directly detect interactions between WIMPs in the Milky Way's galactic dark matter halo using crystals of germanium and silicon. Our Z-sensitive ionization and phonon ('ZIP') detectors simultaneously measure both phonons and ionization produced by particle interactions. In order to find very rare, low-energy WIMP interactions, they must identify and reject background events caused by environmental radioactivity, radioactive contaminants on the detector,s and cosmic rays. In particular, sophisticated analysis of the timing of phonon signals is needed to eliminate signals caused by beta decays at the detector surfaces. This thesis presents the firs two dark matter data sets from the deep underground experimental site at the Soudan Underground Laboratory in Minnesota. These are known as 'Run 118', with six detectors (1 kg Ge, 65.2 live days before cuts) and 'Run 119', with twelve detectors (1.5 kg Ge, 74.5 live days before cuts). They have

  7. Polarized proton collider at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, I.; Allgower, C.; Bai, M.; Batygin, Y.; Bozano, L.; Brown, K.; Bunce, G.; Cameron, P.; Courant, E.; Erin, S.; Escallier, J.; Fischer, W.; Gupta, R.; Hatanaka, K.; Huang, H.; Imai, K.; Ishihara, M.; Jain, A.; Lehrach, A.; Kanavets, V.; Katayama, T.; Kawaguchi, T.; Kelly, E.; Kurita, K.; Lee, S.Y.; Luccio, A.; MacKay, W.W. E-mail: mackay@bnl.govhttp://www.rhichome.bnl.gov/People/waldowaldo@bnl.gov; Mahler, G.; Makdisi, Y.; Mariam, F.; McGahern, W.; Morgan, G.; Muratore, J.; Okamura, M.; Peggs, S.; Pilat, F.; Ptitsin, V.; Ratner, L.; Roser, T.; Saito, N.; Satoh, H.; Shatunov, Y.; Spinka, H.; Syphers, M.; Tepikian, S.; Tominaka, T.; Tsoupas, N.; Underwood, D.; Vasiliev, A.; Wanderer, P.; Willen, E.; Wu, H.; Yokosawa, A.; Zelenski, A.N

    2003-03-01

    In addition to heavy ion collisions (RHIC Design Manual, Brookhaven National Laboratory), RHIC will also collide intense beams of polarized protons (I. Alekseev, et al., Design Manual Polarized Proton Collider at RHIC, Brookhaven National Laboratory, 1998, reaching transverse energies where the protons scatter as beams of polarized quarks and gluons. The study of high energy polarized protons beams has been a long term part of the program at BNL with the development of polarized beams in the Booster and AGS rings for fixed target experiments. We have extended this capability to the RHIC machine. In this paper we describe the design and methods for achieving collisions of both longitudinal and transverse polarized protons in RHIC at energies up to {radical}s=500 GeV.

  8. Leptoquarks at Future Lepton Colliders

    OpenAIRE

    Rizzo, Thomas G.

    1997-01-01

    In this talk I summarize the capability of future lepton colliders to discover leptoquarks and to determine their electroweak quantum numbers. This analysis is an updated discussion based on the results presented in the Snowmass 1996 New Phenomena Working Group report as well as some more recent work that has appeared in the literature as a result of the HERA high-$Q^2$ excess.

  9. Collective accelerator for electron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, R.J.

    1985-05-13

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

  10. 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...

  11. Higgs Measurement at e+e- Circular Colliders

    CERN Document Server

    Ruan, M

    2014-01-01

    Now that the mass of the Higgs boson is known, circular electron positron colliders, able to measure the properties of these particles with high accuracy, are receiving considerable attention. Design studies have been launched (i) at CERN with the Future Circular Colliders (FCC), of which an e+e- collider is a potential first step (FCC-ee, formerly caller TLEP) and (ii) in China with the Circular Electron Positron Collider (CEPC). Hosted in a tunnel of at least 50 km (CEPC) or 80-100 km (FCC), both projects can deliver very high luminosity from the Z peak to HZ threshold (CEPC) and even to the top pair threshold and above (FCC-ee). At the ZH production optimum, around 240 GeV, the FCC-ee (CEPC) will be able to deliver 10 (5) ab-1 integrated luminosity in 5 (10) years with 4 (2) interaction points: hence to produce millions of Higgs bosons through the Higgsstrahlung process and vector boson fusion processes. This sample opens the possibility of subper-cent precision absolute measurements of the Higgs boson cou...

  12. Higgs measurement at $e^+e^-$ circular colliders

    CERN Document Server

    Ruan, Manqi

    2016-01-01

    Now that the mass of the Higgs boson is known, circular electron positron colliders, able to measure the properties of these particles with high accuracy, are receiving considerable attention. Design studies have been launched (i) at CERN with the Future Circular Colliders (FCC), of which an e+e- collider is a potential first step (FCC-ee, formerly caller TLEP) and (ii) in China with the Circular Electron Positron Collider (CEPC). Hosted in a tunnel of at least 50 km (CEPC) or 80-100 km (FCC), both projects can deliver very high luminosity from the Z peak to HZ threshold (CEPC) and even to the top pair threshold and above (FCC-ee). At the ZH production optimum, around 240 GeV, the FCC-ee (CEPC) will be able to deliver 10 (5) ab-1 integrated luminosity in 5 (10) years with 4 (2) interaction points: hence to produce millions of Higgs bosons through the Higgsstrahlung process and vector boson fusion processes. This sample opens the possibility of subper- cent precision absolute measurements of the Higgs boson co...

  13. High Brightness Hadron Injectors for TeV Colliders

    CERN Document Server

    Schindl, Karlheinz

    1998-01-01

    The ambitious performance goals of present and future hadron colliders call for a chain of injectors that are specially designed to provide high quality beams. However, for many reasons, not the least of which is cost, all these colliders make use of existing accelerator complexes that were not built for this new task and have therefore to be upgraded. A key issue such hadron injectors have to deal with is the preservation of transverse normalised emittance. Small transverse emittances are important because (i) the collider luminosity is proportional to N(N/e) and becomes larger for smaller emit tance; (ii) particle losses at injection into the collider are reduced, thus reducing the risk of quenching a superconducting magnet. Sources of emittance blow-up, such as mis-steering and mismatch be tween machines, space charge, instabilities and intra-beam scattering, are covered along with corrective measures. Problems common to the Tevatron, HERA-p, RHIC, LHC injector chains (the latter two in cluding heavy ion p...

  14. High-power multimode X-band rf pulse compression system for future linear colliders

    Directory of Open Access Journals (Sweden)

    Sami G. Tantawi

    2005-04-01

    Full Text Available We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC. The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  15. Status of the relativistic heavy ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Karl, F. [Brookhaven National Lab., Upton, NY (United States)

    1999-07-01

    At the present time, commissioning of the 3.8 kilometer Relativistic Heavy Ion Collider (RHIC) is in full swing. On July 16, 1999, the commissioners were successful in circulating a Gold Ion Beam for the first time, in the Blue Ring, as power supplies were being checked out for beam into the Yellow Ring. The commissioning schedule is to accelerate beam in the Blue Ring, then spiral and accelerate beam in the Yellow Ring, then if all goes well, obtain some collisions, all before a fast approaching shutdown in mid-August. The four experimental regions, Star, Phenix, Brahms and Phobos are gearing up for their maiden beam runs and much effort is being spent to make the thirst glimpse of the beam an exciting one. Our Alignment Group has been working closely with the experimenters in these areas, mostly with MANCAT type component pre-surveys and in the near future installing and locating these various components relative to the RHIC Beam Line. (author)

  16. Fast feedback for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, L.; Adolphsen, C.; Allison, S.; Gromme, T.; Grossberg, P.; Himel, T.; Krauter, K.; MacKenzie, R.; Minty, M.; Sass, R. [and others

    1995-05-01

    A fast feedback system provides beam stabilization for the SLC. As the SLC is in some sense a prototype for future linear colliders, this system may be a prototype for future feedbacks. The SLC provides a good base of experience for feedback requirements and capabilities as well as a testing ground for performance characteristics. The feedback system controls a wide variety of machine parameters throughout the SLC and associated experiments, including regulation of beam position, angle, energy, intensity and timing parameters. The design and applications of the system are described, in addition to results of recent performance studies.

  17. Muon Colliders and Neutrino Factories

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Daniel M. [IIT, Chicago

    2015-05-29

    Muon colliders and neutrino factories are attractive options for future facilities aimed at achieving the highest lepton-antilepton collision energies and precision measurements of Higgs boson and neutrino mixing matrix parameters. The facility performance and cost depend on how well a beam of muons can be cooled. Recent progress in muon cooling design studies and prototype tests nourishes the hope that such facilities could be built starting in the coming decade. The status of the key technologies and their various demonstration experiments is summarized. Prospects "post-P5" are also discussed.

  18. Physics at the linear collider

    Science.gov (United States)

    Moortgat-Pick, G.; Baer, H.; Battaglia, M.; Belanger, G.; Fujii, K.; Kalinowski, J.; Heinemeyer, S.; Kiyo, Y.; Olive, K.; Simon, F.; Uwer, P.; Wackeroth, D.; Zerwas, P. M.; Arbey, A.; Asano, M.; Bagger, J.; Bechtle, P.; Bharucha, A.; Brau, J.; Brümmer, F.; Choi, S. Y.; Denner, A.; Desch, K.; Dittmaier, S.; Ellwanger, U.; Englert, C.; Freitas, A.; Ginzburg, I.; Godfrey, S.; Greiner, N.; Grojean, C.; Grünewald, M.; Heisig, J.; Höcker, A.; Kanemura, S.; Kawagoe, K.; Kogler, R.; Krawczyk, M.; Kronfeld, A. S.; Kroseberg, J.; Liebler, S.; List, J.; Mahmoudi, F.; Mambrini, Y.; Matsumoto, S.; Mnich, J.; Mönig, K.; Mühlleitner, M. M.; Pöschl, R.; Porod, W.; Porto, S.; Rolbiecki, K.; Schmitt, M.; Serpico, P.; Stanitzki, M.; Stål, O.; Stefaniak, T.; Stöckinger, D.; Weiglein, G.; Wilson, G. W.; Zeune, L.; Moortgat, F.; Xella, S.; Bagger, J.; Brau, J.; Ellis, J.; Kawagoe, K.; Komamiya, S.; Kronfeld, A. S.; Mnich, J.; Peskin, M.; Schlatter, D.; Wagner, A.; Yamamoto, H.

    2015-08-01

    A comprehensive review of physics at an linear collider in the energy range of GeV-3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focusses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

  19. Instrumentation for Colliding Beam Physics

    CERN Document Server

    2017-01-01

    INSTR17, the International Conference on Instrumentation for Colliding Beam Physics, will be held in the Budker Institute of Nuclear Physics, Novosibirsk, Russia, on 27 February – 4 March, 2017. The conference covers novel methods of particle detection used in various experiments at particle accelerators as well as in astrophysics. It is organized in close relationship with the Vienna Conference on Instrumentation (last held in 2016) and the Pisa Meeting on Advanced Detectors (last held in 2015). The deadline for registration and abstract submission is 15 January. For more details visit the conference website instr17.inp.nsk.su. Will be published in: JINST

  20. Colliding with a crunching bubble

    Energy Technology Data Exchange (ETDEWEB)

    Freivogel, Ben; Freivogel, Ben; Horowitz, Gary T.; Shenker, Stephen

    2007-03-26

    In the context of eternal inflation we discuss the fate of Lambda = 0 bubbles when they collide with Lambda< 0 crunching bubbles. When the Lambda = 0 bubble is supersymmetric, it is not completely destroyed by collisions. If the domain wall separating the bubbles has higher tension than the BPS bound, it is expelled from the Lambda = 0 bubble and does not alter its long time behavior. If the domain wall saturates the BPS bound, then it stays inside the Lambda = 0 bubble and removes a finite fraction of future infinity. In this case, the crunch singularity is hidden behind the horizon of a stable hyperbolic black hole.

  1. High Luminosity 100 TeV Proton-Antiproton Collider

    Energy Technology Data Exchange (ETDEWEB)

    Oliveros, S. J. [Mississippi U.; Acosta, J. G. [Mississippi U.; Cremaldi, L. M. [Mississippi U.; Hart, T. L. [Mississippi U.; Summers, D. J. [Mississippi U.

    2016-10-01

    The energy scale for new physics is known to be in the multi-TeV range, signaling the potential need for a collider beyond the LHC. A $10^{34}$ cm$^{-2}$ s$^{-1}$ luminosity 100 TeV proton-antiproton collider is explored. Prior engineering studies for 233 and 270 km circumference tunnels were done for Illinois dolomite and Texas chalk signaling manageable tunneling costs. At a $p\\bar{p}$ the cross section for high mass states is of order 10x higher with antiproton collisions, where antiquarks are directly present rather than relying on gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets, because lower beam currents can produce the same rare event rates. In our design the increased momentum acceptance (11 $\\pm$ 2.6 GeV/c) in a Fermilab-like antiproton source is used with septa to collect 12x more antiprotons in 12 channels. For stochastic cooling, 12 cooling systems would be used, each with one debuncher/momentum equalizer ring and two accumulator rings. One electron cooling ring would follow. Finally antiprotons would be recycled during runs without leaving the collider ring, by joining them to new bunches with synchrotron damping.

  2. Electron cloud studies for the LHC and future proton colliders

    CERN Document Server

    Domínguez Sánchez de la Blanca, César Octavio; Zimmermann, Frank

    2014-01-01

    The Large Hadron Collider (LHC) is the world’s largest and most powerful particle collider. Its main objectives are to explore the validity of the standard model of particle physics and to look for new physics beyond it, at unprecedented collision energies and rates. A good luminosity performance is imperative to attain these goals. In the last stage of the LHC commissioning (2011-2012), the limiting factor to achieving the design bunch spacing of 25 ns has been the electron cloud effects. The electron cloud is also expected to be the most important luminosity limitation after the first Long Shut-Down of the LHC (LS1), when the machine should be operated at higher energy and with 25-ns spacing, as well as for the planned luminosity upgrade (HL-LHC) and future high energy proton colliders (HE-LHC and VHE-LHC). This thesis contributes to the understanding of the electron cloud observations during the first run of the LHC (2010-2012), presents the first beam dynamics analysis for the next generation of high en...

  3. Status and plans of the Compact Linear Collider Study

    CERN Document Server

    Doebert, Steffen

    2016-01-01

    The Compact Linear Collider (CLIC) project is exploring the possibility of constructing a multiTeV linear electron-positron collider for high-energy frontier physics studies beyond the LHC era. The CLIC concept is based on high-gradient normal-conducting accelerating structures. The RF power for the acceleration of the colliding beams is produced by a two-beam acceleration scheme, where power is extracted from a high current drive beam that runs parallel with the main linac. The key ongoing studies involve accelerator parameter optimisation, technical studies and component development, alignment and stability, and include a number of system performance studies in test-facilities around the world. The CLIC physics potential and main detector issues, as well as possible implementation staging, are being studied in parallel. A summary of the progress and status of the corresponding studies will be given, as well as an outline of the preparation and work towards developing a CLIC implementation plan by 2018/19

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

    CERN Document Server

    Sessa, Marco; The ATLAS collaboration

    2017-01-01

    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. Standard Model Background of the Cosmological Collider.

    Science.gov (United States)

    Chen, Xingang; Wang, Yi; Xianyu, Zhong-Zhi

    2017-06-30

    The inflationary universe can be viewed as a "cosmological collider" with an energy of the Hubble scale, producing very massive particles and recording their characteristic signals in primordial non-Gaussianities. To utilize this collider to explore any new physics at very high scales, it is a prerequisite to understand the background signals from the particle physics standard model. In this Letter we describe the standard model background of the cosmological collider.

  6. International Workshop on Linear Colliders 2010

    CERN Multimedia

    CERN. Geneva

    2010-01-01

    IWLC2010 International Workshop on Linear Colliders 2010ECFA-CLIC-ILC joint meeting: Monday 18 October - Friday 22 October 2010Venue: CERN and CICG (International Conference Centre Geneva, Switzerland) This year, the International Workshop on Linear Colliders organized by the European Committee for Future Accelerators (ECFA) will study the physics, detectors and accelerator complex of a linear collider covering both CLIC and ILC options.Contact Workshop Secretariat  IWLC2010 is hosted by CERN

  7. Crabbing system for an electron-ion collider

    Energy Technology Data Exchange (ETDEWEB)

    Castilla, Alejandro [Old Dominion Univ., Norfolk, VA (United States)

    2017-05-01

    As high energy and nuclear physicists continue to push further the boundaries of knowledge using colliders, there is an imperative need, not only to increase the colliding beams' energies, but also to improve the accuracy of the experiments, and to collect a large quantity of events with good statistical sensitivity. To achieve the latter, it is necessary to collect more data by increasing the rate at which these processes are being produced and detected in the machine. This rate of events depends directly on the machine's luminosity. The luminosity itself is proportional to the frequency at which the beams are being delivered, the number of particles in each beam, and inversely proportional to the cross-sectional size of the colliding beams. There are several approaches that can be considered to increase the events statistics in a collider other than increasing the luminosity, such as running the experiments for a longer time. However, this also elevates the operation expenses, while increasing the frequency at which the beams are delivered implies strong physical changes along the accelerator and the detectors. Therefore, it is preferred to increase the beam intensities and reduce the beams cross-sectional areas to achieve these higher luminosities. In the case where the goal is to push the limits, sometimes even beyond the machines design parameters, one must develop a detailed High Luminosity Scheme. Any high luminosity scheme on a modern collider considers|in one of their versions|the use of crab cavities to correct the geometrical reduction of the luminosity due to the beams crossing angle. In this dissertation, we present the design and testing of a proof-of-principle compact superconducting crab cavity, at 750 MHz, for the future electron-ion collider, currently under design at Jefferson Lab. In addition to the design and validation of the cavity prototype, we present the analysis of the first order beam dynamics and the integration of the

  8. Very large hadron collider (VLHC)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    A VLHC informal study group started to come together at Fermilab in the fall of 1995 and at the 1996 Snowmass Study the parameters of this machine took form. The VLHC as now conceived would be a 100 TeV hadron collider. It would use the Fermilab Main Injector (now nearing completion) to inject protons at 150 GeV into a new 3 TeV Booster and then into a superconducting pp collider ring producing 100 TeV c.m. interactions. A luminosity of {approximately}10{sup 34} cm{sup -2}s{sup -1} is planned. Our plans were presented to the Subpanel on the Planning for the Future of US High- Energy Physics (the successor to the Drell committee) and in February 1998 their report stated ``The Subpanel recommends an expanded program of R&D on cost reduction strategies, enabling technologies, and accelerator physics issues for a VLHC. These efforts should be coordinated across laboratory and university groups with the aim of identifying design concepts for an economically and technically viable facility`` The coordination has been started with the inclusion of physicists from Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), and Cornell University. Clearly, this collaboration must expanded internationally as well as nationally. The phrase ``economically and technically viable facility`` presents the real challenge.

  9. Disentangling heavy flavor at colliders

    Science.gov (United States)

    Ilten, Philip; Rodd, Nicholas L.; Thaler, Jesse; Williams, Mike

    2017-09-01

    We propose two new analysis strategies for studying charm and beauty quarks at colliders. The first strategy is aimed at testing the kinematics of heavy-flavor quarks within an identified jet. Here, we use the SoftDrop jet-declustering algorithm to identify two subjets within a large-radius jet, using subjet flavor tagging to test the heavy-quark splitting functions of QCD. For subjets containing a J /ψ or ϒ , this declustering technique can also help probe the mechanism for quarkonium production. The second strategy is aimed at isolating heavy-flavor production from gluon splitting. Here, we introduce a new FlavorCone algorithm, which smoothly interpolates from well-separated heavy-quark jets to the gluon-splitting regime where jets overlap. Because of its excellent ability to identify charm and beauty hadrons, the LHCb detector is ideally suited to pursue these strategies, though similar measurements should also be possible at ATLAS and CMS. Together, these SoftDrop and FlavorCone studies should clarify a number of aspects of heavy-flavor physics at colliders, and provide crucial information needed to improve heavy-flavor modeling in parton-shower generators.

  10. Heavy-ion performance of the LHC and future colliders

    Energy Technology Data Exchange (ETDEWEB)

    Schaumann, Michaela

    2015-04-29

    In 2008 the Large Hadron Collider (LHC) and its experiments started operation at the European Centre of Nuclear Research (CERN) in Geneva with the main aim of finding or excluding the Higgs boson. Only four years later, on the 4th of July 2012, the discovery of a Higgs-like particle was proven and first published by the two main experiments ATLAS and CMS. Even though proton-proton collisions are the main operation mode of the LHC, it also acts as an heavy-ion collider. Here, the term ''heavy-ion collisions'' refers to the collision between fully stripped nuclei. While the major hardware system of the LHC is compatible with heavy-ion operation, the beam dynamics and performance limits of ion beams are quite different from those of protons. Because of the higher mass and charge of the ions, beam dynamic effects like intra-beam scattering and radiation damping are stronger. Also the electromagnetic cross-sections in the collisions are larger, leading to significantly faster intensity decay and thus shorter luminosity lifetimes. As the production cross-sections for various physics processes under study of the experiments are still small at energies reachable with the LHC and because the heavy-ion run time is limited to a few days per year, it is essential to obtain the highest possible collision rate, i.e. maximise the instantaneous luminosity, in order to obtain enough events and therefore low statistical errors. Within this thesis, the past performance of the LHC in lead-lead (Pb-Pb) collisions, at a centre-of-mass energy of 2.76 TeV per colliding nucleon pair, is analysed and potential luminosity limitations are identified. Tools are developed to predict future performance and techniques are presented to further increase the luminosity. Finally, a perspective on the future of high energy heavy-ion colliders is given.

  11. Effect of Gu Tong Xian capsule on expression level of type I, II collagen and BMP-2 mRNA in rabbits with fracture during long-distance running

    Directory of Open Access Journals (Sweden)

    Liang Li

    2017-05-01

    Full Text Available The study aims to analyze and investigate the effects of Gu Tong Xian Capsule on the expression level of type I, II collagen and BMP-2 mRNA in rabbits with fracture during long-distance running. 60 adult healthy rabbits were selected as research objects, and then randomly divided into three groups including model group, positive control group and treatment group, each containing 20 rabbits. The three groups were treated with saline gastric lavage, powder for fracture and trauma, and Gu Tong Xian capsule, respectively. The rabbits of the three groups were respectively sacrificed at 1st week, 2nd weeks and 4th week after operation for sample collection. After that, the expression levels of bone collagen type I, II and BMP-2 of three groups were measured and compared with each other. At all stages, the transcriptional level of type I collagen mRNA in the treatment group were significantly higher than that in the positive control group and model group (p < 0.05; Transcriptional level of type II collagen mRNA in the treatment group increased significantly in the first week, then gradually declined in the 2nd and 4th week, with significantly difference to the model group and the positive control group (p < 0.05. In addition, the transcriptional level of bone morphogenetic protein BMP-2 mRNA at fracture site of the treatment group was higher than that of model group and positive control group (p < 0.05. Gu Tong Xian Capsule can significantly promote fracture healing of experiment rabbits and reduce fracture healing time. Moreover, it can well regulate the expression levels of type I, II collagen and transcriptional level ofBMP-2 mRNA in experiment rabbits with fracture.

  12. Dr. Sheehan on Running.

    Science.gov (United States)

    Sheehan, George A.

    This book is both a personal and technical account of the experience of running by a heart specialist who began a running program at the age of 45. In its seventeen chapters, there is information presented on the spiritual, psychological, and physiological results of running; treatment of athletic injuries resulting from running; effects of diet…

  13. The LHC Tier1 at PIC: experience from first LHC run

    Directory of Open Access Journals (Sweden)

    Flix J.

    2013-11-01

    Full Text Available This paper summarizes the operational experience of the Tier1 computer center at Port d’InformacióCientífica (PIC supporting the commissioning and first run (Run1 of the Large Hadron Collider (LHC. Theevolution of the experiment computing models resulting from the higher amounts of data expected after therestart of the LHC are also described.

  14. A Study of The Standard Model Higgs, WW and ZZ Production in Dilepton Plus Missing Transverse Energy Final State at CDF Run II

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Shih-Chieh [Univ. of California, San Diego, CA (United States)

    2008-01-01

    We report on a search for Standard Model (SM) production of Higgs to WW* in the two charged lepton (e, μ) and two neutrino final state in p$\\bar{p}$ collisions at a center of mass energy √s = 1.96 TeV. The data were collected with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 1.9fb-1. The Matrix Element method is developed to calculate the event probability and to construct a likelihood ratio discriminator. There are 522 candidates observed with an expectation of 513 ± 41 background events and 7.8 ± 0.6 signal events for Higgs mass 160GeV/c2 at next-to-next-to-leading logarithmic level calculation. The observed 95% C.L. upper limit is 0.8 pb which is 2.0 times the SM prediction while the median expected limit is 3.1$+1.3\\atop{-0.9}$ with systematics included. Results for 9 other Higgs mass hypotheses ranging from 110GeV/c2 to 200GeV/c2 are also presented. The same dilepton plus large transverse energy imbalance (ET) final state is used in the SM ZZ production search and the WW production study. The observed significance of ZZ → llvv channel is 1.2σ. It adds extra significance to the ZZ → 4l channel and leads to a strong evidence of ZZ production with 4.4 σ significance. The potential improvement of the anomalous triple gauge coupling measurement by using the Matrix Element method in WW production is also studied.

  15. Water transfer and loss in hit-and-run collisions

    Science.gov (United States)

    Burger, C.; Maindl, T. I.; Schäfer, C.

    2017-09-01

    This work focuses on transfer and loss of volatiles, like water, in hit-and-run collisions, where especially the smaller one of the colliding pair is often stripped of considerable amounts of its initial volatile content, but still survives the encounter more or less intact. We find water losses up to 75 percent in a single collision, depending on various parameters, especially velocity, impact angle and mass ratio, but also on the total colliding mass. The physical state, especially vaporization of volatiles, is found to be particularly important in collisions of approximately Mars-sized bodies, with high impact energies, but still potentially easy volatile escape.

  16. Last magnet in place for colossal collider

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "Workers have installed the last magnet for the world's mew highest-energy particle smasher, the Large Hadron Collider (LHC). The installation marks an important milestone; however, researchers still may not get the collider completed in time to start it up in November as planned." (1 page)

  17. Multibillion-dolalr collider plans unveiled

    CERN Multimedia

    Cartlidge, Edwin

    2007-01-01

    "Particle physicists released an outline design for the proposed International Linear Collider (ILC) at a meeting in Beijing this morning. The design details the components needed to build the 31 km-long facility and comes with and initial estimate of the collider's cost: a cool $6.5bn for the core project. (1 page)

  18. Physicist pins hopes on particle collider

    CERN Multimedia

    2007-01-01

    Physicist pins hopes on particle collider By Deseret Morning News Published: Monday, Dec. 31, 27 12:4 a.m. MST FONT Scott Thomas, a 187 State University graduate, is working at the frontiers of science. The theoretical physicist is crafting ways to extract fundamental secrets that seem certain to be uncovered by the Large Hadron Collider.

  19. Vertex Tracking at a Future Linear Collider

    CERN Document Server

    Battaglia, Marco

    2011-01-01

    The anticipated physics program at an high energy e+e- linear collider places special emphasis on the accuracy in extrapolating charged particle tracks to their production vertex to tag heavy quarks and leptons. This paper reviews physics motivations and performance requirements, sensor R&D directions and current results of the studies for a vertex tracker at a future linear collider.

  20. A novel method for modeling the recoil in W boson events at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Abazov, V.M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Abbott, B. [University of Oklahoma, Norman, OK 73019 (United States); Abolins, M. [Michigan State University, East Lansing, MI 48824 (United States); Acharya, B.S. [Tata Institute of Fundamental Research, Mumbai (India); Adams, M. [University of Illinois at Chicago, Chicago, IL 60607 (United States); Adams, T. [Florida State University, Tallahassee, FL 32306 (United States); Aguilo, E. [University of Alberta, Edmonton, Alberta (Canada); Simon Fraser University, Burnaby, British Columbia (Canada); York University, Toronto, Ontario (Canada); McGill University, Montreal, Quebec (Canada); Ahsan, M. [Kansas State University, Manhattan, KS 66506 (United States); Alexeev, G.D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Alkhazov, G. [Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Alton, A. [University of Michigan, Ann Arbor, MI 48109 (United States); Alverson, G. [Northeastern University, Boston, MA 02115 (United States); Alves, G.A. [LAFEX, Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil); Ancu, L.S. [Radboud University Nijmegen/NIKHEF, Nijmegen (Netherlands); Andeen, T.; Anzelc, M.S. [Northwestern University, Evanston, IL 60208 (United States); Aoki, M. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Arnoud, Y. [LPSC, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, Grenoble (France); Arov, M. [Louisiana Tech University, Ruston, LA 71272 (United States); Arthaud, M. [CEA, Irfu, SPP, Saclay (France)] (and others)

    2009-10-11

    We present a new method for modeling the hadronic recoil in W{yields}l{nu} events produced at hadron colliders. The recoil is chosen from a library of recoils in Z{yields}ll data events and overlaid on a simulated W{yields}l{nu} event. Implementation of this method requires that the data recoil library describe the properties of the measured recoil as a function of the true, rather than the measured, transverse momentum of the boson. We address this issue using a multidimensional Bayesian unfolding technique. We estimate the statistical and systematic uncertainties from this method for the W boson mass and width measurements assuming 1fb{sup -1} of data from the Fermilab Tevatron. The uncertainties are found to be small and comparable to those of a more traditional parameterized recoil model. For the high precision measurements that will be possible with data from Run II of the Fermilab Tevatron and from the CERN LHC, the method presented in this paper may be advantageous, since it does not require an understanding of the measured recoil from first principles.

  1. Collide@CERN - public lecture

    CERN Multimedia

    2012-01-01

    CERN, the Republic and Canton of Geneva and the City of Geneva are delighted to invite you to a public lecture by Gilles Jobin, first winner of the Collide@CERN Geneva Dance and Performance Artist-in-residence Prize, and his CERN inspiration partner, Joao Pequenao. They will present their work in dance and science at the Globe of Science and Innovation on Wednesday, 23 May 2012 at 7 p.m. (doors open at 6.30 p.m.).   
                                                  Programme 19:00 Opening address by - Professor Rolf-Dieter Heuer, CERN Director-General, - Ariane Koek...

  2. The Large Hadron Collider project

    CERN Document Server

    Engelen, Joseph J

    2005-01-01

    The Large Hadron Collider (LHC) will enable proton-proton collisions at an energy of more than fourteen thousand times the proton mass. This allows the discovery of new elementary particles with very large masses, in particular of the Higgs boson. The Higgs boson is crucial for understanding the mechanism that Nature chose to give mass to particles. The Higgs boson has turned out to be very hard to find but the LHC should allow a decisive step into new territory, unveiling one or even more Higgs bosons. The new energy domain of the LHC also inspires speculations about discoveries relevant for understanding dark matter and about the discovery of new space dimensions, so far hidden to us. In the talk an overview of the physics at LHC and a report on the status of the project, accelerator and experiments, will be presented.

  3. Odd tracks at hadron colliders.

    Science.gov (United States)

    Meade, Patrick; Papucci, Michele; Volansky, Tomer

    2012-07-20

    New physics that exhibits irregular tracks such as kinks, intermittent hits, or decay in flight may easily be missed at hadron colliders. We demonstrate this by studying viable models of light, O(10  GeV), colored particles that decay predominantly inside the tracker. Such particles can be produced at staggering rates, and yet, may not be identified or triggered on at the LHC, unless specifically searched for. In addition, the models we study provide an explanation for the original measurement of the anomalous charged track distribution by CDF. The presence of irregular tracks in these models reconcile that measurement with the subsequent reanalysis and the null results of ATLAS and CMS. Our study clearly illustrates the need for a comprehensive study of irregular tracks at the LHC.

  4. Accelerator physics at the Tevatron collider

    CERN Document Server

    Shiltsev, Vladimir

    2014-01-01

    This book presents the developments in accelerator physics and technology implemented at the Tevatron proton-antiproton collider, the world’s most powerful accelerator for almost twenty years prior to the completion of the Large Hadron Collider. The book covers the history of collider operation and upgrades, novel arrangements of beam optics and methods of orbit control, antiproton production and cooling, beam instabilities and feedback systems, halo collimation, and advanced beam instrumentation. The topics discussed show the complexity and breadth of the issues associated with modern hadron accelerators, while providing a systematic approach needed in the design and construction of next generation colliders. This book is a valuable resource for researchers in high energy physics and can serve as an introduction for students studying the beam physics of colliders.

  5. The International Linear Collider Progress Report 2015

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Yamamoto, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-07-15

    The International Committee for Future Accelerators (ICFA) set up the Global Design Effort (GDE) for the design of the International Linear Collider (ILC) in 2005. Drawing on the resources of over 300 national laboratories, universities and institutes worldwide, the GDE produced a Reference Design Report in 2007, followed by a more detailed Technical Design Report (TDR) in 2013. Following this report, the GDE was disbanded. A compact core team, the Linear Collider Collaboration (LCC), replaced it. This is still under the auspices of ICFA and is directly overseen by the Linear Collider Board, which reports to ICFA. The LCC is charged with continuing the design effort on a much-reduced scale until the Project is approved for construction. An additional mandate of the LCC was to bring together all linear collider work, including the CERN-based Compact Linear Collider (CLIC) under one structure in order to exploit synergies between the two studies.

  6. Test results of a combined distributed ion pump/non-evaporable getter pump design developed as a proposed alternative pumping system for the PEP-II asymmetric B-Factory collider

    Energy Technology Data Exchange (ETDEWEB)

    Holdener, F.; Behne, D.; Hathaway, D. [Lawrence Livermore National Lab., CA (United States)] [and others

    1995-04-24

    The authors have built and tested an all-in-one combination plate-type distributed ion pump/non-evaporable getter pump design (DIP/NEG) considered as a proposed alternative pumping system for the PEP-II B-Factory High Energy Ring (HER). The DIP portion of the design used a Penning cell hole size of 12 mm in a mostly uniform magnetic field of 0.18 T. The NEG portion of the design used commercially available non-evaporable getter material type St-707{trademark}. A detailed description of the design is presented along with results of pumping speed measurements.

  7. Beamstrahlung spectra in next generation linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.; Chen, P. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Kozanecki, W. (DAPNIA-SPP, CEN-Saclay (France))

    1992-04-01

    For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distribution of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formulation to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.

  8. Self colliding beams ('migma') and controlled fusion

    CERN Document Server

    Maglic, Bogdan C; Mazarakis, M; Miller, R A; Nering, J; Powell, C; Treglio, J

    1975-01-01

    While much of the early work on colliding beams was done in the US, the lead on the development of this technique is now held by Europe. The most spectacular being the only colliding of nuclei in the intersecting storage rings at CERN. The idea of using colliding beams for fusion is nearly as old as is the interest in fusion as a source of power, but the problems of low reaction rate and high Coulomb scattering initially seemed insurmountable. The authors describe recent work done at the Fusion Energy Corporation which attempts to overcome these problems. (9 refs).

  9. SLAC linear collider conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The linear collider system is described in detail, including the transport system, the collider lattice, final focusing system, positron production, beam damping and compression, high current electron source, instrumentation and control, and the beam luminosity. The experimental facilities and the experimental uses are discussed along with the construction schedule and estimated costs. Appendices include a discussion of space charge effects in the linear accelerator, emittance growth in the collider, the final focus system, beam-beam instabilities and pinch effects, and detector backgrounds. (GHT)

  10. 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.

  11. Status of the Electromagnetic Calorimeter Trigger system at the Belle II experiment

    Science.gov (United States)

    Kim, S. H.; Lee, I. S.; Unno, Y.; Cheon, B. G.

    2017-09-01

    The Belle II experiment at the SuperKEKB collider in Japan has been under the construction toward a physics run in 2018 with an ultimate target of 40 times higher instantaneous luminosity than the KEKB collider. The main physics motivation is to search for the New Physics from heavy quark/lepton flavor decays. In order to select an event of interest efficiently under much higher luminosity and beam background environment than the KEKB, we have upgraded the Electromagnetic Calorimeter (ECL) hardware trigger system. It would be realized by the improvement of ECL trigger logic based on two main triggers, the total energy and the number of clusters, with an FPGA-based flexible architecture and a high speed serial link for the data transfer. We report the current status of hardware, firmware, and software that has been achieved so far. The overall scheme of the system will be presented as well.

  12. Design of a High Luminosity 100 TeV Proton-Antiproton Collider

    Science.gov (United States)

    Oliveros Tautiva, Sandra Jimena

    Currently new physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. A 10 34 cm-2 s-1 luminosity 100 TeV proton-antiproton collider is explored with 7x the energy of the LHC. The dipoles are 4.5 T to reduce cost. A proton-antiproton collider is selected as a future machine for several reasons. The cross section for many high mass states is 10 times higher in pp than pp collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per bunch crossing, because lower beam currents can produce the same rare event rates. Events are also more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller beta* for higher luminosity. To adjust to antiproton beam losses (burn rate), a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might follow the stochastic cooling rings for antiproton stacking. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and synchrotron damping. These basic ideas are explored in this work on a future 100 TeV proton-antiproton collider and the main parameters are presented.

  13. Design of a High Luminosity 100 TeV Proton Antiproton Collider

    Energy Technology Data Exchange (ETDEWEB)

    Oliveros Tuativa, Sandra Jimena [Univ. of Mississippi, Oxford, MS (United States)

    2017-04-01

    Currently new physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. A 10$^{\\,34}$ cm$^{-2}$ s$^{-1}$ luminosity 100 TeV proton-antiproton collider is explored with 7$\\times$ the energy of the LHC. The dipoles are 4.5\\,T to reduce cost. A proton-antiproton collider is selected as a future machine for several reasons. The cross section for many high mass states is 10 times higher in $p\\bar{p}$ than $pp$ collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per bunch crossing, because lower beam currents can produce the same rare event rates. Events are also more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller $\\beta^{*}$ for higher luminosity. To adjust to antiproton beam losses (burn rate), a Fermilab-like antiproton source would be adapted to disperse the beam into 12 different momentum channels, using electrostatic septa, to increase antiproton momentum capture 12 times. At Fermilab, antiprotons were stochastically cooled in one Debuncher and one Accumulator ring. Because the stochastic cooling time scales as the number of particles, two options of 12 independent cooling systems are presented. One electron cooling ring might follow the stochastic cooling rings for antiproton stacking. Finally antiprotons in the collider ring would be recycled during runs without leaving the collider ring, by joining them to new bunches with snap bunch coalescence and synchrotron damping. These basic ideas are explored in this work on a future 100 TeV proton-antiproton collider and the main parameters are presented.

  14. Facts about real antimatter collide with fiction

    CERN Multimedia

    Siegfried, Tom

    2004-01-01

    When science collides with fiction, sometimes a best seller emerges from the debris. Take Dan Brown's Angels & Demons, for instance, a murder mystery based on science at CERN, the European nuclear research laboratory outside Geneva

  15. Physics prospects at a linear -collider

    Indian Academy of Sciences (India)

    The talk described the prospects of studying standard model parameters as well as scenarios beyond the standard model, like the minimal supersymmetric standard model, theories with extra dimensions and theories with extra neutral gauge bosons, at a future linear + - collider.

  16. The collider calamity, publ. by Scientific American

    CERN Multimedia

    2006-01-01

    "For decades, the big guns of American science have been the U.S. Department of Energy's particle collider, which investigate the nature of matter by accelerating subatomic particles and smashing them together." (1 page)

  17. Il Collisore LHC (Large Hadron Collider)

    CERN Multimedia

    Brianti, Giorgio

    2004-01-01

    In 2007, in a new Collider in the tunnel of 27km, collisions will be made between very powerful beams of protons and ions. The energies will be very high to try to catch the most tiny particle (1 page)

  18. Photon Collider Physics with Real Photon Beams

    Energy Technology Data Exchange (ETDEWEB)

    Gronberg, J; Asztalos, S

    2005-11-03

    Photon-photon interactions have been an important probe into fundamental particle physics. Until recently, the only way to produce photon-photon collisions was parasitically in the collision of charged particles. Recent advances in short-pulse laser technology have made it possible to consider producing high intensity, tightly focused beams of real photons through Compton scattering. A linear e{sup +}e{sup -} collider could thus be transformed into a photon-photon collider with the addition of high power lasers. In this paper they show that it is possible to make a competitive photon-photon collider experiment using the currently mothballed Stanford Linear Collider. This would produce photon-photon collisions in the GeV energy range which would allow the discovery and study of exotic heavy mesons with spin states of zero and two.

  19. Vertex Reconstruction in ATLAS Run II

    CERN Document Server

    Zhang, Matt; The ATLAS collaboration

    2016-01-01

    Vertex reconstruction is the process of taking reconstructed tracks and using them to determine the locations of proton collisions. In this poster we present the performance of our current vertex reconstruction algorithm, and look at investigations into potential improvements from a new seed finding method.

  20. Higgs results from the Tevatron Run II

    Energy Technology Data Exchange (ETDEWEB)

    Tuchming, B.; /DAPNIA, Saclay

    2005-01-01

    The data taken at the Tevatron experiments have been analyzed to search for Higgs bosons. For the Standard Model Higgs searches, no excess is observed, the data are in good agreement with the expectations, so that limits are set on the production rates. For various theoretical models beyond the Standard Model, there is no excess either, which allows to derive constraints in their respective parameter spaces.

  1. The LHCb trigger in Run II

    CERN Document Server

    Michielin, Emanuele

    2016-01-01

    The LHCb trigger system has been upgraded to allow alignment, calibration and physics analysis to be performed in real time. An increased CPU capacity and improvements in the software have allowed lifetime unbiased selections of beauty and charm decays in the high level trigger. Thanks to offline quality event reconstruction already available online, physics analyses can be performed directly on this information and for the majority of charm physics selections a reduced event format can be written out. Beauty hadron decays are more efficiently triggered by re-optimised inclusive selections, and the HLT2 output event rate is increased by a factor of three.

  2. Tau Identification at CMS in Run II

    CERN Document Server

    Ojalvo, Isabel

    2016-01-01

    During LHC Long Shutdown 1 necessary upgrades to the CMS detector were made. CMS also took the opportunity to improve further particle reconstruction. A number of improvements were made to the Hadronic Tau reconstruction and Identification algorithms. In particular, electromag- netic strip reconstruction of the Hadron plus Strips (HPS) algorithm was improved to better model signal of pi0 from tau decays. This modification improves energy response and removes the tau footprint from isolation area. In addition to this, improvement to discriminators combining iso- lation and tau life time variables, and anti-electron in MultiVariate Analysis technique was also developed. The results of these improvements are presented and validation of Tau Identification using a variety of techniques is shown.

  3. Governance of the International Linear Collider Project

    Energy Technology Data Exchange (ETDEWEB)

    Foster, B.; /Oxford U.; Barish, B.; /Caltech; Delahaye, J.P.; /CERN; Dosselli, U.; /INFN, Padua; Elsen, E.; /DESY; Harrison, M.; /Brookhaven; Mnich, J.; /DESY; Paterson, J.M.; /SLAC; Richard, F.; /Orsay, LAL; Stapnes, S.; /CERN; Suzuki, A.; /KEK, Tsukuba; Wormser, G.; /Orsay, LAL; Yamada, S.; /KEK, Tsukuba

    2012-05-31

    Governance models for the International Linear Collider Project are examined in the light of experience from similar international projects around the world. Recommendations for one path which could be followed to realize the ILC successfully are outlined. The International Linear Collider (ILC) is a unique endeavour in particle physics; fully international from the outset, it has no 'host laboratory' to provide infrastructure and support. The realization of this project therefore presents unique challenges, in scientific, technical and political arenas. This document outlines the main questions that need to be answered if the ILC is to become a reality. It describes the methodology used to harness the wisdom displayed and lessons learned from current and previous large international projects. From this basis, it suggests both general principles and outlines a specific model to realize the ILC. It recognizes that there is no unique model for such a laboratory and that there are often several solutions to a particular problem. Nevertheless it proposes concrete solutions that the authors believe are currently the best choices in order to stimulate discussion and catalyze proposals as to how to bring the ILC project to fruition. The ILC Laboratory would be set up by international treaty and be governed by a strong Council to whom a Director General and an associated Directorate would report. Council would empower the Director General to give strong management to the project. It would take its decisions in a timely manner, giving appropriate weight to the financial contributions of the member states. The ILC Laboratory would be set up for a fixed term, capable of extension by agreement of all the partners. The construction of the machine would be based on a Work Breakdown Structure and value engineering and would have a common cash fund sufficiently large to allow the management flexibility to optimize the project's construction. Appropriate contingency

  4. Photon Linear Collider Gamma-Gamma Summary

    Energy Technology Data Exchange (ETDEWEB)

    Gronberg, J

    2012-02-27

    High energy photon - photon collisions can be achieved by adding high average power short-pulse lasers to the Linear Collider, enabling an expanded physics program for the facility. The technology required to realize a photon linear collider continues to mature. Compton back-scattering technology is being developed around the world for low energy light source applications and high average power lasers are being developed for Inertial Confinement Fusion.

  5. Excited quark production at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Baur, U.; Hinchliffe, I.; Zeppenfeld, D.

    1987-06-01

    Composite models generally predict the existence of excited quark and lepton states. We consider the production and experimental signatures of excited quarks Q* of spin and isospin 1/2 at hadron colliders and estimate the background for those channels which are most promising for Q* identification. Multi-TeV pp-colliders will give access to such particles with masses up to several TeV.

  6. Nuclear collisions at the Future Circular Collider

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, N., E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia-Spain (Spain); Dainese, A. [INFN – Sezione di Padova, 35131 Padova (Italy); D' Enterria, D. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland); Masciocchi, S. [EMMI and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Roland, C. [Massachusetts Institute of Technology, Cambridge, MA 02139-4307 (United States); Salgado, C.A. [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia-Spain (Spain); Leeuwen, M. van [Nikhef, National Institute for Subatomic Physics, Amsterdam (Netherlands); Institute for Subatomic Physics of Utrecht University, Utrecht (Netherlands); Wiedemann, U.A. [Physics Department, CERN, CH-1211 Genéve 23 (Switzerland)

    2016-12-15

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  7. Nuclear collisions at the Future Circular Collider

    CERN Document Server

    Armesto, N.; d'Enterria, D.; Masciocchi, S.; Roland, C.; Salgado, C.A.; van Leeuwen, M.; Wiedemann, U.A.

    2016-01-01

    The Future Circular Collider is a new proposed collider at CERN with centre-of-mass energies around 100 TeV in the pp mode. Ongoing studies aim at assessing its physics potential and technical feasibility. Here we focus on updates in physics opportunities accessible in pA and AA collisions not covered in previous Quark Matter contributions, including Quark-Gluon Plasma and gluon saturation studies, novel hard probes of QCD matter, and photon-induced collisions.

  8. Collider Interplay for Supersymmetry, Higgs and Dark Matter.

    Science.gov (United States)

    Buchmueller, O; Citron, M; Ellis, J; Guha, S; Marrouche, J; Olive, K A; de Vries, K; Zheng, Jiaming

    We discuss the potential impacts on the CMSSM of future LHC runs and possible [Formula: see text] and higher-energy proton-proton colliders, considering searches for supersymmetry via  [Formula: see text] events, precision electroweak physics, Higgs measurements and dark matter searches. We validate and present estimates of the physics reach for exclusion or discovery of supersymmetry via [Formula: see text] searches at the LHC, which should cover the low-mass regions of the CMSSM parameter space favoured in a recent global analysis. As we illustrate with a low-mass benchmark point, a discovery would make possible accurate LHC measurements of sparticle masses using the MT2 variable, which could be combined with cross-section and other measurements to constrain the gluino, squark and stop masses and hence the soft supersymmetry-breaking parameters [Formula: see text] and [Formula: see text] of the CMSSM. Slepton measurements at CLIC would enable [Formula: see text] and [Formula: see text] to be determined with high precision. If supersymmetry is indeed discovered in the low-mass region, precision electroweak and Higgs measurements with a future circular [Formula: see text] collider (FCC-ee, also known as TLEP) combined with LHC measurements would provide tests of the CMSSM at the loop level. If supersymmetry is not discovered at the LHC, it is likely to lie somewhere along a focus-point, stop-coannihilation strip or direct-channel A  /  H resonance funnel. We discuss the prospects for discovering supersymmetry along these strips at a future circular proton-proton collider such as FCC-hh. Illustrative benchmark points on these strips indicate that also in this case FCC-ee could provide tests of the CMSSM at the loop level.

  9. Diffractively produced Z bosons in the muon decay channel in p-pbar collisions at s**(1/2) = 1.96 TeV, and the measurement of the efficiency of the D0 Run II luminosity monitor

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Tamsin L

    2006-04-01

    The first analysis of diffractively produced Z bosons in the muon decay channel is presented, using data taken by the D0 detector at the Tevatron at {radical}s = 1.96 TeV. The data sample corresponds to an integrated luminosity of 109 pb{sup -1}. The diffractive sample is defined using the fractional momentum loss {zeta} of the intact proton or antiproton measured using the calorimeter and muon detector systems. In a sample of 10791 (Z/{gamma})* {yields} {mu}{sup +}{mu}{sup -} events, 24 diffractive candidate events are found with {zeta} < 0.02. The first work towards measuring the cross section times branching ratio for diffractive production of (Z/{gamma})* {yields} {mu}{sup +}{mu}{sup -} is presented for the kinematic region {zeta} < 0.02. The first work towards measuring the cross section times branching ratio for diffractive production of (Z/{gamma})* {yields} {mu}{sup +}{mu}{sup -} is presented for the kinematic region {zeta} < 0.02. The systematic uncertainties are not yet sufficiently understood to present the cross section result. In addition, the first measurement of the efficiency of the Run II D0 Luminosity Monitor is presented, which is used in all cross section measurements. The efficiency is: {var_epsilon}{sub LM} = (90.9 {+-} 1.8)%.

  10. Considerations on Energy Frontier Colliders after LHC

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, Vladimir [Fermilab

    2016-11-15

    Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

  11. The 2015 Heavy-Ion Run of the LHC

    CERN Document Server

    Jowett, John; Bruce, Roderik; Giovannozzi, Massimo; Hermes, Pascal; Höfle, Wolfgang; Lamont, Mike; Mertens, Tom; Redaelli, Stefano; Schaumann, Michaela; Uythoven, Jan; Wenninger, Jorg

    2016-01-01

    In late 2015 the LHC collided lead nuclei at a beam energy of 6.37 Z TeV, chosen to match the 5.02 TeV per colliding nucleon pair of the p-Pb collision run in 2013. In so doing, it surpassed its design luminosity by a factor of 2. Besides the higher energy, the operational configuration had a number of new features with respect to the previous Pb-Pb run at 3.5 Z TeV in 2011; unusual bunch patterns providing collisions in the LHCb experiment for the first time, luminosity levelling and sharing requirements, a vertical displacement of the interaction point in the ALICE experiment, and operation closer to magnet quench limits with mitigation measures. We present a summary of the commissioning and operation and what has been learned in view of future heavy-ion operation at higher luminosity.

  12. vh@nnlo-Higgs Strahlung at hadron colliders

    Science.gov (United States)

    Brein, Oliver; Harlander, Robert V.; Zirke, Tom J. E.

    2013-03-01

    A numerical program for the evaluation of the inclusive cross section for associated Higgs production with a massive weak gauge boson at hadron colliders is described, σ(pp/pp¯→HV), V∈{W,Z}. The calculation is performed in the framework of the Standard Model and includes next-to-next-to-leading order QCD as well as next-to-leading order electro-weak effects. Catalogue identifier: AEOF_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOF_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 32835 No. of bytes in distributed program, including test data, etc.: 206496 Distribution format: tar.gz Programming language: Fortran 77, C++. Computer: Personal computer. Operating system: Unix/Linux, Mac OS. RAM: A few 100 MB Classification: 11.1. External routines: LHAPDF (http://lhapdf.hepforge.org/), CUBA (http://www.feynarts.de/cuba/) Nature of problem: Calculation of the inclusive total cross section for associated Higgs- and W- or Z- boson production at hadron colliders through next-to-next-to-leading order QCD. Solution method: Numerical Monte Carlo integration. Running time: A few seconds for a single set of parameters.

  13. The International Linear Collider Technical Design Report - Volume 4: Detectors

    CERN Document Server

    Behnke, Ties; Burrows, Philip N.; Fuster, Juan; Peskin, Michael; Stanitzki, Marcel; Sugimoto, Yasuhiro; Yamada, Sakue; Yamamoto, Hitoshi

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  14. The International Linear Collider - Volume 1: Executive Summary

    CERN Document Server

    Brau, James E.; Foster, Brian; Fuster, Juan; Harrison, Mike; Paterson, James McEwan; Peskin, Michael; Stanitzki, Marcel; Walker, Nicholas; Yamamoto, Hitoshi

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  15. The International Linear Collider Technical Design Report - Volume 2: Physics

    CERN Document Server

    Barklow, Tim; Fujii, Keisuke; Gao, Yuanning; Hoang, Andre; Kanemura, Shinya; List, Jenny; Logan, Heather E; Nomerotski, Andrei; Perelstein, Maxim; Peskin, Michael E; Pöschl, Roman; Reuter, Jürgen; Riemann, Sabine; Savoy-Navarro, Aurore; Servant, Geraldine; Tait, Tim M P

    2013-01-01

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to incr...

  16. The International Linear Collider Technical Design Report - Volume 2: Physics

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Howard [Univ. of Oklahoma, Norman, OK (United States); Barklow, Tim [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fujii, Keisuke [National Lab. for High Energy Physics (KEK), Tokai (Japan); Gao, Yuanning [Unlisted; Hoang, Andre [Univ. of Vienna (Austria); Kanemura, Shinya [Univ. of Toyama (Japan); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Logan, Heather E. [Carleton Univ., Ottawa, ON (Canada); Nomerotski, Andrei [Univ. of Oxford (United Kingdom); Perelstein, Maxim [Cornell Univ., Ithaca, NY (United States); Peskin, Michael E. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Pöschl, Roman [Univ. Paris-Sud, Orsay (France). Linear Accelerator Lab. (LAL); Reuter, Jürgen [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Riemann, Sabine [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Savoy-Navarro, Aurore [CNRS/IN2P3. Univ. Paris (France). Observatoire de Paris. AstroParticule et Cosmologie (APC); Servant, Geraldine [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Tait, Tim P. [Univ. of California, Los Angeles, CA (United States); Yu, Jaehoon [Univ. of Science and Technology of China, Hefei (China)

    2013-06-26

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.

  17. The International Linear Collider Technical Design Report - Volume 4: Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Behnke, Ties [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-06-26

    The International Linear Collider Technical Design Report (TDR) describes in four volumes the physics case and the design of a 500 GeV centre-of-mass energy linear electron-positron collider based on superconducting radio-frequency technology using Niobium cavities as the accelerating structures. The accelerator can be extended to 1 TeV and also run as a Higgs factory at around 250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator is give, together with associated uncertainties. It is shown that no significant technical issues remain to be solved. Once a site is selected and the necessary site-dependent engineering is carried out, construction can begin immediately. The TDR also gives baseline documentation for two high-performance detectors that can share the ILC luminosity by being moved into and out of the beam line in a "push-pull" configuration. These detectors, ILD and SiD, are described in detail. They form the basis for a world-class experimental programme that promises to increase significantly our understanding of the fundamental processes that govern the evolution of the Universe.

  18. Physics at the high-energy frontier - the Large Hadron Collider project

    CERN Document Server

    Brown, Robert; Evans, David; Gibson, Valerie; Nickerson, Richard; The Royal Society Discussion meeting

    2012-01-01

    The Large Hadron Collider (LHC), achieved its first particle collisions in late 2009 and is now running at 7 TeV, the highest energy ever attained in the laboratory, thereby opening the way for the search for many new phenomena. The aim of the meeting is to discuss the scientific, technical, sociological, political and financial challenges of bringing this huge international project to fruition.

  19. The LHC cryogenic operation for first collisions and physics run

    CERN Document Server

    Brodzinski, K; Benda, V; Bremer, J; Casas-Cubillos, J; Claudet, S; Delikaris, D; Ferlin, G; Fernandez Penacoba, G; Perin, A; Pirotte, O; Soubiran, M; Tavian, L; van Weelderen, R; Wagner, U

    2011-01-01

    The Large Hadron Collider (LHC) cryogenic system was progressively and successfully run for the LHC accelerator operation period starting from autumn 2009. The paper recalls the cryogenic system architecture and main operation principles. The system stability during magnets powering and availability periods for high energy beams with first collisions at 3.5 TeV are presented. Treatment of typical problems, weak points of the system and foreseen future consolidations will be discussed.

  20. Search for Higgs bosons at LEP2 and hadron colliders

    CERN Document Server

    Trefzger, T M

    2001-01-01

    The search for the Higgs boson was one of the most relevant issues of the final years of LEP running at high energies. An excess of 3 sigma beyond the background expectation has been found, consistent with the production of the Higgs boson with a mass near 115 GeV/c/sup 2/. At the upgraded Tevatron and at LHC the search for the Higgs boson will continue. At the Tevatron Higgs bosons can be detected with masses up to 180 GeV with an assumed total integrated luminosity of 20 fb/sup -1/. LHC has the potential to discover the Higgs boson in many different decay channels for Higgs masses up to 1 TeV. It will be possible to measure Higgs boson parameters, such as mass, width, and couplings to fermions and bosons. The results from Higgs searches at LEP2 and the possibilities for searches at hadron colliders will be reviewed. (156 refs).

  1. Beam-beam observations in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  2. Results on QCD Physics from the CDF-II Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Pagliarone, C.; /Cassino U. /INFN, Pisa

    2006-12-01

    In this paper the authors review a selection of recent results obtained, in the area of QCD physics, from the CDF-II experiment that studies p{bar p} collisions at {radical}s = 1.96 TeV provided by the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the Tevatron Run II data samples. In particular they will illustrate the progress achieved and the status of the studies on the following QCD processes: jet inclusive production, using different jet clustering algorithm, W({yields} e{nu}{sub e}) + jets and Z({yields} e{sup +}e{sup -}) + jets production, {gamma} + b-jet production, dijet production in double pomeron exchange and finally exclusive e{sup +}e{sup -} and {gamma}{gamma} production. No deviations from the Standard Model have been observed so far.

  3. Low-Energy Run of Fermilab Electron Cooler's Beam Generation System

    Energy Technology Data Exchange (ETDEWEB)

    Prost, L.R.; Shemyakin, A.; /Fermilab; Fedotov, A.; Kewisch, J.; /Brookhaven

    2011-03-14

    In the context of the evaluation of possibly using the Fermilab Electron Cooler for the proposed low-energy RHIC run at BNL, operating the cooler at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main conclusion of this feasibility study is that the cooler's beam generation system is suitable for BNL needs. The beam recirculation was stable for all tested parameters. In particular, a beam current of 0.38 A was achieved with the cathode magnetic field up to the maximum value presently available of 250 G. The energy ripple was measured to be 40 eV. A striking difference with running the 4.3 MeV beam (nominal for operation at FNAL) is that no unprovoked beam recirculation interruptions were observed. Electron cooling proposed to increase the luminosity of the RHIC collider for heavy ion beam energies below 10 GeV/nucleon [1] needs a good quality, 0.9-5 MeV electron beam. Preliminary design studies indicate that the scheme of the Recycler's electron cooler at FNAL is suitable for low-energy RHIC cooling and most parts of the cooler can be re-used after the end of the Tevatron Run II. To analyze issues related to the generation of the electron beam in the energy recovery mode and to gain experience with the beam transport at lower beam energy, a dedicated study was performed at FNAL with a beam run through a short beam line (so called U-bend). This report summarizes our findings and observations in the course of the measurements.

  4. Status of the Future Circular Collider Study

    Science.gov (United States)

    Benedikt, Michael

    2016-03-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute, to design an energy frontier hadron collider (FCC-hh) in a new 80-100 km tunnel with a centre-of-mass energy of about 100 TeV, an order of magnitude beyond the LHC's, as a long-term goal. The FCC study also includes the design of a 90-350 GeV high-luminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines will be assessed and concepts for experiments will be developed in time for the next update of the European Strategy for Particle Physics by the end of 2018. The presentation will summarize the status of machine designs and parameters and discuss the essential technical components to be developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets with a field of 16 T for the hadron collider and high-power, high-efficiency RF systems for the lepton collider. In addition the unprecedented beam power presents special challenges for the hadron collider for all aspects of beam handling and machine protection. First conclusions of geological investigations and implementation studies will be presented. The status of the FCC collaboration and the further planning for the study will be outlined.

  5. Analysis of failed ramps during the RHIC FY09 run

    Energy Technology Data Exchange (ETDEWEB)

    Minty, M. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-08-15

    The Relativistic Heavy Ion Collider (RHIC) is a versatile accelerator that supports operation with polarized protons of up to 250 GeV and ions with up to 100 GeV/nucleon. During any running period, various operating scenarios with different particle species, beam energies or accelerator optics are commissioned. In this report the beam commissioning periods for establishing full energy beams (ramp development periods) from the FY09 run are summarized and, for the purpose of motivating further developments, we analyze the reasons for all failed ramps.

  6. PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE

    Energy Technology Data Exchange (ETDEWEB)

    KING,B.J.

    2000-05-05

    A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e{sup +}e{sup {minus}} and hadron colliders and three {mu}{sup +}{mu}{sup {minus}} colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory.

  7. Search for WW and WZ production in lepton, neutrino plus jets final states at CDF Run II and Silicon module production and detector control system for the ATLAS SemiConductor Tracker

    Energy Technology Data Exchange (ETDEWEB)

    Sfyrla, Anna [Univ. of Geneva (Switzerland)

    2008-03-10

    In the first part of this work, we present a search for WW and WZ production in charged lepton, neutrino plus jets final states produced in p$\\bar{p}$ collisions with √s = 1.96 TeV at the Fermilab Tevatron, using 1.2 fb-1 of data accumulated with the CDF II detector. This channel is yet to be observed in hadron colliders due to the large singleWplus jets background. However, this decay mode has a much larger branching fraction than the cleaner fully leptonic mode making it more sensitive to anomalous triple gauge couplings that manifest themselves at higher transverse W momentum. Because the final state is topologically similar to associated production of a Higgs boson with a W, the techniques developed in this analysis are also applicable in that search. An Artificial Neural Network has been used for the event selection optimization. The theoretical prediction for the cross section is σWW/WZtheory x Br(W → ℓv; W/Z → jj) = 2.09 ± 0.14 pb. They measured NSignal = 410 ± 212(stat) ± 102(sys) signal events that correspond to a cross section σWW/WZ x Br(W → ℓv; W/Z → jj) = 1.47 ± 0.77(stat) ± 0.38(sys) pb. The 95% CL upper limit to the cross section is estimated to be σ x Br(W → ℓv; W/Z → jj) < 2.88 pb. The second part of the present work is technical and concerns the ATLAS SemiConductor Tracker (SCT) assembly phase. Although technical, the work in the SCT assembly phase is of prime importance for the good performance of the detector during data taking. The production at the University of Geneva of approximately one third of the silicon microstrip end-cap modules is presented. This collaborative effort of the university of Geneva group that lasted two years, resulted in 655 produced modules, 97% of which were good modules, constructed within the mechanical and electrical specifications and delivered in the SCT collaboration for assembly on the end-cap disks. The SCT end-caps and barrels

  8. Working group report: Collider Physics

    Indian Academy of Sciences (India)

    tan β, in the NMSSM and CPV-MSSM, respecting all the LEP-II bounds. In. NMSSM with the H± near its lower mass limit (MH+. ≃ 120 GeV), and a light pseudoscalar (MA0. 1. ≃ 50 GeV) with a very significant doublet component, the charged Higgs boson is expected to decay dominantly via the standard H+ → τ+ν mode.

  9. Progress on $e^{+}e^{-}$ linear colliders

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Siemann, Peter

    2002-01-01

    Physics issues. The physics program will be reviewed for e+e- linear colliders in the TeV energy range. At these prospective facilities central issues of particle physics can be addressed, the problem of mass, unification and structure of space-time. In this context the two lectures will focus on analyses of the Higgs mechanism, supersymmetry and extra space dimensions. Moreover, high-precision studies of the top-quark and the gauge boson sector will be discussed. Combined with LHC results, a comprehensive picture can be developed of physics at the electroweak scale and beyond. Designs and technologies (R. Siemann - 29, 30, 31 May) The physics and technologies of high energy linear colliders will be reviewed. Fundamental concepts of linear colliders will be introduced. They will be discussed in: the context of the Stanford Linear Collider where many ideas changed and new ones were developed in response to operational experience. the requirements for future linear colliders. The different approaches for reac...

  10. 'Outrunning' the running ear

    African Journals Online (AJOL)

    Chantel

    Children in day-care centres are at a higher risk. • Breast-feeding less than 3 months. Other conditions which may mimic acute purulent otitis media should be considered when evaluating a patient with a running ear.These are listed in Table I. To outrun the running ear all these facts should be kept in mind when evaluating ...

  11. RUNNING INJURY DEVELOPMENT

    DEFF Research Database (Denmark)

    Johansen, Karen Krogh; Hulme, Adam; Damsted, Camma

    2017-01-01

    BACKGROUND: Behavioral science methods have rarely been used in running injury research. Therefore, the attitudes amongst runners and their coaches regarding factors leading to running injuries warrants formal investigation. PURPOSE: To investigate the attitudes of middle- and long-distance runne...

  12. Running Injury Development

    DEFF Research Database (Denmark)

    Krogh Johansen, Karen; Hulme, Adam; Damsted, Camma

    2017-01-01

    Background: Behavioral science methods have rarely been used in running injury research. Therefore, the attitudes amongst runners and their coaches regarding factors leading to running injuries warrants formal investigation. Purpose: To investigate the attitudes of middle- and long-distance runne...

  13. Overuse injuries in running

    DEFF Research Database (Denmark)

    Larsen, Lars Henrik; Rasmussen, Sten; Jørgensen, Jens Erik

    2016-01-01

    What is an overuse injury in running? This question is a corner stone of clinical documentation and research based evidence.......What is an overuse injury in running? This question is a corner stone of clinical documentation and research based evidence....

  14. 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...

  15. Druid, event display for the linear collider

    CERN Document Server

    Ruan, M; Musat, G; Jeans, D; Pande, J

    2013-01-01

    Druid is a dedicated event display designed for the future e +e − linear colliders. Druid takes standard linear collider data files and detector geometry description files as input, it can visualize both physics event and detector geometry. Many displaying options are provided by Druid, giving easy access to different information. As a versatile event display, Druid supports all the latest linear collider detector models, Silicon Detector and International Large Detector, as well as the calorimeter prototypes operated in the CALICE test beam experiments. It has been utilized in many studies such as the verification of detector geometry, analysis of the simulated full events and test beam data as well as reconstruction algorithm development and code debugging.

  16. Calorimetry at a Future Linear Collider

    CERN Document Server

    AUTHOR|(CDS)2090195; Marshall, John

    This thesis describes the optimisation of the calorimeter design for collider experiments at the future Compact LInear Collider (CLIC) and the International Linear Collider (ILC). The detector design of these experiments is built around high-granularity Particle Flow Calorimetry that, in contrast to traditional calorimetry, uses the energy measurements for charged particles from the tracking detectors. This can only be realised if calorimetric energy deposits from charged particles can be separated from those of neutral particles. This is made possible with fine granularity calorimeters and sophisticated pattern recognition software, which is provided by the PandoraPFA algorithm. This thesis presents results on Particle Flow calorimetry performance for a number of detector configurations. To obtain these results a new calibration procedure was developed and applied to the detector simulation and reconstruction to ensure optimal performance was achieved for each detector configuration considered. This thesis a...

  17. Electron lenses for super-colliders

    CERN Document Server

    Shiltsev, Vladimir D

    2016-01-01

    This book provides a comprehensive overview of the operating principles and technology of electron lenses in supercolliders.  Electron lenses are a novel instrument for high energy particle accelerators, particularly for the energy-frontier superconducting hadron colliders, including the Tevatron, RHIC, LHC and future very large hadron colliders.  After reviewing the issues surrounding beam dynamics in supercolliders, the book offers an introduction to the electron lens method and its application.  Further chapters describe the technology behind the electron lenses which have recently been proposed, built and employed for compensation of beam-beam effects and for collimation of high-energy high-intensity beams, for compensation of space-charge effects and several other applications in accelerators. The book will be an invaluable resource for those involved in the design, construction and operation of the next generation of hadron colliders.

  18. Final Cooling for a Muon Collider

    Energy Technology Data Exchange (ETDEWEB)

    Acosta Castillo, John Gabriel [Univ. of Mississippi, Oxford, MS (United States)

    2017-05-01

    To explore the new energy frontier, a new generation of particle accelerators is needed. Muon colliders are a promising alternative, if muon cooling can be made to work. Muons are 200 times heavier than electrons, so they produce less synchrotron radiation, and they behave like point particles. However, they have a short lifetime of 2.2 $\\mathrm{\\mu s}$ and the beam is more difficult to cool than an electron beam. The Muon Accelerator Program (MAP) was created to develop concepts and technologies required by a muon collider. An important effort has been made in the program to design and optimize a muon beam cooling system. The goal is to achieve the small beam emittance required by a muon collider. This work explores a final ionization cooling system using magnetic quadrupole lattices with a low enough $\\beta^{\\star} $ region to cool the beam to the required limit with available low Z absorbers.

  19. An analysis of the impact of LHC Run I proton-lead data on nuclear parton densities

    Science.gov (United States)

    Armesto, Néstor; Paukkunen, Hannu; Penín, José Manuel; Salgado, Carlos A.; Zurita, Pía

    2016-04-01

    We report on an analysis of the impact of available experimental data on hard processes in proton-lead collisions during Run I at the large hadron collider on nuclear modifications of parton distribution functions. Our analysis is restricted to the EPS09 and DSSZ global fits. The measurements that we consider comprise production of massive gauge bosons, jets, charged hadrons and pions. This is the first time a study of nuclear PDFs includes this number of different observables. The goal of the paper is twofold: (i) checking the description of the data by nPDFs, as well as the relevance of these nuclear effects, in a quantitative manner; (ii) testing the constraining power of these data in eventual global fits, for which we use the Bayesian reweighting technique. We find an overall good, even too good, description of the data, indicating that more constraining power would require a better control over the systematic uncertainties and/or the proper proton-proton reference from LHC Run II. Some of the observables, however, show sizeable tension with specific choices of proton and nuclear PDFs. We also comment on the corresponding improvements as regards the theoretical treatment.

  20. An analysis of the impact of LHC Run I proton-lead data on nuclear parton densities.

    Science.gov (United States)

    Armesto, Néstor; Paukkunen, Hannu; Penín, José Manuel; Salgado, Carlos A; Zurita, Pía

    2016-01-01

    We report on an analysis of the impact of available experimental data on hard processes in proton-lead collisions during Run I at the large hadron collider on nuclear modifications of parton distribution functions. Our analysis is restricted to the EPS09 and DSSZ global fits. The measurements that we consider comprise production of massive gauge bosons, jets, charged hadrons and pions. This is the first time a study of nuclear PDFs includes this number of different observables. The goal of the paper is twofold: (i) checking the description of the data by nPDFs, as well as the relevance of these nuclear effects, in a quantitative manner; (ii) testing the constraining power of these data in eventual global fits, for which we use the Bayesian reweighting technique. We find an overall good, even too good, description of the data, indicating that more constraining power would require a better control over the systematic uncertainties and/or the proper proton-proton reference from LHC Run II. Some of the observables, however, show sizeable tension with specific choices of proton and nuclear PDFs. We also comment on the corresponding improvements as regards the theoretical treatment.

  1. An analysis of the impact of LHC Run I proton-lead data on nuclear parton densities

    Energy Technology Data Exchange (ETDEWEB)

    Armesto, Nestor; Penin, Jose Manuel; Salgado, Carlos A.; Zurita, Pia [Universidade de Santiago de Compostela, Departamento de Fisica de Particulas and IGFAE, Galicia (Spain); Paukkunen, Hannu [Universidade de Santiago de Compostela, Departamento de Fisica de Particulas and IGFAE, Galicia (Spain); University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); University of Helsinki, Helsinki Institute of Physics, P.O. Box 64, Helsinki (Finland)

    2016-04-15

    We report on an analysis of the impact of available experimental data on hard processes in proton-lead collisions during Run I at the large hadron collider on nuclear modifications of parton distribution functions. Our analysis is restricted to the EPS09 and DSSZ global fits. The measurements that we consider comprise production of massive gauge bosons, jets, charged hadrons and pions. This is the first time a study of nuclear PDFs includes this number of different observables. The goal of the paper is twofold: (i) checking the description of the data by nPDFs, as well as the relevance of these nuclear effects, in a quantitative manner; (ii) testing the constraining power of these data in eventual global fits, for which we use the Bayesian reweighting technique. We find an overall good, even too good, description of the data, indicating that more constraining power would require a better control over the systematic uncertainties and/or the proper proton-proton reference from LHC Run II. Some of the observables, however, show sizeable tension with specific choices of proton and nuclear PDFs. We also comment on the corresponding improvements as regards the theoretical treatment. (orig.)

  2. The Next Linear Collider: NLC2001

    Energy Technology Data Exchange (ETDEWEB)

    D. Burke et al.

    2002-01-14

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.

  3. International linear collider reference design report

    Energy Technology Data Exchange (ETDEWEB)

    Aarons, G.

    2007-06-22

    The International Linear Collider will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. A proposed electron-positron collider, the ILC will complement the Large Hadron Collider, a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, together unlocking some of the deepest mysteries in the universe. With LHC discoveries pointing the way, the ILC -- a true precision machine -- will provide the missing pieces of the puzzle. Consisting of two linear accelerators that face each other, the ILC will hurl some 10 billion electrons and their anti-particles, positrons, toward each other at nearly the speed of light. Superconducting accelerator cavities operating at temperatures near absolute zero give the particles more and more energy until they smash in a blazing crossfire at the centre of the machine. Stretching approximately 35 kilometres in length, the beams collide 14,000 times every second at extremely high energies -- 500 billion-electron-volts (GeV). Each spectacular collision creates an array of new particles that could answer some of the most fundamental questions of all time. The current baseline design allows for an upgrade to a 50-kilometre, 1 trillion-electron-volt (TeV) machine during the second stage of the project. This reference design provides the first detailed technical snapshot of the proposed future electron-positron collider, defining in detail the technical parameters and components that make up each section of the 31-kilometer long accelerator. The report will guide the development of the worldwide R&D program, motivate international industrial studies and serve as the basis for the final engineering design needed to make an official project proposal later this decade.

  4. FFAG Designs for Muon Collider Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J. Scott [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-01-13

    I estimate FFAG parameters for a muon collider with a 70mm longitudinal emittance. I do not discuss the lower emittance beam for a Higgs factory. I produce some example designs, giving only parameters relevant to estimating cost and performance. The designs would not track well, but the parameters of a good design will be close to those described. I compare these cost estimates to those for a fast-ramping synchrotron and a recirculating linear accelerator. I conclude that FFAGs do not appear to be cost-effective for the large longitudinal emittance in a high-energy muon collider.

  5. Top quark studies at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

    1997-01-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  6. Sixth international workshop on linear colliders. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Urakawa, Junji [ed.

    1995-08-01

    The sixth international workshop on linear colliders (LC95) was held by KEK at Tsukuba Center for Institute. In the workshop 8 parallel working group were organized: WG1 (beam sources and injection linacs), WG2 (damping rings and bunch compressors), WG3 (a: RF sources and structures, b: superconducting cavities, c: two beam accelerators), WG4 (beam dynamics in main linacs), WG5 (final focus and integration regions), WG6 (beam instrumentation), WG7 (overall parameters and construction techniques), WG8 (gamma-gamma collider and miscellaneous). This issue compiles materials which were used in the workshop. (J.P.N.).

  7. Final focus designs for crab waist colliders

    CERN Document Server

    AUTHOR|(CDS)2084369; Levichev, Evgeny; Piminov, Pavel

    2016-01-01

    The crab waist collision scheme promises significant luminosity gain. The successful upgrade of the DA$\\Phi$NE collider proved the principle of crab waist collision and increased luminosity 3 times. Therefore, several new projects try to implement the scheme. The paper reviews interaction region designs with the crab waist collision scheme for already existent collider DA$\\Phi$NE and SuperKEKB, presently undergoing commissioning, for the projects of SuperB in Italy, CTau in Novosibirsk and FCC-ee at CERN.

  8. A TeV linear collider

    CERN Document Server

    Hinchliffe, Ian

    2004-01-01

    Various strategies for the development of a linear collider, capable of firing electrons and positrons at each other at collision energies up to about 1 TeV, are discussed. The linear collider's detector will have to detect and precisely measure the energies of electrons, muons, and hadrons. It is suggested that precision must be maintained over the large span of final-state particle energies. Both the superconducting and warm accelerating technologies have demonstrated their viability for a machine starting out with a collision energy of about 500 GeV that could later be upgraded to 1 TeV. (Edited abstract) 9 Refs.

  9. Potential performance for Pb-Pb, p-Pb and p-p collisions in a future circular collider

    CERN Document Server

    Schaumann, Michaela

    2015-09-09

    The hadron collider studied in the Future Circular Collider (FCC) project could operate with protons and lead ions in similar operation modes as the LHC. In this paper the potential performances in lead-lead, proton-lead and proton-proton collisions are investigated. Based on average lattice parameters, the strengths of intra-beam scattering and radiation damping are evaluated and their effect on the beam and luminosity evolution is presented. Estimates for the integrated luminosity per fill and per run are given, depending on the turnaround time. Moreover, the beam-beam tune shift and bound free pair production losses in heavy-ion operation are addressed.

  10. Potential performance for Pb-Pb, p-Pb, and p-p collisions in a future circular collider

    Directory of Open Access Journals (Sweden)

    Michaela Schaumann

    2015-09-01

    Full Text Available The hadron collider studied in the future circular collider (FCC project could operate with protons and lead ions in similar operation modes as the LHC. In this paper the potential performances in lead-lead, proton-lead, and proton-proton collisions are investigated. Based on average lattice parameters, the strengths of intrabeam scattering and radiation damping are evaluated and their effect on the beam and luminosity evolution is presented. Estimates for the integrated luminosity per fill and per run are given, depending on the turnaround time. Moreover, the beam-beam tune shift and bound free pair production losses in heavy-ion operation are addressed.

  11. 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.

  12. Can Unshod Running Reduce Running Injuries?

    Science.gov (United States)

    2012-06-08

    left foot, I decided to have a doctor look at it. The doctor determined the pain was due to Plantar Fasciitis, where the Plantar Tendon pulls away...much of the same activities from the post World War II version. The new fitness program added flexibility, nutrition , circuit drills and other...

  13. CERN-Fermilab Hadron Collider Physics Summer School 2013 open for applications

    CERN Multimedia

    2013-01-01

    Mark your calendar for 28 August - 6 September 2013, when CERN will welcome students to the eighth CERN-Fermilab Hadron Collider Physics Summer School.   Experiments at hadron colliders will continue to provide our best tools for exploring physics at the TeV scale for some time. With the completion of the 7-8 TeV runs of the LHC, and the final results from the full Tevatron data sample becoming available, a new era in particle physics is beginning, heralded by the Higgs-like particle recently discovered at 125 GeV. To realize the full potential of these developments, CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the eighth edition, from 28 August to 6 September 2013. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school which particularly targets young postdocs in exper...

  14. The relationship between negative addiction to running and running ...

    African Journals Online (AJOL)

    The relationship between negative addiction to running and running enjoyment amongst black Zulu-speaking South African runners: an exploratory study. ... running history and the importance placed by the participant on the running activity were shown to play a role in both running dependence and enjoyment processes.

  15. Linear Collider partners woo newly opened India

    CERN Multimedia

    Bagla, Pallava

    2006-01-01

    "With the wheels of Air Force One barely off the tarmac following U.S. President George W. Bush's visit, which ended India's 3 decades as a nuclear pariah state, a delegation of U.S. and European physicists arrived here last week to discuss India's involvement in the International Linear Collider."

  16. Anomalous VVH interactions at a linear collider

    Indian Academy of Sciences (India)

    the SM Higgs boson it will be therefore, necessary to establish its properties such as hypercharge, CP parity etc. At an e+e− collider the dominant Higgs production processes are e+e− → f ¯fH, which proceed via the VVH coupling with V = W, Z and f any light fermion. Demanding Lorentz invariance, the VVH couplings can.

  17. Black Holes and the Large Hadron Collider

    Science.gov (United States)

    Roy, Arunava

    2011-01-01

    The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

  18. Z' Investigations at Future Lepton Colliders

    OpenAIRE

    Rizzo, Thomas G.

    1997-01-01

    In this talk I summarize the capability of future lepton colliders to indirectly discover a new $Z'$ and to determine its couplings to the fermions of the Standard Model. The physics associated with sitting on the $Z'$-pole is also briefly discussed. This analysis is based on the results presented in the Snowmass 1996 New Gauge Boson Working Group report.

  19. Production of electroweak bosons at colliders

    Indian Academy of Sciences (India)

    Abstract. The collider experiments at the Tevatron and LHC are accumulating samples of elec- troweak bosons of unprecedented size. These huge samples can be used to observe rare processes, such as diboson production which have the potential to show enhancements due to new physics. Alternatively, the great ...

  20. Collider Tests of the Little Higgs Model

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Aaron T

    2002-12-16

    The little Higgs model provides an alternative to traditional candidates for new physics at the TeV scale. The new heavy gauge bosons predicted by this model should be observable at the Large Hadron Collider (LHC). We discuss how the LHC experiments could test the little Higgs model by studying the production and decay of these particles.

  1. Physics Case for the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Keisuke; /KEK, Tsukuba; Grojean, Christophe; /DESY /ICREA, Barcelona; Peskin, Michael E.; Barklow, Tim; /SLAC; Gao, Yuanning; /Tsinghua U., Beijing, CHEP; Kanemura, Shinya; /Toyama U.; Kim, Hyungdo; /Seoul Natl U.; List, Jenny; /DESY; Nojiri, Mihoko; /KEK, Tsukuba; Perelstein, Maxim; /Cornell U., LEPP; Poeschl, Roman; /LAL, Orsay; Reuter, Juergen; /DESY; Simon, Frank; /Munich, Max Planck Inst.; Tanabe, Tomohiko; /Tokyo U., ICEPP; Yu, Jaehoon; /Texas U., Arlington; Wells, James D.; /Michigan U., MCTP; Murayama, Hitoshi; /UC, Berkeley /LBNL /Tokyo U., IPMU; Yamamoto, Hitoshi; /Tohoku U.

    2015-06-23

    We summarize the physics case for the International Linear Collider (ILC). We review the key motivations for the ILC presented in the literature, updating the projected measurement uncertainties for the ILC experiments in accord with the expected schedule of operation of the accelerator and the results of the most recent simulation studies.

  2. New physics with the Compact Linear Collider

    CERN Multimedia

    Ellis, Jonathan Richard

    2001-01-01

    Investigating the 'strong' interactions between particles would be best investigated using a lepton-antilepton collider of energy 2 TeV or more. Plans for an accelerator of this type, called CLIC, have been underway at CERN for many years in collaboration with other accelerator laboratories (5 pages).

  3. Timeline for particle collider in doubt

    CERN Multimedia

    2007-01-01

    "The world's most ambitious particle collider - which scientists hope could reveal what matter is made of - might not be fully functional until next year, months after its scheduled startup date, officials at the European Organization for Nuclear Research said Thursday." (2 pages)

  4. Timeline for particle collider in doubt

    CERN Multimedia

    Klapper, Bradley S

    2007-01-01

    "The world's most ambitious particle collider - which scientists hope could reveal what matter is made of - might not be fully functional until next year, months after its scheduled startup date, officiels at the European Organization for Nuclear Reserach said Thursday." (1 page)

  5. Introduction to quantum chromodynamics at hadron colliders

    Indian Academy of Sciences (India)

    Abstract. A basic introduction to the application of QCD at hadron colliders is presented. I briefly review the phenomenological and theoretical origins of QCD, and then discuss factorization and infrared safety, parton distributions, the computation of hard scattering amplitudes and applications of perturbative QCD.

  6. Working group report: Collider and B physics

    Indian Academy of Sciences (India)

    The written reports received are included. Keywords. Higgs boson; supersymmetry; extra dimensions; B-decays. PACS Nos 14.60.St; 14.80.Cp; 13.35.Br. Introduction. It is generally hoped that the Higgs boson, supersymmetric particles, existence of extra dimensions ..... may be discovered at the upcoming colliders. Bulk of ...

  7. Working group report: Collider and flavour physics

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... The activities of the working group took place under two broad subgroups: Collider Physics subgroup and Flavour Physics subgroup. Reports on some of the projects undertaken are included. Also, some of the leading discussions organized by the working group are summarized.

  8. Senate baulks at cost of collider project

    CERN Multimedia

    MacIlwain, C

    1999-01-01

    The US Senate has called for NLC research costs to be cut from 14 to 6 million dollars next year. The intention is to end funding altogether in two years after a report showed that the collider would cost the USA about 5 billion dollars (1 page).

  9. Plans for 40 km linear collider unveiled

    CERN Multimedia

    Cartlidge, Edwin

    2006-01-01

    Particle physicists have released their first tentative design for the International Linear Collider (ILC), a multibillin dollar accelerator that could switch on by the middle of the next decade. The plans also state that the machine should be built in two underground tunnels even though it would be much cheaper to use just one (1 page)

  10. Particle collider magnet self-destructs

    CERN Multimedia

    Higgins, Alexander G

    2007-01-01

    "A 43-foot-long magnet for the world's largest particle collider broke "with a loud band and a cloud of dust" during a high-pressure test, and officils said Tuesday they are working to find a replacement part." (1 page)

  11. Search for new physics at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Chiarelli, Giorgio; /INFN, Pisa

    2005-09-01

    In this paper I present the most recent results of the ongoing searches, mainly from Tevatron Collider experiments, for new physics beyond the Standard Model. While no signal has been seen so far, many analyses are reaching the point in which either a discovery will take place or strong limit on currently popular theories will be set.

  12. Physics possibilities at a linear collider

    Indian Academy of Sciences (India)

    We review some recent studies about the parameter determination of top quarks, bosons, Higgs bosons, supersymmetric particles and in the ADD model of extra dimensions at a linear collider. Author Affiliations. Alfred Bartl1 Stefan Hesselbach1. Institut für Theoretische Physik, Universität Wien, Boltzmanngasse 5, ...

  13. Challenges for highest energy circular colliders

    CERN Document Server

    Benedikt, M; Wenninger, J; Zimmermann, F

    2014-01-01

    A new tunnel of 80–100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCCee/TLEP) as potential intermediate step, and a leptonhadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, topup injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

  14. Physics possibilities at a linear collider

    Indian Academy of Sciences (India)

    clarifying the mechanism of electroweak symmetry breaking will be the central problem which we have to solve with the next generation of high energy colliders. In the SM, electroweak symmetry breaking is achieved by the Higgs mechanism. The scalar Higgs boson, also predicted by this mechanism, has not been found so.

  15. Dreams collide with reality for international experiment

    CERN Multimedia

    Cho, Adrian

    2007-01-01

    "Three weeks ago, an international team released a design and cost estimate for the International Linear Collider (ILC). American physicists want to build the ILC at Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, and researchers had hoped to break ground in 2012 and fire up the ILC's beams of electrons and positrons in 2019." (1 page)

  16. Status of the Future Circular Collider Study

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2016-01-01

    Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute. Its main purpose and long-term goal is to design an energyfrontier hadron collider (FCC-hh) with a centre-of-mass energy of about 100 TeV in a new 80–100 km tunnel. The FCC study also includes the design of a 90–350 GeV highluminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines are being assessed and concepts for experiments will be developed by the end of 2018, in time for the next update of the European Strategy for Particle Physics. This overview summarizes the status of machine designs and parameters, and it discusses the essential technical components being developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets wit...

  17. Future Accelerators, Muon Colliders, and Neutrino Factories

    Energy Technology Data Exchange (ETDEWEB)

    Richard A Carrigan, Jr.

    2001-12-19

    Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this stage in the development of physics, both approaches are needed and important. This chapter first reviews the status of the great accelerator facilities now in operation or coming on within the decade. Next, midrange possibilities are discussed including linear colliders with the adjunct possibility of gamma-gamma colliders, muon colliders, with precursor neutrino factories, and very large hadron colliders. Finally visionary possibilities are considered including plasma and laser accelerators.

  18. Higgs physics at the Large Hadron Collider

    Indian Academy of Sciences (India)

    In this talk I shall begin by summarizing the importance of the Higgs physics studies at the Large Hadron Collider (LHC). I shall then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with ...

  19. Measurement of the $B_{s} \\to K^{+}K^{-}$ lifetime and extraction of the $\\Delta\\Gamma_{CP}/\\Gamma_{CP}$ at CDF Run II and Development of the ATLAS-SCT endcap modules

    Energy Technology Data Exchange (ETDEWEB)

    Donega, Mauro [Univ. of Geneva (Switzerland)

    2006-01-01

    In the first part of the present work we present the first measurement of the Bd and Bs meson lifetimes in charmless decays (Bd → K+π-, Bd → π+π-, Bs → K+K-) based on 360pb-1 of p$\\bar{p}$ collision taken at the CDF Run II detector and the extraction $\\frac{ΔΓCP}{ΓCP}$ for the Bs-meson. We find the Bd-meson lifetime (in the Bd → K+π- and Bd → π+π- decay modes) to be: cτ (Bd) = 452 ± 24 (stat) ± 6 (syst) µm τ (Bd) = 1.51 ± 0.08 (stat) ± 0.02 (syst) ps and the Bs-meson lifetime (in the Bs → K+K- decay mode) to be: cτ (Bs → K+K-) = 458 ± 53 (stat) ± 6 (syst) µm τ (Bs → K+K-) = 1.53 ± 0.18 (stat) ± 0.02 (syst) ps Both measurements are consistent with the world averages. We calculate the ΔΓCP CP for the Bs meson combining the measured lifetime in the Bs → K+K- decay with the world average value of the Bs-meson lifetime in the flavour specific decays: We find: cτfs = 441 ± 13 µm τfs = 1.472 ± 0.045 ps ΔΓCP /ΓCP = -0.08 ± 0.23 (stat.) ± 0.03 (syst.) that is compatible with the theoretical expectation of (7.2 ± 2.4) × 10-2. In the second part of the present work, a few steps of the final R&D of the ATLAS-SCT endcaps modules will be reported. Two module layouts have been developed on two different electrical hybrids de- signs. Both layouts have been produced in small prototype series and tested before and after exposing them to a particle fluence equivalent to that expected at the end of the ATLAS data taking.

  20. Linear Collider Physics Resource Book Snowmass 2001

    Energy Technology Data Exchange (ETDEWEB)

    Ronan (Editor), M.T.

    2001-06-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and

  1. Lepton Colliders at the Energy and Luminosity Frontiers Linear Colliders and SuperB Factories

    CERN Document Server

    Delahaye, Jean Pierre

    2008-01-01

    After a brief review of the performance of the various Lepton Colliders presently in operation at the energy and luminosity frontiers, the article describes their possible evolution and the envisaged new projects to improve their performances. Beauty Factories have the potential to extend the present luminosity frontier of Lepton Colliders by two orders of magnitude into the 1036 cm-2 sec-1 range. Linear Colliders have the potential to extend the present energy frontier of Lepton Colliders by one order of magnitude into the Multi-TeV energy range. The ideas and challenges to boost these frontiers in the next future are described as well as the R&D plans to demonstrate their feasibility and/or to prepare projects proposals through engineering design optimisation and industrialisation. Technically driven schedule for their possible fabrication and installation are presented.

  2. "Towards a Future Linear Collider" and "The Linear Collider Studies at CERN"

    CERN Document Server

    CERN. Geneva

    2010-01-01

    During the week 18-22 October, more than 400 physicists will meet at CERN and in the CICG (International Conference Centre Geneva) to review the global progress towards a future linear collider. The 2010 International Workshop on Linear Colliders will study the physics, detectors and accelerator complex of a linear collider covering both the CLIC and ILC options. Among the topics presented and discussed will be the progress towards the CLIC Conceptual Design Report in 2011, the ILC Technical Design Report in 2012, physics and detector studies linked to these reports, and an increasing numbers of common working group activities. The seminar will give an overview of these topics and also CERN’s linear collider studies, focusing on current activities and initial plans for the period 2011-16. n.b: The Council Chamber is also reserved for this colloquium with a live transmission from the Main Auditorium.

  3. Tracking and Vertexing with the ATLAS Inner Detector in the LHC Run-2

    CERN Document Server

    Choi, Kyungeon; The ATLAS collaboration

    2017-01-01

    Run-2 of the Large Hadron Collider (LHC) has provided new challenges to track and vertex reconstruction with higher centre-of-mass energies and luminosity leading to increasingly high-multiplicity envi- ronments, boosted, and highly-collimated physics objects. We present an overview of the ATLAS Inner Detector tracker in Run-2 including the track reconstruction algorithm, time-dependent alignment, tracking and vertexing performance.

  4. Processes with weak gauge boson pairs at hadron colliders. Precise predictions and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Salfelder, Lukas

    2017-02-08

    percent. Due to the comparably small production cross sections and the generally large QCD backgrounds, studying VBS reactions at hadron colliders is an intricate task, and even with the target luminosity of several 100 fb{sup -1} presumably collected at the end of LHC Run II, dedicated differential analyses will hardly be realizable. In our analysis we therefore investigate the opportunities of a potential follow-up project of the LHC which is proposed to operate at a center-of-mass energy of 100 TeV and assumed to deliver a total integrated luminosity of 30 ab{sup -1}. For several decay modes we perform a detailed signal-to-background analysis, revealing the excellent possibilities for future measurements of VBS processes at yet unprecedented energy scales that such a machine facilitates. With process-specific event-selection criteria we manage to significantly reduce the background contribution, while due to the deep energy reach definitely sufficient events of the VBS signal remain for a detailed examination at the differential level.

  5. Bruno Touschek, from Betatrons to Electron-positron Colliders

    CERN Document Server

    Bernardini, Carlo; Pellegrini, Claudio

    2015-01-01

    Bruno Touschek's life as a physicist spanned the period from World War II to the 1970s. He was a key figure in the developments of electron-positron colliders, storage rings, and gave important contributions to theoretical high energy physics. Storage rings, initially developed for high energy physics, are being widely used in many countries as synchrotron radiation sources and are a tool for research in physics, chemistry, biology environmental sciences and cultural heritage studies. We describe Touschek's life in Austria, where he was born, Germany, where he participated to the construction of a betatron during WWII, and Italy, where he proposed and led to completion the first electron-positron storage ring in 1960, in Frascati. We highlight how his central European culture influenced his life style and work, and his main contributions to physics, such as the discovery of the Touschek effect and beam instabilities in the larger storage ring ADONE.

  6. Measurement of top anti-top cross section in proton - anti-proton collider at √s = 1.96-TeV

    Energy Technology Data Exchange (ETDEWEB)

    Mal, Prolay Kumar [Tata Inst. of Fundamental Research, Bombay (India)

    2005-04-01

    Discovery of the top quark in 1995 at the Fermilab Tevatron collider concluded a long search following the 1977 discovery of bottom (b) quark [1] and represents another triumph of the Standard Model (SM) of elementary particles. Top quark is one of the fundamental fermions in the Standard Model of electroweak interactions and is the weak-isospin partner of the bottom quark. A precise measurement of top pair production cross-section would be a test of Quantum Chromodynamics (QCD) prediction. Presently, Tevatron is the world's highest energy collider where protons (p) and anti-protons ($\\bar{p}$) collide at a centre of mass energy √s of 1.96 TeV. At Tevatron top (t) and anti-top ($\\bar{t}$) quarks are predominantly pair produced through strong interactions--quark annihilation (≅ 85%) and gluon fusion (≅ 15%). Due to the large mass of top quark, t or $\\bar{t}$ decays (~ 10-25 sec) before hadronization and in SM framework, it decays to a W boson and a b quark with ~ 100% branching ratio (BR). The subsequent decay of W boson determines the major signatures of t$\\bar{t}$ decay. If both W bosons (coming from t and $\\bar{t}$ decays) decay into leptons (viz., eve, μvμ or τcτ) the corresponding t$\\bar{t}$ decay is called dileptonic decay. Of all dileptonic decay modes of t$\\bar{t}$, the t$\\bar{t}$ → WWb$\\bar{b}$ → eveμvμb$\\bar{b}$ (eμ channel) decay mode has the smallest background contamination from Z0 production or Drell-Yan process; simultaneously, it has the highest BR (~ 3.16%) [2] amongst all dileptonic decay modes of t$\\bar{t}$. During Run I (1992-1996) of Tevatron, three eμ candidate events were detected by D0 experiment, out of 80 candidate events (inclusive of all decay modes of t$\\bar{t}$). Due to the rarity of the t$\\bar{t}$ events, the measured cross-section has large uncertainty in its value (viz., 5.69 ± 1.21(stat) ± 1.04(sys) pb {at} √s = 1

  7. A new jet reconstruction algorithm for lepton colliders

    CERN Document Server

    Boronat, Marça; Vos, Marcel

    2014-01-01

    We propose a new sequential jet reconstruction algorithm for future lepton colliders at the energy frontier. The Valencia algorithm combines the natural distance criterion for lepton colliders with the greater robustness against backgrounds of algorithms adapted to hadron colliders. Results on a detailed Monte Carlo simulation of $t\\bar{t}$ and $ZZ$ production at future linear $e^+e^-$ colliders (ILC and CLIC) with a realistic level of background overlaid, show that it achieves better performance in the presence of background.

  8. Druid, displaying root module used for linear collider detectors

    CERN Document Server

    Ruan, M

    2012-01-01

    Based on the ROOT TEve/TGeo classes and the standard linear collider data structure, a dedicated linear collider event display has been developed. It supports the latest detector models for both International Linear Collider and Compact Linear Collider as well as the CALICE test beam prototypes. It can be used to visualise event information at the generation, simulation and reconstruction levels. Many options are provided in an intuitive interface. It has been heavily employed in a variety of analyses.

  9. The First LHC p-Pb Run: Performance of the Heavy Ion Production Complex

    CERN Document Server

    Manglunki, D; Bartosik, H; Bellodi, G; Blas, A; Bodendorfer, M; Bohl, T; Carli, C; Carlier, E; Cettour-Cave, S; Cornelis, K; Damerau, H; Findlay, A; Gilardoni, S; Hancock, S; Jowett, J; Küchler, D; O'Neil, M; Papaphilippou, Y; Pasinelli, S; Scrivens, R; Tranquille, G; Vandorpe, B; Wehrle, U; Wenninger, J

    2013-01-01

    The first LHC proton-ion run took place in January-February 2013; it was the first extension to the collider programme, as this mode was not included in the design report. This paper presents the performance of the heavy ion and proton production complex, and details the issues encountered, in particular the creation of the same bunch pattern in both beams.

  10. The First Running Period of the CMS Detector Controls System - A Success Story

    CERN Document Server

    Glege, F; Chaze, O; Cittolin, S; Coarasa, J A; Deldicque, C; Dobson, M; Gigi, D; Gomez-Reino, R; Hartl, C; Masetti, L; Meijers, F; Meschi, E; Morovic, S; Nunez-Barranco-Fernandez, C; Orsini, L; Ozga, W; Bauer, G; Behrens, U; Branson, J; Holzner, A; Erhan, S; Mommsen, R K; O'Dell, V

    2014-01-01

    The Detector Control System (DCS) of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN has been running since the ?rst detector test in summer 2006. It has proven to be robust, ef?cient and easy to maintain.

  11. Setup and Performance of the RHIC Injector Accelerators for the 2005 Run with Copper Ions

    CERN Document Server

    Gardner, Chris J; Alessi, James; Benjamin, John; Blaskiewicz, Michael; Brennan, Joseph M; Brown, Kevin A; Carlson, Charles; De Long, Joseph; Glenn, Joseph; Hayes, Thomas; MacKay, William W; Marr, Gregory J; Morris, John; Roser, Thomas; Severino, Freddy; Smith, Kevin T; Steski, Dannie; Tsoupas, Nicholaos; Zaltsman, Alex; Zeno, Keith

    2005-01-01

    Copper ions for the 2005 run of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory are accelerated in the Tandem, Booster and AGS prior to injection into RHIC. The setup and performance of this chain of accelerators will be reviewed.

  12. 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.

  13. Preliminary design of CERN Future Circular Collider tunnel: first evaluation of the radiation environment in critical areas for electronics

    Directory of Open Access Journals (Sweden)

    Infantino Angelo

    2017-01-01

    Full Text Available As part of its post-LHC high energy physics program, CERN is conducting a study for a new proton-proton collider, called Future Circular Collider (FCC-hh, running at center-of-mass energies of up to 100 TeV in a new 100 km tunnel. The study includes a 90-350 GeV lepton collider (FCC-ee as well as a lepton-hadron option (FCC-he. In this work, FLUKA Monte Carlo simulation was extensively used to perform a first evaluation of the radiation environment in critical areas for electronics in the FCC-hh tunnel. The model of the tunnel was created based on the original civil engineering studies already performed and further integrated in the existing FLUKA models of the beam line. The radiation levels in critical areas, such as the racks for electronics and cables, power converters, service areas, local tunnel extensions was evaluated.

  14. Running Boot Camp

    CERN Document Server

    Toporek, Chuck

    2008-01-01

    When Steve Jobs jumped on stage at Macworld San Francisco 2006 and announced the new Intel-based Macs, the question wasn't if, but when someone would figure out a hack to get Windows XP running on these new "Mactels." Enter Boot Camp, a new system utility that helps you partition and install Windows XP on your Intel Mac. Boot Camp does all the heavy lifting for you. You won't need to open the Terminal and hack on system files or wave a chicken bone over your iMac to get XP running. This free program makes it easy for anyone to turn their Mac into a dual-boot Windows/OS X machine. Running Bo

  15. MADANALYSIS 5, a user-friendly framework for collider phenomenology

    Science.gov (United States)

    Conte, Eric; Fuks, Benjamin; Serret, Guillaume

    2013-01-01

    We present MADANALYSIS 5, a new framework for phenomenological investigations at particle colliders. Based on a C++ kernel, this program allows us to efficiently perform, in a straightforward and user-friendly fashion, sophisticated physics analyses of event files such as those generated by a large class of Monte Carlo event generators. MADANALYSIS 5 comes with two modes of running. The first one, easier to handle, uses the strengths of a powerful PYTHON interface in order to implement physics analyses by means of a set of intuitive commands. The second one requires one to implement the analyses in the C++ programming language, directly within the core of the analysis framework. This opens unlimited possibilities concerning the level of complexity which can be reached, being only limited by the programming skills and the originality of the user. Program summaryProgram title: MadAnalysis 5 Catalogue identifier: AENO_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENO_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Permission to use, copy, modify and distribute this program is granted under the terms of the GNU General Public License. No. of lines in distributed program, including test data, etc.: 31087 No. of bytes in distributed program, including test data, etc.: 399105 Distribution format: tar.gz Programming language: PYTHON, C++. Computer: All platforms on which Python version 2.7, Root version 5.27 and the g++ compiler are available. Compatibility with newer versions of these programs is also ensured. However, the Python version must be below version 3.0. Operating system: Unix, Linux and Mac OS operating systems on which the above-mentioned versions of Python and Root, as well as g++, are available. Classification: 11.1. External routines: ROOT (http://root.cern.ch/drupal/) Nature of problem: Implementing sophisticated phenomenological analyses in high-energy physics through a

  16. Searches for the Standard Model Higgs boson at the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Wade C. [Michigan State Univ., East Lansing, MI (United States). Dept. of Physics and Astronomy; Junk, Thomas R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2016-01-01

    During Run II of the Tevatron collider, which took place from 2001 until 2011, the CDF and D0 detectors each collected approximately 10 fb -1 of collision data at a center-of-mass energy of . This dataset allowed for tests for the presence of the SM Higgs boson in the mass range 90-200 GeV in the production modes gg → H, W/ZH, vector-boson fusion, and H, with H decay modes H → , H → W+W-, H →

  17. Invariant-mass distribution of jet pairs produced in association with a W boson in pp ¯ collisions at √s =1.96 TeV using the full CDF Run II data set

    Science.gov (United States)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Vázquez, F.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2014-05-01

    We report on a study of the dijet invariant-mass distribution in events with one identified lepton, a significant imbalance in the total event transverse momentum, and two jets. This distribution is sensitive to the possible production of a new particle in association with a W boson, where the boson decays leptonically. We use the full data set of proton-antiproton collisions at 1.96 TeV center-of-mass energy collected by the Collider Detector at the Fermilab Tevatron, corresponding to an integrated luminosity of 8.9 fb-1. The data are found to be consistent with standard model expectations, and a 95% confidence level upper limit is set on the production cross section of a W boson in association with a new particle decaying into two jets.

  18. Invariant-mass distribution of jet pairs produced in association with a $W$ boson in $p\\bar{p}$ collisions at $\\sqrt{s}=1.96$ TeV using the full CDF Run II data set

    CERN Document Server

    Aaltonen, T; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V.E.; Barnett, B.A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K.R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H.S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y.C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M.E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C.A.; Cox, D.J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J.R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernandez Ramos, J.P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J.C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A.F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C.M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; Gonzalez Lopez, O.; Gorelov, I.; Goshaw, A.T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R.C.; Guimaraes da Costa, J.; Hahn, S.R.; Han, J.Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R.F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R.E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E.J.; Jindariani, S.; Jones, M.; Joo, K.K.; Jun, S.Y.; Junk, T.R.; Kambeitz, M.; Kamon, T.; Karchin, P.E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D.H.; Kim, H.S.; Kim, J.E.; Kim, M.J.; Kim, S.H.; Kim, S.B.; Kim, Y.J.; Kim, Y.K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D.J.; Konigsberg, J.; Kotwal, A.V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A.T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H.S.; Lee, J.S.; Leo, S.; Leone, S.; Lewis, J.D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Luca, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Martinez, M.; Matera, K.; Mattson, M.E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C.S.; Moore, R.; Morello, M.J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S.Y.; Norniella, O.; Oakes, L.; Oh, S.H.; Oh, Y.D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T.J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernandez, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J.L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W.K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E.E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S.Z.; Shears, T.; Shepard, P.F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J.R.; Snider, F.D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P.K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vazquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizan, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S.M.; Waters, D.; Wester, W.C., III; Whiteson, D.; Wicklund, A.B.; Wilbur, S.; Williams, H.H.; Wilson, J.S.; Wilson, P.; Winer, B.L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U.K.; Yang, Y.C.; Yao, W.M.; Yeh, G.P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G.B.; Yu, I.; Zanetti, A.M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2014-01-01

    We report on a study of the dijet invariant-mass distribution in events with one identified lepton, a significant imbalance in the total event transverse momentum, and two jets. This distribution is sensitive to the possible production of a new particle in association with a $W$ boson, where the boson decays leptonically. We use the full data set of proton-antiproton collisions at 1.96 TeV center-of-mass energy collected by the Collider Detector at the Fermilab Tevatron and corresponding to an integrated luminosity of 8.9 fb$^{-1}$. The data are found to be consistent with standard-model expectations, and a 95$\\%$ confidence level upper limit is set on the cross section for a $W$ boson produced in association with a new particle decaying into two jets.

  19. Luminosity Spectrum Reconstruction at Linear Colliders

    CERN Document Server

    Poss, Stéphane

    2014-04-11

    A good knowledge of the luminosity spectrum is mandatory for many measurements at future e+e- colliders. As the beam-parameters determining the luminosity spectrum cannot be measured precisely, the luminosity spectrum has to be measured through a gauge process with the detector. The measured distributions, used to reconstruct the spectrum, depend on Initial State Radiation, cross-section, and Final State Radiation. To extract the basic luminosity spectrum, a parametric model of the luminosity spectrum is created, in this case the spectrum at the 3 TeV Compact Linear Collider (CLIC). The model is used within a reweighting technique to extract the luminosity spectrum from measured Bhabha event observables, taking all relevant effects into account. The centre-of-mass energy spectrum is reconstructed within 5% over the full validity range of the model. The reconstructed spectrum does not result in a significant bias or systematic uncertainty in the exemplary physics benchmark process of smuon pair production.

  20. 1st Large Hadron Collider Physics Conference

    CERN Document Server

    Juste, A; Martínez, M; Riu, I; Sorin, V

    2013-01-01

    The conference is the result of merging two series of international conferences, "Physics at Large Hadron Collider" (PLHC2012) and "Hadron Collider Physics Symposium" (HCP2012). With a program devoted to topics such as the Standard Model and Beyond, the Higgs Boson, Supersymmetry, Beauty and Heavy Ion Physics, the conference aims at providing a lively forum for discussion between experimenters and theorists of the latest results and of new ideas. LHCP 2013 will be hosted by IFAE (Institut de Fisica d'Altes Energies) in Barcelona (Spain), and will take place from May 13 to 18, 2013. The venue will be the Hotel Catalonia Plaza, Plaza España (Barcelona). More information will be posted soon. For questions, please contact lhcp2013@ifae.es.

  1. Imaging hadron calorimetry for future Lepton Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Repond, José, E-mail: repond@hep.anl.gov

    2013-12-21

    To fully exploit the physics potential of a future Lepton Collider requires detectors with unprecedented jet energy and dijet-mass resolution. To meet these challenges, detectors optimized for the application of Particle Flow Algorithms (PFAs) are being designed and developed. The application of PFAs, in turn, requires calorimeters with very fine segmentation of the readout, so-called imaging calorimeters. This talk reviews progress in imaging hadron calorimetry as it is being developed for implementation in a detector at a future Lepton Collider. Recent results from the large prototypes built by the CALICE Collaboration, such as the Scintillator Analog Hadron Calorimeter (AHCAL) and the Digital Hadron Calorimeters (DHCAL and SDHCAL) are being presented. In addition, various R and D efforts beyond the present prototypes are being discussed.

  2. Imaging hadron calorimetry for future Lepton Colliders

    Science.gov (United States)

    Repond, José

    2013-12-01

    To fully exploit the physics potential of a future Lepton Collider requires detectors with unprecedented jet energy and dijet-mass resolution. To meet these challenges, detectors optimized for the application of Particle Flow Algorithms (PFAs) are being designed and developed. The application of PFAs, in turn, requires calorimeters with very fine segmentation of the readout, so-called imaging calorimeters. This talk reviews progress in imaging hadron calorimetry as it is being developed for implementation in a detector at a future Lepton Collider. Recent results from the large prototypes built by the CALICE Collaboration, such as the Scintillator Analog Hadron Calorimeter (AHCAL) and the Digital Hadron Calorimeters (DHCAL and SDHCAL) are being presented. In addition, various R&D efforts beyond the present prototypes are being discussed.

  3. The CERN SPS proton–antiproton collider

    CERN Document Server

    Schmidt, Rudiger

    2016-01-01

    One of CERN's most ambitious and successful projects was the search for the intermediate bosons, W and Z [1]. The accelerator part of the project relied on a number of innovations in accelerator physics and technology. The invention of the method of stochastic cooling and the extension by many orders of magnitude beyond the initial proof of principle demonstration allowed the construction of the Antiproton Accumulator. Major modifications to the 26 GeV PS complex and the conversion of the 300 GeV SPS, which had just started up as an accelerator, to a collider were required. The SPS collider had to master the beam–beam effect far beyond limits reached before and had to function in a tight symbiosis with the UA1 and UA2 experiments.

  4. The CERN SPS proton-antiproton collider

    Science.gov (United States)

    Schmidt, Rudiger

    One of CERN's most ambitious and successful projects was the search for the intermediate bosons, W and Z [1]. The accelerator part of the project relied on a number of innovations in accelerator physics and technology. The invention of the method of stochastic cooling and the extension by many orders of magnitude beyond the initial proof of principle demonstration allowed the construction of the Antiproton Accumulator. Major modifications to the 26 GeV PS complex and the conversion of the 300 GeV SPS, which had just started up as an accelerator, to a pbar p collider were required. The SPS collider had to master the beam-beam effect far beyond limits reached before and had to function in a tight symbiosis with the UA1 and UA2 experiments.

  5. The Large Hadron Collider, A Megascience Project

    CERN Document Server

    Lebrun, P

    2001-01-01

    The Large Hadron Collider (LHC) will be the next particle accelerator built to serve the world's high-energy physics community at CERN, the European Organisation for Nuclear Research. Reusing the 26.7-km circumference tunnel and infrastructure of the existing LEP collider, the LHC will make use of advanced technology - high-field superconducting magnets operated in superfluid helium - to push the energy frontier up by an order of magnitude, while remaining economically feasible. The LHC demonstrates on a grand scale several typical features of megascience projects, such as the need for international funding, world-wide co-operation and integration in the local environment, which we review in the following.

  6. Running Like Crazy

    National Research Council Canada - National Science Library

    Rushin, Steve

    2002-01-01

    Twenty-seven years and four wives later, [Jerry Dunn] is still running. On Jan. 8,1995, Dunn paused near the nine-mile mark of the Walt Disney World Marathon in Orlando to marry, in front of Cinderella's Castle, fellow runner Elaine Doll...

  7. Running the rat race

    African Journals Online (AJOL)

    SASA Refresher Course Texts: Running the rat race. 74. 2014;20(1) ... and feelings of existential despair which characterise the human condition, to emerge as they are today: whole, satisfied, well .... Pure efficiency only exists on paper. In the ...

  8. Optimizing Running Performance.

    Science.gov (United States)

    Widule, Carol J.

    1989-01-01

    The optimization of step length and step rate (frequency) is essential for sprinters. This article analyzes data that compare step rate and step length to height, as a function of running speed, for ten elite runners. How results of such analyses can be used in training runners is also discussed. (IAH)

  9. Top Quark Production at Hadron Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Phaf, Lukas Kaj [Univ. of Amsterdam (Netherlands)

    2004-03-01

    This thesis describes both theoretical and experimental research into top quark production. The theoretical part contains a calculation of the single-top quark production cross section at hadron colliders, at Next to Leading Order (NLO) accuracy. The experimental part describes a measurement of the top quark pair production cross section in proton-antiproton collisions, at a center of mass energy of 1.96 TeV.

  10. The Large Hadron Collider Pop Up Book

    CERN Document Server

    2013-01-01

    Discover the ATLAS experiment in full 3D pop-up in this promotional video for the Large Hadron Collider pop-up book. The book contains 16 pop-ups telling the story of how the experiment works and its quest to understand what the universe is made of. It is now available in English, French and German. Paper engineer Anton Radevsky, texts Emma Sanders.

  11. Longitudinal damping in the Tevatron collider

    Energy Technology Data Exchange (ETDEWEB)

    Kerns, Q.A.; Jackson, G.; Kerns, C.R.; Miller, H.; Reid, J.; Siemann, R.; Wildman, D.

    1989-03-01

    This paper describes the damper design for 6 proton on 6 pbar bunches in the Tevatron collider. Signal pickup, transient phase detection, derivative networks, and phase correction via the high-level rf are covered. Each rf station is controlled by a slow feedback loop. In addition, global feedback loops control each set of four cavities, one set for protons and one set for antiprotons. Operational experience with these systems is discussed. 7 refs., 9 figs.

  12. BARD: Interpreting new frontier energy collider physics

    Energy Technology Data Exchange (ETDEWEB)

    Knuteson, Bruce; /MIT; Mrenna, Stephen; /Fermilab

    2006-02-01

    No systematic procedure currently exists for inferring the underlying physics from discrepancies observed in high energy collider data. We present Bard, an algorithm designed to facilitate the process of model construction at the energy frontier. Top-down scans of model parameter space are discarded in favor of bottom-up diagrammatic explanations of particular discrepancies, an explanation space that can be exhaustively searched and conveniently tested with existing analysis tools.

  13. Large Hadron Collider The Discovery Machine

    CERN Multimedia

    2008-01-01

    The mammoth machine, after a nine-year construction period, is scheduled (touch wood) to begin producing its beams of particles later this year. The commissioning process is planned to proceed from one beam to two beams to colliding beams; from lower energies to the terascale; from weaker test intensities to stronger ones suitable for producing data at useful rates but more difficult to control.

  14. Top physics at the Tevatron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Margaroli, Fabrizio; /Purdue U.

    2007-10-01

    The top quark has been discovered in 1995 at the CDF and DO experiments located in the Tevatron ring at the Fermilab laboratory. After more than a decade the Tevatron collider, with its center-of-mass energy collisions of 1.96 TeV, is still the only machine capable of producing such exceptionally heavy particle. Here I present a selection of the most recent CDF and DO measurements performed analyzing {approx} 1 fb{sup -1} of integrated luminosity.

  15. Large Hadron Collider commissioning and first operation.

    Science.gov (United States)

    Myers, S

    2012-02-28

    A history of the commissioning and the very successful early operation of the Large Hadron Collider (LHC) is described. The accident that interrupted the first commissioning, its repair and the enhanced protection system put in place are fully described. The LHC beam commissioning and operational performance are reviewed for the period from 2010 to mid-2011. Preliminary plans for operation and future upgrades for the LHC are given for the short and medium term.

  16. Neutrino Factory and Muon Collider Fellow

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Gail G. [Univ. of California, Riverside, CA (United States); Snopak, Pavel [Univ. of California, Riverside, CA (United States); Bao, Yu [Univ. of California, Riverside, CA (United States)

    2015-03-20

    Muons are fundamental particles like electrons but much more massive. Muon accelerators can provide physics opportunities similar to those of electron accelerators, but because of the larger mass muons lose less energy to radiation, allowing more compact facilities with lower operating costs. The way muon beams are produced makes them too large to fit into the vacuum chamber of a cost-effective accelerator, and the short muon lifetime means that the beams must be reduced in size rather quickly, without losing too many of the muons. This reduction in size is called "cooling." Ionization cooling is a new technique that can accomplish such cooling. Intense muon beams can then be accelerated and injected into a storage ring, where they can be used to produce neutrino beams through their decays or collided with muons of the opposite charge to produce a muon collider, similar to an electron-positron collider. We report on the research carried out at the University of California, Riverside, towards producing such muon accelerators, as part of the Muon Accelerator Program based at Fermilab. Since this research was carried out in a university environment, we were able to involve both undergraduate and graduate students.

  17. Muon Collider Machine-Detector Interface

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, Nikolai V.; /Fermilab

    2011-08-01

    In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

  18. 2001 Report on the Next Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Gronnberg, J; Breidenbach; Burke, D; Corlett, J; Dombeck, T; Markiewicz, T

    2001-08-28

    Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider.

  19. Seventh International Accelerator School for Linear Colliders

    CERN Multimedia

    Organizers of the Seventh International Accelerator School for Linear Colliders

    2012-01-01

    We are pleased to announce the Seventh International Accelerator School for Linear Colliders. This school is a continuation of the series of schools which began six years ago.  The first school was held in 2006 in Sokendai, Japan, the second in 2007 in Erice, Italy, the third in 2008 in Oakbrook Hills, USA, the fourth in 2009 in Huairou, China, the fifth in 2010 in Villars-sur-Ollon, Switzerland, and the sixth in 2011 in Pacific Grove, USA.   The school is organized by the International Linear Collider (ILC) Global Design Effort (GDE), the Compact Linear Collider (CLIC) and the International Committee for Future Accelerators (ICFA) Beam Dynamics Panel. The school this year will take place at the Radisson Blu Hotel, Indore, India from November 27 to December 8, 2012. It is hosted by the Raja Ramanna Center for Advanced Technology (RRCAT) and sponsored by a number of funding agencies and institutions around the world including the U.S. Department of Energy (DOE), the U.S. National Science...

  20. Searching for dark matter at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Richard, Francois [IN2P3/CNRS et Universite Paris-Sud 11 Centre Scientifique d' Orsay, Laboratoire de l' Accelerateur Lineaire, Orsay (France); Arcadi, Giorgio; Mambrini, Yann [Universite Paris-Sud, Laboratoire de Physique Theorique, Orsay (France)

    2015-04-01

    Dark Matter (DM) detection prospects at future e{sup +}e{sup -} colliders are reviewed under the assumption that DM particles are fermions of the Majorana or Dirac type. Although the discussion is quite general, one will keep in mind the recently proposed candidate based on an excess of energetic photons observed in the center of our Galaxy with the Fermi-LAT satellite. In the first part we will assume that DM interactions are mediated by vector bosons, Z or Z'. In the case of Z-boson Direct Detection limits force only axial couplings with the DM. This solution can be naturally accommodated by Majorana DM but is disfavored by the GC excess. Viable scenarios can be instead found in the case of Z' mediator. These scenarios can be tested at e{sup +}e{sup -} colliders through ISR events, e{sup +}e{sup -} → XX + γ. A sensitive background reduction can be achieved by using highly polarized beams. In the second part scalar particles, in particular Higgs particles, have been considered as mediators. The case of the SM Higgs mediator is excluded by limits on the invisible branching ratio of the Higgs. On the contrary particularly interesting is the case in which the DM interactions are mediated by the pseudoscalar state A in two Higgs-doublet model scenarios. In this last case the main collider signature is e{sup +}e{sup -} → HA, H → hh, A → XX. (orig.)