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Sample records for hadron collider il

  1. Hadron hadron collider group

    SciTech Connect

    Palmer, R.; Peoples, J.; Ankenbrandt, C.

    1982-01-01

    The objective of this group was to make a rough assessment of the characteristics of a hadron-hadron collider which could make it possible to study the 1 TeV mass scale. Since there is very little theoretical guidance for the type of experimental measurements which could illuminate this mass scale, we chose to extend the types of experiments which have been done at the ISR, and which are in progress at the SPS collider to these higher energies.

  2. Hadron-hadron colliders

    SciTech Connect

    Month, M.; Weng, W.T.

    1983-06-21

    The objective is to investigate whether existing technology might be extrapolated to provide the conceptual framework for a major hadron-hadron collider facility for high energy physics experimentation for the remainder of this century. One contribution to this large effort is to formalize the methods and mathematical tools necessary. In this report, the main purpose is to introduce the student to basic design procedures. From these follow the fundamental characteristics of the facility: its performance capability, its size, and the nature and operating requirements on the accelerator components, and with this knowledge, we can determine the technology and resources needed to build the new facility.

  3. The Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Myers, Stephen

    The Large Hadron Collider (LHC) was first suggested (in a documented way) in 1983 [1] as a possible future hadron collider to be installed in the 27 km "LEP" tunnel. More than thirty years later the collider has been operated successfully with beam for three years with spectacular performance and has discovered the long-sought-after Higgs boson. The LHC is the world's largest and most energetic particle collider. It took many years to plan and build this large complex machine which promises exciting, new physics results for many years to come...

  4. The large hadron collider

    NASA Astrophysics Data System (ADS)

    Brüning, O.; Burkhardt, H.; Myers, S.

    2012-07-01

    The Large Hadron Collider (LHC) is the world’s largest and most energetic particle collider. It took many years to plan and build this large complex machine which promises exciting, new physics results for many years to come. We describe and review the machine design and parameters, with emphasis on subjects like luminosity and beam conditions which are relevant for the large community of physicists involved in the experiments at the LHC. First collisions in the LHC were achieved at the end of 2009 and followed by a period of a rapid performance increase. We discuss what has been learned so far and what can be expected for the future.

  5. The Large Hadron Collider.

    PubMed

    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.

  6. Results from hadron colliders

    SciTech Connect

    Pondrom, L.G. )

    1990-12-14

    The present status of hadron collider physics is reviewed. The total cross section for {bar p} + p has been measured at 1.8 TeV: {sigma}{sub tot} = 72.1 {plus minus} 3.3 mb. New data confirm the UA2 observation of W/Z {yields} {bar q}q. Precision measurements of M{sub W} by UA2 and CDF give an average value M{sub W} = 80.13 {plus minus} 0.30 GeV/c{sup 2}. When combined with measurements of M{sub Z} from LEP and SLC this number gives sin{sup 2}{theta}{sub W} = 0.227 {plus minus} 0.006, or m{sub top} = 130{sub {minus}60}{sup +40} GeV/c{sup 2} from the EWK radiative correction term {Delta}r. Evidence for hadron colliders as practical sources of b quarks has been strengthened, while searches for t quarks have pushed the mass above M{sub W}: m{sub top} > 89 GeV/c{sup 2} 95% cl (CDF Preliminary). Searches beyond the standard model based on the missing E{sub T} signature have not yet produced any positive results. Future prospects for the discovery of the top quark in the range m{sub top} < 200 GeV/c{sup 2} look promising. 80 refs., 35 figs., 7 tabs.

  7. Hadron collider physics at UCR

    SciTech Connect

    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.

  8. Physics at hadron colliders: Experimental view

    SciTech Connect

    Siegrist, J.L.

    1987-08-01

    The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs.

  9. CERN's Large Hadron Collider project

    NASA Astrophysics Data System (ADS)

    Fearnley, Tom A.

    1997-03-01

    The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B.

  10. B physics at hadron colliders

    SciTech Connect

    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.

  11. Beam collimation at hadron colliders

    SciTech Connect

    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.

  12. Future Electron-Hadron Colliders

    SciTech Connect

    Litvinenko, V.

    2010-05-23

    Outstanding research potential of electron-hadron colliders (EHC) was clearly demonstrated by first - and the only - electron-proton collider HERA (DESY, Germany). Physics data from HERA revealed new previously unknown facets of Quantum Chromo-Dynamics (QCD). EHC is an ultimate microscope probing QCD in its natural environment, i.e. inside the hadrons. In contrast with hadrons, electrons are elementary particles with known initial state. Hence, scattering electrons from hadrons provides a clearest pass to their secrets. It turns EHC into an ultimate machine for high precision QCD studies and opens access to rich physics with a great discovery potential: solving proton spin puzzle, observing gluon saturation or physics beyond standard model. Access to this physics requires high-energy high-luminosity EHCs and a wide reach in the center-of-mass (CM) energies. This paper gives a brief overview of four proposed electron-hadron colliders: ENC at GSI (Darmstadt, Germany), ELIC/MEIC at TJNAF (Newport News, VA, USA), eRHIC at BNL (Upton, NY, USA) and LHeC at CERN (Geneva, Switzerland). Future electron-hadron colliders promise to deliver very rich physics not only in the quantity but also in the precision. They are aiming at very high luminosity two-to-four orders of magnitude beyond the luminosity demonstrated by the very successful HERA. While ENC and LHeC are on opposite side of the energy spectrum, eRHIC and ELIC are competing for becoming an electron-ion collider (EIC) in the U.S. Administrations of BNL and Jlab, in concert with US DoE office of Nuclear Physics, work on the strategy for down-selecting between eRHIC and ELIC. The ENC, EIC and LHeC QCD physics programs to a large degree are complimentary to each other and to the LHC physics. In last decade, an Electron Ion Collider (EIC) collaboration held about 25 collaboration meetings to develop physics program for EIC with CM energy {approx}100 GeV. One of these meetings was held at GSI, where ENC topic was in the

  13. Recent results from hadron colliders

    SciTech Connect

    Frisch, H.J. )

    1990-12-10

    This is a summary of some of the many recent results from the CERN and Fermilab colliders, presented for an audience of nuclear, medium-energy, and elementary particle physicists. The topics are jets and QCD at very high energies, precision measurements of electroweak parameters, the remarkably heavy top quark, and new results on the detection of the large flux of B mesons produced at these machines. A summary and some comments on the bright prospects for the future of hadron colliders conclude the talk. 39 refs., 44 figs., 3 tabs.

  14. State of hadron collider physics

    SciTech Connect

    Grannis, P.D. |

    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.

  15. LHC: The Large Hadron Collider

    SciTech Connect

    Lincoln, Don

    2015-03-04

    The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

  16. LHC: The Large Hadron Collider

    ScienceCinema

    Lincoln, Don

    2016-07-12

    The Large Hadron Collider (or LHC) is the world’s most powerful particle accelerator. In 2012, scientists used data taken by it to discover the Higgs boson, before pausing operations for upgrades and improvements. In the spring of 2015, the LHC will return to operations with 163% the energy it had before and with three times as many collisions per second. It’s essentially a new and improved version of itself. In this video, Fermilab’s Dr. Don Lincoln explains both some of the absolutely amazing scientific and engineering properties of this modern scientific wonder.

  17. Bilepton production at hadron colliders

    NASA Astrophysics Data System (ADS)

    Dion, B.; Grégoire, T.; London, D.; Marleau, L.; Nadeau, H.

    1999-04-01

    We examine, as model-independently as possible, the production of bileptons at hadron colliders. When a particular model is necessary or useful, we choose the 3-3-1 model. We consider a variety of processes: qq¯-->Y++Y--, ud¯-->Y++Y-, ūd-->Y+Y--, qq¯-->Y++e-e-, qq¯-->φ++φ--, ud¯-->φ++φ-, and ūd-->φ+φ--, where Y and φ are vector and scalar bileptons, respectively. Given the present low-energy constraints, we find that, at the Fermilab Tevatron, vector bileptons are unobservable, while light scalar bileptons (Mφ<~300 GeV) are just barely observable. At the CERN LHC, the reach is extended considerably: vector bileptons of mass MY<~1 TeV are observable, as are scalar bileptons of mass Mφ<~850 GeV.

  18. XXth Hadron Collider Physics Symposium

    NASA Astrophysics Data System (ADS)

    In 2009, the Hadron Collider Physics Symposium took place in Evian (France), on the shore of the Geneva Lake, from 16-20 November. It was jointly organised by CERN and the French HEP community (CNRS-IN2P3 and CEA-IRFU). This year's symposium come at an important time for both the Tevatron and LHC communities. It stimulated the completion of analyses for a significant Tevatron data sample, and it allowed an in-depth review of the readiness of the LHC and its detectors just before first collisions. The programme includes sessions on top-quark and electro-weak physics, QCD, B physics, new phenomena, electro-weak symmetry breaking, heavy ions, and the status and commissioning of the LHC machine and its experiments. Conference website : http://hcp2009.in2p3.fr/

  19. Very large hadron collider (VLHC)

    SciTech Connect

    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.

  20. Flavourful production at hadron colliders

    NASA Astrophysics Data System (ADS)

    Giudice, Gian Francesco; Gripaios, Ben; Sundrum, Raman

    2011-08-01

    We ask what new states may lie at or below the TeV scale, with sizable flavour-dependent couplings to light quarks, putting them within reach of hadron colliders via resonant production, or in association with Standard Model states. In particular, we focus on the compatibility of such states with stringent flavour-changing neutral current and electric-dipole moment constraints. We argue that the broadest and most theoretically plausible flavour structure of the new couplings is that they are hierarchical, as are Standard Model Yukawa couplings, although the hierarchical pattern may well be different. We point out that, without the need for any more elaborate or restrictive structure, new scalars with "diquark" couplings to standard quarks are particularly immune to existing constraints, and that such scalars may arise within a variety of theoretical paradigms. In particular, there can be substantial couplings to a pair of light quarks or to one light and one heavy quark. For example, the latter possibility may provide a flavour-safe interpretation of the asymmetry in top quark production observed at the Tevatron. We thereby motivate searches for diquark scalars at the Tevatron and LHC, and argue that their discovery represents one of our best chances for new insight into the Flavour Puzzle of the Standard Model.

  1. Top quark studies at hadron colliders

    SciTech Connect

    Sinervo, P.K.; CDF Collaboration

    1996-08-01

    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 {ital b} quark jets in candidate events. The most recent measurements of top quark properties by the CDF and D{null} 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.

  2. Top quark studies at hadron colliders

    SciTech Connect

    Sinervo, P.K.

    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.

  3. Black Holes and the Large Hadron Collider

    ERIC Educational Resources Information Center

    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…

  4. The Large Hadron Collider: Redefining High Energy

    SciTech Connect

    Demers, Sarah

    2007-06-19

    Particle physicists have a description of the forces of nature known as the Standard Model that has successfully withstood decades of testing at laboratories around the world. Though the Standard Model is powerful, it is not complete. Important details like the masses of particles are not explained well, and realities as fundamental as gravity, dark matter, and dark energy are left out altogether. I will discuss gaps in the model and why there is hope that some puzzles will be solved by probing high energies with the Large Hadron Collider. Beginning next year, this machine will accelerate protons to record energies, hurling them around a 27 kilometer ring before colliding them 40 million times per second. Detectors the size of five-story buildings will record the debris of these collisions. The new energy frontier made accessible by the Large Hadron Collider will allow thousands of physicists to explore nature's fundamental forces and particles from a fantastic vantage point.

  5. Hadron colliders (SSC/LHC)

    SciTech Connect

    Chao, A.W.; Palmer, R.B. |; Evans, L.; Gareyte, J.; Siemann, R.H.

    1992-12-31

    The nominal SSC and LHC designs should operate conservatively at luminosities up to 10{sup 33} cm{sup {minus}2} s{sup {minus}1}. This luminosity is dictated by the event rates that can be handled by the detectors. However, this limit is event dependent (e.g. it does not take much of a detector to detect the event pp {yields} elephant; all one needs is extremely high luminosity). As such, it is useful to explore the possibility of going beyond the 10{sup 33} cm{sup {minus}2} s{sup {minus}1} level. Such exploration will also improve the accelerator physics understanding of pp collider designs. If the detector limitations are removed, the first accelerator limits occur when the luminosity is at the level of 10{sup 34} cm{sup {minus}2}s{sup {minus}1}. These accelerator limits will first be reviewed. The authors will then continue on to explore even higher luminosity as the ultimate limit of pp colliders. Accelerator technologies needed to achieve this ultimate luminosity as well as the R and D needed to reach it are discussed.

  6. Collins Asymmetry at Hadron Colliders

    SciTech Connect

    Yuan, Feng

    2008-01-17

    We study the Collins effect in the azimuthal asymmetricdistribution of hadrons inside a high energy jet in the single transversepolarized proton proton scattering. From the detailed analysis ofone-gluon and two-gluon exchange diagrams contributions, the Collinsfunction is found the same as that in the semi-inclusive deep inelasticscattering and e+e- annihilations. The eikonal propagators in thesediagrams do not contribute to the phase needed for the Collins-typesingle spin asymmetry, and the universality is derived as a result of theWard identity. We argue that this conclusion depends on the momentum flowof the exchanged gluon and the kinematic constraints in the fragmentationprocess, and is generic and model-independent.

  7. Really large hadron collider working group summary

    SciTech Connect

    Dugan, G.; Limon, P.; Syphers, M.

    1996-12-01

    A summary is presented of preliminary studies of three 100 TeV center-of-mass hadron colliders made with magnets of different field strengths, 1.8T, 9.5T and 12.6T. Descriptions of the machines, and some of the major and most challenging subsystems, are presented, along with parameter lists and the major issues for future study.

  8. Large Hadron Collider commissioning and first operation.

    PubMed

    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.

  9. The Tevatron Hadron Collider: A short history

    SciTech Connect

    Tollestrup, A.V.

    1994-11-01

    The subject of this presentation was intended to cover the history of hadron colliders. However this broad topic is probably better left to historians. I will cover a much smaller portion of this subject and specialize my subject to the history of the Tevatron. As we will see, the Tevatron project is tightly entwined with the progress in collider technology. It occupies a unique place among accelerators in that it was the first to make use of superconducting magnets and indeed the basic design now forms a template for all machines using this technology. It was spawned in an incredibly productive era when new ideas were being generated almost monthly and it has matured into our highest energy collider complete with two large detectors that provide the major facility in the US for probing high Pt physics for the coming decade.

  10. String resonances at hadron colliders

    NASA Astrophysics Data System (ADS)

    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

  11. Heaviest bound baryons production at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Wu, Su-Zhi; Li, You-Wei; Rashidin, Reyima

    2012-12-01

    We calculate the hadronic production of three heaviest bound baryons Ωbbb, Ωbbc*, and Ωbbc at hadron colliders at tree level. We present the integrated cross section and differential cross section distributions in this paper.

  12. Black holes at the Large Hadron Collider.

    PubMed

    Dimopoulos, S; Landsberg, G

    2001-10-15

    If the scale of quantum gravity is near TeV, the CERN Large Hadron Collider will be producing one black hole (BH) about every second. The decays of the BHs into the final states with prompt, hard photons, electrons, or muons provide a clean signature with low background. The correlation between the BH mass and its temperature, deduced from the energy spectrum of the decay products, can test Hawking's evaporation law and determine the number of large new dimensions and the scale of quantum gravity.

  13. Black Holes and the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Roy, Arunava

    2011-12-01

    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 Society1 website featured an article on BH formation at the LHC.2 This article examines some aspects of mini BHs and explores the possibility of their detection at the LHC.

  14. Mass reach scaling for future hadron colliders

    NASA Astrophysics Data System (ADS)

    Rizzo, Thomas G.

    2015-04-01

    The primary goal of any future hadron collider is to discover new physics (NP) associated with a high mass scale, , beyond the range of the LHC. In order to maintain the same relative mass reach for rate-limited NP, , as increases, Richter recently reminded us that the required integrated luminosity obtainable at future hadron colliders (FHC) must grow rapidly, , in the limit of naive scaling. This would imply, e.g., a 50-fold increase in the required integrated luminosity when going from the 14 TeV LHC to a FHC with TeV, an increase that would prove quite challenging on many different fronts. In this paper we point out, due to the scaling violations associated with the evolution of the parton density functions (PDFs) and the running of the strong coupling, , that the actual luminosity necessary in order to maintain any fixed value of the relative mass reach is somewhat greater than this scaling result indicates. However, the actual values of the required luminosity scaling are found to be dependent upon the detailed nature of the NP being considered. Here we elucidate this point explicitly by employing several specific benchmark examples of possible NP scenarios and briefly discuss the (relatively weak) search impact in each case if these luminosity goals are not met.

  15. QCD and jets at hadron colliders

    NASA Astrophysics Data System (ADS)

    Sapeta, Sebastian

    2016-07-01

    We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in particular for cases in which jets are produced in special configurations, like for example in the region of forward rapidities. We review numerous perturbative methods for calculating predictions for jet processes, including the fixed-order calculations as well as various matching and merging techniques. We also discuss the questions related to non-perturbative effects and the role they play in precision jet studies. We describe the status of calculations for processes with jet vetoes and we also elaborate on production of jets in forward direction. Throughout the article, we present selected comparisons between state-of-the-art theoretical predictions and the data from the LHC.

  16. Illuminating new electroweak states at hadron colliders

    NASA Astrophysics Data System (ADS)

    Ismail, Ahmed; Izaguirre, Eder; Shuve, Brian

    2016-07-01

    In this paper, we propose a novel powerful strategy to perform searches for new electroweak states. Uncolored electroweak states appear in generic extensions of the Standard Model (SM) and yet are challenging to discover at hadron colliders. This problem is particularly acute when the lightest state in the electroweak multiplet is neutral and all multiplet components are approximately degenerate. In this scenario, production of the charged fields of the multiplet is followed by decay into nearly invisible states; if this decay occurs promptly, the only way to infer the presence of the reaction is through its missing energy signature. Our proposal relies on emission of photon radiation from the new charged states as a means of discriminating the signal from SM backgrounds. We demonstrate its broad applicability by studying two examples: a pure Higgsino doublet and an electroweak quintuplet field.

  17. Big Science and the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Giudice, Gian Francesco

    2012-03-01

    The Large Hadron Collider (LHC), the particle accelerator operating at CERN, is probably the most complex and ambitious scientific project ever accomplished by humanity. The sheer size of the enterprise, in terms of financial and human resources, naturally raises the question whether society should support such costly basic-research programs. I address this question by first reviewing the process that led to the emergence of Big Science and the role of large projects in the development of science and technology. I then compare the methodologies of Small and Big Science, emphasizing their mutual linkage. Finally, after examining the cost of Big Science projects, I highlight several general aspects of their beneficial implications for society.

  18. Genesis of the Large Hadron Collider.

    PubMed

    Smith, Chris Llewellyn

    2015-01-13

    This paper describes the scientific, technical and political genesis of the Large Hadron Collider (LHC). It begins with an outline of the early history of the LHC, from first thoughts and accelerator and detector developments that underwrote the project, through the first studies of the LHC and its scientific potential and the genesis of the experimental programme, to the presentation of the proposal to build the LHC to the CERN Council in December 1993. The events that led to the proposal to build the LHC in two stages, which was approved in December 1994, are then described. Next, the role of non-Member State contributions and of the agreement that CERN could take loans, which allowed single stage construction to be approved in December 1996, despite a cut in the Members' contributions, are explained. The paper concludes by identifying points of potential relevance for the approval of possible future large particle physics projects.

  19. Light-gravitino production at hadron colliders

    SciTech Connect

    Kim, J.; Nanopoulos, D.V.; Rangarajan, R.; Lopez, J.L.; Nanopoulos, D.V.; Zichichi, A.

    1998-01-01

    We consider the production of gravitinos ({tilde G}) in association with gluinos ({tilde g}) or squarks ({tilde q}) at hadron colliders, including the three main subprocesses: q{bar q}{r_arrow}{tilde g}{tilde G}, and qg{r_arrow}{tilde q}{tilde G}, and gg{r_arrow}{tilde g}{tilde G}. These channels become enhanced to the point of being observable for sufficiently light gravitino masses (m{sub {tilde G}}{lt}10{sup {minus}4}eV), as motivated by some supersymmetric explanations of the Collider Detector at Fermilab ee{gamma}{gamma}+E{sub T,miss} event. The characteristic signal of such events would be monojets, as opposed to dijets obtained in the more traditional supersymmetric process p{bar p}{r_arrow}{tilde g}{tilde g}. Searches for such events at the Fermilab Tevatron can impose lower limits on the gravitino mass. In the appendixes, we provide a complete set of Feynman rules for the gravitino interactions used in our calculation. {copyright} {ital 1997} {ital The American Physical Society}

  20. Prospects for heavy flavor physics at hadron colliders

    SciTech Connect

    Butler, J.N.

    1997-09-01

    The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the B{sub s} meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with `forward` vs `central` rapidity coverage.

  1. Heavy flavor production and top quark search at hadron colliders

    SciTech Connect

    Baer, H.A.

    1991-01-01

    We review heavy flavor production at hadron colliders, with an eye towards the physics of the top quark. Motivation for existence of top, and current status of top search are reviewed. The physics of event simulation at hadron colliders is reviewed. We discuss characteristics of top quark events at p{bar p} colliders that may aid in distinguishing the top quark signal from Standard Model backgrounds, and illustrate various cuts which may be useful for top discovery. Top physics at hadron supercolliders is commented upon, as well as top quark mass measurement techniques. 22 refs., 5 figs.

  2. Higgs boson production at hadron colliders: Signal and background processes

    SciTech Connect

    David Rainwater; Michael Spira; Dieter Zeppenfeld

    2004-01-12

    We review the theoretical status of signal and background calculations for Higgs boson production at hadron colliders. Particular emphasis is given to missing NLO results, which will play a crucial role for the Tevatron and the LHC.

  3. The ATLAS Experiment at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    ATLAS Collaboration; Aad, G.; Abat, E.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B. A.; Abolins, M.; Abramowicz, H.; Acerbi, E.; Acharya, B. S.; Achenbach, R.; Ackers, M.; Adams, D. L.; Adamyan, F.; Addy, T. N.; Aderholz, M.; Adorisio, C.; Adragna, P.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahmed, H.; Aielli, G.; Åkesson, P. F.; Åkesson, T. P. A.; Akimov, A. V.; Alam, S. M.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Aleppo, M.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alimonti, G.; Aliyev, M.; Allport, P. P.; Allwood-Spiers, S. E.; Aloisio, A.; Alonso, J.; Alves, R.; Alviggi, M. G.; Amako, K.; Amaral, P.; Amaral, S. P.; Ambrosini, G.; Ambrosio, G.; Amelung, C.; Ammosov, V. V.; Amorim, A.; Amram, N.; Anastopoulos, C.; Anderson, B.; Anderson, K. J.; Anderssen, E. C.; Andreazza, A.; Andrei, V.; Andricek, L.; Andrieux, M.-L.; Anduaga, X. S.; Anghinolfi, F.; Antonaki, A.; Antonelli, M.; Antonelli, S.; Apsimon, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Archambault, J. P.; Arguin, J.-F.; Arik, E.; Arik, M.; Arms, K. E.; Armstrong, S. R.; Arnaud, M.; Arnault, C.; Artamonov, A.; Asai, S.; Ask, S.; Åsman, B.; Asner, D.; Asquith, L.; Assamagan, K.; Astbury, A.; Athar, B.; Atkinson, T.; Aubert, B.; Auerbach, B.; Auge, E.; Augsten, K.; Aulchenko, V. M.; Austin, N.; Avolio, G.; Avramidou, R.; Axen, A.; Ay, C.; Azuelos, G.; Baccaglioni, G.; Bacci, C.; Bachacou, H.; Bachas, K.; Bachy, G.; Badescu, E.; Bagnaia, P.; Bailey, D. C.; Baines, J. T.; Baker, O. K.; Ballester, F.; Baltasar Dos Santos Pedrosa, F.; Banas, E.; Banfi, D.; Bangert, A.; Bansal, V.; Baranov, S. P.; Baranov, S.; Barashkou, A.; Barberio, E. L.; Barberis, D.; Barbier, G.; Barclay, P.; Bardin, D. Y.; Bargassa, P.; Barillari, T.; Barisonzi, M.; Barnett, B. M.; Barnett, R. M.; Baron, S.; Baroncelli, A.; Barone, M.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Barriuso Poy, A.; Barros, N.; Bartheld, V.; Bartko, H.; Bartoldus, R.; Basiladze, S.; Bastos, J.; Batchelor, L. E.; Bates, R. L.; Batley, J. R.; Batraneanu, S.; Battistin, M.; Battistoni, G.; Batusov, V.; Bauer, F.; Bauss, B.; Baynham, D. E.; Bazalova, M.; Bazan, A.; Beauchemin, P. H.; Beaugiraud, B.; Beccherle, R. B.; Beck, G. A.; Beck, H. P.; Becks, K. H.; Bedajanek, I.; Beddall, A. J.; Beddall, A.; Bednár, P.; Bednyakov, V. A.; Bee, C.; Behar Harpaz, S.; Belanger, G. A. N.; Belanger-Champagne, C.; Belhorma, B.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellachia, F.; Bellagamba, L.; Bellina, F.; Bellomo, G.; Bellomo, M.; Beltramello, O.; Belymam, A.; Ben Ami, S.; Ben Moshe, M.; Benary, O.; Benchekroun, D.; Benchouk, C.; Bendel, M.; Benedict, B. H.; Benekos, N.; Benes, J.; Benhammou, Y.; Benincasa, G. P.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Beretta, M.; Berge, D.; Bergeaas, E.; Berger, N.; Berghaus, F.; Berglund, S.; Bergsma, F.; Beringer, J.; Bernabéu, J.; Bernardet, K.; Berriaud, C.; Berry, T.; Bertelsen, H.; Bertin, A.; Bertinelli, F.; Bertolucci, S.; Besson, N.; Beteille, A.; Bethke, S.; Bialas, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieri, M.; Biglietti, M.; Bilokon, H.; Binder, M.; Binet, S.; Bingefors, N.; Bingul, A.; Bini, C.; Biscarat, C.; Bischof, R.; Bischofberger, M.; Bitadze, A.; Bizzell, J. P.; Black, K. M.; Blair, R. E.; Blaising, J. J.; Blanch, O.; Blanchot, G.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Boaretto, C.; Bobbink, G. J.; Bocci, A.; Bocian, D.; Bock, R.; Boehm, M.; Boek, J.; Bogaerts, J. A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bondarenko, V. G.; Bonino, R.; Bonis, J.; Bonivento, W.; Bonneau, P.; Boonekamp, M.; Boorman, G.; Boosten, M.; Booth, C. N.; Booth, P. S. L.; Booth, P.; Booth, J. R. A.; Borer, K.; Borisov, A.; Borjanovic, I.; Bos, K.; Boscherini, D.; Bosi, F.; Bosman, M.; Bosteels, M.; Botchev, B.; Boterenbrood, H.; Botterill, D.; Boudreau, J.; Bouhova-Thacker, E. V.; Boulahouache, C.; Bourdarios, C.; Boutemeur, M.; Bouzakis, K.; Boyd, G. R.; Boyd, J.; Boyer, B. H.; Boyko, I. R.; Bozhko, N. I.; Braccini, S.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, O.; Bratzler, U.; Braun, H. M.; Bravo, S.; Brawn, I. P.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Breton, D.; Brett, N. D.; Breugnon, P.; Bright-Thomas, P. G.; Brochu, F. M.; Brock, I.; Brock, R.; Brodbeck, T. J.; Brodet, E.; Broggi, F.; Broklova, Z.; Bromberg, C.; Brooijmans, G.; Brouwer, G.; Broz, J.; Brubaker, E.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Buchanan, N. J.; Buchholz, P.; Budagov, I. A.; Büscher, V.; Bugge, L.; Buira-Clark, D.; Buis, E. J.; Bujor, F.; Buran, T.; Burckhart, H.; Burckhart-Chromek, D.; Burdin, S.; Burns, R.; Busato, E.; Buskop, J. J. F.; Buszello, K. P.; Butin, F.; Butler, J. M.; Buttar, C. M.; Butterworth, J.; Butterworth, J. M.; Byatt, T.; Cabrera Urbán, S.; Cabruja Casas, E.; Caccia, M.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calderón Terol, D.; Callahan, J.; Caloba, L. P.; Caloi, R.; Calvet, D.; Camard, A.; Camarena, F.; Camarri, P.; Cambiaghi, M.; Cameron, D.; Cammin, J.; Campabadal Segura, F.; Campana, S.; Canale, V.; Cantero, J.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Caprio, M.; Caracinha, D.; Caramarcu, C.; Carcagno, Y.; Cardarelli, R.; Cardeira, C.; Cardiel Sas, L.; Cardini, A.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carpentieri, C.; Carr, F. S.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Caso, C.; Castelo, J.; Castillo Gimenez, V.; Castro, N.; Castrovillari, F.; Cataldi, G.; Cataneo, F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caughron, S.; Cauz, D.; Cavallari, A.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerna, C.; Cernoch, C.; Cerqueira, A. S.; Cerri, A.; Cerutti, F.; Cervetto, M.; Cetin, S. A.; Cevenini, F.; Chalifour, M.; Chamizo llatas, M.; Chan, A.; Chapman, J. W.; Charlton, D. G.; Charron, S.; Chekulaev, S. V.; Chelkov, G. A.; Chen, H.; Chen, L.; Chen, T.; Chen, X.; Cheng, S.; Cheng, T. L.; Cheplakov, A.; Chepurnov, V. F.; Cherkaoui El Moursli, R.; Chesneanu, D.; Cheu, E.; Chevalier, L.; Chevalley, J. L.; Chevallier, F.; Chiarella, V.; Chiefari, G.; Chikovani, L.; Chilingarov, A.; Chiodini, G.; Chouridou, S.; Chren, D.; Christiansen, T.; Christidi, I. A.; Christov, A.; Chu, M. L.; Chudoba, J.; Chuguev, A. G.; Ciapetti, G.; Cicalini, E.; Ciftci, A. K.; Cindro, V.; Ciobotaru, M. D.; Ciocio, A.; Cirilli, M.; Citterio, M.; Ciubancan, M.; Civera, J. V.; Clark, A.; Cleland, W.; Clemens, J. C.; Clement, B. C.; Clément, C.; Clements, D.; Clifft, R. W.; Cobal, M.; Coccaro, A.; Cochran, J.; Coco, R.; Coe, P.; Coelli, S.; Cogneras, E.; Cojocaru, C. D.; Colas, J.; Colijn, A. P.; Collard, C.; Collins-Tooth, C.; Collot, J.; Coluccia, R.; Comune, G.; Conde Muiño, P.; Coniavitis, E.; Consonni, M.; Constantinescu, S.; Conta, C.; Conventi, F. A.; Cook, J.; Cooke, M.; Cooper-Smith, N. J.; Cornelissen, T.; Corradi, M.; Correard, S.; Corso-Radu, A.; Coss, J.; Costa, G.; Costa, M. J.; Costanzo, D.; Costin, T.; Coura Torres, R.; Courneyea, L.; Couyoumtzelis, C.; Cowan, G.; Cox, B. E.; Cox, J.; Cragg, D. A.; Cranmer, K.; Cranshaw, J.; Cristinziani, M.; Crosetti, G.; Cuenca Almenar, C.; Cuneo, S.; Cunha, A.; Curatolo, M.; Curtis, C. J.; Cwetanski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; Da Rocha Gesualdi Mello, A.; Da Silva, P. V. M.; Da Silva, R.; Dabrowski, W.; Dael, A.; Dahlhoff, A.; Dai, T.; Dallapiccola, C.; Dallison, S. J.; Dalmau, J.; Daly, C. H.; Dam, M.; Damazio, D.; Dameri, M.; Danielsen, K. M.; Danielsson, H. O.; Dankers, R.; Dannheim, D.; Darbo, G.; Dargent, P.; Daum, C.; Dauvergne, J. P.; David, M.; Davidek, T.; Davidson, N.; Davidson, R.; Dawson, I.; Dawson, J. W.; Daya, R. K.; De, K.; de Asmundis, R.; de Boer, R.; DeCastro, S.; DeGroot, N.; de Jong, P.; de La Broise, X.; DeLa Cruz-Burelo, E.; DeLa Taille, C.; DeLotto, B.; DeOliveira Branco, M.; DePedis, D.; de Saintignon, P.; DeSalvo, A.; DeSanctis, U.; DeSanto, A.; DeVivie DeRegie, J. B.; DeZorzi, G.; Dean, S.; Dedes, G.; Dedovich, D. V.; Defay, P. O.; Degele, R.; Dehchar, M.; Deile, M.; DelPapa, C.; DelPeso, J.; DelPrete, T.; Delagnes, E.; Delebecque, P.; Dell'Acqua, A.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delpierre, P.; Delruelle, N.; Delsart, P. A.; Deluca Silberberg, C.; Demers, S.; Demichev, M.; Demierre, P.; Demirköz, B.; Deng, W.; Denisov, S. P.; Dennis, C.; Densham, C. J.; Dentan, M.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K. K.; Dewhurst, A.; Di Ciaccio, A.; Di Ciaccio, L.; Di Domenico, A.; Di Girolamo, A.; Di Girolamo, B.; Di Luise, S.; Di Mattia, A.; Di Simone, A.; Diaz Gomez, M. M.; Diehl, E. B.; Dietl, H.; Dietrich, J.; Dietsche, W.; Diglio, S.; Dima, M.; Dindar, K.; Dinkespiler, B.; Dionisi, C.; Dipanjan, R.; Dita, P.; Dita, S.; Dittus, F.; Dixon, S. D.; Djama, F.; Djilkibaev, R.; Djobava, T.; do Vale, M. A. B.; Dobbs, M.; Dobinson, R.; Dobos, D.; Dobson, E.; Dobson, M.; Dodd, J.; Dogan, O. B.; Doherty, T.; Doi, Y.; Dolejsi, J.; Dolenc, I.; Dolezal, Z.; Dolgoshein, B. A.; Domingo, E.; Donega, M.; Dopke, J.; Dorfan, D. E.; Dorholt, O.; Doria, A.; Dos Anjos, A.; Dosil, M.; Dotti, A.; Dova, M. T.; Dowell, J. D.; Doyle, A. T.; Drake, G.; Drakoulakos, D.; Drasal, Z.; Drees, J.; Dressnandt, N.; Drevermann, H.; Driouichi, C.; Dris, M.; Drohan, J. G.; Dubbert, J.; Dubbs, T.; Duchovni, E.; Duckeck, G.; Dudarev, A.; Dührssen, M.; Dür, H.; Duerdoth, I. P.; Duffin, S.; Duflot, L.; Dufour, M.-A.; Dumont Dayot, N.; Duran Yildiz, H.; Durand, D.; Dushkin, A.; Duxfield, R.; Dwuznik, M.; Dydak, F.; Dzahini, D.; Díez Cornell, S.; Düren, M.; Ebenstein, W. L.; Eckert, S.; Eckweiler, S.; Eerola, P.; Efthymiopoulos, I.; Egede, U.; Egorov, K.; Ehrenfeld, W.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; Eklund, L. M.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Ely, R.; Emeliyanov, D.; Engelmann, R.; Engström, M.; Ennes, P.; Epp, B.; Eppig, A.; Epshteyn, V. S.; Ereditato, A.; Eremin, V.; Eriksson, D.; Ermoline, I.; Ernwein, J.; Errede, D.; Errede, S.; Escalier, M.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Esteves, F.; Etienne, F.; Etienvre, A. I.; Etzion, E.; Evans, H.; Evdokimov, V. N.; Evtoukhovitch, P.; Eyring, A.; Fabbri, L.; Fabjan, C. W.; Fabre, C.; Faccioli, P.; Facius, K.; Fadeyev, V.; Fakhrutdinov, R. M.; Falciano, S.; Falleau, I.; Falou, A. C.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farrell, J.; Farthouat, P.; Fasching, D.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Fawzi, F.; Fayard, L.; Fayette, F.; Febbraro, R.; Fedin, O. L.; Fedorko, I.; Feld, L.; Feldman, G.; Feligioni, L.; Feng, C.; Feng, E. J.; Fent, J.; Fenyuk, A. B.; Ferencei, J.; Ferguson, D.; Ferland, J.; Fernando, W.; Ferrag, S.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferrer, A.; Ferrer, M. L.; Ferrere, D.; Ferretti, C.; Ferro, F.; Fiascaris, M.; Fichet, S.; Fiedler, F.; Filimonov, V.; Filipčič, A.; Filippas, A.; Filthaut, F.; Fincke-Keeler, M.; Finocchiaro, G.; Fiorini, L.; Firan, A.; Fischer, P.; Fisher, M. J.; Fisher, S. M.; Flaminio, V.; Flammer, J.; Flechl, M.; Fleck, I.; Flegel, W.; Fleischmann, P.; Fleischmann, S.; Fleta Corral, C. M.; Fleuret, F.; Flick, T.; Flix, J.; Flores Castillo, L. R.; Flowerdew, M. J.; Föhlisch, F.; Fokitis, M.; Fonseca Martin, T. M.; Fopma, J.; Forbush, D. A.; Formica, A.; Foster, J. M.; Fournier, D.; Foussat, A.; Fowler, A. J.; Fox, H.; Francavilla, P.; Francis, D.; Franz, S.; Fraser, J. T.; Fraternali, M.; Fratianni, S.; Freestone, J.; French, R. S.; Fritsch, K.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fulachier, J.; Fullana Torregrosa, E.; Fuster, J.; Gabaldon, C.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Gallas, E. J.; Gallas, M. V.; Gallop, B. J.; Gan, K. K.; Gannaway, F. C.; Gao, Y. S.; Gapienko, V. A.; Gaponenko, A.; Garciá, C.; Garcia-Sciveres, M.; Garcìa Navarro, J. E.; Garde, V.; Gardner, R. W.; Garelli, N.; Garitaonandia, H.; Garonne, V. G.; Garvey, J.; Gatti, C.; Gaudio, G.; Gaumer, O.; Gautard, V.; Gauzzi, P.; Gavrilenko, I. L.; Gay, C.; Gayde, J.-C.; Gazis, E. N.; Gazo, E.; Gee, C. N. P.; Geich-Gimbel, C.; Gellerstedt, K.; Gemme, C.; Genest, M. H.; Gentile, S.; George, M. A.; George, S.; Gerlach, P.; Gernizky, Y.; Geweniger, C.; Ghazlane, H.; Ghete, V. M.; Ghez, P.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giakoumopoulou, V.; Giangiobbe, V.; Gianotti, F.; Gibbard, B.; Gibson, A.; Gibson, M. D.; Gibson, S. M.; Gieraltowski, G. F.; Gil Botella, I.; Gilbert, L. M.; Gilchriese, M.; Gildemeister, O.; Gilewsky, V.; Gillman, A. R.; Gingrich, D. M.; Ginzburg, J.; Giokaris, N.; Giordani, M. P.; Girard, C. G.; Giraud, P. F.; Girtler, P.; Giugni, D.; Giusti, P.; Gjelsten, B. K.; Glasman, C.; Glazov, A.; Glitza, K. W.; Glonti, G. L.; Gnanvo, K. G.; Godlewski, J.; Göpfert, T.; Gössling, C.; Göttfert, T.; Goldfarb, S.; Goldin, D.; Goldschmidt, N.; Golling, T.; Gollub, N. P.; Golonka, P. J.; Golovnia, S. N.; Gomes, A.; Gomes, J.; Gonçalo, R.; Gongadze, A.; Gonidec, A.; Gonzalez, S.; González de la Hoz, S.; González Millán, V.; Gonzalez Silva, M. L.; Gonzalez-Pineiro, B.; González-Sevilla, S.; Goodrick, M. J.; Goodson, J. J.; Goossens, L.; Gorbounov, P. A.; Gordeev, A.; Gordon, H.; Gorelov, I.; Gorfine, G.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Gorokhov, S. A.; Gorski, B. T.; Goryachev, S. V.; Goryachev, V. N.; Gosselink, M.; Gostkin, M. I.; Gouanère, M.; Gough Eschrich, I.; Goujdami, D.; Goulette, M.; Gousakov, I.; Gouveia, J.; Gowdy, S.; Goy, C.; Grabowska-Bold, I.; Grabski, V.; Grafström, P.; Grah, C.; Grahn, K.-J.; Grancagnolo, F.; Grancagnolo, S.; Grassmann, H.; Gratchev, V.; Gray, H. M.; Graziani, E.; Green, B.; Greenall, A.; Greenfield, D.; Greenwood, D.; Gregor, I. M.; Grewal, A.; Griesmayer, E.; Grigalashvili, N.; Grigson, C.; Grillo, A. A.; Grimaldi, F.; Grimm, K.; Gris, P. L. Y.; Grishkevich, Y.; Groenstege, H.; Groer, L. S.; Grognuz, J.; Groh, M.; Gross, E.; Grosse-Knetter, J.; Grothe, M. E. M.; Grudzinski, J.; Gruse, C.; Gruwe, M.; Grybel, K.; Grybos, P.; Gschwendtner, E. M.; Guarino, V. J.; Guicheney, C. 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N.; Pylypchenko, Y.; Qi, M.; Qian, J.; Qian, W.; Qian, Z.; Qing, D.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Rabbers, J. J.; Radeka, V.; Rafi, J. M.; Ragusa, F.; Rahimi, A. M.; Rahm, D.; Raine, C.; Raith, B.; Rajagopalan, S.; Rajek, S.; Rammer, H.; Ramstedt, M.; Rangod, S.; Ratoff, P. N.; Raufer, T.; Rauscher, F.; Rauter, E.; Raymond, M.; Reads, A. L.; Rebuzzi, D.; Redlinger, G. R.; Reeves, K.; Rehak, M.; Reichold, A.; Reinherz-Aronis, E.; Reisinger, I.; Reljic, D.; Rembser, C.; Ren, Z.; Renaudin-Crepe, S. R. C.; Renkel, P.; Rensch, B.; Rescia, S.; Rescigno, M.; Resconi, S.; Resende, B.; Rewiersma, P.; Rey, J.; Rey-Campagnolle, M.; Rezaie, E.; Reznicek, P.; Richards, R. A.; Richer, J.-P.; Richter, R. H.; Richter, R.; Richter-Was, E.; Ridel, M.; Riegler, W.; Rieke, S.; Rijpstra, M.; Rijssenbeek, M.; Rimoldi, A.; Rios, R. R.; Riu Dachs, I.; Rivline, M.; Rivoltella, G.; Rizatdinova, F.; Robertson, S. H.; Robichaud-Veronneau, A.; Robins, S.; Robinson, D.; Robson, A.; Rochford, J. H.; Roda, C.; Rodier, S.; Roe, S.; Røhne, O.; Rohrbach, F.; Roldán, J.; Rolli, S.; Romance, J. B.; Romaniouk, A.; Romanov, V. M.; Romeo, G.; Roos, L.; Ros, E.; Rosati, S.; Rosenbaum, F.; Rosenbaum, G. A.; Rosenberg, E. I.; Rosselet, L.; Rossi, L. P.; Rossi, L.; Rotaru, M.; Rothberg, J.; Rottländer, I.; Rousseau, D.; Rozanov, A.; Rozen, Y.; Ruber, R.; Ruckert, B.; Rudolph, G.; Rühr, F.; Ruggieri, F.; Ruggiero, G.; Ruiz, H.; Ruiz-Martinez, A.; Rulikowska-Zarebska, E.; Rumiantsev, V.; Rumyantsev, L.; Runge, K.; Runolfsson, O.; Rusakovich, N. A.; Rust, D. R.; Rutherfoord, J. P.; Ruwiedel, C.; Ryabov, Y. F.; Ryadovikov, V.; Ryan, P.; Rybkine, G.; da Costa, J. Sá; Saavedra, A. F.; Saboumazrag, S.; F-W Sadrozinski, H.; Sadykov, R.; Sakamoto, H.; Sala, P.; Salamon, A.; Saleem, M.; Salihagic, D.; Salt, J.; Saltó Bauza, O.; Salvachúa Ferrando, B. M.; Salvatore, D.; Salzburger, A.; Sampsonidis, D.; Samset, B. H.; Sánchez Sánchez, C. A.; Sanchis Lozano, M. A.; Sanchis Peris, E.; Sandaker, H.; Sander, H. G.; Sandhoff, M.; Sandvoss, S.; Sankey, D. P. C.; Sanny, B.; Sansone, S.; Sansoni, A.; Santamarina Rios, C.; Santander, J.; Santi, L.; Santoni, C.; Santonico, R.; Santos, J.; Sapinski, M.; Saraiva, J. G.; Sarri, F.; Sasaki, O.; Sasaki, T.; Sasao, N.; Satsounkevitch, I.; Sauvage, D.; Sauvage, G.; Savard, P.; Savine, A. Y.; Savinov, V.; Savoy-Navarro, A.; Savva, P.; Saxon, D. H.; Says, L. P.; Sbarra, C.; Sbrissa, E.; Sbrizzi, A.; Scannicchio, D. A.; Schaarschmidt, J.; Schacht, P.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schaller, M.; Schamov, A. G.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schick, H.; Schieck, J.; Schieferdecker, P.; Schioppa, M.; Schlager, G.; Schlenker, S.; Schlereth, J. L.; Schmid, P.; Schmidt, M. P.; Schmitt, C.; Schmitt, K.; Schmitz, M.; Schmücker, H.; Schoerner, T.; Scholte, R. C.; Schott, M.; Schouten, D.; Schram, M.; Schricker, A.; Schroff, D.; Schuh, S.; Schuijlenburg, H. W.; Schuler, G.; Schultes, J.; Schultz-Coulon, H.-C.; Schumacher, J.; Schumacher, M.; Schune, Ph; Schwartzman, A.; Schweiger, D.; Schwemling, Ph; Schwick, C.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Scott, W. G.; Secker, H.; Sedykh, E.; Seguin-Moreau, N.; Segura, E.; Seidel, S. C.; Seiden, A.; Seixas, J. M.; Sekhniaidze, G.; Seliverstov, D. M.; Selldén, B.; Seman, M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Seuster, R.; Severini, H.; Sevior, M. E.; Sexton, K. A.; Sfyrla, A.; Shah, T. P.; Shan, L.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaver, L.; Shaw, C.; Shears, T. G.; Sherwood, P.; Shibata, A.; Shield, P.; Shilov, S.; Shimojima, M.; Shin, T.; Shiyakova, M.; Shmeleva, A.; Shoa, M.; Shochet, M. J.; Shupe, M. A.; Sicho, P.; Sidoti, A.; Siebel, A.; Siebel, M.; Siegrist, J.; Sijacki, D.; Silva, J.; Silverstein, S. B.; Simak, V.; Simic, Lj; Simion, S.; Simmons, B.; Simonyan, M.; Sinervo, P.; Sipica, V.; Siragusa, G.; Sisakyan, A. N.; Sivoklokov, S.; Sjölin, J.; Skubic, P.; Skvorodnev, N.; Slattery, P.; Slavicek, T.; Sliwa, K.; Sloan, T. J.; Sloper, J.; Smakhtin, V.; Small, A.; Smirnov, S. Yu; Smirnov, Y.; Smirnova, L.; Smirnova, O.; Smith, N. A.; Smith, B. C.; Smith, D. S.; Smith, J.; Smith, K. M.; Smith, B.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snow, S. W.; Snow, J.; Snuverink, J.; Snyder, S.; Soares, M.; Soares, S.; Sobie, R.; Sodomka, J.; Söderberg, M.; Soffer, A.; Solans, C. A.; Solar, M.; Sole, D.; Solfaroli Camillocci, E.; Solodkov, A. A.; Solov'yanov, O. V.; Soloviev, I.; Soluk, R.; Sondericker, J.; Sopko, V.; Sopko, B.; Sorbi, M.; Soret Medel, J.; Sosebee, M.; Sosnovtsev, V. V.; Sospedra Suay, L.; Soukharev, A.; Soukup, J.; Spagnolo, S.; Spano, F.; Speckmayer, P.; Spegel, M.; Spencer, E.; Spighi, R.; Spigo, G.; Spila, F.; Spiriti, E.; Spiwoks, R.; Spogli, L.; Spousta, M.; Sprachmann, G.; Spurlock, B.; St. Denis, R. D.; Stahl, T.; Staley, R. J.; Stamen, R.; Stancu, S. N.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stapnes, S.; Starchenko, E. A.; Staroba, P.; Stastny, J.; Staude, A.; Stavina, P.; Stavrianakou, M.; Stavropoulos, G.; Stefanidis, E.; Steffens, J. L.; Stekl, I.; Stelzer, H. J.; Stenzel, H.; Stewart, G.; Stewart, T. D.; Stiller, W.; Stockmanns, T.; Stodulski, M.; Stonjek, S.; Stradling, A.; Straessner, A.; Strandberg, J.; Strandlie, A.; Strauss, M.; Strickland, V.; Striegel, D.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Strong, J. A.; Stroynowski, R.; Stugu, B.; Stumer, I.; Su, D.; Subramania, S.; Suchkov, S. I.; Sugaya, Y.; Sugimoto, T.; Suk, M.; Sulin, V. V.; Sultanov, S.; Sun, Z.; Sundal, B.; Sushkov, S.; Susinno, G.; Sutcliffe, P.; Sutton, M. R.; Sviridov, Yu M.; Sykora, I.; Szczygiel, R. R.; Szeless, B.; Szymocha, T.; Sánchez, J.; Ta, D.; Taboada Gameiro, S.; Tadel, M.; Tafirout, R.; Taga, A.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Talby, M.; Talyshev, A.; Tamsett, M. C.; Tanaka, J.; Tanaka, K.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanaka, Y.; Tappern, G. P.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tarrant, J.; Tartarelli, G.; Tas, P.; Tasevsky, M.; Tayalati, Y.; Taylor, F. E.; Taylor, G.; Taylor, G. N.; Taylor, R. P.; Tcherniatine, V.; Tegenfeldt, F.; Teixeira-Dias, P.; Ten Kate, H.; Teng, P. K.; Ter-Antonyan, R.; Terada, S.; Terron, J.; Terwort, M.; Teuscher, R. J.; Tevlin, C. M.; Thadome, J.; Thion, J.; Thioye, M.; Thomas, A.; Thomas, J. P.; Thomas, T. L.; Thomas, E.; Thompson, R. J.; Thompson, A. S.; Thun, R. P.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Y. A.; Timm, S.; Timmermans, C. J. W. P.; Tipton, P.; Tique Aires Viegas, F. J.; Tisserant, S.; Titov, M.; Tobias, J.; Tocut, V. M.; Toczek, B.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tomasek, L.; Tomasek, M.; Tomasz, F.; Tomoto, M.; Tompkins, D.; Tompkins, L.; Toms, K.; Tonazzo, A.; Tong, G.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torrence, E.; Torres Pais, J. G.; Toth, J.; Touchard, F.; Tovey, D. R.; Tovey, S. N.; Towndrow, E. F.; Trefzger, T.; Treichel, M.; Treis, J.; Tremblet, L.; Tribanek, W.; Tricoli, A.; Trigger, I. M.; Trilling, G.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trka, Z.; Trocmé, B.; Troncon, C.; C-L Tseng, J.; Tsiafis, I.; Tsiareshka, P. V.; Tsipolitis, G.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Turala, M.; Turk Cakir, I.; Turlay, E.; Tuts, P. M.; Twomey, M. S.; Tyndel, M.; Typaldos, D.; Tyrvainen, H.; Tzamarioudaki, E.; Tzanakos, G.; Ueda, I.; Uhrmacher, M.; Ukegawa, F.; Ullán Comes, M.; Unal, G.; Underwood, D. G.; Undrus, A.; Unel, G.; Unno, Y.; Urkovsky, E.; Usai, G.; Usov, Y.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valderanis, C.; Valenta, J.; Valente, P.; Valero, A.; Valkar, S.; Valls Ferrer, J. A.; Van der Bij, H.; van der Graaf, H.; van der Kraaij, E.; Van Eijk, B.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Van Berg, R.; Vandelli, W.; Vandoni, G.; Vaniachine, A.; Vannucci, F.; Varanda, M.; Varela Rodriguez, F.; Vari, R.; Varnes, E. W.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vassilieva, L.; Vataga, E.; Vaz, L.; Vazeille, F.; Vedrine, P.; Vegni, G.; Veillet, J. J.; Vellidis, C.; Veloso, F.; Veness, R.; Veneziano, S.; Ventura, A.; Ventura, S.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vertogardov, L.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Viehhauser, G. H. A.; Vigeolas, E.; Villa, M.; Villani, E. G.; Villate, J.; Villella, I.; Vilucchi, E.; Vincent, P.; Vincke, H.; Vincter, M. G.; Vinogradov, V. B.; Virchaux, M.; Viret, S.; Virzi, J.; Vitale, A.; Vivarelli, I.; Vives, R.; Vives Vaques, F.; Vlachos, S.; Vogt, H.; Vokac, P.; Vollmer, C. F.; Volpi, M.; Volpini, G.; von Boehn-Buchholz, R.; von der Schmitt, H.; von Toerne, E.; Vorobel, V.; Vorobiev, A. P.; Vorozhtsov, A. S.; Vorozhtsov, S. B.; Vos, M.; Voss, K. C.; Voss, R.; Vossebeld, J. H.; Vovenko, A. S.; Vranjes, N.; Vrba, V.; Vreeswijk, M.; Anh, T. Vu; Vuaridel, B.; Vudragovic, M.; Vuillemin, V.; Vuillermet, R.; Wänanen, A.; Wahlen, H.; Walbersloh, J.; Walker, R.; Walkowiak, W.; Wall, R.; Wallny, R. S.; Walsh, S.; Wang, C.; Wang, J. C.; Wappler, F.; Warburton, A.; Ward, C. P.; Warner, G. P.; Warren, M.; Warsinsky, M.; Wastie, R.; Watkins, P. M.; Watson, A. T.; Watts, G.; Waugh, A. T.; Waugh, B. M.; Weaverdyck, C.; Webel, M.; Weber, G.; Weber, J.; Weber, M.; Weber, P.; Weidberg, A. R.; Weilhammer, P. M.; Weingarten, J.; Weiser, C.; Wellenstein, H.; Wellisch, H. P.; Wells, P. S.; Wemans, A.; Wen, M.; Wenaus, T.; Wendler, S.; Wengler, T.; Wenig, S.; Wermes, N.; Werneke, P.; Werner, P.; Werthenbach, U.; Wheeler-Ellis, S. J.; Whitaker, S. P.; White, A.; White, M. J.; White, S.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiesmann, M.; Wiesmann, M.; Wijnen, T.; Wildauer, A.; Wilhelm, I.; Wilkens, H. G.; Williams, H. H.; Willis, W.; Willocq, S.; Wilmut, I.; Wilson, J. A.; Wilson, A.; Wingerter-Seez, I.; Winton, L.; Witzeling, W.; Wlodek, T.; Woehrling, E.; Wolter, M. W.; Wolters, H.; Wosiek, B.; Wotschack, J.; Woudstra, M. J.; Wright, C.; Wu, S. L.; Wu, X.; Wuestenfeld, J.; Wunstorf, R.; Xella-Hansen, S.; Xiang, A.; Xie, S.; Xie, Y.; Xu, G.; Xu, N.; Yamamoto, A.; Yamamoto, S.; Yamaoka, H.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, J. C.; Yang, S.; Yang, U. K.; Yang, Y.; Yang, Z.; Yao, W.-M.; Yao, Y.; Yarradoddi, K.; Yasu, Y.; Ye, J.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, H.; Yoshida, R.; Young, C.; Youssef, S. P.; Yu, D.; Yu, J.; Yu, M.; Yu, X.; Yuan, J.; Yurkewicz, A.; Zaets, V. G.; Zaidan, R.; Zaitsev, A. M.; Zajac, J.; Zajacova, Z.; Zalite, A. Yu; Zalite, Yo K.; Zanello, L.; Zarzhitsky, P.; Zaytsev, A.; Zdrazil, M.; Zeitnitz, C.; Zeller, M.; Zema, P. F.; Zendler, C.; Zenin, A. V.; Zenis, T.; Zenonos, Z.; Zenz, S.; Zerwas, D.; Zhang, H.; Zhang, J.; Zheng, W.; Zhang, X.; Zhao, L.; Zhao, T.; Zhao, X.; Zhao, Z.; Zhelezko, A.; Zhemchugov, A.; Zheng, S.; Zhichao, L.; Zhou, B.; Zhou, N.; Zhou, S.; Zhou, Y.; Zhu, C. G.; Zhu, H. Z.; Zhuang, X. A.; Zhuravlov, V.; Zilka, B.; Zimin, N. I.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Zivkovic, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; Zoeller, M. M.; Zolnierowski, Y.; Zsenei, A.; zur Nedden, M.; Zychacek, V.

    2008-08-01

    The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

  4. A feedback microprocessor for hadron colliders

    SciTech Connect

    Herrup, D.A.; Chapman, L.; Franck, A.; Groves, T.; Lublinsky, B. )

    1995-02-01

    A feedback microprocessor has been built for the Tevatron. It has been constructed to be applicable to hadron colliders in general. Its inputs are realtime accelerator measurements, data describing the state of the Tevatron, and ramp tables. The microprocessor software includes a finite-state machine. Each state corresponds to a specific Tevatron operation and has a state-specific Tevatron model. Transitions between states are initiated by the global Tevatron clock. Each state includes a cyclic routine, which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast Tevatron-wide link from which the power supplies will read the real time corrections. We also store all of the input data and output corrections in a set of buffers that can easily be retrieved for diagnostic analysis. In this paper we describe this device and its use to control the Tevatron tunes as well as other possible applications. [copyright] 1995 [ital American] [ital Institute] [ital of] [ital Physics

  5. A large hadron electron collider at CERN

    DOE PAGES

    Abelleira Fernandez, J. L.

    2015-04-06

    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 eletron-ion physics. The LHeC is designed to run synchronously withmore » 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.« less

  6. A large hadron electron collider at CERN

    SciTech Connect

    Abelleira Fernandez, J. L.

    2015-04-06

    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 eletron-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.

  7. Computing and data handling requirements for SSC (Superconducting Super Collider) and LHC (Large Hadron Collider) experiments

    SciTech Connect

    Lankford, A.J.

    1990-05-01

    A number of issues for computing and data handling in the online in environment at future high-luminosity, high-energy colliders, such as the Superconducting Super Collider (SSC) and Large Hadron Collider (LHC), are outlined. Requirements for trigger processing, data acquisition, and online processing are discussed. Some aspects of possible solutions are sketched. 6 refs., 3 figs.

  8. Hadron collider potential for excited bosons search

    NASA Astrophysics Data System (ADS)

    Chizhov, M. V.; Boyko, I. R.; Bednyakov, V. A.; Budagov, J. A.

    2014-05-01

    The e + e - and μ+μ- dilepton final states are the most clear channels for a new heavy neutral resonance search. Their advantage is that usually in the region of expected heavy-mass resonance peak the main irreducible background, from the Standard Model Drell-Yan process, contributes two orders of magnitude smaller than the signal. In this paper we consider the future prospects for search for the excited neutral Z*-bosons. The bosons can be observed as a Breit-Wigner resonance peak in the dilepton invariant mass distributions in the same way as the well-known extra gauge Z' bosons. However, the Z* bosons have unique signatures in transverse momentum, angular and pseudorapidity distributions of the final leptons, which allow to distinguish them from the other heavy neutral resonances. At present only the ATLAS Collaboration has looked for such new excitations at the Large Hadron Collider and has published its results for 7 TeV collision energy. After successful comparison of our evaluation with these official results we present our estimations for the discovery potential and the exclusion limits on the Z*-boson search in pp collisions at higher centre-of-mass energies and different luminosities. In particular, LHC Run 2 can discover Z*-boson with its mass up to 5.3 TeV, while the High Luminosity LHC can extend that reach to 6.2 TeV. The High Energy LHC (with collision energy of 33 TeV) will be able to probe two times heavier resonance masses at the same integrated luminosities.

  9. Production of Electroweak Bosons at Hadron Colliders: Theoretical Aspects

    NASA Astrophysics Data System (ADS)

    Mangano, Michelangelo L.

    2016-10-01

    Since the W± and Z0 discovery, hadron colliders have provided a fertile ground, in which continuously improving measurements and theoretical predictions allow to precisely determine the gauge boson properties, and to probe the dynamics of electroweak and strong interactions. This article will review, from a theoretical perspective, the role played by the study, at hadron colliders, of electroweak boson production properties, from the better understanding of the proton structure, to the discovery and studies of the top quark and of the Higgs, to the searches for new phenomena beyond the Standard Model.

  10. Jet Reconstruction and Spectroscopy at Hadron Colliders

    NASA Astrophysics Data System (ADS)

    Bellettini, Giorgio

    2011-11-01

    Dear colleagues and friends, Major new particle discoveries were made in the past by exploring the mass spectrum of lepton pairs. These searches still have great potential. However, new particle searches are now being extended to masses larger than the W, Z mass. More and more decay channels open up and the branching ratios into lepton pairs are reduced. Also, physics may dictate that states with heavy bosons and quarks become dominant. Examples are the decay of top quarks, and the expected final states of the standard model Higgs boson. Supersymmetry in any of its wide spectrum of models predicts intrigued final states where jets are major observables. To reconstruct masses and to study the dynamics of these states one must exploit the energy-momentum four-vectors of jets. Past experiments at the CERN SPS collider, at HERA, at LEP and now at the Tevatron collider and at LHC, have studied how best to reconstruct hadron jets. However, originally the role of jets in searching for new physics was primarily to sense new parton contact interactions by means of increased large pt tails in inclusive jet spectra, or studying jet events with large missing Et, or measuring branching ratios into jets of different flavour. These studies did not require as accurate a measure of jet four-momenta as needed in new particle searches in multi-jets final states. Figure 1 Figure 1. W, Z associated production in CDF events with large Et, miss and 2 jets. Consider for example (figure 1) the mass spectrum of dijets in events with large missing Et recently measured by CDF [1]. Trigger and analysis cuts were chosen so as to favour production of heavy boson pairs, with decay of one Z boson into neutrinos tagging the event and another W or Z boson decaying into jets. Associated production of boson pairs is observed, but the dijet mass resolution does not allow the separation of W from Z. A broad agreement of the overall observed rate with expectation is found, but a comparative study of the

  11. TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

    SciTech Connect

    Jabeen, Shabnam

    2013-10-20

    This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of √ s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of √ s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

  12. The future of the Large Hadron Collider and CERN.

    PubMed

    Heuer, Rolf-Dieter

    2012-02-28

    This paper presents the Large Hadron Collider (LHC) and its current scientific programme and outlines options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design luminosity and energy, as well as upgrades to the LHC and its injectors. This may be followed by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and the International Linear Collider collaborations, or by a high-energy electron-proton machine. This contribution describes the past, present and future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

  13. Large Hadron collider tests of the little Higgs model.

    PubMed

    Burdman, Gustavo; Perelstein, Maxim; Pierce, Aaron

    2003-06-20

    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 CERN 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. PMID:12857187

  14. High-brightness injectors for hadron colliders

    SciTech Connect

    Wangler, T.P.

    1990-01-01

    The counterrotating beams in collider rings consist of trains of beam bunches with N{sub B} particles per bunch, spaced a distance S{sub B} apart. When the bunches collide, the interaction rate is determined by the luminosity, which is defined as the interaction rate per unit cross section. For head-on collisions between cylindrical Gaussian beams moving at speed {beta}c, the luminosity is given by L = N{sub B}{sup 2}{beta}c/4{pi}{sigma}{sup 2}S{sub B}, where {sigma} is the rms beam size projected onto a transverse plane (the two transverse planes are assumed identical) at the interaction point. This beam size depends on the rms emittance of the beam and the focusing strength, which is a measure of the 2-D phase-space area in each transverse plane, and is defined in terms of the second moments of the beam distribution. Our convention is to use the rms normalized emittance, without factors of 4 or 6 that are sometimes used. The quantity {tilde {beta}} is the Courant-Synder betatron amplitude function at the interaction point, a characteristic of the focusing lattice and {gamma} is the relativistic Lorentz factor. Achieving high luminosity at a given energy, and at practical values of {tilde {beta}} and S{sub B}, requires a large value for the ratio N{sub B}{sup 2}/{var epsilon}{sub n}, which implies high intensity and small emittance. Thus, specification of the luminosity sets the requirements for beam intensity and emittance, and establishes the requirements on the performance of the injector to the collider ring. In general, for fixed N{sub B}, the luminosity can be increased if {var epsilon}{sub n} can be reduced. The minimum emittance of the collider is limited by the performance of the injector; consequently the design of the injector is of great importance for the ultimate performance of the collider.

  15. SEARCHING FOR HIGGS BOSONS AND NEW PHYSICS AT HADRON COLLIDERS

    SciTech Connect

    Chung Kao

    2007-09-05

    The objectives of research activities in particle theory are predicting the production cross section and decay branching fractions of Higgs bosons and new particles at hadron colliders, developing techniques and computer software to discover these particles and to measure their properties, and searching for new phenomena and new interactions at the Fermilab Tevatron and the CERN Large Hadron Collider. The results of our project could lead to the discovery of Higgs bosons, new particles, and signatures for new physics, or we will be able to set meaningful limits on important parameters in particle physics. We investigated the the prospects for the discovery at the CERN Large Hadron Collider of Higgs bosons and supersymmetric particles. Promising results are found for the CP-odd pseudoscalar ($A^0$) and the heavier CP-even scalar ($H^0$) Higgs bosons with masses up to 800 GeV. Furthermore, we study properties of the lightest neutralino ($\\chi^0$) and calculate its cosmological relic density in a supersymmetric $U(1)'$ model as well as the muon anomalous magnetic moment $a_\\mu = (g_\\mu - 2)/2$ in a supersymmetric $U(1)'$ model. We found that there are regions of the parameter space that can explain the experimental deviation of $a_\\mu$ from the Standard Model calculation and yield an acceptable cold dark matter relic density without conflict with collider experimental constraints. % Recently, we presented a complete next-to-leading order (NLO) calculation for the total cross section of inclusive Higgs pair production via bottom-quark fusion ($b\\bar{b} \\to hh$) at the CERN Large Hadron Collider (LHC) in the Standard Model and the minimal supersymmetric model. We plan to predict the Higgs pair production rate and to study the trilinear coupling among the Higgs bosons. % In addition, we have made significant contributions in B physics, single top production, charged Higgs search at the Fermilab as well as in grid computing for both D0 and ATLAS.

  16. Parton-Hadron-String Dynamics at relativistic collider energies

    NASA Astrophysics Data System (ADS)

    Bratkovskaya, E. L.; Cassing, W.; Konchakovski, V. P.; Linnyk, O.

    2011-04-01

    The novel Parton-Hadron-String Dynamics (PHSD) transport approach is applied to nucleus-nucleus collisions at RHIC energies with respect to differential hadronic spectra in comparison to available data. The PHSD approach is based on a dynamical quasiparticle model for partons (DQPM) matched to reproduce recent lattice-QCD results from the Wuppertal-Budapest group in thermodynamic equilibrium. The transition from partonic to hadronic degrees of freedom is described by covariant transition rates for the fusion of quark-antiquark pairs or three quarks (antiquarks), respectively, obeying flavor current-conservation, color neutrality as well as energy-momentum conservation. Our dynamical studies for heavy-ion collisions at relativistic collider energies are compared to earlier results from the Hadron-String Dynamics (HSD) approach - incorporating no explicit dynamical partonic phase - as well as to experimental data from the STAR, PHENIX, BRAHMS and PHOBOS Collaborations for Au + Au collisions at the top RHIC energy of √{s}=200 GeV. We find a reasonable reproduction of hadron rapidity distributions and transverse mass spectra and also a fair description of the elliptic flow of charged hadrons as a function of the centrality of the reaction and the transverse momentum p. Furthermore, an approximate quark-number scaling of the elliptic flow v of hadrons is observed in the PHSD results, too.

  17. Invisible Higgs decay at the Large Hadron-Electron Collider

    NASA Astrophysics Data System (ADS)

    Tang, Yi-Lei; Zhang, Chen; Zhu, Shou-hua

    2016-07-01

    The possibility that the 125 GeV Higgs boson may decay into invisible non-standard-model (non-SM) particles is theoretically and phenomenologically intriguing. In this paper, we investigate the sensitivity of the Large Hadron Electron Collider (LHeC) to an invisibly decaying Higgs, in its proposed high-luminosity running mode. We focus on the neutral current Higgs production channel which offers more kinematical handles than its charged current counterpart. The signal contains one electron, one jet, and large missing energy. With a cut-based parton-level analysis, we estimate that if the h Z Z coupling is at its standard model (SM) value, then assuming an integrated luminosity of 1 ab-1 , the LHeC with the proposed 60 GeV electron beam (with -0.9 polarization) and 7 TeV proton beam is capable of probing Br (h →TE)=6 % at 2 σ level. Good lepton veto performance (especially hadronic τ veto) in the forward region is crucial to the suppression of the dominant W j e background. We also explicitly point out the important role that may be played by the LHeC in probing a wide class of exotic Higgs decay processes and emphasize the general function of lepton-hadron colliders in the precision study of new resonances after their discovery in hadron-hadron collisions.

  18. Searches for scalar and vector leptoquarks at future hadron colliders

    SciTech Connect

    Rizzo, T.G.

    1996-09-01

    The search reaches for both scalar(S) and vector(V) leptoquarks at future hadron colliders are summarized. In particular the authors evaluate the production cross sections of both leptoquark types at TeV33 and LHC as well as the proposed 60 and 200 TeV colliders through both quark-antiquark annihilation and gluon-gluon fusion: q{anti q},gg {r_arrow} SS,VV. Experiments at these machines should easily discover such particles if their masses are not in excess of the few TeV range.

  19. Collider Detector at Fermilab (CDF): Data from B Hadrons Research

    DOE Data Explorer

    The Collider Detector at Fermilab (CDF) is a Tevatron experiment at Fermilab. The Tevatron, a powerful particle accelerator, accelerates protons and antiprotons close to the speed of light, and then makes them collide head-on inside the CDF detector. The CDF detector is used to study the products of such collisions. The CDF Physics Group is organized into six working groups, each with a specific focus. The Bottom group studies the production and decay of B hadrons. Their public web page makes data and numerous figures available from both CDF Runs I and II.

  20. The Structure of Jets at Hadron Colliders

    SciTech Connect

    Larkoski, Andrew James

    2012-08-01

    Particle physics seeks to understand the interactions and properties of the fundamental particles. To gain understanding, there is an interplay between theory and experiment. Models are proposed to explain how particles behave and interact. These models make precise predictions that can be tested. Experiments are built and executed to measure the properties of these particles, providing necessary tests for the theories that attempt to explain the realm of fundamental particles. However, there is also another level of interaction between theory and experiment; the development of new experiments demands the study of how particles will behave with respect to the measured observables toward the goal of understanding the details and idiosyncrasies of the measurements very well. Only once these are well-modeled and understood can one be con dent that the data that are measured is trustworthy. The modeling and interpretation of the physics of a proton collider, such as the LHC, is the main topic of this thesis.

  1. Tracking study of hadron collider boosters

    SciTech Connect

    Machida, S.; Bourianoff, G.; Huang, Y.; Mahale, N.

    1992-07-01

    A simulation code SIMPSONS (previously called 6D-TEASE T) of single- and multi-particle tracking has been developed for proton synchrotrons. The 6D phase space coordinates are calculated each time step including acceleration with an arbitrary ramping curve by integration of the rf phase. Space-charge effects are modelled by means of the Particle In Cell (PIC) method. We observed the transverse emittance growth around the injection energy of the Low Energy Booster (LEB) of the Superconducting Super Collider (SSC) with and without second harmonic rf cavities which reduce peak line density. We also employed the code to see the possible transverse emittance deterioration around the transition energy in the Medium Energy Booster (MEB) and to estimate the emittance dilution due to an injection error of the MEB.

  2. Higgs Boson Searches at Hadron Colliders (1/4)

    ScienceCinema

    None

    2016-07-12

    In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

  3. The technical challenges of the Large Hadron Collider.

    PubMed

    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. PMID:26949802

  4. Higgs Boson Searches at Hadron Colliders (1/4)

    SciTech Connect

    2010-06-21

    In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

  5. The technical challenges of the Large Hadron Collider.

    PubMed

    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.

  6. Learning to See at the Large Hadron Collider

    SciTech Connect

    Quigg, Chris

    2010-01-01

    The staged commissioning of the Large Hadron Collider presents an opportunity to map gross features of particle production over a significant energy range. I suggest a visual tool - event displays in (pseudo)rapidity-transverse-momentum space - as a scenic route that may help sharpen intuition, identify interesting classes of events for further investigation, and test expectations about the underlying event that accompanies large-transverse-momentum phenomena.

  7. Lattice optimization for a really large hadron collider (RLHC)

    SciTech Connect

    Peggs, S.; Dell, F.; Harrison, M.; Syphers, M.; Tepikian, S.

    1996-07-01

    Long arc cells would lead to major cost savings in a high field high T{sub c} hadron collider, operating in the regime of significant synchrotron radiation. Two such lattices, with half cell lengths of 110 and 260 m, are compared. Both allow flexible tuning, and have large dynamic apertures when dominated by chromatic sextupoles. Lattices with longer cells are much more sensitive to systematic magnet errors, which are expected to dominate.

  8. Electron Lenses for the Large Hadron Collider

    SciTech Connect

    Stancari, Giulio; Valishev, Alexander; Bruce, Roderik; Redaelli, Stefano; Rossi, Adriana; Salvachua, Belen

    2014-07-01

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in RHIC at BNL. Within the US LHC Accelerator Research Program and the European HiLumi LHC Design Study, hollow electron beam collimation was studied as an option to complement the collimation system for the LHC upgrades. This project is moving towards a technical design in 2014, with the goal to build the devices in 2015-2017, after resuming LHC operations and re-assessing needs and requirements at 6.5 TeV. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles.

  9. Disambiguating seesaw models using invariant mass variables at hadron colliders

    DOE PAGES

    Dev, P. S. Bhupal; Kim, Doojin; Mohapatra, Rabindra N.

    2016-01-19

    Here, we propose ways to distinguish between different mechanisms behind the collider signals of TeV-scale seesaw models for neutrino masses using kinematic endpoints of invariant mass variables. We particularly focus on two classes of such models widely discussed in literature: (i) Standard Model extended by the addition of singlet neutrinos and (ii) Left-Right Symmetric Models. Relevant scenarios involving the same "smoking-gun" collider signature of dilepton plus dijet with no missing transverse energy differ from one another by their event topology, resulting in distinctive relationships among the kinematic endpoints to be used for discerning them at hadron colliders. Furthermore, these kinematic endpoints are readily translated to the mass parameters of the on-shell particles through simple analytic expressions which can be used for measuring the masses of the new particles. We also conducted a Monte Carlo simulation with detector effects in order to test the viability of the proposed strategy in a realistic environment. Finally, we discuss the future prospects of testing these scenarios at themore » $$\\sqrt{s}$$ = 14 and 100TeV hadron colliders.« less

  10. Disambiguating seesaw models using invariant mass variables at hadron colliders

    NASA Astrophysics Data System (ADS)

    Dev, P. S. Bhupal; Kim, Doojin; Mohapatra, Rabindra N.

    2016-01-01

    We propose ways to distinguish between different mechanisms behind the collider signals of TeV-scale seesaw models for neutrino masses using kinematic endpoints of invariant mass variables. We particularly focus on two classes of such models widely discussed in literature: (i) Standard Model extended by the addition of singlet neutrinos and (ii) Left-Right Symmetric Models. Relevant scenarios involving the same "smoking-gun" collider signature of dilepton plus dijet with no missing transverse energy differ from one another by their event topology, resulting in distinctive relationships among the kinematic endpoints to be used for discerning them at hadron colliders. These kinematic endpoints are readily translated to the mass parameters of the on-shell particles through simple analytic expressions which can be used for measuring the masses of the new particles. A Monte Carlo simulation with detector effects is conducted to test the viability of the proposed strategy in a realistic environment. Finally, we discuss the future prospects of testing these scenarios at the √{s}=14 and 100 TeV hadron colliders.

  11. Hunting electroweakinos at future hadron colliders and direct detection experiments

    NASA Astrophysics Data System (ADS)

    di Cortona, Giovanni Grilli

    2015-05-01

    We analyse the mass reach for electroweakinos at future hadron colliders and their interplay with direct detection experiments. Motivated by the LHC data, we focus on split supersymmetry models with different electroweakino spectra. We find for example that a 100 TeV collider may explore Winos up to ˜ 7 TeV in low scale gauge mediation models or thermal Wino dark matter around 3 TeV in models of anomaly mediation with long-lived Winos. We show moreover how collider searches and direct detection experiments have the potential to cover large part of the parameter space even in scenarios where the lightest neutralino does not contribute to the whole dark matter relic density.

  12. Physics and Analysis at a Hadron Collider - An Introduction (1/3)

    SciTech Connect

    2010-01-20

    This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

  13. Physics and Analysis at a Hadron Collider - An Introduction (1/3)

    ScienceCinema

    None

    2016-07-12

    This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

  14. A 233 km tunnel for lepton and hadron colliders

    SciTech Connect

    Summers, D. J.; Cremaldi, L. M.; Datta, A.; Duraisamy, M.; Luo, T.; Lyons, G. T.

    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.

  15. QCD corrections to stoponium production at hadron colliders

    SciTech Connect

    Younkin, James E.; Martin, Stephen P.

    2010-03-01

    If the lighter top squark has no kinematically allowed two-body decays that conserve flavor, then it will live long enough to form hadronic bound states. The observation of the diphoton decays of stoponium could then provide a uniquely precise measurement of the top squark mass. In this paper, we calculate the cross section for the production of stoponium in a hadron collider at next-to-leading order (NLO) in QCD. We present numerical results for the cross section for production of stoponium at the LHC and study the dependence on beam energy, stoponium mass, and the renormalization and factorization scale. The cross-section is substantially increased by the NLO corrections, counteracting a corresponding decrease found earlier in the NLO diphoton branching ratio.

  16. Possible Signals of Wino LSP at the Large Hadron Collider

    SciTech Connect

    Ibe, M.; Moroi, Takeo; Yanagida, T.T.; /Tokyo U. /Tokyo U., RESCEU

    2006-11-27

    We consider a class of anomaly-mediated supersymmetry breaking models where gauginos acquire masses mostly from anomaly mediation while masses of other superparticles are from Kaehler interactions, which are as large as gravitino mass {approx} {Omicron}(10-100) TeV. In this class of models, the neutral Wino becomes the lightest superparticle in a wide parameter region. The mass splitting between charged and neutral Winos are very small and experimental discovery of such Winos is highly non-trivial. We discuss how we should look for Wino-induced signals at Large Hadron Collider.

  17. NLO QCD corrections to ZZ jet production at hadron colliders

    SciTech Connect

    Binoth, T.; Gleisberg, T.; Karg, S.; Kauer, N.; Sanguinetti, G.; /Annecy, LAPTH

    2010-05-26

    A fully differential calculation of the next-to-leading order QCD corrections to the production of Z-boson pairs in association with a hard jet at the Tevatron and LHC is presented. This process is an important background for Higgs particle and new physics searches at hadron colliders. We find sizable corrections for cross sections and differential distributions, particularly at the LHC. Residual scale uncertainties are typically at the 10% level and can be further reduced by applying a veto against the emission of a second hard jet. Our results confirm that NLO corrections do not simply rescale LO predictions.

  18. INTERACTION REGION LOCAL CORRECTION FOR THE LARGE HADRON COLLIDER.

    SciTech Connect

    WEI,J.; FISCHER,W.; PTITSIN,V.; OSTOJIC,R.; STRAIT,J.

    1999-03-29

    The performance of the Large Hadron Collider (LHC) at collision energy is limited by the field quality of the interaction region (IB) quadrupoles and dipoles. In this paper we study the impact of the expected field errors of these magnets on the dynamic aperture (DA). Since the betatron phase advance is well defined for magnets that are located in regions of large beta functions, local corrections can be very effective and robust. We compare possible compensation schemes and propose a corrector layout to meet the required DA performance.

  19. vh@nnlo-Higgs Strahlung at hadron colliders

    NASA Astrophysics Data System (ADS)

    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.

  20. High luminosity electron-hadron collider eRHIC

    SciTech Connect

    Ptitsyn, V.; Aschenauer, E.; Bai, M.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M..; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hammons, L.; Hahn, H.; Hammons, L.; He, P.; Hao, Y.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Rao, T.; Roser, T.; Skaritka, J.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Pozdeyev, E.; Tsentalovich, E.

    2011-03-28

    We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

  1. Higgs boson production with heavy quarks at hadron colliders

    NASA Astrophysics Data System (ADS)

    Jackson, Christopher B.

    2005-11-01

    One of the remaining puzzles in particle physics is the origin of electroweak symmetry breaking. In the Standard Model (SM), a single doublet of complex scalar fields is responsible for breaking the SU(2) L x U(1)Y gauge symmetry thus giving mass to the electroweak gauge bosons via the Higgs mechanism and to the fermions via Yukawa couplings. The remnant of the process is a vet to he discovered scalar particle, the Higgs boson (h). However, current and future experiments at hadron colliders hold great promise. Of particular interest at hadron colliders is the production of a Higgs boson in association with a pair of heavy quarks, pp¯(pp) → QQ¯h, where Q can be either a top or a bottom quark. Indeed, the production of a Higgs boson with a pair of top quarks provides a very distinctive signal in hadronic collisions where background processes are formidable, and it will be instrumental in the discovery of a Higgs boson below about 130 GeV at the LHC. On the other hand, the production of a Higgs boson with bottom quarks can be strongly enhanced in models of new physics beyond the SM, e.g. supersymmetric models. If this is the case, bb¯h production will play a crucial role at the Tevatron where it could provide the first signal of new physics. Given the prominent role that Higgs production with heavy quarks can play at hadron colliders, it becomes imperative to have precise theoretical predictions for total and differential cross sections. In this dissertation, we outline and present detailed results for the next-to-leading order (NLO) calculation of the Quantum Chromodynamic (QCD) corrections to QQ¯h production at both the Tevatron and the LHC. This calculation involves several difficult issues due to the three massive particles in the final state, a situation which is at the frontier of radiative correction calculations in quantum field theory. We detail the novel techniques developed to deal with these challenges. The calculation of pp¯(pp) → bb¯h at NLO in

  2. Challenges for MSSM Higgs searches at hadron colliders

    SciTech Connect

    Carena, Marcela S.; Menon, A.; Wagner, C.E.M.; /Argonne /Chicago U., EFI /KICP, Chicago /Chicago U.

    2007-04-01

    In this article we analyze the impact of B-physics and Higgs physics at LEP on standard and non-standard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B-decays b {yields} s{gamma} and B{sub u} {yields} {tau}{nu} and the experimental limit on the B{sub s} {yields} {mu}{sup +}{mu}{sup -} branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter A{sub t}, rendering the non-standard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of A{sub t} and large values of the Higgsino mass parameter {mu}, enhancing the prospects for the direct detection of non-standard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC's ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs h {yields} b{bar b} channel to show that it may be able to find 3 {sigma} evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.

  3. Summary of the very large hadron collider physics and detector workshop

    SciTech Connect

    Anderson, G.; Berger, M.; Brandt, A.; Eno, S.

    1997-10-01

    One of the options for an accelerator beyond the LHC is a hadron collider with higher energy. Work is going on to explore accelerator technologies that would make such a machine feasible. This workshop concentrated on the physics and detector issues associated with a hadron collider with an energy in the center of mass of the order of 100 to 200 TeV.

  4. Direct measurement of the top quark charge at hadron colliders

    NASA Astrophysics Data System (ADS)

    Baur, U.; Buice, M.; Orr, Lynne H.

    2001-11-01

    We consider photon radiation in t¯t events at the upgraded Fermilab Tevatron and the CERN Large Hadron Collider (LHC) as a tool to measure the electric charge of the top quark. We analyze the contributions of t¯tγ production and radiative top quark decays to pp(-)-->γl+/-νb¯bjj, assuming that both b quarks are tagged. With 20 fb-1 at the Tevatron, the possibility that the ``top quark'' discovered in run I is actually an exotic charge -4/3 quark can be ruled out at the ~95% confidence level. At the CERN LHC, it will be possible to determine the charge of the top quark with an accuracy of about 10%.

  5. Modification of Fox-Wolfram moments for hadron colliders

    NASA Astrophysics Data System (ADS)

    Spiller, L. A.

    2016-03-01

    Collisions of composite particles impose an arbitrary boost in the longitudinal direction on a given event. This implies that the centre-of-mass frame at hadron colliders is undetermined for processes with missing energy in the final state. This motivates the modification of the Fox-Wolfram moments such that the moments for a given event are identical when viewed in the lab or centre-of-mass frame of the beam. The resulting moments are invariant under rotations in the plane transverse to the beam and boosts parallel to the beam. These moments are then used to demonstrate improved signal separation in the channel where the Higgs decays to two b-quarks while being produced in association with a vector boson.

  6. Flavour physics and the Large Hadron Collider beauty experiment.

    PubMed

    Gibson, Valerie

    2012-02-28

    An exciting new era in flavour physics has just begun with the start of the Large Hadron Collider (LHC). The LHCb (where b stands for beauty) experiment, designed specifically to search for new phenomena in quantum loop processes and to provide a deeper understanding of matter-antimatter asymmetries at the most fundamental level, is producing many new and exciting results. It gives me great pleasure to describe a selected few of the results here-in particular, the search for rare B(0)(s)-->μ+ μ- decays and the measurement of the B(0)(s) charge-conjugation parity-violating phase, both of which offer high potential for the discovery of new physics at and beyond the LHC energy frontier in the very near future.

  7. Calculations of bottom quark production at hadron colliders

    SciTech Connect

    Kuebel, D.

    1991-06-29

    This thesis studies Monte Carlo simulations of QCD heavy flavor production processes (p{bar p} {yields} Q({anti Q})X) at hadron colliders. ISAJET bottom quark cross-sections are compared to the O({alpha} {sub s}{sup 3}) perturbative calculation of Nason, Dawson, and Ellis. These Monte Carlo cross-sections are computed from data samples which use different parton distribution functions and physics parameters. Distributions are presented in the heavy quark`s transverse momentum and rapidity. Correlations in rapidity and azimuthal angle are computed for the heavy flavor pair. Theory issues which arise are the behavior of the cross-section at low and high values of transverse momentum and the treatment of double counting problems in the flavor excitation samples. An important result is that ISAJET overestimates bottom quark production cross-sections and K factors. These findings are relevant for estimates of rates and backgrounds of heavy floor events.

  8. Calculations of bottom quark production at hadron colliders

    SciTech Connect

    Kuebel, D.

    1991-06-29

    This thesis studies Monte Carlo simulations of QCD heavy flavor production processes (p{bar p} {yields} Q({anti Q})X) at hadron colliders. ISAJET bottom quark cross-sections are compared to the O({alpha} {sub s}{sup 3}) perturbative calculation of Nason, Dawson, and Ellis. These Monte Carlo cross-sections are computed from data samples which use different parton distribution functions and physics parameters. Distributions are presented in the heavy quark's transverse momentum and rapidity. Correlations in rapidity and azimuthal angle are computed for the heavy flavor pair. Theory issues which arise are the behavior of the cross-section at low and high values of transverse momentum and the treatment of double counting problems in the flavor excitation samples. An important result is that ISAJET overestimates bottom quark production cross-sections and K factors. These findings are relevant for estimates of rates and backgrounds of heavy floor events.

  9. General-Purpose Detectors for the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Froidevaux, Daniel; Sphicas, Paris

    2006-11-01

    This review describes the two general-purpose experiments, ATLAS and CMS, that have been designed to study proton-proton collisions at 14 TeV, the highest center-of-mass energy ever achieved, at the Large Hadron Collider at CERN in Geneva, Switzerland. These experiments have undergone a long research and development and construction period since 1989 and are now in the middle of a strenuous and exciting integration, installation, and commissioning period. After a brief introduction to the physics context and prospects as perceived today, this review presents an overview of both projects in terms of their global design characteristics. The main features and challenges related to the tracking systems, to the calorimetry, and to the muon spectrometers are described. The various aspects of the trigger and data acquisition systems and of the computing and software are also discussed broadly. Finally, we conclude with the lessons learned during the design and construction years.

  10. Precise Predictions for Z + 4 Jets at Hadron Colliders

    SciTech Connect

    Ita, H.; Bern, Z.; Dixon, L.J.; Cordero, F.Febres; Kosower, D.A.; Maitre, D.

    2011-12-09

    We present the cross section for production of a Z boson in association with four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. When the Z decays to neutrinos, this process is a key irreducible background to many searches for new physics. Its computation has been made feasible through the development of the on-shell approach to perturbative quantum field theory. We present the total cross section for pp collisions at {radical}s = 7 TeV, after folding in the decay of the Z boson, or virtual photon, to a charged-lepton pair. We also provide distributions of the transverse momenta of the four jets, and we compare cross sections and distributions to the corresponding ones for the production of a W boson with accompanying jets.

  11. 120-mm supercondcting quadrupole for interaction regions of hadron colliders

    SciTech Connect

    Zlobin, A.V.; Kashikhin, V.V.; Mokhov, N.V.; Novitski, I.; /Fermilab

    2010-05-01

    Magnetic and mechanical designs of a Nb{sub 3}Sn quadrupole magnet with 120-mm aperture suitable for interaction regions of hadron colliders are presented. The magnet is based on a two-layer shell-type coil and a cold iron yoke. Special spacers made of a low-Z material are implemented in the coil mid-planes to reduce the level of radiation heat deposition and radiation dose in the coil. The quadrupole mechanical structure is based on aluminum collars supported by an iron yoke and a stainless steel skin. Magnet parameters including maximum field gradient and field harmonics, Nb3Sn coil pre-stress and protection at the operating temperatures of 4.5 and 1.9 K are reported. The level and distribution of radiation heat deposition in the coil and other magnet components are discussed.

  12. Double vector meson production in photon-hadron interactions at hadronic colliders

    NASA Astrophysics Data System (ADS)

    Gonçalves, V. P.; Moreira, B. D.; Navarra, F. S.

    2016-07-01

    In this paper we analyze the double vector meson production in photon-hadron (γ h) interactions at pp / pA / AA collisions and present predictions for the ρ ρ , J/Ψ J/Ψ , and ρ J/Ψ production considering the double scattering mechanism. We estimate the total cross sections and rapidity distributions at LHC energies and compare our results with the predictions for the double vector meson production in γ γ interactions at hadronic colliders. We present predictions for the different rapidity ranges probed by the ALICE, ATLAS, CMS, and LHCb Collaborations. Our results demonstrate that the ρ ρ and J/Ψ J/Ψ production in PbPb collisions is dominated by the double-scattering mechanism, while the two-photon mechanism dominates in pp collisions. Moreover, our results indicate that the analysis of the ρ J/Ψ production at LHC can be useful to constrain the double-scattering mechanism.

  13. Design study for a staged Very Large Hadron Collider

    SciTech Connect

    Peter J. Limon et al.

    2001-06-26

    Advancing accelerator designs and technology to achieve the highest energies has enabled remarkable discoveries in particle physics. This report presents the results of a design study for a new collider at Fermilab that will create exceptional opportunities for particle physics--a two-stage very large hadron collider. In its first stage, the machine provides a facility for energy-frontier particle physics research, at an affordable cost and on a reasonable time scale. In a second-stage upgrade in the same tunnel, the VLHC offers the possibility of reaching 100 times the collision energy of the Tevatron. The existing Fermilab accelerator complex serves as the injector, and the collision halls are on the Fermilab site. The Stage-1 VLHC reaches a collision energy of 40 TeV and a luminosity comparable to that of the LHC, using robust superferric magnets of elegant simplicity housed in a large-circumference tunnel. The Stage-2 VLHC, constructed after the scientific potential of the first stage has been fully realized, reaches a collision energy of at least 175 TeV with the installation of high-field magnets in the same tunnel. It makes optimal use of the infrastructure developed for the Stage-1 machine, using the Stage-1 accelerator itself as the injector. The goals of this study, commissioned by the Fermilab Director in November 2000, are: to create reasonable designs for the Stage-1 and Stage-2 VLHC in the same tunnel; to discover the technical challenges and potential impediments to building such a facility at Fermilab; to determine the approximate costs of the major elements of the Stage-1 VLHC; and to identify areas requiring significant R and D to establish the basis for the design.

  14. Supersymmetric dark matter in the harsh light of the Large Hadron Collider

    PubMed Central

    Peskin, Michael E.

    2015-01-01

    I review the status of the model of dark matter as the neutralino of supersymmetry in the light of constraints on supersymmetry given by the 7- to 8-TeV data from the Large Hadron Collider (LHC). PMID:25331902

  15. One-Loop Helicity Amplitudes for tt Production at Hadron Colliders

    SciTech Connect

    Badger, Simon; Sattler, Ralf; Yundin, Valery

    2011-04-01

    We present compact analytic expressions for all one-loop helicity amplitudes contributing to tt production at hadron colliders. Using recently developed generalized unitarity methods and a traditional Feynman based approach we produce a fast and flexible implementation.

  16. Development of superconducting links for the Large Hadron Collider machine

    NASA Astrophysics Data System (ADS)

    Ballarino, Amalia

    2014-04-01

    In the framework of the upgrade of the Large Hadron Collider (LHC) machine, new superconducting lines are being developed for the feeding of the LHC magnets. The proposed electrical layout envisages the location of the power converters in surface buildings, and the transfer of the current from the surface to the LHC tunnel, where the magnets are located, via superconducting links containing tens of cables feeding different circuits and transferring altogether more than 150 kA. Depending on the location, the links will have a length ranging from 300 m to 500 m, and they will span a vertical distance of about 80 m. An overview of the R&D program that has been launched by CERN is presented, with special attention to the development of novel types of cables made from MgB2 and high temperature superconductors (Bi-2223 and REBCO) and to the results of the tests performed on prototype links. Plans for future activities are presented, together with a timeline for potential future integration in the LHC machine.

  17. First electron-cloud studies at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Domínguez, O.; Li, K.; Arduini, G.; Métral, E.; Rumolo, G.; Zimmermann, F.; Cuna, H. Maury

    2013-01-01

    During the beam commissioning of the Large Hadron Collider (LHC) [LHC Design Report No. CERN-2004-003-V-1, 2004 [http://cds.cern.ch/record/782076?ln=en]; O. Brüning, H. Burkhardt, and S. Myers, Prog. Part. Nucl. Phys. 67, 705 (2012)10.1016/j.ppnp.2012.03.001PPNPDB0146-6410] with 150, 75, 50, and 25-ns bunch spacing, important electron-cloud effects, like pressure rise, cryogenic heat load, beam instabilities, or emittance growth, were observed. Methods have been developed to infer different key beam-pipe surface parameters by benchmarking simulations and pressure rise as well as heat-load observations. These methods allow us to monitor the scrubbing process, i.e., the reduction of the secondary emission yield as a function of time, in order to decide on the most appropriate strategies for machine operation. To better understand the influence of electron clouds on the beam dynamics, simulations have been carried out to examine both the coherent and the incoherent effects on the beam. In this paper we present the methodology and first results for the scrubbing monitoring process at the LHC. We also review simulated instability thresholds and tune footprints for beams of different emittance, interacting with an electron cloud in field-free or dipole regions.

  18. The Hunt for New Physics at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Nath, Pran; Nelson, Brent; Davoudiasl, Hooman; Dutta, Bhaskar; Feldman, Daniel; Liu, Zuowei; Han, Tao; Langacker, Paul; Mohapatra, Rabi; Valle, Jose; Pilaftsis, Apostolos; Zerwas, Dirk; AbdusSalam, Shehu; Adam-Bourdarios, Claire; Aguilar-Saavedra, J. A.; Allanach, Benjamin; Altunkaynak, B.; Anchordoqui, Luis A.; Baer, Howard; Bajc, Borut; Buchmueller, O.; Carena, M.; Cavanaugh, R.; Chang, S.; Choi, Kiwoon; Csáki, C.; Dawson, S.; de Campos, F.; De Roeck, A.; Dührssen, M.; Éboli, O. J. P.; Ellis, J. R.; Flächer, H.; Goldberg, H.; Grimus, W.; Haisch, U.; Heinemeyer, S.; Hirsch, M.; Holmes, M.; Ibrahim, Tarek; Isidori, G.; Kane, Gordon; Kong, K.; Lafaye, Remi; Landsberg, G.; Lavoura, L.; Lee, Jae Sik; Lee, Seung J.; Lisanti, M.; Lüst, Dieter; Magro, M. B.; Mahbubani, R.; Malinsky, M.; Maltoni, Fabio; Morisi, S.; Mühlleitner, M. M.; Mukhopadhyaya, B.; Neubert, M.; Olive, K. A.; Perez, Gilad; Pérez, Pavel Fileviez; Plehn, T.; Pontón, E.; Porod, Werner; Quevedo, F.; Rauch, M.; Restrepo, D.; Rizzo, T. G.; Romão, J. C.; Ronga, F. J.; Santiago, J.; Schechter, J.; Senjanović, G.; Shao, J.; Spira, M.; Stieberger, S.; Sullivan, Zack; Tait, Tim M. P.; Tata, Xerxes; Taylor, T. R.; Toharia, M.; Wacker, J.; Wagner, C. E. M.; Wang, Lian-Tao; Weiglein, G.; Zeppenfeld, D.; Zurek, K.

    2010-03-01

    The Large Hadron Collider presents an unprecedented opportunity to probe the realm of new physics in the TeV region and shed light on some of the core unresolved issues of particle physics. These include the nature of electroweak symmetry breaking, the origin of mass, the possible constituent of cold dark matter, new sources of CP violation needed to explain the baryon excess in the universe, the possible existence of extra gauge groups and extra matter, and importantly the path Nature chooses to resolve the hierarchy problem - is it supersymmetry or extra dimensions. Many models of new physics beyond the standard model contain a hidden sector which can be probed at the LHC. Additionally, the LHC will be a top factory and accurate measurements of the properties of the top and its rare decays will provide a window to new physics. Further, the LHC could shed light on the origin of neutralino masses if the new physics associated with their generation lies in the TeV region. Finally, the LHC is also a laboratory to test the hypothesis of TeV scale strings and D brane models. An overview of these possibilities is presented in the spirit that it will serve as a companion to the Technical Design Reports (TDRs) by the particle detector groups ATLAS and CMS to facilitate the test of the new theoretical ideas at the LHC. Which of these ideas stands the test of the LHC data will govern the course of particle physics in the subsequent decades.

  19. Discovering Higgs Boson Decays to Lepton Jets at Hadron Colliders

    SciTech Connect

    Falkowski, Adam; Ruderman, Joshua T.; Volansky, Tomer; Zupan, Jure

    2010-12-10

    The Higgs boson may decay predominantly into a hidden sector, producing lepton jets instead of the standard Higgs signatures. We propose a search strategy for such a signal at hadron colliders. A promising channel is the associated production of the Higgs boson with a Z or W. The dominant background is Z or W plus QCD jets. The lepton jets can be discriminated from QCD jets by cutting on the electromagnetic fraction and charge ratio. The former is the fraction of jet energy deposited in the electromagnetic calorimeter and the latter is the ratio of energy carried by charged particles to the electromagnetic energy. We use a Monte Carlo description of detector response to estimate QCD rejection efficiencies of O(10{sup -3}) per jet. The expected 5{sigma} (3{sigma}) discovery reach in Higgs boson mass is {approx}115 GeV (150 GeV) at the Tevatron with 10 fb{sup -1} of data and {approx}110 GeV (130 GeV) at the 7 TeV LHC with 1 fb{sup -1}.

  20. Resolving gluon fusion loops at current and future hadron colliders

    NASA Astrophysics Data System (ADS)

    Azatov, Aleksandr; Grojean, Christophe; Paul, Ayan; Salvioni, Ennio

    2016-09-01

    Inclusive Higgs measurements at the LHC have limited resolution on the gluon fusion loops, being unable to distinguish the long-distance contributions mediated by the top quark from possible short-distance new physics effects. Using an Effective Field Theory (EFT) approach we compare several proposed methods to lift this degeneracy, including toverline{t}h and boosted, off-shell and double Higgs production, and perform detailed projections to the High-Luminosity LHC and a future hadron collider. In addition, we revisit off-shell Higgs production. Firstly, we point out its sensitivity to modifications of the top- Z couplings, and by means of a general analysis we show that the reach is comparable to that of tree-level processes such as toverline{t}Z production. Implications for composite Higgs models are also discussed. Secondly, we assess the regime of validity of the EFT, performing an explicit comparison for a simple extension of the Standard Model containing one vector-like quark.

  1. Resummation of the transverse-energy distribution in Higgs boson production at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Grazzini, Massimiliano; Papaefstathiou, Andreas; Smillie, Jennifer M.; Webber, Bryan R.

    2014-09-01

    We compute the resummed hadronic transverse-energy ( E T ) distribution due to initial-state QCD radiation in the production of a Standard Model Higgs boson of mass 126 GeV by gluon fusion at the Large Hadron Collider, with matching to next-to-leading order calculations at large E T . Effects of hadronization, underlying event and limited detector acceptance are estimated using aMC@NLO with the Herwig++ and Pythia8 event generators.

  2. Investigating Electroweak Physics at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Tien, Pin-Ju

    The basic principle of naturalness has driven the majority of the Large Hadron Collider (LHC) program, but so far all searches for new physics beyond the Standard Model (SM) have come up empty. On the other hand, a few existing measurements of SM processes contain interesting anomalies, for instance in the measurement of the WW cross section. The deviation of WW cross section was seen both at ATLAS and CMS and both at 7 and 8 TeV. The discrepancy also became larger at 8 TeV. Combined results with LHC 7 TeV and 8 TeV implies around a three sigma deviation from the SM NLO calculation. This allows for the possibility of new physics with mass scales very close to the Electroweak Scale. We show that the addition of physics beyond the SM at electroweak scale can improve the agreement with the data. In particular supersymmetric models involving charginos, stops and sleptons all provide better fits with the data. In the case of models of sleptons that agree better with the WW data, they can also explain dark matter and the (g-2) anomaly. Furthermore, we show that there are several different classes of stop driven scenarios that not only evade all direct searches, but improve the agreement with the data in the SM measurement of the WW cross section. We also demonstrate that even if these anomalies are not due to new physics, the WW channel can also be used to derive new exclusion limits which are more powerful than existing results using the same ATLAS and CMS datasets. By examining the differential WW cross section we show that the gap between LHC and LEP exclusions can be start to be closed. In particular, we lay out a program under which the diffcult to search for regions of new physics models with large SM backgrounds can be investigated.

  3. Accelerator physics and technology challenges of very high energy hadron colliders

    DOE PAGES

    Shiltsev, Vladimir D.

    2015-08-20

    High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton–proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This article briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

  4. Precise Predictions for W+4-Jet Production at the Large Hadron Collider

    SciTech Connect

    Berger, C. F.; Bern, Z.; Ita, H.; Dixon, L. J.; Cordero, F. Febres; Forde, D.; Gleisberg, T.; Kosower, D. A.; Maitre, D.

    2011-03-04

    We present the next-to-leading order (NLO) QCD results for W+4-jet production at hadron colliders. This is the first hadron-collider process with five final-state objects to be computed at NLO. It represents an important background to many searches for new physics at the energy frontier. Total cross sections, as well as distributions in the jet transverse momenta, are provided for the initial LHC energy of {radical}(s)=7 TeV. We use a leading-color approximation, known to be accurate to 3% for W production with fewer jets. The calculation uses the BlackHat library along with the SHERPA package.

  5. Production of tidal-charged black holes at the Large Hadron Collider

    SciTech Connect

    Gingrich, Douglas M.

    2010-03-01

    Tidal-charged black hole solutions localized on a three-brane in the five-dimensional gravity scenario of Randall and Sundrum have been known for some time. The solutions have been used to study the decay, and growth, of black holes with initial mass of about 10 TeV. These studies are interesting in that certain black holes, if produced at the Large Hadron Collider, could live long enough to leave the detectors. I examine the production of tidal-charged black holes at the Large Hadron Collider and show that it is very unlikely that they will be produced during the lifetime of the accelerator.

  6. Diffractive Higgs boson production at the Fermilab Tevatron and the CERN Large Hadron Collider.

    PubMed

    Enberg, R; Ingelman, G; Kissavos, A; Tîmneanu, N

    2002-08-19

    Improved possibilities to find the Higgs boson in diffractive events, having less hadronic activity, depend on whether the cross section is large enough. Based on the soft color interaction models that successfully describe diffractive hard scattering at DESY HERA and the Fermilab Tevatron, we find that only a few diffractive Higgs events may be produced at the Tevatron, but we predict a substantial rate at the CERN Large Hadron Collider.

  7. Probing the Higgs sector of the minimal Left-Right symmetric model at future hadron colliders

    NASA Astrophysics Data System (ADS)

    Dev, P. S. Bhupal; Mohapatra, Rabindra N.; Zhang, Yongchao

    2016-05-01

    If neutrino masses arise from a TeV-scale minimal Left-Right seesaw model, the ensuing extended Higgs sector with neutral, singly and doubly-charged scalars has a plethora of implications for new Higgs boson searches beyond the Standard Model at future hadron colliders, such as the √{s} = 14 TeV High-Luminosity Large Hadron Collider (HL-LHC) and the proposed √{s} = 100 TeV collider (FCC-hh or SPPC). In this article, we provide a glimpse of this new physics in the Higgs sector. Our discussion focuses on the minimal non-supersymmetric version of the Left-Right model with high-scale parity breaking but TeV-scale SU(2) R -breaking, a property desirable to suppress the type-II seesaw contribution to neutrino masses. We analyze the masses and couplings of the physical Higgs bosons in this model, and discuss their dominant production and decay modes at hadron colliders. We identify the best discovery channels for each of the non-SM Higgs bosons and estimate the expected SM backgrounds in these channels to derive the sensitivity reaches for the new Higgs sector at future hadron colliders under discussion. Following a rather conservative approach, we estimate that the heavy Higgs sector can be effectively probed up to 15 TeV at the √{s} = 100 TeV machine. We also discuss how the LR Higgs sector can be distinguished from other extended Higgs sectors.

  8. NCG gluon fusion for the Higgs production at large hadron colliders

    SciTech Connect

    Chadou, I.; Mebarki, N.; Bekli, M. R.

    2012-06-27

    A pure NCG gluon fusion contribution to the Higgs production at large hadron colliders is discussed. It is shown that the NCG results become relevant at very high energies. This can be a good signal for the space-time non commutativity events.

  9. Summary of the Very Large Hadron Collider Physics and Detector subgroup

    SciTech Connect

    Denisov, D.; Keller, S.

    1996-12-31

    We summarize the activity of the Very Large Hadron Collider Physics and Detector subgroup during Snowmass 96. Members of the group: M. Albrow, R. Diebold, S. Feher, L. Jones, R. Harris, D. Hedin, W. Kilgore, J. Lykken, F. Olness, T. Rizzo, V. Sirotenko, and J. Womersley. 9 refs.

  10. Physics and Analysis at a Hadron Collider - Searching for New Physics (2/3)

    SciTech Connect

    2010-01-20

    This is the second lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This second lecture discusses techniques important for analyses searching for new physics using the CDF B_s --> mu+ mu- search as a specific example. The lectures are aimed at graduate students.

  11. Taking Energy to the Physics Classroom from the Large Hadron Collider at CERN

    ERIC Educational Resources Information Center

    Cid, Xabier; Cid, Ramon

    2009-01-01

    In 2008, the greatest experiment in history began. When in full operation, the Large Hadron Collider (LHC) at CERN will generate the greatest amount of information that has ever been produced in an experiment before. It will also reveal some of the most fundamental secrets of nature. Despite the enormous amount of information available on this…

  12. Physics and Analysis at a Hadron Collider - Searching for New Physics (2/3)

    ScienceCinema

    None

    2016-07-12

    This is the second lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This second lecture discusses techniques important for analyses searching for new physics using the CDF B_s --> mu+ mu- search as a specific example. The lectures are aimed at graduate students.

  13. Signatures for Right-Handed Neutrinos at the Large Hadron Collider

    SciTech Connect

    Huitu, Katri; Rai, Santosh Kumar; Khalil, Shaaban; Okada, Hiroshi

    2008-10-31

    We explore possible signatures for right-handed neutrinos in a TeV scale B-L extension of the standard model at the Large Hadron Collider. The studied four lepton signal has a tiny standard model background. We find the signal experimentally accessible at the LHC for the considered parameter regions.

  14. Constraints on new physics from baryogenesis and Large Hadron Collider data.

    PubMed

    Damgaard, Poul H; O'Connell, Donal; Petersen, Troels C; Tranberg, Anders

    2013-11-27

    We demonstrate the power of constraining theories of new physics by insisting that they lead to electroweak baryogenesis, while agreeing with current data from the Large Hadron Collider. The general approach is illustrated with a singlet scalar extension of the standard model. Stringent bounds can already be obtained, which reduce the viable parameter space to a small island.

  15. Low-cost hadron colliders at Fermilab: A discussion paper

    SciTech Connect

    Foster, G.W.; Malamud, E.

    1996-06-21

    New more economic approaches are required to continue the dramatic exponential rise in collider energies as represented by the well known Livingston plot. The old idea of low cost, low field iron dominated magnets in a small diameter pipe may become feasible in the next decade with dramatic recent advances in technology: (1) advanced tunneling technologies for small diameter, non human accessible tunnels, (2) accurate remote guidance systems for tunnel survey and boring machine steering, (3) high T{sub c} superconductors operating at liquid N{sub 2} or liquid H{sub 2} temperatures, (4) industrial applications of remote manipulation and robotics, (5) digitally multiplexed electronics to minimize cables, (6) achievement of high luminosities in p-p and p-{anti P} colliders. The goal of this paper is to stimulate continuing discussions on approaches to this new collider and to identify critical areas needing calculations, construction of models, proof of principle experiments, and full scale prototypes in order to determine feasibility and arrive at cost estimates.

  16. Precision Studies of Hadronic and Electro-Weak Interactions for Collider Physics. Final Report

    SciTech Connect

    Yost, Scott A

    2014-04-02

    This project was directed toward developing precision computational tools for proton collisions at the Large Hadron Collider, focusing primarily on electroweak boson production and electroweak radiative corrections. The programs developed under this project carried the name HERWIRI, for High Energy Radiation With Infra-Red Improvements, and are the first steps in an ongoing program to develop a set of hadronic event generators based on combined QCD and QED exponentiation. HERWIRI1 applied these improvements to the hadronic shower, while HERWIRI2 will apply the electroweak corrections from the program KKMC developed for electron-positron scattering to a hadronic event generator, including exponentiated initial and final state radiation together with first-order electroweak corrections to the hard process. Some progress was also made on developing differential reduction techniques for hypergeometric functions, for application to the computation of Feynman diagrams.

  17. Production of doubly heavy-flavored hadrons at e+e- colliders

    NASA Astrophysics Data System (ADS)

    Zheng, Xu-Chang; Chang, Chao-Hsi; Pan, Zan

    2016-02-01

    Production of the doubly heavy-flavored hadrons (Bc meson, doubly heavy baryons Ξc c , Ξb c , Ξb b , their excited states, and antiparticles of them as well) at e+e- colliders is investigated under two different approaches: LO (leading-order QCD complete calculation) and LL (leading-logarithm fragmentation calculation). The results for the production obtained by the LO and LL approaches, including the angle distributions of the produced hadrons with unpolarized and polarized incoming beams, the behaviors on the energy fraction of the produced doubly heavy-flavored hadron, and comparisons of results between the two approaches, are presented in tables and figures. Thus, characteristics of the production and uncertainties of the approaches are shown precisely, and it is concluded that only if the colliders run at the energies around the Z pole (which may be called the Z factories) and the luminosity of the colliders is as high as possible is the study of the doubly heavy-flavored hadrons completely accessible.

  18. ORAL ISSUE OF THE JOURNAL "USPEKHI FIZICHESKIKH NAUK": Physics at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Dremin, Igor M.

    2009-06-01

    The goals of the physics to be studied at the Large Hadron Collider (LHC) are very impressive. Four major experimental installations are ready to compete in obtaining and analyzing the data from high-energy hadron collisions. The main hope is to answer the most intricate questions ever asked concerning the most fundamental problems of matter and its fundamental forces and space structure. The design of the LHC and its four detectors is briefly described. We then review the main facts revealed previously by experimentalists at other accelerators. The most pertinent topics and the stage-by-stage plans for LHC investigations are discussed. Further prospects for high-energy physics are outlined.

  19. The frontier of high energy physics and the large hadron collider

    SciTech Connect

    Mishra, Kalanand

    2013-09-09

    High Energy Physics explores the most fundamental questions about the nature of the universe, e.g., basic building blocks of matter and energy, existence of the smallest sub-atomic particles, dark matter, dark energy etc. The Large Hadron Collider (LHC) is the most powerful accelerator on earth located near Geneva, Switzerland. It recreates the conditions just after the Big Bang by colliding two proton beams head-on at very high energy every 25-50 nanosecond. With the recent discovery of Higgs boson, the LHC is firmly marching on to explore the TeV energy scale.

  20. Particle Physics after the Higgs-Boson Discovery: Opportunities for the Large Hadron Collider

    DOE PAGES

    Quigg, Chris

    2015-08-24

    The first run of the Large Hadron Collider at CERN brought the discovery of the Higgs boson, an apparently elementary scalar particle with a mass of 125 GeV, the avatar of the mechanism that hides the electroweak symmetry. Then, a new round of experimentation is beginning, with the energy of the proton–proton colliding beams raised to 6.5 TeV per beam, from 4 TeV at the end of the first run. I summarize what we have learned about the Higgs boson, and calls attention to some issues that will be among our central concerns in the near future.

  1. Higgs bosons, electroweak symmetry breaking, and the physics of the Large Hadron Collider

    SciTech Connect

    Quigg, Chris; /Fermilab /CERN

    2007-02-01

    The Large Hadron Collider, a 7 {circle_plus} 7 TeV proton-proton collider under construction at CERN (the European Laboratory for Particle Physics in Geneva), will take experiments squarely into a new energy domain where mysteries of the electroweak interaction will be unveiled. What marks the 1-TeV scale as an important target? Why is understanding how the electroweak symmetry is hidden important to our conception of the world around us? What expectations do we have for the agent that hides the electroweak symmetry? Why do particle physicists anticipate a great harvest of discoveries within reach of the LHC?

  2. TRADING STUDIES OF A VERY LARGE HADRON COLLIDER

    SciTech Connect

    RUGGIERO,A.G.

    1996-11-04

    The authors have shown that the design of the ELOISATRON can be approached in five separate steps. In this report they deal with the two major issues of the collider: the size and the strength of the superconducting magnets. The reference design of the SSC calls for a collider circumference of 86 km. It represents the largest size that until recently was judged feasible. The reference design of the LHC requires a bending field of 9 Tesla, that industries are presently determined to demonstrate. Clearly the large size of the project presents problem with magnet tolerances, and collider operation and management. The high field of the superconducting magnets needs to be demonstrated, and the high-field option in excess of 9 Tesla requires extensive research and development. It is obvious from the start that, if the ELOISATRON has to allow large beam energies, the circumference has also to be larger than that of the SSC, probably of few hundred kilometers. On the other end, Tevatron, RHIC and SSC type of superconducting magnets have been built and demonstrated on a large scale and proven to be cost effective and reliable. Their field, nevertheless, hardly can exceed a value of 7.5 Tesla, without major modifications that need to be studied. The LHC type of magnets may be capable of 9 Tesla, but they are being investigated presently by the European industries. It is desired that if one wants to keep the size of the ring under reasonable limits, a somewhat higher bending field is required for the ELOISATRON, especially if one wants also to take advantage of the synchrotron radiation effects. A field value of 13 Tesla, twice the value of the SSC superconducting magnets, has recently been proposed, but it clearly needs a robust program of research and development. This magnet will not probably be of the RHIC/SSC type and not even of the LHC type. It will have to be designed and conceived anew. In the following they examine two possible approaches. In the first approach

  3. Electroweak and flavor dynamics at hadron colliders - I

    SciTech Connect

    Elchtent, E.; Lane, K.

    1998-02-01

    This is the first of two reports cataloging the principal signatures of electroweak and flavor dynamics at {anti p}p and pp colliders. Here, we discuss some of the signatures of dynamical electroweak and flavor symmetry breaking. The framework for dynamical symmetry breaking we assume is technicolor, with a walking coupling {alpha}{sub TC}, and extended technicolor. The reactions discussed occur mainly at subprocess energies {radical}{cflx s}{approx_lt} 1 TeV. They include production of color-singlet and octet technirhos and their decay into pairs of technipions, longitudinal weak bosons, or jets. Technipions, in turn, decay predominantly into heavy fermions. This report will appear in the Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics (Snowmass 96).

  4. Azimuthally sensitive femtoscopy in hydrodynamics with statistical hadronization from the BNL Relativistic Heavy Ion Collider to the CERN Large Hadron Collider

    SciTech Connect

    Kisiel, Adam; Broniowski, Wojciech; Florkowski, Wojciech; Chojnacki, Mikolaj

    2009-01-15

    Azimuthally sensitive femtoscopy for heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) is explored within the approach consisting of the hydrodynamics of perfect fluid followed by statistical hadronization. It is found that for the RHIC initial conditions, employing the Gaussian shape of the initial energy density, the very same framework that reproduces the standard soft observables [including the transverse-momentum spectra, the elliptic flow, and the azimuthally averaged Hanbury-Brown-Twiss (HBT) radii] leads to a proper description of the azimuthally sensitive femtoscopic observables; we find that the azimuthal variation of the side and out HBT radii as well as out-side cross term are very well reproduced for all centralities. Concerning the dependence of the femtoscopic parameters on k{sub T} we find that it is very well reproduced. The model is then extrapolated to the LHC energy. We predict the overall moderate growth of the HBT radii and the decrease of their azimuthal oscillations. Such effects are naturally caused by longer evolution times. In addition, we discuss in detail the space-time patterns of particle emission. We show that they are quite complex and argue that the overall shape seen by the femtoscopic methods cannot be easily disentangled on the basis of simple-minded arguments.

  5. Thermal Photon Radiation in High Multiplicity p+Pb Collisions at the Large Hadron Collider.

    PubMed

    Shen, Chun; Paquet, Jean-François; Denicol, Gabriel S; Jeon, Sangyong; Gale, Charles

    2016-02-19

    The collective behavior of hadronic particles has been observed in high multiplicity proton-lead collisions at the Large Hadron Collider, as well as in deuteron-gold collisions at the Relativistic Heavy-Ion Collider. In this work we present the first calculation, in the hydrodynamic framework, of thermal photon radiation from such small collision systems. Owing to their compact size, these systems can reach temperatures comparable to those in central nucleus-nucleus collisions. The thermal photons can thus shine over the prompt background, and increase the low p_{T} direct photon spectrum by a factor of 2-3 in 0%-1% p+Pb collisions at 5.02 TeV. This thermal photon enhancement can therefore serve as a signature of the existence of a hot quark-gluon plasma during the evolution of these small collision systems, as well as validate hydrodynamic behavior in small systems.

  6. Thermal Photon Radiation in High Multiplicity p+Pb Collisions at the Large Hadron Collider

    DOE PAGES

    Shen, Chun; Paquet, Jean-François; Denicol, Gabriel S.; Jeon, Sangyong; Gale, Charles

    2016-02-18

    We observed the collective behavior of hadronic particles in high multiplicity proton-lead collisions at the Large Hadron Collider, as well as in deuteron-gold collisions at the Relativistic Heavy-Ion Collider. In our work we present the first calculation, in the hydrodynamic framework, of thermal photon radiation from such small collision systems. Owing to their compact size, these systems can reach temperatures comparable to those in central nucleus-nucleus collisions. Moreover, the thermal photons can thus shine over the prompt background, and increase the low pT direct photon spectrum by a factor of 2–3 in 0%–1% p+Pb collisions at 5.02 TeV. This thermalmore » photon enhancement can therefore serve as a signature of the existence of a hot quark-gluon plasma during the evolution of these small collision systems, as well as validate hydrodynamic behavior in small systems.« less

  7. Thermal Photon Radiation in High Multiplicity p+Pb Collisions at the Large Hadron Collider.

    PubMed

    Shen, Chun; Paquet, Jean-François; Denicol, Gabriel S; Jeon, Sangyong; Gale, Charles

    2016-02-19

    The collective behavior of hadronic particles has been observed in high multiplicity proton-lead collisions at the Large Hadron Collider, as well as in deuteron-gold collisions at the Relativistic Heavy-Ion Collider. In this work we present the first calculation, in the hydrodynamic framework, of thermal photon radiation from such small collision systems. Owing to their compact size, these systems can reach temperatures comparable to those in central nucleus-nucleus collisions. The thermal photons can thus shine over the prompt background, and increase the low p_{T} direct photon spectrum by a factor of 2-3 in 0%-1% p+Pb collisions at 5.02 TeV. This thermal photon enhancement can therefore serve as a signature of the existence of a hot quark-gluon plasma during the evolution of these small collision systems, as well as validate hydrodynamic behavior in small systems. PMID:26943529

  8. Is hadronic flow produced in p-Pb collisions at the Large Hadron Collider?

    NASA Astrophysics Data System (ADS)

    Zhou, You; Zhu, Xiangrong; Li, Pengfei; Song, Huichao

    2016-05-01

    Using the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model, we investigate the azimuthal correlations in p-Pb collisions at √sNN = 5.02 TeV. It is shown that the simulated hadronic p-Pb system can not generate the collective flow signatures, but mainly behaves as a non-flow dominant system. However, the characteristic υ2(pT) mass-ordering of pions, kaons and protons is observed in UrQMD simulations, which is the consequence of hadronic interactions and not necessarily associated with strong fluid-like expansions.

  9. Determining the structure of Higgs couplings at the CERN LargeHadron Collider.

    PubMed

    Plehn, Tilman; Rainwater, David; Zeppenfeld, Dieter

    2002-02-01

    Higgs boson production via weak boson fusion at the CERN Large Hadron Collider has the capability to determine the dominant CP nature of a Higgs boson, via the tensor structure of its coupling to weak bosons. This information is contained in the azimuthal angle distribution of the two outgoing forward tagging jets. The technique is independent of both the Higgs boson mass and the observed decay channel.

  10. Next-to-Leading-Order QCD Corrections to tt+jet Production at Hadron Colliders

    SciTech Connect

    Dittmaier, S.; Uwer, P.; Weinzierl, S.

    2007-06-29

    We report on the calculation of the next-to-leading-order QCD corrections to the production of top-quark-top-antiquark pairs in association with a hard jet at the Fermilab Tevatron and the CERN Large Hadron Collider. We present results for the tt+jet cross section and the forward-backward charge asymmetry. The corrections stabilize the leading-order prediction for the cross section. The charge asymmetry receives large corrections.

  11. Next-to-Leading-Order QCD Corrections to WW+Jet Production at Hadron Colliders

    SciTech Connect

    Dittmaier, S.; Kallweit, S.; Uwer, P.

    2008-02-15

    We report on the calculation of the next-to-leading-order QCD corrections to the production of W-boson pairs in association with a hard jet at the Fermilab Tevatron and CERN Large Hadron Collider, which is an important source of background for Higgs boson and new-physics searches. The corrections stabilize the leading-order prediction for the cross section considerably, in particular, if a veto against the emission of a second hard jet is applied.

  12. Nucleon Decay and Neutrino Experiments, Experiments at High Energy Hadron Colliders, and String Theor

    SciTech Connect

    Jung, Chang Kee; Douglas, Michaek; Hobbs, John; McGrew, Clark; Rijssenbeek, Michael

    2013-07-29

    This is the final report of the DOE grant DEFG0292ER40697 that supported the research activities of the Stony Brook High Energy Physics Group from November 15, 1991 to April 30, 2013. During the grant period, the grant supported the research of three Stony Brook particle physics research groups: The Nucleon Decay and Neutrino group, the Hadron Collider Group, and the Theory Group.

  13. Physics and Analysis at a Hadron Collider - Making Measurements (3/3)

    ScienceCinema

    None

    2016-07-12

    This is the third lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This third lecture discusses techniques important for analyses making a measurement (e.g. determining a cross section or a particle property such as its mass or lifetime) using some CDF top-quark analyses as specific examples. The lectures are aimed at graduate students.

  14. MSSM Higgs Discovery Potential at Tevatron with new Benchmark Scenarios for Hadron Colliders

    NASA Astrophysics Data System (ADS)

    Drollinger, Volker; Gold, Michael; Jarrell, Jason; Rekovic, Vladimir; Smirnov, Dmitri

    2003-04-01

    Four benchmark scenarios for MSSM Higgs boson searches at hadron colliders have recently been suggested. We discuss two aspects of the Higgs discovery potential in these scenarios. In the first part of this study, cross sections times branching ratios are computed for the most important search channel pbarp arrow W^± h^0 arrow l^± ν b barb. The second part is dedicated to the Higgs mass behavior in the parameter space and two independent Higgs mass calculations are compared.

  15. Construction of block-coil high-field model dipoles for future hadron colliders

    SciTech Connect

    Blackburn, Raymond; Elliott, Tim; Henchel, William; McInturff, Al; McIntyre, Peter; Sattarov, Akhdior

    2002-08-04

    A family of high-field dipoles is being developed at Texas A&M University, as part of the program to improve the cost-effectiveness of superconducting magnet technology for future hadron colliders. The TAMU technology employs stress management, flux-plate control of persistent-current multipoles, conductor optimization using mixed-strand cable, and metal-filled bladders to provide pre-load and surface compliance. Construction details and status of the latest model dipole will be presented.

  16. Probing neutral gauge boson self-interactions in ZZ production at hadron colliders

    NASA Astrophysics Data System (ADS)

    Baur, U.; Rainwater, D.

    2000-12-01

    A detailed analysis of ZZ production at the upgraded Fermilab Tevatron and the CERN Large Hadron Collider is presented for general ZZZ and ZZγ couplings. Deviations from the standard model gauge theory structure for each of these can be parametrized in terms of two form factors which are severely restricted by unitarity at high energy. Achievable limits on these couplings are shown to be a dramatic improvement over the limits currently obtained by e+e- experiments.

  17. Lattices for a high-field 30 TeV hadron collider

    SciTech Connect

    Peggs, S.; Dell, F.; Harrison, M.; Syphers, M.; Tepikian, S.

    1996-12-01

    Long arc cells would lead to major cost savings in a high field high T{sub c} hadron collider, operating in the regime of significant synchrotron radiation. Two such lattices, with half cell lengths of 110 and 260 m, are compared. Both allow flexible tuning, and have large dynamic apertures when dominated by chromatic sextupoles. Lattices with longer cells are much more sensitive to systematic magnet errors, which are expected to dominate.

  18. [Calorimeter based detectors for high energy hadron colliders]. [Progress report

    SciTech Connect

    Not Available

    1992-08-04

    This document provides a progress report on research that has been conducted under DOE Grant DEFG0292ER40697 for the past year, and describes proposed work for the second year of this 8 year grant starting November 15, 1992. Personnel supported by the contract include 4 faculty, 1 research faculty, 4 postdocs, and 9 graduate students. The work under this grant has in the past been directed in two complementary directions -- DO at Fermilab, and the second SSC detector GEM. A major effort has been towards the construction and commissioning of the new Fermilab Collider detector DO, including design, construction, testing, the commissioning of the central tracking and the central calorimeters. The first DO run is now underway, with data taking and analysis of the first events. Trigger algorithms, data acquisition, calibration of tracking and calorimetry, data scanning and analysis, and planning for future upgrades of the DO detector with the advent of the FNAL Main Injector are all involved. The other effort supported by this grant has been towards the design of GEM, a large and general-purpose SSC detector with special emphasis on accurate muon measurement over a large solid angle. This effort will culminate this year in the presentation to the SSC laboratory of the GEM Technical Design Report. Contributions are being made to the detector design, coordination, and physics simulation studies with special emphasis on muon final states. Collaboration with the RD5 group at CERN to study muon punch through and to test cathode strip chamber prototypes was begun.

  19. Toward particle-level filtering of individual collision events at the Large Hadron Collider and beyond

    NASA Astrophysics Data System (ADS)

    Colecchia, Federico

    2014-03-01

    Low-energy strong interactions are a major source of background at hadron colliders, and methods of subtracting the associated energy flow are well established in the field. Traditional approaches treat the contamination as diffuse, and estimate background energy levels either by averaging over large data sets or by restricting to given kinematic regions inside individual collision events. On the other hand, more recent techniques take into account the discrete nature of background, most notably by exploiting the presence of substructure inside hard jets, i.e. inside collections of particles originating from scattered hard quarks and gluons. However, none of the existing methods subtract background at the level of individual particles inside events. We illustrate the use of an algorithm that will allow particle-by-particle background discrimination at the Large Hadron Collider, and we envisage this as the basis for a novel event filtering procedure upstream of the official reconstruction chains. Our hope is that this new technique will improve physics analysis when used in combination with state-of-the-art algorithms in high-luminosity hadron collider environments.

  20. Probing gluon number fluctuation effects in future electron-hadron colliders

    NASA Astrophysics Data System (ADS)

    Amaral, J. T.; Gonçalves, V. P.; Kugeratski, M. S.

    2014-10-01

    The description of the QCD dynamics in the kinematical range which will be probed in the future electron-hadron colliders is still an open question. Although phenomenological studies indicate that the gluon number fluctuations, which are related to discreteness in the QCD evolution, are negligible at HERA, the magnitude of these effects for the next generation of colliders still should be estimated. In this paper we investigate inclusive and diffractive ep observables considering a model for the physical scattering amplitude which describes the HERA data. Moreover, we estimate, for the first time, the contribution of the fluctuation effects for the nuclear structure functions. Our results indicate that the study of these observables in the future colliders can be useful to constrain the presence of gluon number fluctuations.

  1. Hadrons from coalescence plus fragmentation in A A collisions at energies available at the BNL Relativistic Heavy Ion Collider to the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Minissale, Vincenzo; Scardina, Francesco; Greco, Vincenzo

    2015-11-01

    In a coalescence plus independent fragmentation approach we calculate the pT spectra of the main hadrons: π ,K ,p ,p ¯,Λ ,ϕ in a wide range of transverse momentum from low pT up to about 10 GeV. The approach in its main features was developed several years ago at Relativistic Heavy Ion Collider (RHIC) energy. Augmenting the model with the inclusion of some more main resonance decays, we show that the approach correctly predicts the evolution of the pT spectra from RHIC to LHC (Large Hadron Collider) energy and in particular the baryon-to-meson ratios p /π ,p ¯/π ,Λ /K that reach a value of the order of unit at pT˜3 GeV . This is achieved without any change of the coalescence parameters. The more recent availability of experimental data up to pT˜10 GeV for Λ spectrum as well as for p /π and Λ /K shows some lack of yield in a limited pT range around 6 GeV. This indicates that the baryons pT spectra from Albino-Kniehl-Kramer fragmentation functions are too flat at pT≲8 GeV . We also show that in a coalescence plus fragmentation approach one predicts a nearly pT independent p /ϕ ratio up to pT˜4 GeV followed by a significant decrease at higher pT. Such a behavior is driven by a similar radial flow effect at pT<2 GeV and the dominance of fragmentation for ϕ at larger pT.

  2. Aspects of perturbative QCD at a 100 TeV future hadron collider

    NASA Astrophysics Data System (ADS)

    Bothmann, Enrico; Ferrarese, Piero; Krauss, Frank; Kuttimalai, Silvan; Schumann, Steffen; Thompson, Jennifer

    2016-08-01

    In this paper we consider particle production at a future circular hadron collider with 100 TeV center-of-mass energy within the Standard Model, and in particular their QCD aspects. Accurate predictions for these processes pose severe theoretical challenges related to large hierarchies of scales and possible large multiplicities of final-state particles. We investigate scaling patterns in multijet-production rates allowing to extrapolate predictions to very high final-state multiplicities. Furthermore, we consider large-area QCD jets and study the expectation for the mean number of subjets to be reconstructed from their constituents and confront these with analytical resummed predictions and with the expectation for boosted hadronic decays of top quarks and W bosons. We also discuss the validity of Higgs effective field theory in making predictions for Higgs-boson production in association with jets. Finally, we consider the case of new physics searches at such a 100 TeV hadron-collider machine and discuss the expectations for corresponding Standard-Model background processes.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    SciTech Connect

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

    2010-09-07

    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 {sup 197}Au{sup 79}+ beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle 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 {sup 208}Pb+{sup 82+} beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

  5. A new micro-strip tracker for the new generation of experiments at hadron colliders

    SciTech Connect

    Dinardo, Mauro E.

    2005-12-01

    This thesis concerns the development and characterization of a prototype Silicon micro-strip detector that can be used in the forward (high rapidity) region of a hadron collider. These detectors must operate in a high radiation environment without any important degradation of their performance. The innovative feature of these detectors is the readout electronics, which, being completely data-driven, allows for the direct use of the detector information at the lowest level of the trigger. All the particle hits on the detector can be readout in real-time without any external trigger and any particular limitation due to dead-time. In this way, all the detector information is available to elaborate a very selective trigger decision based on a fast reconstruction of tracks and vertex topology. These detectors, together with the new approach to the trigger, have been developed in the context of the BTeV R&D program; our aim was to define the features and the design parameters of an optimal experiment for heavy flavour physics at hadron colliders. Application of these detectors goes well beyond the BTeV project and, in particular, involves the future upgrades of experiments at hadron colliders, such as Atlas, CMS and LHCb. These experiments, indeed, are already considering for their future high-intensity runs a new trigger strategy a la BTeV. Their aim is to select directly at trigger level events containing Bhadrons, which, on several cases, come from the decay of Higgs bosons, Zo's or W±'s; the track information can also help on improving the performance of the electron and muon selection at the trigger level. For this reason, they are going to develop new detectors with practically the same characteristics as those of BTeV. To this extent, the work accomplished in this thesis could serve as guide-line for those upgrades.

  6. Probing charged Higgs boson couplings at a future circular hadron collider

    NASA Astrophysics Data System (ADS)

    Ćakır, I. T.; Kuday, S.; Saygın, H.; Şenol, A.; ćakır, O.

    2016-07-01

    Many of the new physics models predict a light Higgs boson similar to the Higgs boson of the Standard Model (SM) and also extra scalar bosons. Beyond the search channels for a SM Higgs boson, the future collider experiments will explore additional channels that are specific to extended Higgs sectors. We study the charged Higgs boson production within the framework of two Higgs doublet models (THDM) in the proton-proton collisions at a future circular hadron collider (FCC-hh). With an integrated luminosity of Lint=500 fb-1 at very high energy frontier (√{s }=100 TeV ), we obtain a significant coverage of the parameter space and distinguish the charged Higgs-top-bottom interaction within the THDM or other new physics models with charged Higgs boson mass up to 1.5 TeV.

  7. Test of Relativistic Gravity for Propulsion at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Felber, Franklin

    2010-01-01

    A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

  8. Signatures of the anomalous Zγ and ZZ production at lepton and hadron colliders

    NASA Astrophysics Data System (ADS)

    Gounaris, G. J.; Layssac, J.; Renard, F. M.

    2000-04-01

    The possible form of new physics (NP) interactions affecting the ZZZ, ZZγ, and Zγγ vertices is critically examined. Their signatures and the possibilities to study them, through ZZ and Zγ production, at the CERN e-e+ colliders LEP and LC and at the hadronic colliders, the Fermilab Tevatron and CERN LHC, are investigated. Experimental limits obtained or expected on each coupling are collected. A simple theoretical model based on virtual effects due to some heavy fermions is used for acquiring some guidance on the plausible forms of these NP vertices. In such a case specific relations among the various neutral couplings are predicted, which can be experimentally tested and possibly used to constrain the form of the responsible NP structure.

  9. Overview of the Large Hadron Collider and of the ATLAS and CMS experiments

    NASA Astrophysics Data System (ADS)

    Nisati, Aleandro; Sharma, Vivek

    2016-10-01

    The Large Hadron Collider is the most powerful particle accelerator ever built. It has allowed the discovery of a Higgs boson with mass near 125 GeV in 2012 by the ATLAS and CMS experiments. This chapter provides first an overview of the main characteristics of this collider, as well as a short description of the two general purpose experiments, ATLAS and CMS, which discovered in 2012 a Higgs boson with mass close to 125 GeV. This is followed by a summary of the main aspects of particle identification and reconstruction by these two detectors, together with a short presentation of the main analysis tools used to extract the LHC results of the Higgs boson(s) searches and measurements.

  10. Transverse-momentum resummation for top-quark pairs at hadron colliders.

    PubMed

    Zhu, Hua Xing; Li, Chong Sheng; Li, Hai Tao; Shao, Ding Yu; Yang, Li Lin

    2013-02-22

    We develop a framework for a systematic resummation of the transverse momentum distribution of top-quark pairs produced at hadron colliders based on effective field theory. Compared to Drell-Yan and Higgs production, a novel soft function matrix is required to account for the soft gluon emissions from the final states. We calculate this soft function at the next-to-leading order, and perform the resummation at the next-to-next-to-leading logarithmic accuracy. We compare our results with parton shower programs and with the experimental data at the Tevatron and the LHC. We also discuss the implications for the top quark charge asymmetry.

  11. W production at large transverse momentum at the CERN Large Hadron Collider.

    PubMed

    Gonsalves, Richard J; Kidonakis, Nikolaos; Sabio Vera, Agustín

    2005-11-25

    We study the production of W bosons at large transverse momentum in pp collisions at the CERN Large Hadron Collider. We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable result.

  12. Lower limit on dark matter production at the CERN Large Hadron Collider.

    PubMed

    Feng, Jonathan L; Su, Shufang; Takayama, Fumihiro

    2006-04-21

    We evaluate the prospects for finding evidence of dark matter production at the CERN Large Hadron Collider. We consider weakly interacting massive particles (WIMPs) and superWIMPs and characterize their properties through model-independent parametrizations. The observed relic density then implies lower bounds on dark matter production rates as functions of a few parameters. For WIMPs, the resulting signal is indistinguishable from background. For superWIMPs, however, this analysis implies significant production of metastable charged particles. For natural parameters, these rates may far exceed Drell-Yan cross sections and yield spectacular signals.

  13. Boosting Higgs CP properties via VH production at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Godbole, Rohini; Miller, David J.; Mohan, Kirtimaan; White, Chris D.

    2014-03-01

    We consider ZH and WH production at the Large Hadron Collider, where the Higgs decays to a bbbar pair. We use jet substructure techniques to reconstruct the Higgs boson and construct angular observables involving leptonic decay products of the vector bosons. These efficiently discriminate between the tensor structure of the HVV vertex expected in the Standard Model and that arising from possible new physics, as quantified by higher dimensional operators. This can then be used to examine the CP nature of the Higgs as well as CP mixing effects in the HZZ and HWW vertices separately.

  14. Technical challenges of the Large Hadron Collider experiments (ATLAS and CMS).

    PubMed

    Ball, Austin

    2015-01-13

    This review article introduces the design of the general purpose experiments ATLAS and CMS, which independently discovered the Higgs boson, showing how generic features are motivated by the characteristics needed to explore the physics landscape made accessible by the Large Hadron Collider accelerator, whose high collision rate creates an extremely challenging operating environment for instrumentation. Examples of the very different component designs chosen by the two experiment collaborations are highlighted, as an introduction to briefly describing techniques used in the construction of some of these elements and, subsequently, in the assembly of both detection systems in their respective underground caverns. PMID:26949803

  15. Compressed supersymmetry after 1 fb⁻¹ at the Large Hadron Collider

    SciTech Connect

    LeCompte, Thomas J.; Martin, Stephen P.

    2012-02-22

    We study the reach of the Large Hadron Collider with 1 fb⁻¹ of data at √s=7 TeV for several classes of supersymmetric models with compressed mass spectra, using jets and missing transverse energy cuts like those employed by ATLAS for summer 2011 data. In the limit of extreme compression, the best limits come from signal regions that do not require more than 2 or 3 jets and that remove backgrounds by requiring more missing energy rather than a higher effective mass.

  16. Observable T{sub 7} Lepton Flavor Symmetry at the Large Hadron Collider

    SciTech Connect

    Cao Qinghong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi

    2011-04-01

    More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T{sub 7} and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.

  17. Technical challenges of the Large Hadron Collider experiments (ATLAS and CMS).

    PubMed

    Ball, Austin

    2015-01-13

    This review article introduces the design of the general purpose experiments ATLAS and CMS, which independently discovered the Higgs boson, showing how generic features are motivated by the characteristics needed to explore the physics landscape made accessible by the Large Hadron Collider accelerator, whose high collision rate creates an extremely challenging operating environment for instrumentation. Examples of the very different component designs chosen by the two experiment collaborations are highlighted, as an introduction to briefly describing techniques used in the construction of some of these elements and, subsequently, in the assembly of both detection systems in their respective underground caverns.

  18. Testing the handedness of a heavy {ital W}{prime} at future hadron colliders

    SciTech Connect

    Cvetic, M.; Langacker, P.; Liu, J.

    1994-03-01

    We show that the associated production {ital pp}{r_arrow}{ital W}{prime}{ital W} and the rare dec at future hadron colliders. For {ital M}{sub {ital W}{prime}}{similar_to}(1--3) TeV they would allow a clean determination on whether the {ital W}{prime} couples to {ital V}{minus}{ital A} or {ital V}+{ital A} currents. As an illustration a model in which the {ital W}{prime}{sup {plus_minus}} couples only to {ital V}{minus}{ital A} currents is contrasted with the left-right-symmetric models which involve {ital V}+{ital A} currents.

  19. Kinematical Correlations for Higgs Boson Plus High P_{T} Jet Production at Hadron Colliders.

    PubMed

    Sun, Peng; Yuan, C-P; Yuan, Feng

    2015-05-22

    We investigate the effect of QCD resummation to kinematical correlations in the Higgs boson plus high transverse momentum (P(T)) jet events produced at hadron colliders. We show that at the complete one-loop order, the Collins-Soper-Sterman resummation formalism can be applied to derive the Sudakov form factor. We compare the singular behavior of resummation calculation to fixed order prediction in the case that a Higgs boson and high P(T) jet are produced nearly back to back in their transverse momenta, and find perfect agreement. The phenomenological importance of the resummation effect at the LHC is also demonstrated. PMID:26047222

  20. Observable T7 lepton flavor symmetry at the Large Hadron Collider.

    PubMed

    Cao, Qing-Hong; Khalil, Shaaban; Ma, Ernest; Okada, Hiroshi

    2011-04-01

    More often than not, models of flavor symmetry rely on the use of nonrenormalizable operators (in the guise of flavons) to accomplish the phenomenologically successful tribimaximal mixing of neutrinos. We show instead how a simple renormalizable two-parameter neutrino mass model of tribimaximal mixing can be constructed with the non-Abelian discrete symmetry T(7) and the gauging of B-L. This is also achieved without the addition of auxiliary symmetries and particles present in almost all other proposals. Most importantly, it is verifiable at the Large Hadron Collider.

  1. Beam dynamics aspects of crab cavities in the CERN Large Hadron Collider

    SciTech Connect

    Sun, Y.; Calaga, R.; Assmann, R.; Barranco, J.; Tomas, R.; Weiler, T.; Zimmermann, F.; Morita, A.

    2009-10-14

    Modern colliders bring into collision a large number of bunches to achieve a high luminosity. The long-range beam-beam effects arising from parasitic encounters at such colliders are mitigated by introducing a crossing angle. Under these conditions, crab cavities (CC) can be used to restore effective head-on collisions and thereby to increase the geometric luminosity. Such crab cavities have been proposed for both linear and circular colliders. The crab cavities are rf cavities operated in a transverse dipole mode, which imparts on the beam particles a transverse kick that varies with the longitudinal position along the bunch. The use of crab cavities in the Large Hadron Collider (LHC) may not only raise the luminosity, but it could also complicate the beam dynamics, e.g., crab cavities might not only cancel synchrobetatron resonances excited by the crossing angle but they could also excite new ones, they could reduce the dynamic aperture for off-momentum particles, they could influence the aperture and orbit, also degrade the collimation cleaning efficiency, and so on. In this paper, we explore the principal feasibility of LHC crab cavities from a beam dynamics point of view. The implications of the crab cavities for the LHC optics, analytical and numerical luminosity studies, dynamic aperture, aperture and beta beating, emittance growth, beam-beam tune shift, long-range collisions, and synchrobetatron resonances, crab dispersion, and collimation efficiency will be discussed.

  2. Secondary particle in background levels and effects on detectors at future hadron colliders

    NASA Astrophysics Data System (ADS)

    Pal, T.

    1993-06-01

    The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC (LHC) the square root of s = 40 TeV (the square root of s = 16 TeV) and L = 10(exp 33) cm(exp -2)s(exp -1) (L = 3 x 10(exp 34) cm(exp -2)s(exp -1)). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the 'task force on radiation levels in the SSC interaction regions.' The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes. Following Groom's work, extensive Monte Carlo simulations were performed to address the issues of backgrounds and radiation environments for the GEM and SD C3 experiments proposed at the SSC and for the ATLAS and CMS experiments planned for the LHC. The purpose of the present article is to give a brief summary of some aspects of the methods, assumptions, and calculations performed to date (principally for the SSC detectors) and to stress the relevance of such calculations to the detectors proposed for the study of B-physics in particular.

  3. Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

    SciTech Connect

    Stancari, Giulio; Previtali, Valentina; Valishev, Alexander; Bruce, Roderik; Redaelli, Stefano; Rossi, Adriana; Salvachua Ferrando, Belen

    2014-06-26

    Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. We are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.

  4. Signals of supersymmetry with inaccessible first two families at the Large Hadron Collider

    SciTech Connect

    Desai, Nishita; Mukhopadhyaya, Biswarup

    2009-09-01

    We investigate the signals of supersymmetry in a scenario where only the third family squarks and sleptons can be produced at the Large Hadron Collider, in addition to the gluino, charginos, and neutralinos. The final states in such cases are marked by a multiplicity of top or bottom quarks. We study, in particular, the case when the top squark, bottom squark, and gluino masses are near the TeV scale due to which, the final state t's and b's are very energetic. We point out the difficulty in b tagging and identifying energetic tops and suggest several event selection criteria which allow the signals to remain significantly above the standard model background. We show that such scenarios with gluino mass up to 2 TeV can be successfully probed at the Large Hadron Collider. Information on tan{beta} can also be obtained by looking at associated Higgs production in the cascades of accompanying neutralinos. We also show that a combined analysis of event rates in the different channels and the effective mass distribution allows one to differentiate this scenario from the one where all three sfermion families are accessible.

  5. Fully automated precision predictions for heavy neutrino production mechanisms at hadron colliders

    NASA Astrophysics Data System (ADS)

    Degrande, Céline; Mattelaer, Olivier; Ruiz, Richard; Turner, Jessica

    2016-09-01

    Motivated by TeV-scale neutrino mass models, we propose a systematic treatment of heavy neutrino (N ) production at hadron colliders. Our simple and efficient modeling of the vector boson fusion (VBF) W±γ →N ℓ± and N ℓ±+nj signal definitions resolve collinear and soft divergences that have plagued past studies, and is applicable to other color-singlet processes, e.g., associated Higgs (W±h), sparticle (ℓ˜±νℓ˜), and charged Higgs (h±±h∓) production. We present, for the first time, a comparison of all leading N production modes, including both gluon fusion (GF) g g →Z*/h*→N νℓ (-) and VBF. We obtain fully differential results up to next-to-leading order (NLO) in QCD accuracy using a Monte Carlo tool chain linking feynrules, nloct, and madgraph5_amc@nlo. Associated model files are publicly available. At the 14 TeV LHC, the leading order GF rate is small and comparable to the NLO N ℓ±+1 j rate; at a future 100 TeV Very Large Hadron Collider, GF dominates for mN=300 - 1500 GeV , beyond which VBF takes the lead.

  6. Heavy-Quark Associated Production with One Hard Photon at Hadron Colliders

    SciTech Connect

    Hartanto, Heribertus Bayu

    2013-01-01

    We present the calculation of heavy-quark associated production with a hard photon at hadron colliders, namely $pp(p\\bar p) → Q\\bar Q +X$γ (for $Q=t,b$), at Next-to-Leading Order (NLO) in Quantum Chromodynamics (QCD). We study the impact of NLO QCD corrections on the total cross section and several differential distributions at both the Tevatron and the Large Hadron Collider (LHC). For $t\\bar t$γ production we observe a sizeable reduction of the renormalization and factorization scale dependence when the NLO QCD corrections are included, while for $b\\bar b$γ production a considerable scale dependence still persists at NLO in QCD. This is consistent with what emerges in similar processes involving $b$ quarks and vector bosons and we explain its origin in detail. For $b\\bar b$γ production we study both the case in which at least one $b$ jet and the case in which at least two $b$ jets are observed. We perform the $b\\bar b$γ calculation using the Four Flavor Number Scheme (4FNS) and compare the case where at least one $b$ jet is observed with the corresponding results from the Five Flavor Number Scheme (5FNS) calculation. Finally we compare our results for $p\\bar p →+b+X$γ with the Tevatron data.

  7. Fully automated precision predictions for heavy neutrino production mechanisms at hadron colliders

    NASA Astrophysics Data System (ADS)

    Degrande, Céline; Mattelaer, Olivier; Ruiz, Richard; Turner, Jessica

    2016-09-01

    Motivated by TeV-scale neutrino mass models, we propose a systematic treatment of heavy neutrino (N ) production at hadron colliders. Our simple and efficient modeling of the vector boson fusion (VBF) W±γ →N ℓ± and N ℓ±+nj signal definitions resolve collinear and soft divergences that have plagued past studies, and is applicable to other color-singlet processes, e.g., associated Higgs (W±h), sparticle (ℓ˜±νℓ˜),and charged Higgs (h±±h∓) production. We present, for the first time, a comparison of all leading N production modes, including both gluon fusion (GF) g g →Z*/h*→N ν ℓ (-) and VBF. We obtain fully differential results up to next-to-leading order (NLO) in QCD accuracy using a Monte Carlo tool chain linking feynrules, nloct, and madgraph5_amc@nlo. Associated model files are publicly available. At the 14 TeV LHC, the leading order GF rate is small and comparable to the NLO N ℓ±+1 j rate; at a future 100 TeV Very Large Hadron Collider, GF dominates for mN=300 - 1500 GeV , beyond which VBF takes the lead.

  8. Dual topological unitarization of hard and soft hadronic cross sections: A new approach to multiparticle production at hadron colliders in the TeV energy range

    SciTech Connect

    Ranft, J.; Hahn, K. . SSC Central Design Group); Aurenche, P.; Maire, P. . Lab. de Physique des Particules Elementaires); Bopp, F. . Fachbereich Physik); Capella, A.; Tran Thanh Van, J. . Lab. de Physique Theorique et Particules Elementaires); Kwi

    1987-12-01

    The dual topological unitarization of hard and soft hadronic collisions is formulated as a Monte-Carlo event generator for events containing both the soft (low p{perpendicular}) and hard (jets, minijets) component of hadron production. The parameters of the model are determined from fits to the energy dependence of the total and inelastic hadron cross-sections and from the predictions of the QCD-parton model for the perturbative hard constituent scattering cross sections. The properties of the model are studied. Good agreement of the model predictions is found with data at present accelerator and collider energies. The predictions of the model for TeV colliders are presented. Interesting changes of the produced multiparticle system are formed when selecting classes of events with and without hard jets or minijets. 35 refs., 22 figs., 3 tabs.

  9. Analysis of the Laser Calibration System for the CMS HCAL at CERN's Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Lebolo, Luis

    2005-11-01

    The European Organization for Nuclear Physics' (CERN) Large Hadron Collider uses the Compact Muon Solenoid (CMS) detector to measure collision products from proton-proton interactions. CMS uses a hadron calorimeter (HCAL) to measure the energy and position of quarks and gluons by reconstructing their hadronic decay products. An essential component of the detector is the calibration system, which was evaluated in terms of its misalignment, linearity, and resolution. In order to analyze the data, the authors created scripts in ROOT 5.02/00 and C++. The authors also used Mathematica 5.1 to perform complex mathematics and AutoCAD 2006 to produce optical ray traces. The misalignment of the optical components was found to be satisfactory; the Hybrid Photodiodes (HPDs) were confirmed to be linear; the constant, noise and stochastic contributions to its resolution were analyzed; and the quantum efficiency of most HPDs was determined to be approximately 40%. With a better understanding of the laser calibration system, one can further understand and improve the HCAL.

  10. New avenues to heavy right-handed neutrinos with pair production at hadronic colliders

    NASA Astrophysics Data System (ADS)

    Kang, Zhaofeng; Ko, P.; Li, Jinmian

    2016-04-01

    In many models incorporating the type-I seesaw mechanism, the right-handed neutrino (N ) couples to heavy vector/scalar bosons and thereby has resonant pair production. It has barely received attention thus far; however, it may provide the best avenue to probe TeV scale N without requiring anomalously large mixing between N and the active neutrino νL . In this paper we explore the discovery prospects of (mainly heavy) N pair production at the 14 TeV LHC and future 100 TeV p p collider, based on the three signatures: (1) trilepton from N (→ℓWℓ)N (→ℓWh) with Wℓ/h being the leptonically/hadronically decaying W ; (2) boosted di-Higgs boson plus ET from N (→νLh )N (→νLh ) ; (3) a single boosted Higgs boson with leptons and ET from N (→ℓWℓ)N (→νLh ) . At the 100 TeV collider, we also consider the situation when the Higgs boson is overboosted, thus losing its jet substructure. Interpreting our tentative results in the benchmark model, the local B -L model, we find that the (multi-) TeV scale N can be probed at the (100) 14 TeV colliders.

  11. Uniform description of bulk observables in the hydrokinetic model of A+A collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Karpenko, Iu. A.; Sinyukov, Yu. M.; Werner, K.

    2013-02-01

    A simultaneous description of hadronic yields; pion, kaon, and proton spectra; elliptic flows; and femtoscopy scales in the hydrokinetic model of A+A collisions is presented at different centralities for the top BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) 2.76-TeV energies. The initial conditions are based on the Monte Carlo Glauber simulations. When going from RHIC to LHC energy in the model, the only parameters changed are the normalization of the initial entropy defined by the number of all charged particles in most central collisions, contribution to entropy from binary collisions, and barionic chemical potential. The hydrokinetic model is used in its hybrid version, which provides the correct match (at the isochronic hypersurface) of the decaying hadron matter evolution with hadronic ultrarelativistic quantum molecular dynamics cascade. The results are compared with the standard hybrid models where hydrodynamics and hadronic cascade are matching just at the non-space-like hypersurface of chemical freeze-out or on the isochronic hypersurface. The modification of the particle-number ratios at LHC caused, in particular, by the particle annihilations at the afterburn stage is also analyzed.

  12. Design Concept and Parameters of a 15 T $Nb_{3}Sn$ Dipole Demonstrator for a 100 TEV Hadron Collider

    SciTech Connect

    Zlobin, A. V.; Andreev, N.; Barzi, E.; Kashikhin, V. V.; Novitski, I.

    2015-06-01

    FNAL has started the development of a 15 T $Nb_{3}Sn$ dipole demonstrator for a 100 TeV scale hadron collider. This paper describes the design concept and parameters of the 15 T $Nb_{3}Sn$ dipole demonstrator. The dipole magnetic, mechanical and quench protection concept and parameters are presented and discussed.

  13. Higgs self-coupling measurements at a 100 TeV hadron collider

    SciTech Connect

    Barr, Alan J.; Dolan, Matthew J.; Englert, Christoph; Ferreira de Lima, Enoque Danilo; Spannowsky, Michael

    2015-02-03

    An important physics goal of a possible next-generation high-energy hadron collider will be precision characterisation of the Higgs sector and electroweak symmetry breaking. A crucial part of understanding the nature of electroweak symmetry breaking is measuring the Higgs self-interactions. We study dihiggs production in proton-proton collisions at 100 TeV centre of mass energy in order to estimate the sensitivity such a machine would have to variations in the trilinear Higgs coupling around the Standard Model expectation. We focus on the bb¯γγ final state, including possible enhancements in sensitivity by exploiting dihiggs recoils against a hard jet. In conclusion, we find that it should be possible to measure the trilinear self-coupling with 40% accuracy given 3/ab and 12% with 30/ab of data.

  14. Summary and highlights of the 14th Topical Conference on Hadron Collider Physics (HCP2002)

    SciTech Connect

    John Womersley

    2002-11-13

    First of all, I would like to thank the scientific committee, the conference organizers, the University of Karlsruhe and the Institute for Experimental Nuclear Physics, all of the speakers, and the conference secretariat, for making this an extremely well-organized and uniformly high-quality meeting. I would also like to thank all of the speakers who provided me with material for my talk before and during the conference. There is obviously no point in these proceedings in attempting to repeat all of the material from the individual contributions; by definition, these are all available earlier in this volume. In the written version, therefore, I will try to give a high level overview of the current state of hadron collider physics and to highlight the connections between the many presentations at this conference.

  15. Landscape of supersymmetric particle mass hierarchies and their signature space at the CERN Large Hadron Collider.

    PubMed

    Feldman, Daniel; Liu, Zuowei; Nath, Pran

    2007-12-21

    The minimal supersymmetric standard model with soft breaking has a large landscape of supersymmetric particle mass hierarchies. This number is reduced significantly in well-motivated scenarios such as minimal supergravity and alternatives. We carry out an analysis of the landscape for the first four lightest particles and identify at least 16 mass patterns, and provide benchmarks for each. We study the signature space for the patterns at the CERN Large Hadron Collider by analyzing the lepton+ (jet> or =2) + missing P{T} signals with 0, 1, 2, and 3 leptons. Correlations in missing P{T} are also analyzed. It is found that even with 10 fb{-1} of data a significant discrimination among patterns emerges.

  16. Black holes in many dimensions at the CERN Large Hadron Collider: testing critical string theory.

    PubMed

    Hewett, JoAnne L; Lillie, Ben; Rizzo, Thomas G

    2005-12-31

    We consider black hole production at the CERN Large Hadron Collider (LHC) in a generic scenario with many extra dimensions where the standard model fields are confined to a brane. With approximately 20 dimensions the hierarchy problem is shown to be naturally solved without the need for large compactification radii. We find that in such a scenario the properties of black holes can be used to determine the number of extra dimensions, . In particular, we demonstrate that measurements of the decay distributions of such black holes at the LHC can determine if is significantly larger than 6 or 7 with high confidence and thus can probe one of the critical properties of string theory compactifications.

  17. Closing in on supersymmetric electroweak baryogenesis with dark matter searches and the Large Hadron Collider

    SciTech Connect

    Kozaczuk, Jonathan; Profumo, Stefano E-mail: profumo@scipp.ucsc.edu

    2011-11-01

    We study the impact of recent direct and indirect searches for particle dark matter on supersymmetric models with resonant neutralino- or chargino-driven electroweak baryogenesis (EWB) and heavy sfermions. We outline regions of successful EWB on the planes defined by gaugino and higgsino mass parameters, and calculate the portions of those planes excluded by dark matter search results, and the regions soon to be probed by current and future experiments. We conclude that dark matter searches robustly exclude a wino-like lightest supersymmetric particle in successful EWB regions. Bino-like dark matter is still a possibility, although one that will be probed with a modest improvement in the sensitivity of current direct and indirect detection experiments. We also calculate the total production cross section of chargino and neutralino pairs at the Large Hadron Collider, with a center of mass energy of 7 and 14 TeV.

  18. Cryogenic safety aspect of the low -$\\beta$ magnest systems at the Large Hadron Collider (LHC)

    SciTech Connect

    Darve, C.; /Fermilab

    2010-07-01

    The low-{beta} magnet systems are located in the LHC insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process and will allow proton collisions at a luminosity of up to 10{sup 34}cm{sup -2}s{sup -1}. Large radiation dose deposited at the proximity of the beam collisions dictate stringent requirements for the design and operation of the systems. The hardware commissioning phase of the LHC was completed in the winter of 2010 and permitted to validate this system safe operation. This paper presents the analysis used to qualify and quantify the safe operation of the low-{beta} magnet systems in the Large Hadron Collider (LHC) for the first years of operation.

  19. The Large Hadron Collider project: organizational and financial matters (of physics at the terascale).

    PubMed

    Engelen, Jos

    2012-02-28

    In this paper, I present a view of organizational and financial matters relevant for the successful construction and operation of the experimental set-ups at the Large Hadron Collider of CERN, the European Laboratory for Particle Physics in Geneva. Construction of these experiments was particularly challenging: new detector technologies had to be developed; experimental set-ups that are larger and more complex than ever before had to be constructed; and larger collaborations than ever before had to be organized. Fundamental to the success were: the 'reference' provided by CERN, peer review, signed memoranda of understanding, well-organized resources review boards as an interface to the national funding agencies and collegial, but solidly organized, experimental collaborations. PMID:22253248

  20. The data acquisition and reduction challenge at the Large Hadron Collider.

    PubMed

    Cittolin, Sergio

    2012-02-28

    The Large Hadron Collider detectors are technological marvels-which resemble, in functionality, three-dimensional digital cameras with 100 Mpixels-capable of observing proton-proton (pp) collisions at the crossing rate of 40 MHz. Data handling limitations at the recording end imply the selection of only one pp event out of each 10(5). The readout and processing of this huge amount of information, along with the selection of the best approximately 200 events every second, is carried out by a trigger and data acquisition system, supplemented by a sophisticated control and monitor system. This paper presents an overview of the challenges that the development of these systems has presented over the past 15 years. It concludes with a short historical perspective, some lessons learnt and a few thoughts on the future.

  1. Search for a light fermiophobic Higgs boson produced via gluon fusion at hadron colliders

    SciTech Connect

    Arhrib, Abdesslam; Benbrik, Rachid; Guedes, R. B.; Santos, R.

    2008-10-01

    In this study, we propose new Higgs production mechanisms with multiphoton final states in the fermiophobic limit of the two Higgs doublet model. The processes are: gg{yields}hh, gg{yields}Hh followed by H{yields}hh and gg{yields}Ah followed by A{yields}hZ. In the fermiophobic limit, gg{yields}hh and gg{yields}Ah{yields}hhZ would give rise to 4{gamma} signature while gg{yields}Hh{yields}hhh can give a 6{gamma} final state. We show that both the Fermilab Tevatron and CERN's Large Hadron Collider can probe a substantial slice of the parameter space in this fermiophobic scenario of the two Higgs doublet model. If observed the above processes can give some information on the triple Higgs couplings involved.

  2. EXERGY ANALYSIS OF THE CRYOGENIC HELIUM DISTRIBUTION SYSTEM FOR THE LARGE HADRON COLLIDER (LHC)

    SciTech Connect

    Claudet, S.; Lebrun, Ph.; Tavian, L.; Wagner, U.

    2010-04-09

    The Large Hadron Collider (LHC) at CERN features the world's largest helium cryogenic system, spreading over the 26.7 km circumference of the superconducting accelerator. With a total equivalent capacity of 145 kW at 4.5 K including 18 kW at 1.8 K, the LHC refrigerators produce an unprecedented exergetic load, which must be distributed efficiently to the magnets in the tunnel over the 3.3 km length of each of the eight independent sectors of the machine. We recall the main features of the LHC cryogenic helium distribution system at different temperature levels and present its exergy analysis, thus enabling to qualify second-principle efficiency and identify main remaining sources of irreversibility.

  3. The Large Hadron Collider project: organizational and financial matters (of physics at the terascale).

    PubMed

    Engelen, Jos

    2012-02-28

    In this paper, I present a view of organizational and financial matters relevant for the successful construction and operation of the experimental set-ups at the Large Hadron Collider of CERN, the European Laboratory for Particle Physics in Geneva. Construction of these experiments was particularly challenging: new detector technologies had to be developed; experimental set-ups that are larger and more complex than ever before had to be constructed; and larger collaborations than ever before had to be organized. Fundamental to the success were: the 'reference' provided by CERN, peer review, signed memoranda of understanding, well-organized resources review boards as an interface to the national funding agencies and collegial, but solidly organized, experimental collaborations.

  4. Observing light-by-light scattering at the Large Hadron Collider.

    PubMed

    d'Enterria, David; da Silveira, Gustavo G

    2013-08-23

    Elastic light-by-light scattering (γγ→γγ) is open to study at the Large Hadron Collider thanks to the large quasireal photon fluxes available in electromagnetic interactions of protons (p) and lead (Pb) ions. The γγ→γγ cross sections for diphoton masses m(γγ)>5 GeV amount to 12 fb, 26 pb, and 35 nb in p-p, p-Pb, and Pb-Pb collisions at nucleon-nucleon center-of-mass energies √(s(NN))=14, 8.8, and 5.5 TeV, respectively. Such a measurement has no substantial background in Pb-Pb collisions where one expects about 20 signal events per run, after typical detector acceptance and reconstruction efficiency selections.

  5. Signatures of non-universal gaugino and scalar masses at the Large Hadron Collider (LHC)

    SciTech Connect

    Bhattacharya, Subhaditya

    2008-11-23

    We perform a multichannel analysis in context of the Large Hadron Collider (LHC) for supersymmetric (SUSY) theories with high-scale non-universal gaugino masses arising from different non-singlet representations of SU(5) and SO(10) gauge groups in a SUSY-GUT scenario and non-universal scalar masses in form of squark-slepton non-universality, third family scalar non-universality and that arising due to SO(10) D-terms. We present the numerical predictions over a wide region of parameter space using event generator Pythia. Certain broad features emerge from the study which may be useful to identify these non-universal schemes and distinguish them from the minimal supergravity (mSUGRA) framework.

  6. Search for a light fermiophobic Higgs boson produced via gluon fusion at hadron colliders

    NASA Astrophysics Data System (ADS)

    Arhrib, Abdesslam; Benbrik, Rachid; Guedes, R. B.; Santos, R.

    2008-10-01

    In this study, we propose new Higgs production mechanisms with multiphoton final states in the fermiophobic limit of the two Higgs doublet model. The processes are: gg→hh, gg→Hh followed by H→hh and gg→Ah followed by A→hZ. In the fermiophobic limit, gg→hh and gg→Ah→hhZ would give rise to 4γ signature while gg→Hh→hhh can give a 6γ final state. We show that both the Fermilab Tevatron and CERN’s Large Hadron Collider can probe a substantial slice of the parameter space in this fermiophobic scenario of the two Higgs doublet model. If observed the above processes can give some information on the triple Higgs couplings involved.

  7. Non-Standard ZZ Production with Leptonic Decays at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Sun, Hao

    2012-04-01

    The prospects of anomalous ZZγ and ZZZ triple gauge boson couplings are investigated at the Large Hadron Collider (LHC) through an excess of events in ZZ diboson production. Two such channels are selected and the tree level results including leptonic final states are discussed: ZZ → l1-l1+l2-l2+ and ZZ → l-l+νν¯(l, l1,2 = e, μ). The results in the full finite width method are compared with the narrow width approximation (NWA) method in detail. Besides the Z boson transverse momentum distributions, the azimuthal angle between the Z boson decay to fermions, ΔΦ, and their separations in the pseudo-rapidity-azimuthal angle plane, ΔR, as well as the sensitivity on anomalous couplings are displayed at the 14 TeV LHC.

  8. First beta-beating measurement and optics analysis for the CERN Large Hadron Collider

    SciTech Connect

    Tomas, R.; Calaga, R.; Aiba, M.; Fartoukh, S.; Franchi, A.; Giovannozzi, M.; Kain, V.; Lamont, M.; Vanbavinckhove, G.; Wenninger, J.; Zimmermann, F.; Morita, A.

    2009-08-13

    Proton beams were successfully steered through the entire ring of the CERN Large Hadron Collider (LHC) on September the 10th of 2008. A reasonable lifetime was achieved for the counterclockwise beam, namely beam 2, after the radiofrequency capture of the particle bunch was established. This provided the unique opportunity of acquiring turn-by-turn betatron oscillations for a maximum of 90 turns right at injection. Transverse coupling was not corrected and chromaticity was estimated to be large. Despite this largely constrained scenario, reliable optics measurements have been accomplished. These measurements together with the application of new algorithms for the reconstruction of optics errors have led to the identification of a dominant error source.

  9. Higgs self-coupling measurements at a 100 TeV hadron collider

    NASA Astrophysics Data System (ADS)

    Barr, Alan J.; Dolan, Matthew J.; Englert, Christoph; de Lima, Danilo Enoque Ferreira; Spannowsky, Michael

    2015-02-01

    An important physics goal of a possible next-generation high-energy hadron collider will be precision characterisation of the Higgs sector and electroweak symmetry breaking. A crucial part of understanding the nature of electroweak symmetry breaking is measuring the Higgs self-interactions. We study dihiggs production in proton-proton collisions at 100 TeV centre of mass energy in order to estimate the sensitivity such a machine would have to variations in the trilinear Higgs coupling around the Standard Model expectation. We focus on the final state, including possible enhancements in sensitivity by exploiting dihiggs recoils against a hard jet. We find that it should be possible to measure the trilinear self-coupling with 40% accuracy given 3/ab and 12% with 30/ab of data.

  10. Precise Predictions for W 4 Jet Production at the Large Hadron Collider

    SciTech Connect

    Berger, C.F.; Bern, Z.; Dixon, Lance J.; Cordero, F.Febres; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.; /Durham U.

    2010-09-14

    We present the first next-to-leading order QCD results for W + 4-jet production at hadron colliders. Total cross sections, as well as distributions in the jet transverse momenta and in the total transverse energy HT, are provided for the initial LHC energy of {radical}s = 7 TeV. We use a leading-color approximation, known to be accurate to 3% for W production with fewer jets. The virtual matrix elements and the most complicated real-emission matrix elements are handled by the BlackHat library, based on on-shell methods. The remaining parts of the calculation, including the integration over phase space, are performed by the SHERPA package.

  11. QCD corrections to associated production of tt{gamma} at hadron colliders

    SciTech Connect

    Duan Pengfei; Ma Wengan; Zhang Renyou; Han Liang; Guo Lei; Wang Shaoming

    2009-07-01

    We report on the next-to-leading order (NLO) QCD computation of top-quark pair production in association with a photon at the Fermilab Tevatron RUN II and CERN Large Hadron Collider. We describe the impact of the complete NLO QCD radiative corrections to this process, and provide the predictions of the leading order (LO) and NLO integrated cross sections, distributions of the transverse momenta of the top quark and photon for the LHC and Tevatron, and the LO and NLO forward-backward top-quark charge asymmetries for the Tevatron. We investigate the dependence of the LO and NLO cross sections on the renormalization/factorization scale, and find the scale dependence of the LO cross section is obviously improved by the NLO QCD corrections. The K-factor of the NLO QCD correction is 0.977(1.524) for the Tevatron (LHC)

  12. Viewpoint: the End of the World at the Large Hadron Collider?

    SciTech Connect

    Peskin, Michael E.; /SLAC

    2011-11-21

    New arguments based on astrophysical phenomena constrain the possibility that dangerous black holes will be produced at the CERN Large Hadron Collider. On 8 August, the Large Hadron Collider (LHC) at CERN injected its first beams, beginning an experimental program that will produce proton-proton collisions at an energy of 14 TeV. Particle physicists are waiting expectantly. The reason is that the Standard Model of strong, weak, and electromagnetic interactions, despite its many successes, is clearly incomplete. Theory says that the holes in the model should be filled by new physics in the energy region that will be studied by the LHC. Some candidate theories are simple quick fixes, but the most interesting ones involve new concepts of spacetime waiting to be discovered. Look up the LHC on Wikipedia, however, and you will find considerable space devoted to safety concerns. At the LHC, we will probe energies beyond those explored at any previous accelerator, and we hope to create particles that have never been observed. Couldn't we, then, create particles that would actually be dangerous, for example, ones that would eat normal matter and eventually turn the earth into a blob of unpleasantness? It is morbid fun to speculate about such things, and candidates for such dangerous particles have been suggested. These suggestions have been analyzed in an article in Reviews of Modern Physics by Jaffe, Busza, Wilczek, and Sandweiss and excluded on the basis of constraints from observation and from the known laws of physics. These conclusions have been upheld by subsequent studies conducted at CERN.

  13. A Novel method for modeling the recoil in W boson events at hadron collider

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Aguilo, Ernest; Ahsan, Mahsana; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls /Northeastern U.

    2009-07-01

    We present a new method for modeling the hadronic recoil in W {yields} {ell}{nu} events produced at hadron colliders. The recoil is chosen from a library of recoils in Z {yields} {ell}{ell} data events and overlaid on a simulated W {yields} {ell}{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 1 fb{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.

  14. Heavy-ion physics with the ALICE experiment at the CERN Large Hadron Collider.

    PubMed

    Schukraft, J

    2012-02-28

    After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.

  15. Long term dynamics of the high luminosity Large Hadron Collider with crab cavities

    NASA Astrophysics Data System (ADS)

    Barranco García, J.; De Maria, R.; Grudiev, A.; Tomás García, R.; Appleby, R. B.; Brett, D. R.

    2016-10-01

    The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) aims to achieve an integrated luminosity of 200 - 300 fb-1 per year, including the contribution from the upgrade of the injector chain. For the HL-LHC the larger crossing angle together with a smaller beta function at the collision point would result in more than 70% luminosity loss due to the incomplete geometric overlap of colliding bunches. To recover head-on collisions at the high-luminosity particle-physics detectors ATLAS and CMS and benefit from the very low β* provided by the Achromatic Telescopic Squeezing (ATS) optics, a local crab cavity scheme provides transverse kicks to the proton bunches. The tight space constraints at the location of these cavities leads to designs which are axially non-symmetric, giving rise to high order multipoles components of the main deflecting mode and, since these kicks are harmonic in time, we expand them in a series of multipoles in a similar fashion as is done for static field magnets. In this work we calculate, for the first time, the higher order multipoles and their impact on beam dynamics for three different crab cavity prototypes. Different approaches to calculate the multipoles are presented. Furthermore, we perform the first calculation of their impact on the long term stability of the machine using the concept of dynamic aperture.

  16. Left-right symmetry and lepton number violation at the Large Hadron electron Collider

    NASA Astrophysics Data System (ADS)

    Lindner, Manfred; Queiroz, Farinaldo S.; Rodejohann, Werner; Yaguna, Carlos E.

    2016-06-01

    We show that the proposed Large Hadron electron Collider (LHeC) will provide an opportunity to search for left-right symmetry and establish lepton number violation, complementing current and planned searches based on LHC data and neutrinoless double beta decay. We consider several plausible configurations for the LHeC — including different electron energies and polarizations, as well as distinct values for the charge misidentification rate. Within left-right symmetric theories we determine the values of right-handed neutrino and gauge boson masses that could be tested at the LHeC after one, five and ten years of operation. Our results indicate that this collider might probe, via the Δ L = 2 signal e - p → e + jjj, Majorana neutrino masses up to 1 TeV and W R masses up to ˜ 6 .5 TeV. Interestingly, part of this parameter space is beyond the expected reach of the LHC and of future neutrinoless double beta decay experiments.

  17. Next-to-Leading-Order QCD Corrections to W{sup +}W{sup -}bb Production at Hadron Colliders

    SciTech Connect

    Denner, A.; Dittmaier, S.; Kallweit, S.; Pozzorini, S.

    2011-02-04

    Top-antitop quark pairs belong to the most abundantly produced and precisely measurable heavy-particle signatures at hadron colliders and allow for crucial tests of the standard model and new physics searches. Here we report on the calculation of the next-to-leading order (NLO) QCD corrections to hadronic W{sup +}W{sup -}bb production, which provides a complete NLO description of the production of top-antitop pairs and their subsequent decay into W bosons and bottom quarks, including interferences, off-shell effects, and nonresonant backgrounds. Numerical predictions for the Tevatron and the LHC are presented.

  18. Searches for Lorentz Violation in Top-Quark Production and Decay at Hadron Colliders

    SciTech Connect

    Whittington, Denver Wade

    2012-07-01

    We present a first-of-its-kind confirmation that the most massive known elementary particle obeys the special theory of relativity. Lorentz symmetry is a fundamental aspect of special relativity which posits that the laws of physics are invariant regardless of the orientation and velocity of the reference frame in which they are measured. Because this symmetry is a fundamental tenet of physics, it is important to test its validity in all processes. We quantify violation of this symmetry using the Standard-Model Extension framework, which predicts the effects that Lorentz violation would have on elementary particles and their interactions. The top quark is the most massive known elementary particle and has remained inaccessible to tests of Lorentz invariance until now. This model predicts a dependence of the production cross section for top and antitop quark pairs on sidereal time as the orientation of the experiment in which these events are produced changes with the rotation of the Earth. Using data collected with the DØ detector at the Fermilab Tevatron Collider, we search for violation of Lorentz invariance in events involving the production of a $t\\bar{t}$ pair. Within the experimental precision, we find no evidence for such a violation and set upper limits on parameters describing its possible strength within the Standard-Model Extension. We also investigate the prospects for extending this analysis using the ATLAS detector at the Large Hadron Collider which, because of the higher rate of $t\\bar{t}$ events at that experiment, has the potential to improve the limits presented here.

  19. High energy proton-proton elastic scattering at the Large Hadron Collider and nucleon structure

    NASA Astrophysics Data System (ADS)

    Luddy, Richard Joseph

    To gain insight into the structure of the nucleon, we pursue the development of the phenomenological model of Islam et al. (IIFS model) for high energy elastic pp and p¯p scattering. We determine the energy dependence of the parameters of the IIFS model using the available elastic differential cross section data from SPS Collider and Tevatron and the known asymptotic behavior of sigmatot (s) and rho(s) from dispersion relation calculations and more recent analyses of Cudell et al. (COMPETE Collaboration). Next, we incorporate a high energy elastic valence quark-quark scattering amplitude into the model based on BFKL pomeron to describe small impact parameter (large | t|) pp collisions. Finally, we predict the pp elastic differential cross section at the unprecedented c.m. energy of s = 14.0 TeV at the Large Hadron Collider (LHC). This prediction assumes crucial significance---because of an approved experiment at LHC: TOTal and Elastic Measurement (TOTEM). The TOTEM group plans to measure pp elastic dsigma/dt at 14.0 TeV all the way from momentum transfer |t| = 0 to |t| ≃ 10 GeV 2. Their measurement will stringently test not only the diffraction and o-exchange descriptions of the original IIFS model, but also the additional valence quark-quark scattering contribution that we find to be dominant for large |t|. Successful quantitative verification of the predicted dsigma/dt will mean that our picture of the nucleon with an outer cloud of qq¯ condensed ground state, an inner core of topological baryonic charge, and a still smaller core of massless valence quarks provides a realistic description of nucleon structure.

  20. Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Bruce, R.; Assmann, R. W.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

    2014-08-01

    The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

  1. MEKS: A program for computation of inclusive jet cross sections at hadron colliders

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Liang, Zhihua; Soper, Davison E.; Lai, Hung-Liang; Nadolsky, Pavel M.; Yuan, C.-P.

    2013-06-01

    EKS is a numerical program that predicts differential cross sections for production of single-inclusive hadronic jets and jet pairs at next-to-leading order (NLO) accuracy in a perturbative QCD calculation. We describe MEKS 1.0, an upgraded EKS program with increased numerical precision, suitable for comparisons to the latest experimental data from the Large Hadron Collider and Tevatron. The program integrates the regularized patron-level matrix elements over the kinematical phase space for production of two and three partons using the VEGAS algorithm. It stores the generated weighted events in finely binned two-dimensional histograms for fast offline analysis. A user interface allows one to customize computation of inclusive jet observables. Results of a benchmark comparison of the MEKS program and the commonly used FastNLO program are also documented. Program SummaryProgram title: MEKS 1.0 Catalogue identifier: AEOX_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOX_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.: 9234 No. of bytes in distributed program, including test data, etc.: 51997 Distribution format: tar.gz Programming language: Fortran (main program), C (CUBA library and analysis program). Computer: All. Operating system: Any UNIX-like system. RAM: ˜300 MB Classification: 11.1. External routines: LHAPDF (https://lhapdf.hepforge.org/) Nature of problem: Computation of differential cross sections for inclusive production of single hadronic jets and jet pairs at next-to-leading order accuracy in perturbative quantum chromodynamics. Solution method: Upon subtraction of infrared singularities, the hard-scattering matrix elements are integrated over available phase space using an optimized VEGAS algorithm. Weighted events are generated and filled

  2. Production of b-quark jets at the large Hadron Collider in the parton-reggeization approach

    SciTech Connect

    Saleev, V. A. Shipilova, A. V.

    2013-11-15

    The inclusive hadroproduction of b-quark jets and bb-bar-quark dijets at the Large Hadron Collider is considered by using the hypothesis of gluon Reggeization in t-channel exchanges at high energies. Experimental data obtained by the ATLAS Collaboration are described well within all of the presented kinematical regions for single b-quark jets and bb-bar-quark dijets without resort to any free parameters.

  3. Journey in the search for the Higgs boson: the ATLAS and CMS experiments at the Large Hadron Collider.

    PubMed

    Della Negra, M; Jenni, P; Virdee, T S

    2012-12-21

    The search for the standard model Higgs boson at the Large Hadron Collider (LHC) started more than two decades ago. Much innovation was required and diverse challenges had to be overcome during the conception and construction of the LHC and its experiments. The ATLAS and CMS Collaboration experiments at the LHC have discovered a heavy boson that could complete the standard model of particle physics. PMID:23258886

  4. Journey in the search for the Higgs boson: the ATLAS and CMS experiments at the Large Hadron Collider.

    PubMed

    Della Negra, M; Jenni, P; Virdee, T S

    2012-12-21

    The search for the standard model Higgs boson at the Large Hadron Collider (LHC) started more than two decades ago. Much innovation was required and diverse challenges had to be overcome during the conception and construction of the LHC and its experiments. The ATLAS and CMS Collaboration experiments at the LHC have discovered a heavy boson that could complete the standard model of particle physics.

  5. Thermomechanical response of Large Hadron Collider collimators to proton and ion beam impacts

    NASA Astrophysics Data System (ADS)

    Cauchi, Marija; Assmann, R. W.; Bertarelli, A.; Carra, F.; Cerutti, F.; Lari, L.; Redaelli, S.; Mollicone, P.; Sammut, N.

    2015-04-01

    The CERN Large Hadron Collider (LHC) is designed to accelerate and bring into collision high-energy protons as well as heavy ions. Accidents involving direct beam impacts on collimators can happen in both cases. The LHC collimation system is designed to handle the demanding requirements of high-intensity proton beams. Although proton beams have 100 times higher beam power than the nominal LHC lead ion beams, specific problems might arise in case of ion losses due to different particle-collimator interaction mechanisms when compared to protons. This paper investigates and compares direct ion and proton beam impacts on collimators, in particular tertiary collimators (TCTs), made of the tungsten heavy alloy INERMET® 180. Recent measurements of the mechanical behavior of this alloy under static and dynamic loading conditions at different temperatures have been done and used for realistic estimates of the collimator response to beam impact. Using these new measurements, a numerical finite element method (FEM) approach is presented in this paper. Sequential fast-transient thermostructural analyses are performed in the elastic-plastic domain in order to evaluate and compare the thermomechanical response of TCTs in case of critical beam load cases involving proton and heavy ion beam impacts.

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

    NASA Astrophysics Data System (ADS)

    Backhaus, M.

    2016-09-01

    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 included the installation of new service quarter panels, the repair of cables, and the installation of the new Diamond Beam Monitor (DBM). Additionally, a completely new innermost pixel detector layer, the Insertable B-Layer (IBL), was constructed and installed in May 2014 between a new smaller beam pipe and the existing Pixel Detector. With a radius of 3.3 cm the IBL is located extremely close to the interaction point. Therefore, a new readout chip and two new sensor technologies (planar and 3D) are used in the IBL. In order to achieve best possible physics performance the material budget was improved with respect to the existing Pixel Detector. This is realized using lightweight staves for mechanical support and a CO2 based cooling system. This paper describes the improvements achieved during the maintenance of the existing Pixel Detector as well as the performance of the IBL during the construction and commissioning phase. Additionally, first results obtained during the LHC Run 2 demonstrating the distinguished tracking performance of the new Four Layer ATLAS Pixel Detector are presented.

  7. Study of the Standard Model W angular coefficients and associated helicity cross sections at hadron colliders.

    NASA Astrophysics Data System (ADS)

    Strologas, John

    2002-04-01

    We present the Standard Model prediction for the W angular coefficients and the corresponding helicity cross sections at hadron colliders. There are eight angular coefficients, four of which are present in high transverse momentum events associated with the production of a jet, while the last three ones are related to gluon loops and they are T-odd and P-odd, thus a probable source of CP violation in W production and decay. All angular coefficients are ratios of the W helicity cross sections and the unpolarized total W cross section. If the W is produced with zero transverse momentum, its spin is parallel to the beam-axis and only one coefficient survives, giving us the familiar formula (dσ/(dp_T^Wd\\cosθ)=(1±\\cosθ)^2, where θ is the azimuthal angle of the final state charged lepton in the W^mp rest frame), if only valence quarks contribute to the W production. In the case of W production with non-trivial transverse momentum, the differential W cross section is more involved and also a function of the polar angle of the charged lepton. We discuss a method of experimentally extracting the W angular coefficients and helicity cross sections using W+jet events at next-to-leading order in QCD (gluon loops), without dividing the data with any Monte Carlo isotropic gauge boson decays, as it was proposed in the past.

  8. The CERN Large Hadron Collider as a tool to study high-energy density matter.

    PubMed

    Tahir, N A; Kain, V; Schmidt, R; Shutov, A; Lomonosov, I V; Gryaznov, V; Piriz, A R; Temporal, M; Hoffmann, D H H; Fortov, V E

    2005-04-01

    The Large Hadron Collider (LHC) at CERN will generate two extremely powerful 7 TeV proton beams. Each beam will consist of 2808 bunches with an intensity per bunch of 1.15x10(11) protons so that the total number of protons in one beam will be about 3x10(14) and the total energy will be 362 MJ. Each bunch will have a duration of 0.5 ns and two successive bunches will be separated by 25 ns, while the power distribution in the radial direction will be Gaussian with a standard deviation, sigma=0.2 mm. The total duration of the beam will be about 89 mus. Using a 2D hydrodynamic code, we have carried out numerical simulations of the thermodynamic and hydrodynamic response of a solid copper target that is irradiated with one of the LHC beams. These calculations show that only the first few hundred proton bunches will deposit a high specific energy of 400 kJ/g that will induce exotic states of high energy density in matter.

  9. Mathematical formulation to predict the harmonics of the superconducting Large Hadron Collider magnets

    NASA Astrophysics Data System (ADS)

    Sammut, Nicholas; Bottura, Luca; Micallef, Joseph

    2006-01-01

    CERN is currently assembling the LHC (Large Hadron Collider) that will accelerate and bring in collision 7 TeV protons for high energy physics. Such a superconducting magnet-based accelerator can be controlled only when the field errors of production and installation of all magnetic elements are known to the required accuracy. The ideal way to compensate the field errors obviously is to have direct diagnostics on the beam. For the LHC, however, a system solely based on beam feedback may be too demanding. The present baseline for the LHC control system hence requires an accurate forecast of the magnetic field and the multipole field errors to reduce the burden on the beam-based feedback. The field model is the core of this magnetic prediction system, that we call the field description for the LHC (FIDEL). The model will provide the forecast of the magnetic field at a given time, magnet operating current, magnet ramp rate, magnet temperature, and magnet powering history. The model is based on the identification and physical decomposition of the effects that contribute to the total field in the magnet aperture of the LHC dipoles. Each effect is quantified using data obtained from series measurements, and modeled theoretically or empirically depending on the complexity of the physical phenomena involved. This paper presents the developments of the new finely tuned magnetic field model and, using the data accumulated through series tests to date, evaluates its accuracy and predictive capabilities over a sector of the machine.

  10. Finite-width effects in unstable-particle production at hadron colliders

    NASA Astrophysics Data System (ADS)

    Falgari, P.; Papanastasiou, A. S.; Signer, A.

    2013-05-01

    We present a general formalism for the calculation of finite-width contributions to the differential production cross sections of unstable particles at hadron colliders. In this formalism, which employs an effective-theory description of unstable-particle production and decay, the matrix element computation is organized as a gauge-invariant expansion in powers of Γ X /m X , with Γ X and m X the width and mass of the unstable particle. This framework allows for a systematic inclusion of off-shell and non-factorizable effects whilst at the same time keeping the computational effort minimal compared to a full calculation in the complex-mass scheme. As a proof-of-concept example, we give results for an NLO calculation of top-antitop production in the qoverline{q} partonic channel. As already found in a similar calculation of single-top production, the finite-width effects are small for the total cross section, as expected from the naïve counting Γ t /m t 1%. However, they can be sizeable, in excess of 10%, close to edges of certain kinematical distributions. The dependence of the results on the mass renormalization scheme, and its implication for a precise extraction of the top-quark mass, is also discussed.

  11. Measurement of nonlinear observables in the Large Hadron Collider using kicked beams

    NASA Astrophysics Data System (ADS)

    Maclean, E. H.; Tomás, R.; Schmidt, F.; Persson, T. H. B.

    2014-08-01

    The nonlinear dynamics of a circular accelerator such as the Large Hadron Collider (LHC) may significantly impact its performance. As the LHC progresses to more challenging regimes of operation it is to be expected that the nonlinear single particle dynamics in the transverse planes will play an increasing role in limiting the reach of the accelerator. As such it is vital that the nonlinear sources are well understood. The nonlinear fields of a circular accelerator may be probed through measurement of the amplitude detuning: the variation of tune with single particle emittance. This quantity may be assessed experimentally by exciting the beam to large amplitudes with kicks, and obtaining the tunes and actions from turn-by-turn data at Beam Position Monitors. The large amplitude excitations inherent to such a measurement also facilitate measurement of the dynamic aperture from an analysis of beam losses following the kicks. In 2012 these measurements were performed on the LHC Beam 2 at injection energy (450 GeV) with the nominal magnetic configuration. Nonlinear coupling was also observed. A second set of measurements were performed following the application of corrections for b4 and b5 errors. Analysis of the experimental results, and a comparison to simulation are presented herein.

  12. Next-to-Leading Order Predictions for W + 3-Jet Distributions at Hadron Colliders

    SciTech Connect

    Berger, C.F.; Bern, Z.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.; /Durham U.

    2009-12-09

    We present next-to-leading order QCD predictions for a variety of distributions in W + 3-jet production at both the Tevatron and the Large Hadron Collider. We include all subprocesses and incorporate the decay of the W boson into leptons. Our results are in excellent agreement with existing Tevatron data and provide the first quantitatively precise next-to-leading order predictions for the LHC. We include all terms in an expansion in the number of colors, confirming that the specific leading-color approximation used in our previous study is accurate to within three percent. The dependence of the cross section on renormalization and factorization scales is reduced significantly with respect to a leading-order calculation. We study different dynamical scale choices, and find that the total transverse energy is significantly better than choices used in previous phenomenological studies. We compute the one-loop matrix elements using on-shell methods, as numerically implemented in the BlackHat code. The remaining parts of the calculation, including generation of the real-emission contributions and integration over phase space, are handled by the SHERPA package.

  13. Performance Analysis of the Ironless Inductive Position Sensor in the Large Hadron Collider Collimators Environment

    PubMed Central

    Danisi, Alessandro; Masi, Alessandro; Losito, Roberto

    2015-01-01

    The Ironless Inductive Position Sensor (I2PS) has been introduced as a valid alternative to Linear Variable Differential Transformers (LVDTs) when external magnetic fields are present. Potential applications of this linear position sensor can be found in critical systems such as nuclear plants, tokamaks, satellites and particle accelerators. This paper analyzes the performance of the I2PS in the harsh environment of the collimators of the Large Hadron Collider (LHC), where position uncertainties of less than 20 µm are demanded in the presence of nuclear radiation and external magnetic fields. The I2PS has been targeted for installation for LHC Run 2, in order to solve the magnetic interference problem which standard LVDTs are experiencing. The paper describes in detail the chain of systems which belong to the new I2PS measurement task, their impact on the sensor performance and their possible further optimization. The I2PS performance is analyzed evaluating the position uncertainty (on 30 s), the magnetic immunity and the long-term stability (on 7 days). These three indicators are assessed from data acquired during the LHC operation in 2015 and compared with those of LVDTs. PMID:26569259

  14. Higgs boson pair production in new physics models at hadron, lepton, and photon colliders

    SciTech Connect

    Asakawa, Eri; Harada, Daisuke; Okada, Yasuhiro; Kanemura, Shinya; Tsumura, Koji

    2010-12-01

    We study Higgs boson pair production processes at future hadron and lepton colliders including the photon collision option in several new physics models; i.e., the two-Higgs-doublet model, the scalar leptoquark model, the sequential fourth generation fermion model and the vectorlike quark model. Cross sections for these processes can deviate significantly from the standard model predictions due to the one-loop correction to the triple Higgs boson coupling constant. For the one-loop induced processes such as gg{yields}hh and {gamma}{gamma}{yields}hh, where h is the (lightest) Higgs boson and g and {gamma} respectively represent a gluon and a photon, the cross sections can also be affected by new physics particles via additional one-loop diagrams. In the two-Higgs-doublet model and scalar leptoquark models, cross sections of e{sup +}e{sup -}{yields}hhZ and {gamma}{gamma}{yields}hh can be enhanced due to the nondecoupling effect in the one-loop corrections to the triple Higgs boson coupling constant. In the sequential fourth generation fermion model, the cross section for gg{yields}hh becomes very large because of the loop effect of the fermions. In the vectorlike quark model, effects are small because the theory has decoupling property. Measurements of the Higgs boson pair production processes can be useful to explore new physics through the determination of the Higgs potential.

  15. Dijet Signals for Low Mass Strings at the Large Hadron Collider

    SciTech Connect

    Anchordoqui, Luis A.; Nawata, Satoshi; Goldberg, Haim; Taylor, Tomasz R.; Luest, Dieter; Stieberger, Stephan

    2008-12-12

    Assuming that the fundamental string mass scale is in the TeV range and the theory is weakly coupled, we discuss possible signals of string physics at the Large Hadron Collider (LHC). In D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets 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 resonant pole to determine the discovery potential of LHC for the first Regge excitations of the quark and gluon. Remarkably, the reach of LHC after a few years of running can be as high as 6.8 TeV. Even after the first 100 pb{sup -1} of integrated luminosity, string scales as high as 4.0 TeV can be discovered. Data on pp{yields}direct{gamma}+ jet can provide corroboration for string physics at scales as high as 5 TeV.

  16. Jet Signals for Low Mass Strings at the Large Hadron Collider

    SciTech Connect

    Anchordoqui, Luis A.; Nawata, Satoshi; Goldberg, Haim; Taylor, Tomasz R.

    2008-05-02

    The mass scale M{sub s} of superstring theory is an arbitrary parameter that can be as low as few TeVs if the Universe contains large extra dimensions. We propose a search for the effects of Regge excitations of fundamental strings at the CERN Large Hadron Collider (LHC), in the process pp{yields}{gamma}+jet. The underlying parton process is dominantly the single photon production in gluon fusion, gg{yields}{gamma}g, with open string states propagating in intermediate channels. If the photon mixes with the gauge boson of the baryon number, which is a common feature of D-brane quivers, the amplitude appears already at the string disk level. It is completely determined by the mixing parameter--and it is otherwise model (compactification) independent. Even for relatively small mixing, 100 fb{sup -1} of LHC data could probe deviations from standard model physics, at a 5{sigma} significance, for M{sub s} as large as 3.3 TeV.

  17. Physics requirements for the design of the ATLAS and CMS experiments at the Large Hadron Collider.

    PubMed

    Virdee, T S

    2012-02-28

    The ATLAS and CMS experiments at the CERN Large Hadron Collider are discovery experiments. Thus, the aim was to make them sensitive to the widest possible range of new physics. New physics is likely to reveal itself in addressing questions such as: how do particles acquire mass; what is the particle responsible for dark matter; what is the path towards unification; do we live in a world with more space-time dimensions than the familiar four? The detection of the Higgs boson, conjectured to give mass to particles, was chosen as a benchmark to test the performance of the proposed experiment designs. Higgs production is one of the most demanding hypothesized processes in terms of required detector resolution and background discrimination. ATLAS and CMS feature full coverage, 4π-detectors to measure precisely the energies, directions and identity of all the particles produced in proton-proton collisions. Realizing this goal has required the collaborative efforts of enormous teams of people from around the world. PMID:22253241

  18. Jet signals for low mass strings at the large hadron collider.

    PubMed

    Anchordoqui, Luis A; Goldberg, Haim; Nawata, Satoshi; Taylor, Tomasz R

    2008-05-01

    The mass scale M{s} of superstring theory is an arbitrary parameter that can be as low as few TeVs if the Universe contains large extra dimensions. We propose a search for the effects of Regge excitations of fundamental strings at the CERN Large Hadron Collider (LHC), in the process pp-->gamma+jet. The underlying parton process is dominantly the single photon production in gluon fusion, gg-->gammag, with open string states propagating in intermediate channels. If the photon mixes with the gauge boson of the baryon number, which is a common feature of D-brane quivers, the amplitude appears already at the string disk level. It is completely determined by the mixing parameter-and it is otherwise model (compactification) independent. Even for relatively small mixing, 100 fb{-1} of LHC data could probe deviations from standard model physics, at a 5sigma significance, for M{s} as large as 3.3 TeV.

  19. Dijet signals for low mass strings at the Large Hadron Collider.

    PubMed

    Anchordoqui, Luis A; Goldberg, Haim; Lüst, Dieter; Nawata, Satoshi; Stieberger, Stephan; Taylor, Tomasz R

    2008-12-12

    Assuming that the fundamental string mass scale is in the TeV range and the theory is weakly coupled, we discuss possible signals of string physics at the Large Hadron Collider (LHC). In D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets 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 resonant pole to determine the discovery potential of LHC for the first Regge excitations of the quark and gluon. Remarkably, the reach of LHC after a few years of running can be as high as 6.8 TeV. Even after the first 100 pb(-1) of integrated luminosity, string scales as high as 4.0 TeV can be discovered. Data on pp-->directgamma + jet can provide corroboration for string physics at scales as high as 5 TeV.

  20. Search for Microscopic Black Hole Signatures at the Large Hadron Collider

    SciTech Connect

    Tsang, Ka Vang

    2011-05-01

    A search for microscopic black hole production and decay in proton-proton collisions at a center-of-mass energy of 7 TeV has been conducted using Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider. A total integrated luminosity of 35 pb-1 data sample, taken by CMS Collaboration in year 2010, has been analyzed. A novel background estimation for multi-jet events beyond TeV scale has been developed. A good agreement with standard model backgrounds, dominated by multi-jet production, is observed for various final-state multiplicities. Using semi-classical approximation, upper limits on minimum black hole mass at 95% confidence level are set in the range of 3.5 - 4.5 TeV for values of the Planck scale up to 3 TeV. Model-independent limits are provided to further constrain microscopic black hole models with additional regions of parameter space, as well as new physics models with multiple energetic final states. These are the first limits on microscopic black hole production at a particle accelerator.

  1. Performance Analysis of the Ironless Inductive Position Sensor in the Large Hadron Collider Collimators Environment.

    PubMed

    Danisi, Alessandro; Masi, Alessandro; Losito, Roberto

    2015-01-01

    The Ironless Inductive Position Sensor (I2PS) has been introduced as a valid alternative to Linear Variable Differential Transformers (LVDTs) when external magnetic fields are present. Potential applications of this linear position sensor can be found in critical systems such as nuclear plants, tokamaks, satellites and particle accelerators. This paper analyzes the performance of the I2PS in the harsh environment of the collimators of the Large Hadron Collider (LHC), where position uncertainties of less than 20 µm are demanded in the presence of nuclear radiation and external magnetic fields. The I2PS has been targeted for installation for LHC Run 2, in order to solve the magnetic interference problem which standard LVDTs are experiencing. The paper describes in detail the chain of systems which belong to the new I2PS measurement task, their impact on the sensor performance and their possible further optimization. The I2PS performance is analyzed evaluating the position uncertainty (on 30 s), the magnetic immunity and the long-term stability (on 7 days). These three indicators are assessed from data acquired during the LHC operation in 2015 and compared with those of LVDTs.

  2. Dijet signals for low mass strings at the Large Hadron Collider.

    PubMed

    Anchordoqui, Luis A; Goldberg, Haim; Lüst, Dieter; Nawata, Satoshi; Stieberger, Stephan; Taylor, Tomasz R

    2008-12-12

    Assuming that the fundamental string mass scale is in the TeV range and the theory is weakly coupled, we discuss possible signals of string physics at the Large Hadron Collider (LHC). In D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets 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 resonant pole to determine the discovery potential of LHC for the first Regge excitations of the quark and gluon. Remarkably, the reach of LHC after a few years of running can be as high as 6.8 TeV. Even after the first 100 pb(-1) of integrated luminosity, string scales as high as 4.0 TeV can be discovered. Data on pp-->directgamma + jet can provide corroboration for string physics at scales as high as 5 TeV. PMID:19113614

  3. Instrumentation status of the low-b magnet systems at the Large Hadron Collider (LHC)

    SciTech Connect

    Darve, C.; Balle, C.; Casas-Cubillos, J.; Perin, A.; Vauthier, N.; /CERN

    2011-05-01

    The low-{beta} magnet systems are located in the Large Hadron Collider (LHC) insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process allowing proton collisions at luminosity up to 10{sup 34}cm{sup -2}s{sup -1}. Those systems are a contribution of the US-LHC Accelerator project. The systems are mainly composed of the quadrupole magnets (triplets), the separation dipoles and their respective electrical feed-boxes (DFBX). The low-{beta} magnet systems operate in an environment of extreme radiation, high gradient magnetic field and high heat load to the cryogenic system due to the beam dynamic effect. Due to the severe environment, the robustness of the diagnostics is primordial for the operation of the triplets. The hardware commissioning phase of the LHC was completed in February 2010. In the sake of a safer and more user-friendly operation, several consolidations and instrumentation modifications were implemented during this commissioning phase. This paper presents the instrumentation used to optimize the engineering process and operation of the final focusing/defocusing quadrupole magnets for the first years of operation.

  4. Phenomenology of Rotating Extra-Dimensional Black Holes at Hadron Colliders

    SciTech Connect

    Frost, James A.

    2010-02-10

    Results are presented from CHARYBDIS2, a new Monte Carlo simulation of black hole production and decay at hadron colliders. The main new features of CHARYBDIS2 are a full treatment of the spin-down phase of the decay process using the angular and energy distributions of the associated Hawking radiation, improved modelling of the loss of angular momentum and energy in the production process as well as a wider range of options for the Planck-scale termination of the decay. The new features allow the study of the effects of black hole rotation and the feasibility of its observation. We present results, with emphasis on the consequences and experimental signatures of black hole rotation at the LHC. The effects of rotation are found to be large, with substantial changes to particle energies and distributions. Rotation persists throughout evaporation, invalidating the approximation of a rapid spin-down followed by isotropic emission in a non-rotating Schwarzschild phase. A selection of results are presented from the original article, arXiv:0904:0979.

  5. Performance Analysis of the Ironless Inductive Position Sensor in the Large Hadron Collider Collimators Environment.

    PubMed

    Danisi, Alessandro; Masi, Alessandro; Losito, Roberto

    2015-01-01

    The Ironless Inductive Position Sensor (I2PS) has been introduced as a valid alternative to Linear Variable Differential Transformers (LVDTs) when external magnetic fields are present. Potential applications of this linear position sensor can be found in critical systems such as nuclear plants, tokamaks, satellites and particle accelerators. This paper analyzes the performance of the I2PS in the harsh environment of the collimators of the Large Hadron Collider (LHC), where position uncertainties of less than 20 µm are demanded in the presence of nuclear radiation and external magnetic fields. The I2PS has been targeted for installation for LHC Run 2, in order to solve the magnetic interference problem which standard LVDTs are experiencing. The paper describes in detail the chain of systems which belong to the new I2PS measurement task, their impact on the sensor performance and their possible further optimization. The I2PS performance is analyzed evaluating the position uncertainty (on 30 s), the magnetic immunity and the long-term stability (on 7 days). These three indicators are assessed from data acquired during the LHC operation in 2015 and compared with those of LVDTs. PMID:26569259

  6. Magnetic-field-induced squeezing effect at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Pang, Long-Gang; Endrődi, Gergely; Petersen, Hannah

    2016-04-01

    In off-central heavy-ion collisions, quark-gluon plasma (QGP) is exposed to the strongest magnetic fields ever created in the universe. Because of the paramagnetic nature of the QGP at high temperatures, the spatially inhomogeneous magnetic field configuration exerts an anisotropic force density that competes with the pressure gradients resulting from purely geometric effects. In this paper, we simulate (3+1)-dimensional ideal hydrodynamics with external magnetic fields to estimate the effect of this force density on the anisotropic expansion of the QGP in collisions at the Relativistic Heavy Ion Collider and at the Large Hadron Collider (LHC). While negligible for quickly decaying magnetic fields, we find that long-lived fields generate a substantial force density that suppresses the momentum anisotropy of the plasma by up to 20 % at the LHC energy and also leaves its imprint on the elliptic flow v2 of charged pions.

  7. Chiral electric field in relativistic heavy-ion collisions at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Zhong, Yang; Yang, Chun-Bin; Cai, Xu; Feng, Sheng-Qin

    2016-08-01

    It has been proposed that electric fields may lead to chiral separation in quark-gluon plasma (QGP). This is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both be completely produced in off-central nuclear-nuclear collision. We use the Woods-Saxon nucleon distribution to calculate the electric field distributions of off-central collisions. The chiral electric field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. The dependence of the electric field produced by the thermal quark in the central position with different impact parameters on the proper time with different collision energies in the RHIC and LHC energy regions are studied in this paper. Supported by National Natural Science Foundation of China (11375069, 11435054, 11075061, 11221504) and Key Laboratory Foundation of Quark and Lepton Physics (Hua-Zhong Normal University)(QLPL2014P01)

  8. Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation

    SciTech Connect

    Bruce, R.; Bocian, D.; Gilardoni, S.; Jowett, J.M.; /CERN

    2009-08-01

    Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of {sup 208}Pb{sup 82+} ion operation in the LHC, with focus on the alice interaction region, and show that the expected heat load during nominal {sup 208}Pb{sup 82+} operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

  9. An e^+e^- Top Factory in a 50+50 TeV Hadron Collider Tunnel

    NASA Astrophysics Data System (ADS)

    Norem, J.; Jagger, J.; Noonan, J.; Sharma, S.; Keil, E.; Foster, G. W.; Malamud, E.; Chojnacki, E.; Winn, D.

    1997-05-01

    We have begun to look at the parameters of an e^+e^- collider in the tunnel of a 50 + 50 TeV superferric hadron collider. This machine would be an extrapolation of LEP technology. Assuming a diameter of 170 km, a maximum radiated power of 100 MW, this collider should have a maximum energy of 500 - 600 GeV (c.m.) and should be able to produce a luminosity L = 0.9 \\cdot 10^33 cm-2sec-1 at a center of mass energy of 360 GeV, (somewhat less at higher or lower energies) which would make it useful for producing top quarks or light Higgs bosons. Design problems include the very low field magnets, synchrotron radiation power, beam stability, and vacuum systems. Preliminary magnet, vacuum chamber and cooling designs will be presented along with possible construction techniques, and some costing algorithms.

  10. QCD corrections to pair production of Type III Seesaw leptons at hadron colliders

    NASA Astrophysics Data System (ADS)

    Ruiz, Richard

    2015-12-01

    If kinematically accessible, hadron collider experiments provide an ideal laboratory for the direct production of heavy lepton partners in Seesaw models. In the context of the Type III Seesaw Mechanism, the O({α}_s) rate and shape corrections are presented for the pair production of hypothetical, heavy SU(2) L triplet leptons in pp collisions at √{s} = 13, 14 and 100TeV. The next-to-leading order (NLO) K-factors span, approximately, K NLO = 1 .1 - 1 .4 for both charged current and neutral current processes over a triplet mass range m T = 100 GeV - 2 TeV. Total production cross sections exhibit a - 6 % + 5 % scale dependence at 14 TeV and ±1% at 100 TeV. The NLO differential K-factors for heavy lepton kinematics are largely flat, suggesting that na¨ıve scaling by the total K NLO is reasonably justified. The resummed transverse momentum distribution of the dilepton system is presented at leading logarithmic (LL) accuracy. The effects of resummation are large in TeV-scale dilepton systems. Discovery potential to heavy lepton pairs at 14 and 100 TeV is briefly explored: at the High-Luminosity LHC, we estimate a 4 .8 - 6 .3 σ discovery potential maximally for m T = 1 .5 - 1 .6 TeV after 3000 fb-1. With 300 (3000) fb-1, there is 2σ sensitivity up to m T = 1 .3 - 1 .4 TeV (1 .7 - 1 .8 TeV) in the individual channels. At 100 TeV and with 10 fb-1, a 5 σ discovery can be achieved for m T = 1 .4 - 1 .6 TeV. Due to the factorization properties of Drell-Yan-type systems, the fixed order and resummed calculations reduce to convolutions over tree-level quantities.

  11. Measured and simulated heavy-ion beam loss patterns at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Hermes, P. D.; Bruce, R.; Jowett, J. M.; Redaelli, S.; Salvachua Ferrando, B.; Valentino, G.; Wollmann, D.

    2016-05-01

    The Large Hadron Collider (LHC) at CERN pushes forward to new regimes in terms of beam energy and intensity. In view of the combination of very energetic and intense beams together with sensitive machine components, in particular the superconducting magnets, the LHC is equipped with a collimation system to provide protection and intercept uncontrolled beam losses. Beam losses could cause a superconducting magnet to quench, or in the worst case, damage the hardware. The collimation system, which is optimized to provide a good protection with proton beams, has shown a cleaning efficiency with heavy-ion beams which is worse by up to two orders of magnitude. The reason for this reduced cleaning efficiency is the fragmentation of heavy-ion beams into isotopes with a different mass to charge ratios because of the interaction with the collimator material. In order to ensure sufficient collimation performance in future ion runs, a detailed theoretical understanding of ion collimation is needed. The simulation of heavy-ion collimation must include processes in which 82+208Pb ions fragment into dozens of new isotopes. The ions and their fragments must be tracked inside the magnetic lattice of the LHC to determine their loss positions. This paper gives an overview of physical processes important for the description of heavy-ion loss patterns. Loss maps simulated by means of the two tools ICOSIM [1,2] and the newly developed STIER (SixTrack with Ion-Equivalent Rigidities) are compared with experimental data measured during LHC operation. The comparison shows that the tool STIER is in better agreement.

  12. Forward-backward asymmetries of lepton pairs in events with a large-transverse-momentum jet at hadron colliders.

    PubMed

    del Aguila, F; Ametller, Ll; Talavera, P

    2002-10-14

    We discuss forward-backward charge asymmetries for lepton-pair production in association with a large-transverse-momentum jet at hadron colliders. The lepton charge asymmetry relative to the jet direction A(j)(FB) gives a new determination of the effective weak mixing angle sin((2)theta(lept)(eff)(M(2)(Z)) with a statistical precision after cuts of approximately 10(-3) (8x10(-3)) at LHC (Tevatron). This is to be compared with the current uncertainty at LEP and SLD from the asymmetries alone, 2x10(-4). The identification of b jets also allows for the measurement of the bottom-quark-Z asymmetry A(b)(FB) at hadron colliders, the resulting statistical precision for sin((2)theta(lept)(eff)(M(2)(Z)) being approximately 9x10(-4) (2x10(-2) at Tevatron), also lower than the reported precision at e(+)e(-) colliders, 3x10(-4).

  13. Drag of heavy quarks in quark gluon plasma at energies available at the CERN Large Hadron Collider (LHC)

    SciTech Connect

    Das, Santosh K.; Alam, Jan-e; Mohanty, Payal

    2010-07-15

    The drag and diffusion coefficients of charm and bottom quarks propagating through quark gluon plasma (QGP) have been evaluated for conditions relevant to nuclear collisions at the Large Hadron Collider (LHC). The dead cone and Landau-Pomeronchuk-Migdal (LPM) effects on radiative energy loss of heavy quarks have been considered. Both radiative and collisional processes of energy loss are included in the effective drag and diffusion coefficients. With these effective transport coefficients, we solve the Fokker-Plank (FP) equation for the heavy quarks executing Brownian motion in the QGP. The solution of the FP equation has been used to evaluate the nuclear suppression factor, R{sub AA}, for the nonphotonic single-electron spectra resulting from the semileptonic decays of hadrons containing charm and bottom quarks. The effects of mass on R{sub AA} have also been highlighted.

  14. Technicolor corrections to bb{yields}W{sup {+-}{pi}}{sub t}{sup {+-}}at the CERN Large Hadron Collider

    SciTech Connect

    Huang Jinshu; Pan, Qunna; Song, Taiping; Lu, Gongru

    2010-07-01

    In this paper we calculate the technicolor correction to the production of a charged top pion in association with a W boson via bb annihilation at the CERN Large Hadron Collider in the context of the topcolor assisted technicolor model. We find that the cross section of pp{yields}bb{yields}W{sup {+-}{pi}}{sub t}{sup {+-}}at the tree level can reach a few hundred femtobarns for reasonable ranges of the parameters, roughly corresponding to the result of the process pp{yields}bb{yields}W{sup {+-}H{+-}}in the minimal supersymmetric standard model; the relative corrections arising from the one-loop diagrams are about a few percent to two dozen percent, and they will increase the cross section at the tree level. As a comparison, we also discuss the size of the hadron cross section via the other subprocess gg{yields}W{sup {+-}{pi}}{sub t}{sup {+-}.}

  15. Probing small parton densities in ultraperipheral A A and pA collisions at the CERN large Hadron Collider.

    PubMed

    Strikman, Mark; Vogt, Ramona; White, Sebastian

    2006-03-01

    We calculate photoproduction rates for several hard processes in ultraperipheral proton-lead and lead-lead collisions at the CERN Large Hadron Collider (LHC) with square root of sNN = 8.8 and 5.5 TeV, respectively, which could be triggered in the large LHC detectors. We use ATLAS as an example. The lead ion is treated as a source of (coherently produced) photons with energies and intensities greater than those of equivalent ep collisions at the DESY collider HERA. We find very large rates for both inclusive and diffractive production that will extend the HERA x range by nearly an order of magnitude for similar virtualities. We demonstrate that it is possible to reach the kinematic regime where nonlinear effects are larger than at HERA.

  16. The high field superferric magnet Design and test of a new dipole magnet for future hadron colliders

    NASA Astrophysics Data System (ADS)

    Colvin, John C.; Hinterberger, Henry; Russell Huson, F.; Mackay, William W.; Mann, Thomas L.; McIntyre, Peter M.; Phillips, Gerald C.; Pissanetzky, Sergio; Rocha, Richard; Schmidt, William M.; Shotzman, Garry; Wenzel, William A.; Fen Xie, Wan; Zeigler, John C.

    1988-07-01

    The Texas Accelerator Center has successfully tested a 6 T superferric dipole magnet of a design appropriate for future hadron colliders. The magnet surpassed the design field (90% of the short sample limit) on its first quench without training. The measured field quality is in excellent agreement with design calculations and meets collider requirements. The magnetic field design was developed at Rice University and is the subject of a Master's thesis. The features of the design include simple construction, efficient use of superconductor, and adequate containment of magnetic forces. A straightforward extension of the design to an 8 T dipole is under development. The high-field superferric magnet constitutes a significant improvement in magnet performance and cost for future accelerators.

  17. Four-Jet Production at the Large Hadron Collider at Next-to-Leading Order in QCD

    NASA Astrophysics Data System (ADS)

    Bern, Z.; Diana, G.; Dixon, L. J.; Cordero, F. Febres; Höche, S.; Kosower, D. A.; Ita, H.; Maître, D.; Ozeren, K.

    2012-07-01

    We present the cross sections for production of up to four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. We use the BlackHat library in conjunction with SHERPA and a recently developed algorithm for assembling primitive amplitudes into color-dressed amplitudes. We adopt the cuts used by ATLAS in their study of multijet events in pp collisions at s=7TeV. We include estimates of nonperturbative corrections and compare to ATLAS data. We store intermediate results in a framework that allows the inexpensive computation of additional results for different choices of scale or parton distributions.

  18. Searches for and identification of effects of extra spatial dimensions in dilepton and diphoton production at the Large Hadron Collider

    SciTech Connect

    Pankov, A. A. Serenkova, I. A. Tsytrinov, A. V. Bednyakov, V. A.

    2015-06-15

    Prospects of discovering and identifying effects of extra spatial dimensions in dilepton and diphoton production at the Large Hadron Collider (LHC) are studied. Such effects may be revealed by the characteristic behavior of the invariant-mass distributions of dileptons and diphotons, and their identification can be performed on the basis of an analysis of their angular distributions. The discovery and identification reaches are estimated for the scale parameter M{sub S} of the Kaluza-Klein gravitational towers, which can be determined in experiments devoted to measuring the dilepton and diphoton channels at the LHC.

  19. Four-jet production at the Large Hadron Collider at next-to-leading order in QCD.

    PubMed

    Bern, Z; Diana, G; Dixon, L J; Febres Cordero, F; Höche, S; Kosower, D A; Ita, H; Maître, D; Ozeren, K

    2012-07-27

    We present the cross sections for production of up to four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. We use the BLACKHAT library in conjunction with SHERPA and a recently developed algorithm for assembling primitive amplitudes into color-dressed amplitudes. We adopt the cuts used by ATLAS in their study of multijet events in pp collisions at √s=7 TeV. We include estimates of nonperturbative corrections and compare to ATLAS data. We store intermediate results in a framework that allows the inexpensive computation of additional results for different choices of scale or parton distributions.

  20. Large Hadron Collider at CERN: Beams generating high-energy-density matter.

    PubMed

    Tahir, N A; Schmidt, R; Shutov, A; Lomonosov, I V; Piriz, A R; Hoffmann, D H H; Deutsch, C; Fortov, V E

    2009-04-01

    This paper presents numerical simulations that have been carried out to study the thermodynamic and hydrodynamic responses of a solid copper cylindrical target that is facially irradiated along the axis by one of the two Large Hadron Collider (LHC) 7 TeV/ c proton beams. The energy deposition by protons in solid copper has been calculated using an established particle interaction and Monte Carlo code, FLUKA, which is capable of simulating all components of the particle cascades in matter, up to multi-TeV energies. These data have been used as input to a sophisticated two-dimensional hydrodynamic computer code BIG2 that has been employed to study this problem. The prime purpose of these investigations was to assess the damage caused to the equipment if the entire LHC beam is lost at a single place. The FLUKA calculations show that the energy of protons will be deposited in solid copper within about 1 m assuming constant material parameters. Nevertheless, our hydrodynamic simulations have shown that the energy deposition region will extend to a length of about 35 m over the beam duration. This is due to the fact that first few tens of bunches deposit sufficient energy that leads to high pressure that generates an outgoing radial shock wave. Shock propagation leads to continuous reduction in the density at the target center that allows the protons delivered in subsequent bunches to penetrate deeper and deeper into the target. This phenomenon has also been seen in case of heavy-ion heated targets [N. A. Tahir, A. Kozyreva, P. Spiller, D. H. H. Hoffmann, and A. Shutov, Phys. Rev. E 63, 036407 (2001)]. This effect needs to be considered in the design of a sacrificial beam stopper. These simulations have also shown that the target is severely damaged and is converted into a huge sample of high-energy density (HED) matter. In fact, the inner part of the target is transformed into a strongly coupled plasma with fairly uniform physical conditions. This work, therefore, has

  1. Full one-loop electroweak and NLO QCD corrections to the associated production of chargino and neutralino at hadron colliders

    SciTech Connect

    Sun Hao; Han Liang; Zhang Renyou; Jiang Yi; Guo Lei; Ma Wengan

    2006-03-01

    We study the process of the association production of chargino and neutralino including the next-to-leading order (NLO) QCD and the complete one-loop electroweak corrections in the framework of the minimal supersymmetric standard model at the Fermilab Tevatron and the CERN Large Hadron Collider. In both the NLO QCD and one-loop electroweak calculations we apply the algorithm of the phase-space slicing method. We find that the NLO QCD corrections generally increase the Born cross sections, while the electroweak relative corrections decrease the Born cross section in most of the chosen parameter space. The NLO QCD and electroweak relative corrections typically have the values of about 32% and -8% at the Tevatron, and about 42% and -6% at the Large Hadron Collider, respectively. The results show that both the NLO QCD and the complete one-loop electroweak corrections to the processes pp/pp{yields}{chi}-tilde{sub 1}{sup {+-}}{chi}-tilde{sub 2}{sup 0}+X are generally significant and should be taken into consideration in precision experimental analysis.

  2. Discovery and measurement of excited b hadrons at the Collider Detector at Fermilab

    SciTech Connect

    Pursley, Jennifer Marie

    2007-08-01

    This thesis presents evidence for the B**0 and Σ$(*)±\\atop{b}$ hadrons in proton-antiproton collisions at a center of mass energy of 1.96 TeV, using data collected by the Collider Detector at Fermilab. In the search for B**0 → B± π, two B± decays modes are reconstructed: B± → J/ΨK±, where J/Ψ → μ+μ-, and B± → $\\bar{D}$0π±, where $\\bar{D}$0 → K± π±. Both modes are reconstructed using 370 ± 20 pb-1 of data. Combining the B± meson with a charged pion to reconstruct B**0 led to the observation and measurement of the masses of the two narrow B**0 states, B$1\\atop{0}$ and B$*0\\atop{2}$, of m(B$1\\atop{0}$) = 5734 ± 3(stat.) ± 2(syst.) MeV/c2; m(B$*0\\atop{2}$) = 5738 ± 5(stat.) ± 1(syst.) MeV/c{sup 2}. In the search for Σ$(*)±\\atop{b}$ → Λ$0\\atop{b}$π±, the Λ$0\\atop{b}$ is reconstructed in the decay mode Λ$0\\atop{b}$ → Λ$+\\atop{c}$π-, where Λ$+\\atop{c}$→ pK- π+, using 1070 ± 60 pb-1 of data. Upon combining the Λ$0\\atop{b}$ candidate with a charged pion, all four of the Σ$(*)±\\atop{b}$ states are observed and their masses measured to be: m(Σ$+\\atop{b}$) = 5807.8$+2.0\\atop{-2.2}$(stat.) ± 1.7(syst.) MeV/c2; m(Σ$+\\atop{b}$) = 5815.2 ± 1.0(stat.) ± 1.7(syst.) MeV/c2; m(Σ$*+\\atop{b}$) = 5829.0$+1.6\\atop{-1.8}$(stat.)$+1.7\\atop{-1.8}$(syst.) MeV/c 2; M(Σ$*-±\\atop{b}$) - 5836.4 ± 2.0(stat.)$+1.8\\atop{-1.7}$(syst.) MeV/c2. This is the first observation of Σ$(*)±\\atop{b}$ baryons.

  3. Are the collective phenomena a universal feature of the hadronic matter created in p-p, p-A and A-A colliding systems?

    NASA Astrophysics Data System (ADS)

    Flores, Eleazar Cuautle

    2016-06-01

    Collective phenomena in ion-ion collisions are well-known, but the research in small systems, like proton-proton and proton-lead, is starting both from the experimental and theoretical side. In this paper, we present a short review of the most important observables related to flow, as well as phenomenological results to explain the Relativistic Heavy Ion Collider and Large Hadron Collider results. Different variables and their relations to collectivity in small systems are discussed.

  4. High Energy Colliders

    NASA Astrophysics Data System (ADS)

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

    INTRODUCTION PHYSICS CONSIDERATIONS GENERAL REQUIRED LUMINOSITY FOR LEPTON COLLIDERS THE EFFECTIVE PHYSICS ENERGIES OF HADRON COLLIDERS HADRON-HADRON MACHINES LUMINOSITY SIZE AND COST CIRCULAR e^{+}e^- MACHINES LUMINOSITY SIZE AND COST e^{+}e^- LINEAR COLLIDERS LUMINOSITY CONVENTIONAL RF SUPERCONDUCTING RF AT HIGHER ENERGIES γ - γ COLLIDERS μ ^{+} μ^- COLLIDERS ADVANTAGES AND DISADVANTAGES DESIGN STUDIES STATUS AND REQUIRED R AND D COMPARISION OF MACHINES CONCLUSIONS DISCUSSION

  5. Les Houches guidebook to Monte Carlo generators for hadron collider physics

    SciTech Connect

    Dobbs, Matt A.; Frixione, Stefano; Laenen, Eric; Tollefson, Kirsten

    2004-03-01

    Recently the collider physics community has seen significant advances in the formalisms and implementations of event generators. This review is a primer of the methods commonly used for the simulation of high energy physics events at particle colliders. We provide brief descriptions, references, and links to the specific computer codes which implement the methods. The aim is to provide an overview of the available tools, allowing the reader to ascertain which tool is best for a particular application, but also making clear the limitations of each tool.

  6. Les Houches Guidebook to Monte Carlo generators for hadron collider physics

    SciTech Connect

    Dobbs, M.A

    2004-08-24

    Recently the collider physics community has seen significant advances in the formalisms and implementations of event generators. This review is a primer of the methods commonly used for the simulation of high energy physics events at particle colliders. We provide brief descriptions, references, and links to the specific computer codes which implement the methods. The aim is to provide an overview of the available tools, allowing the reader to ascertain which tool is best for a particular application, but also making clear the limitations of each tool.

  7. W+n-jet predictions at the Large Hadron Collider at next-to-leading order matched with a parton shower.

    PubMed

    Höche, Stefan; Krauss, Frank; Schönherr, Marek; Siegert, Frank

    2013-02-01

    For the first time, differential cross sections for the production of W bosons in conjunction with up to three jets, computed at next-to leading order in QCD and including parton shower corrections, are presented and compared to recent experimental data from the Large Hadron Collider.

  8. Centrality dependence of high energy jets in p +Pb collisions at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Bzdak, Adam; Skokov, Vladimir; Bathe, Stefan

    2016-04-01

    The recently measured centrality dependence of high energy jets in proton-lead collisions at the CERN Large Hadron Collider (LHC) is investigated. We hypothesize that events with jets of very high energy (a few hundred GeV) are characterized by a suppressed number of soft particles, thus shifting these events into more peripheral bins. This naturally results in the suppression (enhancement) of the nuclear modification factor, Rp A, in central (peripheral) collisions. Our calculations suggest that a moderate suppression of the order of 20 % , for 103 GeV jets, can quantitatively reproduce the experimental data. We further extract the suppression factor as a function of jet energy and test our conjecture using available Rp A data for various centralities.

  9. CERN-RD39 collaboration activities aimed at cryogenic silicon detector application in high-luminosity Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Li, Zheng; Eremin, Vladimir; Verbitskaya, Elena; Dehning, Bernd; Sapinski, Mariusz; Bartosik, Marcin R.; Alexopoulos, Andreas; Kurfürst, Christoph; Härkönen, Jaakko

    2016-07-01

    Beam Loss Monitors (BLM) made of silicon are new devices for monitoring of radiation environment in the vicinity of superconductive magnets of the Large Hadron Collider. The challenge of BLMs is extreme radiation hardness, up to 1016 protons/cm2 while placed in superfluid helium (temperature of 1.9 K). CERN BE-BI-BL group, together with CERN-RD39 collaboration, has developed prototypes of BLMs and investigated their device physics. An overview of this development-results of the in situ radiation tests of planar silicon detectors at 1.9 K, performed in 2012 and 2014-is presented. Our main finding is that silicon detectors survive under irradiation to 1×1016 p/cm2 at 1.9 K. In order to improve charge collection, current injection into the detector sensitive region (Current Injection Detector (CID)) was tested. The results indicate that the detector signal increases while operated in CID mode.

  10. A particle consistent with the Higgs boson observed with the ATLAS detector at the Large Hadron Collider.

    PubMed

    2012-12-21

    Nearly 50 years ago, theoretical physicists proposed that a field permeates the universe and gives energy to the vacuum. This field was required to explain why some, but not all, fundamental particles have mass. Numerous precision measurements during recent decades have provided indirect support for the existence of this field, but one crucial prediction of this theory has remained unconfirmed despite 30 years of experimental searches: the existence of a massive particle, the standard model Higgs boson. The ATLAS experiment at the Large Hadron Collider at CERN has now observed the production of a new particle with a mass of 126 giga-electron volts and decay signatures consistent with those expected for the Higgs particle. This result is strong support for the standard model of particle physics, including the presence of this vacuum field. The existence and properties of the newly discovered particle may also have consequences beyond the standard model itself.

  11. Polarized window for left-right symmetry and a right-handed neutrino at the Large Hadron-Electron Collider

    NASA Astrophysics Data System (ADS)

    Mondal, Subhadeep; Rai, Santosh Kumar

    2016-01-01

    The breaking of parity, a fundamental symmetry between left and right, is best understood in the framework of left-right symmetric extension of the standard model. We show that the production of a heavy right-handed neutrino at the proposed Large Hadron-Electron Collider (LHeC) could give us the most simple and direct hint of the scale of this breaking in left-right symmetric theories. This production mode gives a lepton number violating signal with Δ L =2 which is very clean and has practically no standard model background. We highlight that the right-handed nature of WR exchange which defines the left-right symmetric theories can be confirmed by using a polarized electron beam and also enhance the production rates with relatively lower beam energy.

  12. Cryogenic testing of by-pass diode stacks for the superconducting magnets of the large hadron collider at CERN

    NASA Astrophysics Data System (ADS)

    della Corte, A.; Gharib, A.; Hagedorn, D.; Turtù, S.; Basile, G. L.; Catitti, A.; Chiarelli, S.; Di Ferdinando, E.; Taddia, G.; Talli, M.; Verdini, L.; Viola, R.

    2002-05-01

    A dedicated facility prepared by ENEA (Italian Agency for Energy and Environment) for the cryogenic testing of by-pass diodes for the protection of the CERN Large Hadron Collider main magnets will be described. This experimental activity is in the frame of a contract awarded to OCEM, an Italian firm active in the field of electronic devices and power supplies, in collaboration with ENEA, for the manufacture and testing of all the diode stacks. In particular, CERN requests the measurement of the reverse and forward voltage diode characteristics at 300 K and 77 K, and endurance test cycles at liquid helium temperature. The experimental set-up at ENEA and data acquisition system developed for the scope will be described and the test results reported.

  13. Optimising charged Higgs boson searches at the Large Hadron Collider across b b bar W± final states

    NASA Astrophysics Data System (ADS)

    Moretti, Stefano; Santos, Rui; Sharma, Pankaj

    2016-09-01

    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 b b bar W± final states, wherein the contributing channels can be H+ → t b bar , 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.

  14. Charm production in Pb + Pb collisions at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Song, Taesoo; Berrehrah, Hamza; Cabrera, Daniel; Cassing, Wolfgang; Bratkovskaya, Elena

    2016-03-01

    We study charm production in Pb +Pb collisions at √{sN N}=2.76 TeV in the parton-hadron-string-dynamics (PHSD) transport approach and the charm dynamics in the partonic and hadronic medium. The charm quarks are produced through initial binary nucleon-nucleon collisions by using the pythia event generator, taking into account the (anti-)shadowing incorporated in the eps09 package. The produced charm quarks interact with off-shell massive partons in the quark-gluon plasma and are hadronized into D mesons through coalescence or fragmentation close to the critical energy density, and then interact with hadrons in the final hadronic stage with scattering cross sections calculated in an effective Lagrangian approach with heavy-quark spin symmetry. The PHSD results show a reasonable RAA and elliptic flow of D mesons in comparison to the experimental data for Pb +Pb collisions at √{sN N}=2.76 TeV from the ALICE Collaboration. We also study the effect of temperature-dependent off-shell charm quarks in relativistic heavy-ion collisions. We find that the scattering cross sections are only moderately affected by off-shell charm degrees of freedom. However, the position of the peak of RAA for D mesons depends on the strength of the scalar partonic forces which also have an impact on the D meson elliptic flow. The comparison with experimental data on the RAA suggests that the repulsive force is weaker for off-shell charm quarks as compared to that for light quarks. Furthermore, the effects from radiative charm energy loss appear to be low compared to the collisional energy loss up to transverse momenta of ˜15 GeV/c .

  15. NLO QED contributions to top-pair production at hadron colliders

    SciTech Connect

    Hollik, W.; Kollar, M.

    2008-01-01

    Electroweak one-loop calculations for production of top-quark pairs at colliders are completed by providing the missing QED type contributions from real and virtual photons, where also effects from interference between QED and QCD contributions have to be taken into account. Moreover, photon-induced tt production is included as another partonic channel.

  16. Light-by-light scattering in ultraperipheral Pb-Pb collisions at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Kłusek-Gawenda, Mariola; Lebiedowicz, Piotr; Szczurek, Antoni

    2016-04-01

    We calculate cross sections for diphoton production in (semi)exclusive PbPb collisions, relevant for the CERN Large Hadron Collider (LHC). The calculation is based on the equivalent photon approximation in the impact parameter space. The cross sections for the elementary γ γ →γ γ subprocess are calculated including two different mechanisms. We take into account box diagrams with leptons and quarks in the loops. In addition, we consider a vector-meson dominance (VDM-Regge) contribution with virtual intermediate hadronic (vector-like) excitations of the photons. We get measurable cross sections in PbPb collisions. This opens a possibility to study the γ γ →γ γ (quasi)elastic scattering at the LHC. We present many interesting differential distributions which could be measured by the ALICE, CMS, or ATLAS Collaborations at the LHC. We study whether a separation or identification of different components (boxes, VDM-Regge) is possible. We find that the cross section for elastic γ γ scattering could be measured in the heavy-ion collisions for subprocess energies smaller than Wγ γ≈15 -20 GeV.

  17. First evidence for WW and WZ diboson production with semi-leptonic decays at a Hadron Collider

    SciTech Connect

    Haley, Joseph Glenn Biddle

    2009-06-01

    Presented is a measurement of the simultaneous production of a W± boson in association with a second weak boson (W± or Z0) in p$\\bar{p}$ collisions at √s = 1.96 TeV. Events are consider with one electron or one muon, missing transverse energy, and at least two hadronic jets. The data were collected by the D0 detector in Run IIa of the Tevatron accelerator and correspond to 1.07 fb-1 of integrated luminosity for each of the two channels (WW/WZ → evq$\\bar{q}$ and WW/WZ → μvq$\\bar{q}$). The cross section for WW + WZ production is measured to be 20.2 ± 2.5(stat) ± 3.6(sys) ± 1.2(lum) pb with a Gaussian significance of 4.4 standard deviations above the background-only scenario. This measurement is consistent with the Standard Model prediction and represents the first direct evidence for WW and WZ production with semi-leptonic decays at a hadron collider.

  18. Evidence for x -dependent proton color fluctuations in p A collisions at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Alvioli, M.; Cole, B. A.; Frankfurt, L.; Perepelitsa, D. V.; Strikman, M.

    2016-01-01

    The centrality dependence of forward jet production in p A collisions at the Large Hadron Collider (LHC) has been found to grossly violate the Glauber model prediction in a way that depends on the x in the proton. We argue that this modification pattern provides the first experimental evidence for x -dependent proton color fluctuation effects. On average, parton configurations in the projectile proton containing a parton with large x interact with a nuclear target with a significantly smaller than average cross section and have smaller than average size. We implement the effects of fluctuations of the interaction strength and, using the ATLAS analysis of how hadron production at backward rapidities depends on the number of wounded nucleons, make quantitative predictions for the centrality dependence of the jet production rate as a function of the x -dependent interaction strength σ (x ) . We find that σ (x ) ˜0.6 <σ > gives a good description of the data at x =0.6 . These findings support an explanation of the European Muon Collaboration effect as arising from the suppression of small-size nucleon configurations in the nucleus.

  19. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    The ALICE Collaboration

    2016-01-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. In this paper, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density ρμ > 5.9 m-2. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 1016 eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. The development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  20. The Quest for the Higgs Boson and the Planck Black Hole Production at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Haramein, Nassim; Rauscher, E. A.

    2003-10-01

    When the CERN 7 TeV Large Hadron Collider (LHC) comes on line in the next few years, hypothesis is that significant experimental discoveries may verify the Higgs boson and the production of short lived Planck size mini Schwarzchild black holes, both of which are fundamental to a unified particle and cosmological standard and supersymmetry model. The Higgs mechanism relates to particle mass in the standard model and the mini black holes may relate to the cosmological mini mass problem as well as yield clues as to the structure of the vacuum. These points are of particular interest to our research [1,2], and the discovery and identification of mini black holes (mbh) is basic to our scaling law model [1]. Hawking radiation from the production of mini black holes from accelerated Hadrons are expected to be observed from x- and γ-ray lepton production from subcomponents of quarks or partons. Our model [1,2] and Hawking's picture [3] may demonstrate that mbh hold basic clues about the very nature of the fabric of spacetime itself. We examine the Kerr-Newman black hole production cross section in detail at the energies of the LHC. (1) N. Haramein, Bull. Am. Phys. Soc. AB006, 1154 (2001), (2) E.A. Rauscher, lett. Nuovo Cimento 3, 661 (1972), (3) S.W. Hawking, Phys. Rev. D53, 3099 (1996).

  1. Drell-Yan process as an avenue to test a noncommutative standard model at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    J, Selvaganapathy; Das, Prasanta Kumar; Konar, Partha

    2016-06-01

    We study the Drell-Yan process at the Large Hadron Collider in the presence of the noncommutative extension of the standard model. Using the Seiberg-Witten map, we calculate the production cross section to first order in the noncommutative parameter Θμ ν . Although this idea has been evolving for a long time, only a limited amount of phenomenological analysis has been completed, and this was mostly in the context of the linear collider. An outstanding feature from this nonminimal noncommutative standard model not only modifies the couplings over the SM production channel but also allows additional nonstandard vertices which can play a significant role. Hence, in the Drell-Yan process, as studied in the present analysis, one also needs to account for the gluon fusion process at the tree level. Some of the characteristic signatures, such as oscillatory azimuthal distributions, are an outcome of the momentum-dependent effective couplings. We explore the noncommutative scale ΛNC≥0.4 TeV , considering different machine energy ranging from 7 to 13 TeV.

  2. Eventwise mean-pt fluctuations versus minimum-bias jets (minijets) at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Trainor, Thomas A.

    2015-08-01

    Fluctuation measurements of eventwise mean transverse momentum for p -p and Pb-Pb collisions at the CERN Large Hadron Collider (LHC) have been reported recently. In that study it was concluded that the strength of "nonstatistical" fluctuations decreases with increasing particle multiplicity nch (or A -A centrality) and is nearly independent of collision energy over a large interval. Among several potential mechanisms for those trends the onset of thermalization and collectivity are mentioned. The LHC analysis employed one fluctuation measure selected from several possibilities. An alternative fluctuation measure reveals a strong increase of pt fluctuations with nc h (or A -A centrality) and collision energy, consistent with previous measurements at the BNL Relativistic Heavy Ion Collider (RHIC). The pt fluctuation data for LHC p -p collisions can be described accurately by a two-component (soft +hard ) model (TCM) in which the hard component represents dijet production. The data for Pb-Pb collisions are described accurately by a TCM reference for more-peripheral collisions (suggesting transparent collisions), but the data deviate quantitatively from the reference for more-central collisions, suggesting a modification of jet formation. Overall fluctuation data trends suggest that minimum-bias jets (minijets) dominate pt fluctuations at both the LHC and the RHIC.

  3. Jet Substructure as a New Higgs-Search Channel at the Large Hadron Collider

    SciTech Connect

    Butterworth, Jonathan M.; Davison, Adam R.; Rubin, Mathieu; Salam, Gavin P.

    2008-06-20

    It is widely considered that, for Higgs boson searches at the CERN Large Hadron Colider, WH and ZH production where the Higgs boson decays to bb are poor search channels due to large backgrounds. We show that at high transverse momenta, employing state-of-the-art jet reconstruction and decomposition techniques, these processes can be recovered as promising search channels for the standard model Higgs boson around 120 GeV in mass00.

  4. Prospects for electroweakino discovery at a 100 TeV hadron collider

    NASA Astrophysics Data System (ADS)

    Gori, Stefania; Jung, Sunghoon; Wang, Lian-Tao; Wells, James D.

    2014-12-01

    We investigate the prospects of discovering split Supersymmetry at a future 100 TeV proton-proton collider through the direct production of electroweakino next-to-lightest- supersymmetric-particles (NLSPs). We focus on signatures with multi-lepton and missing energy: 3ℓ, opposite-sign dileptons and same-sign dileptons. We perform a comprehensive study of different electroweakino spectra. A 100 TeV collider with 3000 /fb data is expected to exclude Higgsino thermal dark matter candidates with m LSP ~ 1 TeV if Wino NLSPs are lighter than about 3.2 TeV. The 3ℓ search usually offers the highest mass reach, which varies in the range of (2-4) TeV depending on scenarios. In particular, scenarios with light Higgsinos have generically simplified parameter dependences. We also demonstrate that, at a 100 TeV collider, lepton collimation becomes a crucial issue for NLSPs heavier than about 2.5 TeV. We finally compare our results with the discovery prospects of gluino pair productions and deduce which SUSY breaking model can be discovered first by electroweakino searches.

  5. CONCLUSIONS OF THE WORKSHOP [Hadron Colliders at the highest energy and luminosity

    SciTech Connect

    RUGGIERO,A.G.

    1996-11-04

    During this Workshop, it was concluded that a Proton-Proton Collider with an energy of 100 TeV per beam and a luminosity of about 10{sup 35} cm{sup {minus}2} s{sup {minus}1} is feasible. The most important technical requirement for the realization of such a project is a large bending field. For instance, a field of 13 Tesla would be desirable. This is twice the field of the SSC superconducting magnets, which very likely may be achieved in a non-too-far future by extrapolation of the present technology. The design of this Collider would follow very closely the methods used for the design of the SSC and of the LHC, with the major noticeable difference that, because of the larger bending field and the larger beam energy, the performance is determined by the effects of the Synchrotron Radiation in the similar manner they affect the performance of an electron-positron collider. This fact has considerable beneficial consequences since it allows the attainment of large luminosity by reducing the beam dimensions at collision and by requiring, to some degree, less number of particles per beam. On the other end. the losses to synchrotron radiation are to be absorbed by the cryogenic system, and the vacuum system should be capable to cope with them. A more significant rf system may also be required.

  6. Associated Higgs-W-Boson Production at Hadron Colliders: A Fully Exclusive QCD Calculation at NNLO

    SciTech Connect

    Ferrera, Giancarlo; Grazzini, Massimiliano; Tramontano, Francesco

    2011-10-07

    We consider QCD radiative corrections to standard model Higgs-boson production in association with a W boson in hadron collisions. We present a fully exclusive calculation up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. To perform this NNLO computation, we use a recently proposed version of the subtraction formalism. Our calculation includes finite-width effects, the leptonic decay of the W boson with its spin correlations, and the decay of the Higgs boson into a bb pair. We present selected numerical results at the Tevatron and the LHC.

  7. Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron Centre; Kent State Univ.; Particle Physic Lab.; STAR Collaboration

    2009-01-01

    Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at {radical}s{sub NN} = 200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be {theta} = 1.37 {+-} 0.02(stat){sub -0.07}{sup +0.06} (syst), independent of p.

  8. Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Baumgart, S; Beavis, D R; Bellwied, R; Benedosso, F; Betts, R R; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Biritz, B; Bland, L C; Bombara, M; Bonner, B E; Botje, M; Bouchet, J; Braidot, E; Brandin, A V; Bruna, E; Bueltmann, S; Burton, T P; Bystersky, M; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Callner, J; Catu, O; Cebra, D; Cendejas, R; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Choi, K E; Christie, W; Chung, S U; Clarke, R F; Codrington, M J M; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Daugherity, M; De Silva, C; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; de Souza, R Derradi; Didenko, L; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, F; Dunlop, J C; Dutta Mazumdar, M R; Edwards, W R; Efimov, L G; Elhalhuli, E; Elnimr, M; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Eun, L; Fachini, P; Fatemi, R; Fedorisin, J; Feng, A; Filip, P; Finch, E; Fine, V; Fisyak, Y; Gagliardi, C A; Gaillard, L; Gangadharan, D R; Ganti, M S; Garcia-Solis, E; Ghazikhanian, V; Ghosh, P; Gorbunov, Y N; Gordon, A; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Guimaraes, K S F F; Gupta, A; Gupta, N; Guryn, W; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Heppelmann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Huang, H Z; Humanic, T J; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jin, F; Jones, P G; Joseph, J; Judd, E G; Kabana, S; Kajimoto, K; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Kettler, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kopytine, M; Kotchenda, L; Kouchpil, V; Kravtsov, P; Kravtsov, V I; Krueger, K; Krus, M; Kuhn, C; Kumar, L; Kurnadi, P; Lamont, M A C; Landgraf, J M; Lapointe, S; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Levine, M J; Li, C; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, Y G; Mahapatra, D P; Majka, R; Mall, O I; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Matis, H S; Matulenko, Yu A; McShane, T S; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mischke, A; Mitchell, J; Mohanty, B; Molnar, L; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, C; Netrakanti, P K; Ng, M J; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okada, H; Okorokov, V; Olson, D; Pachr, M; Page, B S; Pal, S K; Pandit, Y; Panebratsev, Y; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Planinic, M; Pluta, J; Poljak, N; Poskanzer, A M; Potukuchi, B V K S; Prindle, D; Pruneau, C; Pruthi, N K; Putschke, J; Raniwala, R; Raniwala, S; Ray, R L; Reed, R; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Rykov, V; Sahoo, R; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shi, S S; Shi, X-H; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Staszak, D; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thein, D; Thomas, J H; Tian, J; Timmins, A R; Timoshenko, S; Tlusty, D; Tokarev, M; Trainor, T A; Tram, V N; Trattner, A L; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van Leeuwen, M; Vander Molen, A M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasilevski, I M; Vasiliev, A N; Videbaek, F; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, Q; Wang, X; Wang, X L; Wang, Y; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, Y; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yepes, P; Yoo, I-K; Yue, Q; Zawisza, M; Zbroszczyk, H; Zhan, W; Zhang, H; Zhang, S; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zhou, J; Zoulkarneev, R; Zoulkarneeva, Y; Zuo, J X

    2009-02-01

    Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}. PMID:19257508

  9. Measurement of Hadronic Event Shapes and Jet Substructure in Proton-Proton Collisions at 7.0 TeV Center-of-Mass Energy with the ATLAS Detector at the Large Hadron Collider

    SciTech Connect

    Miller, David Wilkins

    2012-03-20

    This thesis presents the first measurement of 6 hadronic event shapes in proton-proton collisions at a center-of-mass energy of {radical}s = 7 TeV using the ATLAS detector at the Large Hadron Collider. Results are presented at the particle-level, permitting comparisons to multiple Monte Carlo event generator tools. Numerous tools and techniques that enable detailed analysis of the hadronic final state at high luminosity are described. The approaches presented utilize the dual strengths of the ATLAS calorimeter and tracking systems to provide high resolution and robust measurements of the hadronic jets that constitute both a background and a signal throughout ATLAS physics analyses. The study of the hadronic final state is then extended to jet substructure, where the energy flow and topology within individual jets is studied at the detector level and techniques for estimating systematic uncertainties for such measurements are commissioned in the first data. These first substructure measurements in ATLAS include the jet mass and sub-jet multiplicity as well as those concerned with multi-body hadronic decays and color flow within jets. Finally, the first boosted hadronic object observed at the LHC - the decay of the top quark to a single jet - is presented.

  10. First observation of vector boson pairs in a hadronic final state at the tevatron collider.

    PubMed

    Aaltonen, T; Adelman, J; Akimoto, T; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burke, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Chwalek, T; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cordelli, M; Cortiana, G; Cox, C A; Cox, D J; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; Di Canto, A; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Garosi, P; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, S W; Leone, S; Lewis, J D; Lin, C-S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lucchesi, D; Luci, C; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Nett, J; Neu, C; Neubauer, M S; Neubauer, S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Griso, S Pagan; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Peiffer, T; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Renz, M; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Rutherford, B; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Trovato, M; Tsai, S-Y; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Wagner, P; Wagner, R G; Wagner, R L; Wagner, W; Wagner-Kuhr, J; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Weinelt, J; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Würthwein, F; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; 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; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zhang, X; Zheng, Y; Zucchelli, S

    2009-08-28

    We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V = W, Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb(-1) of integrated luminosity of pp[over ] collisions at sqrt[s] = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516 + or - 239(stat) + or - 144(syst) diboson candidate events and measure a cross section sigma(pp[over ]-->VV + X) of 18.0 + or - 2.8(stat) + or - 2.4(syst) + or -1.1(lumi) pb, in agreement with the expectations of the standard model.

  11. First Observation of Vector Boson Pairs in a Hadronic Final State at the Tevatron Collider

    SciTech Connect

    Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-05-01

    We present the first observation in hadronic collisions of the electroweak production of vector boson pairs (VV, V = W,Z) where one boson decays to a dijet final state. The data correspond to 3.5 fb{sup -1} of integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron. We observe 1516 {+-} 239(stat) {+-} 144(syst) diboson candidate events and measure a cross section {sigma}(p{bar p} {yields} VV + X) of 18.0 {+-} 2.8(stat) {+-} 2.4(syst) {+-} 1.1(lumi) pb, in agreement with the expectations of the standard model.

  12. Top++: A program for the calculation of the top-pair cross-section at hadron colliders

    NASA Astrophysics Data System (ADS)

    Czakon, Michał; Mitov, Alexander

    2014-11-01

    We present the program Top++ for the numerical evaluation of the total inclusive cross-section for producing top quark pairs at hadron colliders. The program calculates the cross-section in (a) fixed order approach with exact next-to-next-to leading order (NNLO) accuracy and (b) by including soft-gluon resummation for the hadronic cross-section in Mellin space with full next-to-next-to-leading logarithmic (NNLL) accuracy. The program offers the user significant flexibility through the large number (29) of available options. Top++ is written in C++. It has a very simple to use interface that is intuitive and directly reflects the physics. The running of the program requires no programming experience from the user. Catalogue identifier: AETR_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETR_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 15 896 No. of bytes in distributed program, including test data, etc.: 695 919 Distribution format: tar.gz Programming language: C++. Computer: any running a unix operating system. Program was developed and tested with GNU Compiler Collection, C++ compiler. Operating system: Linux; Mac OS X; can be adapted for other unix systems. RAM: typically less than 200 MB. Classification: 11.1. External routines: GNU Scientific Library (GSL); the Les Houches Accord pdf Interface (LHAPDF). Nature of problem: computation of the total cross-section in perturbative QCD. Solution method: numerical integration of the product of hard partonic cross-section (with or without soft gluon resummation) with two parton distribution functions. Additional comments: sub per-mill accuracy achievable in realistic time (program does not employ Monte Carlo methods). Running time: depending on the options. The program is optimized for speed.

  13. Study of cosmic ray events with high muon multiplicity using the ALICE detector at the CERN Large Hadron Collider

    SciTech Connect

    Collaboration: ALICE Collaboration

    2016-01-01

    ALICE is one of four large experiments at the CERN Large Hadron Collider near Geneva, specially designed to study particle production in ultra-relativistic heavy-ion collisions. Located 52 meters underground with 28 meters of overburden rock, it has also been used to detect muons produced by cosmic ray interactions in the upper atmosphere. In this paper, we present the multiplicity distribution of these atmospheric muons and its comparison with Monte Carlo simulations. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density ρ{sub μ} > 5.9 m{sup −2}. Similar events have been studied in previous underground experiments such as ALEPH and DELPHI at LEP. While these experiments were able to reproduce the measured muon multiplicity distribution with Monte Carlo simulations at low and intermediate multiplicities, their simulations failed to describe the frequency of the highest multiplicity events. In this work we show that the high multiplicity events observed in ALICE stem from primary cosmic rays with energies above 10{sup 16} eV and that the frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic rays in this energy range. The development of the resulting air showers was simulated using the latest version of QGSJET to model hadronic interactions. This observation places significant constraints on alternative, more exotic, production mechanisms for these events.

  14. Design considerations for the semi-digital hadronic calorimeter (SDHCAL) for future leptonic colliders

    NASA Astrophysics Data System (ADS)

    Pingault, A.

    2016-07-01

    The first technological SDHCAL prototype having been successfully tested, a new phase of R&D, to validate completely the SDHCAL option for the International Linear Detector (ILD) project of the International Linear Collider (ILC), has started with the conception and the realisation of a new prototype. The new one is intended to host few but large active layers of the future SDHCAL. The new active layers, made of Glass Resistive Plate Chambers (GRPC) with sizes larger than 2 m2 will be equipped with a new version of the electronic readout, fulfilling the requirements of the future ILD detector. The new GRPC are conceived to improve the homogeneity with a new gas distribution scheme. Finally the mechanical structure will be achieved using the electron beam welding technique. The progress realised will be presented and future steps will be discussed.

  15. Charm and bottom production in inclusive double Pomeron exchange in heavy-ion collisions at energies available at the CERN Large Hadron Collider

    SciTech Connect

    Gay Ducati, M. B.; Machado, M. M.; Machado, M. V. T.

    2011-01-15

    The inclusive double Pomeron exchange cross section for heavy-quark pair production is calculated for nucleus-nucleus collisions at the Large Hadron Collider. The present estimate is based on hard diffractive factorization, corrected by absorptive corrections and nuclear effects. The theoretical uncertainties for nuclear collisions are investigated and a comparison to other approaches is presented. The production channels giving a similar final state configuration are discussed as well.

  16. Kaluza-Klein gluon + jets associated production at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Iyer, A. M.; Mahmoudi, F.; Manglani, N.; Sridhar, K.

    2016-08-01

    The Kaluza-Klein excitations of gluons offer the exciting possibility of probing bulk Randall-Sundrum (RS) models. In these bulk models either a custodial symmetry or a deformation of the metric away from AdS is invoked in order to deal with electroweak precision tests. Addressing both these models, we suggest a new channel in which to study the production of KK-gluons (gKK): one where it is produced in association with one or more hard jets. The cross-section for the gKK + jets channel is significant because of several contributing sub-processes. In particular, the 1-jet and the 2-jet associated processes are important because at these orders in QCD the qg and the gg initial states respectively come into play. We have performed a hadron-level simulation of the signal and present strategies to effectively extract the signal from what could potentially be a huge background. We present results for the kinematic reach of the LHC Run-II for different gKK masses in bulk-RS models.

  17. Integrated analysis of particle interactions at hadron colliders Report of research activities in 2010-2015

    SciTech Connect

    Nadolsky, Pavel M.

    2015-08-31

    The report summarizes research activities of the project ”Integrated analysis of particle interactions” at Southern Methodist University, funded by 2010 DOE Early Career Research Award DE-SC0003870. The goal of the project is to provide state-of-the-art predictions in quantum chromodynamics in order to achieve objectives of the LHC program for studies of electroweak symmetry breaking and new physics searches. We published 19 journal papers focusing on in-depth studies of proton structure and integration of advanced calculations from different areas of particle phenomenology: multi-loop calculations, accurate long-distance hadronic functions, and precise numerical programs. Methods for factorization of QCD cross sections were advanced in order to develop new generations of CTEQ parton distribution functions (PDFs), CT10 and CT14. These distributions provide the core theoretical input for multi-loop perturbative calculations by LHC experimental collaborations. A novel ”PDF meta-analysis” technique was invented to streamline applications of PDFs in numerous LHC simulations and to combine PDFs from various groups using multivariate stochastic sampling of PDF parameters. The meta-analysis will help to bring the LHC perturbative calculations to the new level of accuracy, while reducing computational efforts. The work on parton distributions was complemented by development of advanced perturbative techniques to predict observables dependent on several momentum scales, including production of massive quarks and transverse momentum resummation at the next-to-next-to-leading order in QCD.

  18. Double vector meson production in γ γ interactions at hadronic colliders

    NASA Astrophysics Data System (ADS)

    Gonçalves, V. P.; Moreira, B. D.; Navarra, F. S.

    2016-03-01

    In this paper we revisit the double vector meson production in γ γ interactions at heavy ion collisions and present, by the first time, predictions for the ρ ρ and J/Ψ J/Ψ production in proton-nucleus and proton-proton collisions. In order to obtain realistic predictions for rapidity distributions and total cross sections for the double vector production in ultra peripheral hadronic collisions we take into account the description of γ γ → VV cross section at low energies as well as its behavior at large energies, associated to the gluonic interaction between the color dipoles. Our results demonstrate that the double ρ production is dominated by the low energy behavior of the γ γ → VV cross section. In contrast, for the double J/Ψ production, the contribution associated to the description of the QCD dynamics at high energies contributes significantly, mainly in pp collisions. Predictions for the RHIC, LHC, FCC, and CEPC-SPPC energies are shown.

  19. Sources of machine-induced background in the ATLAS and CMS detectors at the CERN Large Hadron Collider

    SciTech Connect

    Bruce, R.; et al.,

    2013-11-21

    One source of experimental background in the CERN Large Hadron Collider (LHC) is particles entering the detectors from the machine. These particles are created in cascades, caused by upstream interactions of beam protons with residual gas molecules or collimators. We estimate the losses on the collimators with SixTrack and simulate the showers with FLUKA and MARS to obtain the flux and distribution of particles entering the ATLAS and CMS detectors. We consider some machine configurations used in the first LHC run, with focus on 3.5 TeV operation as in 2011. Results from FLUKA and MARS are compared and a very good agreement is found. An analysis of logged LHC data provides, for different processes, absolute beam loss rates, which are used together with further simulations of vacuum conditions to normalize the results to rates of particles entering the detectors. We assess the relative importance of background from elastic and inelastic beam-gas interactions, and the leakage out of the LHC collimation system, and show that beam-gas interactions are the dominating source of machine-induced background for the studied machine scenarios. Our results serve as a starting point for the experiments to perform further simulations in order to estimate the resulting signals in the detectors.

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

    NASA Astrophysics Data System (ADS)

    Sammut, Nicholas J.; Bottura, Luca; Bauer, Pierre; Velev, George; Pieloni, Tatiana; Micallef, Joseph

    2007-08-01

    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.

  1. W- and Z-boson production with a massive bottom-quark pair at the Large Hadron Collider

    SciTech Connect

    Cordero, F. Febres; Reina, L.; Wackeroth, D.

    2009-08-01

    We present total and differential cross sections for Wbb and Zbb production at the CERN Large Hadron Collider with a center-of-mass energy of {radical}(s)=14 TeV, including next-to-leading order (NLO) QCD corrections and full bottom-quark mass effects. We also provide numerical results obtained with a center-of-mass energy of {radical}(s)=10 TeV. We study the scale uncertainty of the total cross sections due to the residual renormalization- and factorization-scale dependence of the truncated perturbative series. While in the case of Zbb production the scale uncertainty of the total cross section is reduced by NLO QCD corrections, the Wbb production process at NLO in QCD still suffers from large scale uncertainties, in particular, in the inclusive case. We also perform a detailed comparison with a calculation that considers massless bottom quarks, as implemented in the Monte Carlo program MCFM. The effects of a nonzero bottom-quark mass (m{sub b}) cannot be neglected in phase-space regions where the relevant kinematic observable, such as the transverse-momentum of the bottom quarks or the invariant-mass of the bottom-quark pair, are of the order of m{sub b}. The effects on the total production cross sections are usually smaller than the residual scale uncertainty at NLO in QCD.

  2. Thermomechanical assessment of the effects of a jaw-beam angle during beam impact on Large Hadron Collider collimators

    NASA Astrophysics Data System (ADS)

    Cauchi, Marija; Assmann, R. W.; Bertarelli, A.; Carra, F.; Lari, L.; Rossi, A.; Mollicone, P.; Sammut, N.

    2015-02-01

    The correct functioning of a collimation system is crucial to safely and successfully operate high-energy particle accelerators, such as the Large Hadron Collider (LHC). However, the requirements to handle high-intensity beams can be demanding, and accident scenarios must be well studied in order to assess if the collimator design is robust against possible error scenarios. One of the catastrophic, though not very probable, accident scenarios identified within the LHC is an asynchronous beam dump. In this case, one (or more) of the 15 precharged kicker circuits fires out of time with the abort gap, spraying beam pulses onto LHC machine elements before the machine protection system can fire the remaining kicker circuits and bring the beam to the dump. If a proton bunch directly hits a collimator during such an event, severe beam-induced damage such as magnet quenches and other equipment damage might result, with consequent downtime for the machine. This study investigates a number of newly defined jaw error cases, which include angular misalignment errors of the collimator jaw. A numerical finite element method approach is presented in order to precisely evaluate the thermomechanical response of tertiary collimators to beam impact. We identify the most critical and interesting cases, and show that a tilt of the jaw can actually mitigate the effect of an asynchronous dump on the collimators. Relevant collimator damage limits are taken into account, with the aim to identify optimal operational conditions for the LHC.

  3. (Calorimeter based detectors for high energy hadron colliders). [State Univ. of New York

    SciTech Connect

    Not Available

    1992-08-04

    This document provides a progress report on research that has been conducted under DOE Grant DEFG0292ER40697 for the past year, and describes proposed work for the second year of this 8 year grant starting November 15, 1992. Personnel supported by the contract include 4 faculty, 1 research faculty, 4 postdocs, and 9 graduate students. The work under this grant has in the past been directed in two complementary directions -- DO at Fermilab, and the second SSC detector GEM. A major effort has been towards the construction and commissioning of the new Fermilab Collider detector DO, including design, construction, testing, the commissioning of the central tracking and the central calorimeters. The first DO run is now underway, with data taking and analysis of the first events. Trigger algorithms, data acquisition, calibration of tracking and calorimetry, data scanning and analysis, and planning for future upgrades of the DO detector with the advent of the FNAL Main Injector are all involved. The other effort supported by this grant has been towards the design of GEM, a large and general-purpose SSC detector with special emphasis on accurate muon measurement over a large solid angle. This effort will culminate this year in the presentation to the SSC laboratory of the GEM Technical Design Report. Contributions are being made to the detector design, coordination, and physics simulation studies with special emphasis on muon final states. Collaboration with the RD5 group at CERN to study muon punch through and to test cathode strip chamber prototypes was begun.

  4. Reliability of Beam Loss Monitors System for the Large Hadron Collider

    SciTech Connect

    Guaglio, G.; Dehning, B.; Santoni, C.

    2004-11-10

    The employment of superconducting magnets in high energy colliders opens challenging failure scenarios and brings new criticalities for the whole system protection. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particle losses, while at medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standard databases. All the data have been processed by reliability software (Isograph). The analysis ranges from the components data to the system configuration.

  5. Z{prime} phenomenology: Constraints from low-energy measurements, and detailed study at TeV-scale lepton and hadron colliders

    SciTech Connect

    Austern, M.H.

    1994-05-01

    In this dissertation, I discuss the phenomenology of new massive neutral gauge bosons, or Z{prime} bosons, concentrating on experimental tests by which the properties of a Z{prime} boson could be determined. In Chapter I, I briefly review the Standard Model of elementary particle physics, and discuss the motivation for extending it. I review some of the extensions to the Standard Model that predict the existence of Z{prime} bosons, and present a general, model-independent parameterization of the Z{prime}s properties, as well as a simpler parameterization that applies to the most important class of models. In Chapter II, I discuss present-day limits on the existence of Z{prime} bosons, both from direct searches, and from indirect higher-order tests. In Chapter III, I discuss the production and discovery of a Z{prime} at a future hadron collider, such as the CERN Large Hadron Collider (LHC). Discovery of a Z{prime} at the LHC may be possible if its mass is less than 5 TeV. I also discuss the experimental tests of its properties that could be performed at such a collider, emphasizing the measurement of leptonic asymmetries. Finally, the Chapter IV, I discuss the experimental tests that could be performed at an e{sup +}e{sup {minus}} collider with {radical}s = M{sub Z{prime}}. I include several higher-order effects, such as initial-state radiation and beamstrahlung, whose inclusion is necesary for a realistic description of the experimental environment at a very high energy e{sup +}e{sup {minus}} collider. The combination of leptonic and hadronic experiments permits the measurement of all of the parameters.

  6. Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Tahir, N. A.; Sancho, J. Blanco; Shutov, A.; Schmidt, R.; Piriz, A. R.

    2012-05-01

    The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%-20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect). It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials) at CERN using the proton beam from the Super Proton Synchrotron (SPS), to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle energy in the SPS beam is 440

  7. A study on dual readout crystal calorimeter for hadron and jet energy measurement at a future lepton collider

    SciTech Connect

    Yeh, G.P.; /Fermilab

    2010-01-01

    Studies of requirements and specifications of crystals are necessary to develop a new generation of crystals for dual readout crystal hadron or total absorption calorimeter. This is a short and basic study of the characteristics and hadron energy measurement of PbWO4 and BGO crystals for scintillation and Cerenkov Dual Readout hadron calorimeter.

  8. Mass and Spin Measurement Techniques (for the Large Hadron Collider):. Lectures Given at TASI 2011, Boulder, Colorado

    NASA Astrophysics Data System (ADS)

    Lester, Christopher G.

    2013-12-01

    For TASI 2011, I was asked to give a series of lectures on "Mass and Spin Measurement Techniques" with relevance to the Large Hadron Collider. This document provides a written record of those lectures - or more precisely of what I said while giving the lectures - warts and all. It is provided as my contribution to the proceedings primarily for the benefit of those who heard the lectures first hand and may wish to refer back to them. What it is not is a scientific paper or a teaching resource. Though lecture slides may be prepared in advance, what is actually said in a lecture is usually extemporaneous, may be partial, can be influenced by audience reaction, and may not even make sense without a visual record of the concomitant gesticulations of the lecturer. More worryingly, some of the statements made may be down-right false, if the lecturer's tongue is in a twist. Accordingly, these proceedings are provided without warranty of any kind - not least in respect of accuracy or impartiality. The lectures were intended to engage the audience and get them thinking about a number of topics that they had not seen before. They were not expected to be the sort of sombre or well-balanced overview of the field that one might hope to achive in a review. These proceedings are provided to jog the memory of those who saw the lectures first hand, and for little other purpose. Footnotes, where they appear, indicate text/thoughts I have added during the editing process that were not voiced during the lectures themselves. Copies of the lecture slides are inserted at approximately the locations they would have become visible in the lectures.

  9. Mono-jet, -photon and - Z signals of a supersymmetric ( B - L) model at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Abdallah, W.; Fiaschi, J.; Khalil, S.; Moretti, S.

    2016-02-01

    Search for invisible final states produced at the Large Hadron Collider (LHC) by new physics scenarios are normally carried out resorting to a variety of probes emerging from the initial state, in the form of single-jet, -photon and - Z boson signatures. These are particularly effective for models of Supersymmetry (SUSY) in presence of R-parity conservation, owing to the presence in their spectra of a stable neutralino as a Dark Matter (DM) candidate. We assume here as theoretical framework the Supersymmetric version of the ( B - L) extension of the Standard Model (BLSSM), wherein a mediator for invisible decays can be the Z ' boson present in this scenario. The peculiarity of the signal is thus that the final state objects carry a very large (transverse) missing energy, since the Z ' is naturally massive and constrained by direct searches and Electro-Weak Precision Tests (EWPTs) to be at least in the TeV scale region. Under these circumstances the efficiency in accessing the invisible final state and rejecting the Standard Model (SM) background is very high. This somehow compensates the rather meagre production rates. Another special feature of this invisible BLSSM signal is its composition, which is often dominated by sneutrino decays (alongside the more traditional neutrino and neutralino modes). Sensitivity of the CERN machine to these two features can therefore help disentangling the BLSSM from more popular SUSY models. We assess in this analysis the scope of the LHC in establishing the aforementioned invisible signals through a sophisticated signal-to-background simulation carried out in presence of parton shower, hadronisation as well as detector effects. We find that significant sensitivity exists already after 300 fb-1 during Run 2. We find that mono-jet events can be readily accessible at the LHC, so as to enable one to claim a prompt discovery, while mono-photon and - Z signals can be used as diagnostic tools of the underlying scenario.

  10. Muon colliders

    SciTech Connect

    Palmer, R.B. |; Sessler, A.; Skrinsky, A.

    1996-01-01

    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 {micro}{sup +}{micro}{sup {minus}}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. Problems of detector background are also discussed.

  11. Top Quark Pair Production in Association with a Jet with Next-to-Leading-Order QCD Off-Shell Effects at the Large Hadron Collider.

    PubMed

    Bevilacqua, G; Hartanto, H B; Kraus, M; Worek, M

    2016-02-01

    We present a complete description of top quark pair production in association with a jet in the dilepton channel. Our calculation is accurate to next-to-leading order (NLO) in QCD and includes all nonresonant diagrams, interferences, and off-shell effects of the top quark. Moreover, nonresonant and off-shell effects due to the finite W gauge boson width are taken into account. This calculation constitutes the first fully realistic NLO computation for top quark pair production with a final state jet in hadronic collisions. Numerical results for differential distributions as well as total cross sections are presented for the Large Hadron Collider at 8 TeV. With our inclusive cuts, NLO predictions reduce the unphysical scale dependence by more than a factor of 3 and lower the total rate by about 13% compared to leading-order QCD predictions. In addition, the size of the top quark off-shell effects is estimated to be below 2%.

  12. Strong and Electroweak Corrections to the Production of a Higgs Boson+2 Jets via Weak Interactions at the Large Hadron Collider

    SciTech Connect

    Ciccolini, M.; Denner, A.; Dittmaier, S.

    2007-10-19

    Radiative corrections of strong and electroweak interactions are presented at next-to-leading order for the production of a Higgs boson plus two hard jets via weak interactions at the CERN Large Hadron Collider. The calculation includes all weak-boson fusion and quark-antiquark annihilation diagrams as well as the corresponding interferences. The electroweak corrections, which are discussed here for the first time, reduce the cross sections by 5% and thus are of the same order of magnitude as the QCD corrections.

  13. Shadowing effects on J /ψ and Υ production at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Vogt, R.

    2015-09-01

    Background: Proton-nucleus collisions have been used as a intermediate baseline for the determination of cold-medium effects. They lie between proton-proton collisions in vacuum and nucleus-nucleus collisions which are expected to be dominated by hot-matter effects. Modifications of the quark densities in nuclei relative to those of the proton are well established, although those of the gluons in the nucleus are not well understood. The effect of these modifications on quarkonium production are studied in proton-lead collisions at the CERN Large Hadron Collider (LHC) at a center-of-mass energy of 5.02 TeV. Purpose: The possibility of whether the LHC proton-lead data can be described by nuclear modifications of the parton densities, referred to as shadowing, alone is examined. The results are compared to the nuclear modification factor and to the forward-backward ratio, as a function of both transverse momentum, pT, and rapidity, y . Methods: The color evaporation model of quarkonium production is employed at next-to-leading order (NLO) in the total cross section and leading order in the transverse momentum dependence. The EPS09 NLO modifications are used as a standard of comparison. The effect of the proton parton density and the choice of shadowing parametrization on the pT and rapidity dependence of the result is studied. The consistency of the shadowing calculations at LO and NLO are checked. The size of the mass and scale uncertainties relative to the uncertainty on the shadowing parametrization is also investigated. Finally, whether the expected cold-matter effect in nucleus-nucleus collisions can be modeled as the product of proton-nucleus results at forward and backward rapidity is studied. Results: The rapidity and pT dependence of the nuclear modification factor is found to be generally consistent with the NLO calculations in the color evaporation model. The forward-backward ratio is more difficult to describe with shadowing alone. The LO and NLO

  14. Probing triple-Higgs productions via 4b2γ decay channel at a 100 TeV hadron collider

    DOE PAGES

    Chen, Chien-Yi; Yan, Qi-Shu; Zhao, Xiaoran; Zhao, Zhijie; Zhong, Yi-Ming

    2016-01-11

    We report that the quartic self-coupling of the Standard Model Higgs boson can only be measured by observing the triple-Higgs production process, but it is challenging for the LHC Run 2 or International Linear Collider (ILC) at a few TeV because of its extremely small production rate. In this paper, we present a detailed Monte Carlo simulation study of the triple-Higgs production through gluon fusion at a 100 TeV hadron collider and explore the feasibility of observing this production mode. We focus on the decay channel HHH →more » $$b\\bar{b}$$$$b\\bar{b}$$γγ, investigating detector effects and optimizing the kinematic cuts to discriminate the signal from the backgrounds. Our study shows that, in order to observe the Standard Model triple-Higgs signal, the integrated luminosity of a 100 TeV hadron collider should be greater than 1.8×104 ab₋1. We also explore the dependence of the cross section upon the trilinear (λ3) and quartic (λ4) self-couplings of the Higgs. Ultimately, we find that, through a search in the triple-Higgs production, the parameters λ3 and λ4 can be restricted to the ranges [₋1,5] and [₋20,30], respectively. We also examine how new physics can change the production rate of triple-Higgs events. For example, in the singlet extension of the Standard Model, we find that the triple-Higgs production rate can be increased by a factor of O(10).« less

  15. Measurement of very forward neutron energy spectra for 7 TeV proton-proton collisions at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Adriani, O.; Berti, E.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Del Prete, M.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Kawade, K.; Makino, Y.; Masuda, K.; Matsubayashi, E.; Menjo, H.; Mitsuka, G.; Muraki, Y.; Okuno, Y.; Papini, P.; Perrot, A.-L.; Ricciarini, S.; Sako, T.; Sakurai, N.; Sugiura, Y.; Suzuki, T.; Tamura, T.; Tiberio, A.; Torii, S.; Tricomi, A.; Turner, W. C.; Zhou, Q. D.

    2015-11-01

    The Large Hadron Collider forward (LHCf) experiment is designed to use the LHC to verify the hadronic-interaction models used in cosmic-ray physics. Forward baryon production is one of the crucial points to understand the development of cosmic-ray showers. We report the neutron-energy spectra for LHC √{ s} = 7 TeV proton-proton collisions with the pseudo-rapidity η ranging from 8.81 to 8.99, from 8.99 to 9.22, and from 10.76 to infinity. The measured energy spectra obtained from the two independent calorimeters of Arm1 and Arm2 show the same characteristic feature before unfolding the detector responses. We unfolded the measured spectra by using the multidimensional unfolding method based on Bayesian theory, and the unfolded spectra were compared with current hadronic-interaction models. The QGSJET II-03 model predicts a high neutron production rate at the highest pseudo-rapidity range similar to our results, and the DPMJET 3.04 model describes our results well at the lower pseudo-rapidity ranges. However, no model perfectly explains the experimental results over the entire pseudo-rapidity range. The experimental data indicate a more abundant neutron production rate relative to the photon production than any model predictions studied here.

  16. Thermalization, evolution, and observables at energies available at the CERN Large Hadron Collider in an integrated hydrokinetic model of A +A collisions

    NASA Astrophysics Data System (ADS)

    Naboka, V. Yu.; Karpenko, Iu. A.; Sinyukov, Yu. M.

    2016-02-01

    A further development of the evolutionary picture of A +A collisions, which we call the integrated hydrokinetic model (iHKM), is proposed. The model comprises a generator of the initial state GLISSANDO, prethermal dynamics of A +A collisions leading to thermalization, subsequent relativistic viscous hydrodynamic expansion of quark-gluon and hadron medium (vHLLE), its particlization, and finally the hadronic cascade ultrarelativistic QMD. We calculate midrapidity charged-particle multiplicities, pion, kaon, and antiproton spectra, charged-particle elliptic flows, and pion interferometry radii for Pb + Pb collisions at the energies available at the CERN Large Hadron Collider, √{s }=2.76 TeV, at different centralities. We find that the best description of the experimental data is reached when the initial states are attributed to the very small initial time 0.1 fm/c , the prethermal stage (thermalization process) lasts at least until 1 fm/c , and the shear viscosity at the hydrodynamic stage of the matter evolution has its minimal value, η /s =1/4 π . At the same time it is observed that the various momentum anisotropies of the initial states, different initial and relaxation times, as well as even a treatment of the prethermal stage within just viscous or ideal hydrodynamic approach, lead sometimes to worse but nevertheless similar results if the normalization of maximal initial energy density in most central events is adjusted to reproduce the final hadron multiplicity in each scenario. This can explain a good enough data description in numerous variants of hybrid models without a prethermal stage when the initial energy densities are defined up to a common factor.

  17. Confronting fragmentation function universality with single hadron inclusive production at HERA and e{sup +}e{sup -} colliders

    SciTech Connect

    Albino, S.; Kniehl, B. A.; Kramer, G.; Sandoval, C.

    2007-02-01

    Predictions for light charged hadron production data in the current fragmentation region of deeply inelastic scattering from the H1 and ZEUS experiments are calculated using perturbative quantum chromodynamics at next-to-leading order, and using fragmentation functions obtained by fitting to similar data from e{sup +}e{sup -} reactions. General good agreement is found when the magnitude Q{sup 2} of the hard photon's virtuality is sufficiently large. The discrepancy at low Q and small scaled momentum x{sub p} is reduced by incorporating mass effects of the detected hadron. By performing quark tagging, the contributions to the overall fragmentation from the various quark flavours in the ep reactions are studied and compared to the contributions in e{sup +}e{sup -} reactions. The yields of the various hadron species are also calculated.

  18. Entropy production in chemically nonequilibrium quark-gluon plasma created in central Pb +Pb collisions at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Vovchenko, V.; Gorenstein, M. I.; Satarov, L. M.; Mishustin, I. N.; Csernai, L. P.; Kisel, I.; Stöcker, H.

    2016-01-01

    We study the possibility that partonic matter produced at an early stage of ultrarelativistic heavy-ion collisions is out of chemical equilibrium. It is assumed that initially this matter is mostly composed of gluons, but quarks and antiquarks are produced at later times. The dynamical evolution of partonic system is described by the Bjorken-like ideal hydrodynamics with a time-dependent quark fugacity. The results of this model are compared with those obtained by assuming the complete chemical equilibrium of partons already at the initial stage. It is shown that in a chemically nonequilibrium scenario the entropy gradually increases, and about 25% of the total final entropy is generated during the hydrodynamic evolution of deconfined matter. We argue that the (anti)quark suppression included in this approach may be responsible for reduced (anti)baryon-to-meson ratios observed in heavy-ion collisions at energies available at the CERN Large Hadron Collider.

  19. Using single top rapidity to measure V{sub td}, V{sub ts}, V{sub tb} at hadron colliders

    SciTech Connect

    Aguilar-Saavedra, J. A.; Onofre, A.

    2011-04-01

    Single top production processes are usually regarded as the ones in which V{sub tb} can be directly measured at hadron colliders. We show that the analysis of the single top rapidity distribution in t-channel and tW production can also set direct limits on V{sub td}. At LHC with 10 fb{sup -1} at 14 TeV, the combined limits on V{sub td} may be reduced by almost a factor of 2 when the top rapidity distribution is used. This also implies that the limits on V{sub tb} can also be reduced by 15%, since both parameters, as well as V{sub ts}, must be simultaneously obtained from a global fit to data. At Tevatron, the exploitation of this distribution would require very high statistics.

  20. Results of a higgs boson searches in the ATLAS and CMS experiments at the large hadron collider at energies 7 and 8 TeV

    NASA Astrophysics Data System (ADS)

    Artamonov, A. A.; Epshteyn, V. S.; Gavrilov, V. B.; Gavrilyuk, A. A.; Gorbounov, P. A.; Jokin, A. S.; Lychkovskaya, N. V.; Popov, V. P.; Safronov, G. B.; Shamanov, V. V.; Shatalov, P. B.; Spiridonov, A. A.; Tsukerman, I. I.

    2016-05-01

    Recent achievements of the ATLAS and CMS experiments at the Large Hadron Collider searching for a Higgs boson are summarized. A new particle with the mass of 125 GeV and properties expected for the Standard Model Higgs boson was discovered three years ago in these experiments in proton-proton collisions when analyzing part of the data taken at the centre-of-mass energies 7 TeV and 8 TeV in 2011 and 2012 year exposures. Today all the data are processed and fully analyzed. Experimental results of studies of individual Higgs boson decay channels as well as their combination to extract such properties as mass, signal strength, coupling constants, spin and parity are reviewed. All experimental results are found to be compatible with the Standard Model predictions.

  1. On theoretical uncertainty of color dipole phenomenology in the J/\\psi and ϒ photoproduction in pA and AA collisions at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Sampaio dos Santos, G.; Machado, M. V. T.

    2015-10-01

    We investigate the theoretical uncertainty of the predictions for the photoproduction of J/\\psi and ϒ states in proton-nucleus and nucleus-nucleus collisions at the Large Hadron Collider (LHC) within the color dipole formalism. Predictions for the rapidity distributions are presented and the dependence on the meson wavefunction, heavy quark mass as well as the models for the dipole cross section are analyzed. We compare the theoretical results directly with recent data from the ALICE Collaboration on J/\\psi production in pPb collisions at a centre-of-mass energy per nucleon pair of 5.02 TeV and in PbPb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Predictions are also performed for ϒ state in PbPb and pPb collisions at LHC energies, including the coherent and incoherent contributions.

  2. Next-to-leading order QCD predictions for A{sup 0}{gamma} associated production at the CERN Large Hadron Collider

    SciTech Connect

    Dai Liang; Shao Dingyu; Gao Jun; Zhang Hao; Li Chongsheng

    2011-03-01

    We calculate the complete next-to-leading order (NLO) QCD corrections (including SUSY QCD corrections) to the inclusive total cross sections of the associated production processes pp{yields}A{sup 0}{gamma}+X in the minimal supersymmetric standard model (MSSM) at the CERN Large Hadron Collider (LHC). Our results show that the enhancement of the total cross sections from the NLO QCD corrections can reach 25%{approx}15% for 200 GeV

  3. Next-to-leading order QCD corrections to the single top quark production via model-independent tqg flavor-changing neutral-current couplings at hadron colliders

    SciTech Connect

    Gao Jun; Li Chongsheng; Zhang Jiajun; Zhu Huaxing

    2009-12-01

    We present the calculations of the complete next-to-leading order (NLO) QCD effects on the single top productions induced by model-independent tqg flavor-changing neutral-current couplings at hadron colliders. Our results show that, for the tcg coupling, the NLO QCD corrections can enhance the total cross sections by about 60% and 30%, and for the tug coupling by about 50% and 20% at the Tevatron and LHC, respectively, which means that the NLO corrections can increase the experimental sensitivity to the flavor-changing neutral-current couplings by about 10%-30%. Moreover, the NLO corrections reduce the dependence of the total cross sections on the renormalization or factorization scale significantly, which lead to increased confidence on the theoretical predictions. Besides, we also evaluate the NLO corrections to several important kinematic distributions, and find that for most of them the NLO corrections are almost the same and do not change the shape of the distributions.

  4. Next-to-leading order QCD effects in associated charged Higgs and W boson production in the MSSM at the CERN Large Hadron Collider

    SciTech Connect

    Gao Jun; Li Chongsheng; Li Zhao

    2008-01-01

    We present the calculations of the next-to-leading order (NLO) QCD corrections to the inclusive total cross sections for the associated production of the W{sup {+-}}H{sup {+-}} through bb annihilation in the minimal supersymmetric standard model at the CERN Large Hadron Collider. The NLO QCD corrections can either enhance or reduce the total cross sections, but they generally efficiently reduce the dependence of the total cross sections on the renormalization/factorization scale. The magnitude of the NLO QCD corrections is about 10% in most of the parameter space and can reach 15% in some parameter regions. We also show the Monte Carlo simulation results for the 2j+{tau}{sub jet}+pe{sub T} signature from the W{sup {+-}} and the H{sup {+-}} decays including the NLO QCD effects, and find an observable signal at a 5{sigma} level in some parameter region of the minimal supergravity model.

  5. First measurement and correction of nonlinear errors in the experimental insertions of the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Maclean, E. H.; Tomás, R.; Giovannozzi, M.; Persson, T. H. B.

    2015-12-01

    Nonlinear magnetic errors in low-β insertions can contribute significantly to detuning with amplitude, linear and nonlinear chromaticity, and lead to degradation of dynamic aperture and beam lifetime. As such, the correction of nonlinear errors in the experimental insertions of colliders can be of critical significance for successful operation. This is expected to be of particular relevance to the LHC's second run and its high luminosity upgrade, as well as to future colliders such as the Future Circular Collider. Current correction strategies envisioned for these colliders assume it will be possible to calculate optimized local corrections through the insertions, using a magnetic model of the errors. This paper shows however, that reliance purely upon magnetic measurements of the nonlinear errors of insertion elements is insufficient to guarantee a good correction quality in the relevant low-β* regime. It is possible to perform beam-based examination of nonlinear magnetic errors via the feed-down to readily observed beam properties upon application of closed orbit bumps, and methods based upon feed-down to tune have been utilized at RHIC, SIS18, and SPS. This paper demonstrates the extension of such methodology to include direct observation of feed-down to linear coupling in the LHC. It is further shown that such beam-based studies can be used to complement magnetic measurements performed during LHC construction, in order to validate and refine the magnetic model of the collider. Results from first attempts of the measurement and correction of nonlinear errors in the LHC experimental insertions are presented. Several discrepancies of beam-based studies with respect to the LHC magnetic model are reported.

  6. Top Quark Pair Production in Association with a Jet with Next-to-Leading-Order QCD Off-Shell Effects at the Large Hadron Collider.

    PubMed

    Bevilacqua, G; Hartanto, H B; Kraus, M; Worek, M

    2016-02-01

    We present a complete description of top quark pair production in association with a jet in the dilepton channel. Our calculation is accurate to next-to-leading order (NLO) in QCD and includes all nonresonant diagrams, interferences, and off-shell effects of the top quark. Moreover, nonresonant and off-shell effects due to the finite W gauge boson width are taken into account. This calculation constitutes the first fully realistic NLO computation for top quark pair production with a final state jet in hadronic collisions. Numerical results for differential distributions as well as total cross sections are presented for the Large Hadron Collider at 8 TeV. With our inclusive cuts, NLO predictions reduce the unphysical scale dependence by more than a factor of 3 and lower the total rate by about 13% compared to leading-order QCD predictions. In addition, the size of the top quark off-shell effects is estimated to be below 2%. PMID:26894704

  7. Comment on "Polarized window for left-right symmetry and a right-handed neutrino at the Large Hadron-Electron Collider"

    NASA Astrophysics Data System (ADS)

    Queiroz, Farinaldo S.

    2016-06-01

    Reference [1 S. Mondal and S. K. Rai, Phys. Rev. D 93, 011702 (2016).] recently argued that the projected Large Hadron Electron Collider (LHeC) presents a unique opportunity to discover a left-right symmetry since the LHeC has availability for polarized electrons. In particular, the authors apply some basic pT cuts on the jets and claim that the on-shell production of right-handed neutrinos at the LHeC, which violates lepton number in two units, has practically no standard model background and, therefore, that the right-handed nature of WR interactions that are intrinsic to left-right symmetric models can be confirmed by using colliding beams consisting of an 80% polarized electron and a 7 TeV proton. In this Comment, we show that their findings, as presented, have vastly underestimated the SM background which prevents a Left-Right symmetry signal from being seen at the LHeC.

  8. Proton enhancement at large pT at the CERN large hadron collider without structure in associated-particle distribution.

    PubMed

    Hwa, Rudolph C; Yang, C B

    2006-07-28

    The production of pions and protons in the pT range between 10 and 20 GeV/c for Pb+Pb collisions at CERN LHC is studied in the recombination model. It is shown that the dominant mechanism for hadronization is the recombination of shower partons from neighboring jets when the jet density is high. Protons are more copiously produced than pions in that pT range because the coalescing partons can have lower momentum fractions, but no thermal partons are involved. The proton-to-pion ratio can be as high as 20. When such high pT hadrons are used as trigger particles, there will not be any associated particles that are not in the background.

  9. Supersymmetric QCD one-loop effects in (un)polarized top-pair production at hadron colliders

    SciTech Connect

    Berge, Stefan; Hollik, Wolfgang; Mosle, Wolf M.; Wackeroth, Doreen

    2007-08-01

    We study the effects of O({alpha}{sub s}) supersymmetric QCD (SQCD) corrections on the total production rate and kinematic distributions of polarized and unpolarized top-pair production in pp and pp collisions. At the Fermilab Tevatron pp collider, top-quark pairs are mainly produced via quark-antiquark annihilation, qq{yields}tt, while at the CERN LHC pp collider gluon-gluon scattering, gg{yields}tt, dominates. We compute the complete set of O({alpha}{sub s}) SQCD corrections to both production channels and study their dependence on the parameters of the minimal supersymmetric standard model. In particular, we discuss the prospects for observing strong, loop-induced SUSY effects in top-pair production at the Tevatron run II and the LHC.

  10. Z0-tagged jet event asymmetry in heavy-ion collisions at the CERN large hadron collider.

    PubMed

    Neufeld, R B; Vitev, I

    2012-06-15

    Tagged jet measurements provide a promising experimental channel to quantify the similarities and differences in the mechanisms of jet production in proton-proton and nucleus-nucleus collisions. We present the first calculation of the transverse momentum asymmetry of Z0/γ*-tagged jet events in sqrt[s]=2.76  TeV reactions at the LHC. Our results combine the O(G(F)α(s)2) perturbative cross sections with the radiative and collisional processes that modify parton showers in the presence of dense strongly interacting matter. We find that a strong asymmetry is generated in central lead-lead reactions that has little sensitivity to the fluctuations of the underlying soft hadronic background. We present theoretical model predictions for its shape and magnitude.

  11. Comparison of electric dipole moments and the Large Hadron Collider for probing CP violation in triple boson vertices

    SciTech Connect

    Jung, Sunghoon; Wells, James D.

    2009-07-01

    CP violation from physics beyond the standard model may reside in triple boson vertices of the electroweak theory. We review the effective theory description and discuss how CP-violating contributions to these vertices might be discerned by electric dipole moments (EDM) or diboson production at the LHC. Despite triple boson CP-violating interactions entering EDMs only at the two-loop level, we find that EDM experiments are generally more powerful than the diboson processes. To give an example to these general considerations we perform the comparison between EDMs and collider observables within supersymmetric theories that have heavy sfermions, such that substantive EDMs at the one-loop level are disallowed. EDMs generally remain more powerful probes, and next-generation EDM experiments may surpass even the most optimistic assumptions for LHC sensitivities.

  12. Particle multiplicities in lead-lead collisions at the CERN large hadron collider from nonlinear evolution with running coupling corrections.

    PubMed

    Albacete, Javier L

    2007-12-31

    We present predictions for the pseudorapidity density of charged particles produced in central Pb-Pb collisions at the LHC. Particle production in such collisions is calculated in the framework of k(t) factorization. The nuclear unintegrated gluon distributions at LHC energies are determined from numerical solutions of the Balitsky-Kovchegov equation including recently calculated running coupling corrections. The initial conditions for the evolution are fixed by fitting Relativistic Heavy Ion Collider data at collision energies square root[sNN]=130 and 200 GeV per nucleon. We obtain dNch(Pb-Pb)/deta(square root[sNN]=5.5 TeV)/eta=0 approximately 1290-1480.

  13. Development of Large Area Gas Electron Multiplier Detector and Its Application to a Digital Hadron Calorimeter for Future Collider Experiments

    SciTech Connect

    Yu, Jaehoon; White, Andrew

    2014-09-25

    The UTA High Energy Physics Group conducted generic detector development based on large area, very thin and high sensitivity gas detector using gas electron multiplier (GEM) technology. This is in preparation for a use as a sensitive medium for sampling calorimeters in future collider experiments at the Energy Frontier as well as part of the tracking detector in Intensity Frontier experiments. We also have been monitoring the long term behavior of one of the prototype detectors (30cmx30cm) read out by the SLAC-developed 13-bit KPiX analog chip over three years and have made presentations of results at various APS meetings. While the important next step was the development of large area (1m x 1m) GEM planes, we also have looked into opportunities of applying this technology to precision tracking detectors to significantly improve the performance of the Range Stack detector for CP violation experiments and to provide an amplification layer for the liquid Argon Time Projection Chamber in the LBNE experiment. We have jointly developed 33cmx100cm large GEM foils with the CERN gas detector development group to construct 33cm x100cm unit chambers. Three of these unit chambers will be put together to form a 1m x 1m detector plane. Following characterization of one 33cmx100cm unit chamber prototype, a total of five 1m x 1m planes will be constructed and inserted into an existing 1m3 RPC DHCAL stack to test the performance of the new GEM DHCAL in particle beams. The large area GEM detector we planned to develop in this proposal not only gives an important option to DHCAL for future collider experiments but also the potential to expand its use to Intensity Frontier and Cosmic Frontier experiments as high efficiency, high amplification anode planes for liquid Argon time projection chambers. Finally, thanks to its sensitivity to X-rays and other neutral radiations and its light-weight characteristics, the large area GEM has a great potential for the use in medical imaging and

  14. Electromagnetic probes of a pure-glue initial state in nucleus-nucleus collisions at energies available at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Vovchenko, V.; Karpenko, Iu. A.; Gorenstein, M. I.; Satarov, L. M.; Mishustin, I. N.; Kämpfer, B.; Stoecker, H.

    2016-08-01

    Partonic matter produced in the early stage of ultrarelativistic nucleus-nucleus collisions is assumed to be composed mainly of gluons, and quarks and antiquarks are produced at later times. To study the implications of such a scenario, the dynamical evolution of a chemically nonequilibrated system is described by ideal (2+1)-dimensional hydrodynamics with a time dependent (anti)quark fugacity. The equation of state interpolates linearly between the lattice data for the pure gluonic matter and the lattice data for the chemically equilibrated quark-gluon plasma. The spectra and elliptic flows of thermal dileptons and photons are calculated for central Pb+Pb collisions at the CERN Large Hadron Collider energy of √{sN N}=2.76 TeV. We test the sensitivity of the results to the choice of equilibration time, including also the case where the complete chemical equilibrium of partons is reached already at the initial stage. It is shown that a suppression of quarks at early times leads to a significant reduction of the yield of the thermal dileptons, but only to a rather modest suppression of the pT distribution of direct photons. It is demonstrated that an enhancement of photon and dilepton elliptic flows might serve as a promising signature of the pure-glue initial state.

  15. Hadronic resonance production in d+au collisions at {radical}{ovr s}{sub NN} =200 GeV measured at the BNL relativistic heavy ion collider.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron Centre; Kent State Univ.; Particle Physic Lab.

    2008-01-01

    We present the first measurements of the {rho}(770){sup 0},K*(892), {Delta}(1232){sup ++}, {sigma}(1385), and {Lambda}(1520) resonances in d+Au collisions at {radical}s{sub NN} = 200 GeV, reconstructed via their hadronic decay channels using the STAR detector (the solenoidal tracker at the BNL Relativistic Heavy Ion Collider). The masses and widths of these resonances are studied as a function of transverse momentum p{sub T}. We observe that the resonance spectra follow a generalized scaling law with the transverse mass m{sub T}. The of resonances in minimum bias collisions are compared with the of {pi},K and {bar p}. The {rho}{sup 0}/{pi}{sup -}, K{sup +}/K{sup -}, {Delta}{sup ++}/p, {Sigma}(1385)/{Lambda}, and {Lambda}(1520)/{Lambda} ratios in d+Au collisions are compared with the measurements in minimum bias p+p interactions, where we observe that both measurements are comparable. The nuclear modification factors (R{sub dAu}) of the {rho}{sup 0},K{sup +}, and {Sigma}{sup +} scale with the number of binary collisions (N{sub bin}) for p{sub T} > 1.2 GeV/c.

  16. A new boson with a mass of 125 GeV observed with the CMS experiment at the Large Hadron Collider.

    PubMed

    2012-12-21

    The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a complex scalar field thought to give mass to three of the carriers of the electroweak force-the W(+), W(-), and Z(0) bosons-as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1 in 3 × 10(6). The new particle is a boson with spin not equal to 1 and has a mass of about 125 [corrected] giga-electron volts. Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle.

  17. Spin identification of graviton resonances in the process pp {sup {yields}}e{sup +}e{sup -} + X at the Large Hadron Collider (LHC)

    SciTech Connect

    Serenkova, I. A. Pankov, A.A. Tsytrinov, A.V.; Bednyakov, V. A.

    2010-07-15

    Prospects for discovering heavy graviton resonances in decays to an electron-positron pair and for identifying the nature of these resonances in the ATLAS experiment at the Large Hadron Collider (LHC) are investigated. Gravitons in the Randall-Sundrum model, which features extra spatial dimensions, are considered by way of example. A comparative analysis of effects of new different-spin heavy resonances, scalar [supersymmetric neutrino (sneutrino)], vector (new gauge Z' boson), and tensor (graviton) ones, is performed in order to identify the graviton spin. An identification of gravitons is performed by using the integrated center-edge asymmetry. For LHC, the graviton discovery (identification) reach is found to be 2.1 TeV (1.2 TeV) and 3.9 TeV (2.9 TeV) at a confidence level of 5{delta} (95%) for the graviton coupling constants of k/bar M {sub Pl} = 0.01 and 0.1, respectively. This analysis is the most general, since, for the first time, it takes into account the possible existence of scalar resonances, which affects substantially quantitative estimates of the identification reach.

  18. Beam-loss induced pressure rise of Large Hadron Collider collimator materials irradiated with 158 GeV/u In49+ ions at the CERN Super Proton Synchrotron

    NASA Astrophysics Data System (ADS)

    Mahner, E.; Efthymiopoulos, I.; Hansen, J.; Page, E.; Vincke, H.

    2004-10-01

    During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 104 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for Large Hadron Collider (LHC) ion operation. In 2003, a desorption experiment was installed at the Super Proton Synchrotron to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316LN (low carbon with nitrogen) stainless steel were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental setup, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.

  19. Next-to-leading order QCD predictions for t{gamma} associated production via model-independent flavor-changing neutral-current couplings at hadron colliders

    SciTech Connect

    Zhang Yue; Li Bohua; Li Chongsheng; Gao Jun; Zhu Huaxing

    2011-05-01

    We present the complete next-to-leading order (NLO) QCD predictions for the t{gamma} associated production induced by model-independent tq{gamma} and tqg flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the tq{gamma} and tqg FCNC couplings for this process. Our results show that, for the tq{gamma} couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the tq{gamma}, tqg FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the tu{gamma} and tug FCNC couplings, and by about 80% for the tc{gamma} and tcg FCNC couplings at the LHC, respectively. Moreover, the NLO corrections reduce the dependence of the total cross section on the renormalization and factorization scale significantly. We also evaluate the NLO corrections for several important kinematic distributions.

  20. A new boson with a mass of 125 GeV observed with the CMS experiment at the Large Hadron Collider.

    PubMed

    2012-12-21

    The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a complex scalar field thought to give mass to three of the carriers of the electroweak force-the W(+), W(-), and Z(0) bosons-as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1 in 3 × 10(6). The new particle is a boson with spin not equal to 1 and has a mass of about 125 [corrected] giga-electron volts. Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle. PMID:23258887

  1. Single and double production of the Higgs boson at hadron and lepton colliders in minimal composite Higgs models

    NASA Astrophysics Data System (ADS)

    Kanemura, Shinya; Kaneta, Kunio; Machida, Naoki; Odori, Shinya; Shindou, Tetsuo

    2016-07-01

    In the composite Higgs models, originally proposed by Georgi and Kaplan, the Higgs boson is a pseudo Nambu-Goldstone boson (pNGB) of spontaneous breaking of a global symmetry. In the minimal version of such models, global SO(5) symmetry is spontaneously broken to SO(4), and the pNGBs form an isospin doublet field, which corresponds to the Higgs doublet in the Standard Model (SM). Predicted coupling constants of the Higgs boson can in general deviate from the SM predictions, depending on the compositeness parameter. The deviation pattern is determined also by the detail of the matter sector. We comprehensively study how the model can be tested via measuring single and double production processes of the Higgs boson at the LHC and future electron-positron colliders. The possibility to distinguish the matter sector among the minimal composite Higgs models is also discussed. In addition, we point out differences in the cross section of double Higgs boson production from the prediction in other new physics models.

  2. Proton-Λ correlation functions at energies available at the CERN Large Hadron Collider taking into account residual correlations

    NASA Astrophysics Data System (ADS)

    Shapoval, V. M.; Sinyukov, Yu. M.; Naboka, V. Yu.

    2015-10-01

    The theoretical analysis of the p ¯-Λ ⊕p -Λ ¯ correlation function in 10% most central Au+Au collisions at Relativistic Heavy Ion Collider (RHIC) energy √{sNN}=200 GeV shows that the contribution of residual correlations is a necessary factor for obtaining a satisfactory description of the experimental data. Neglecting the residual correlation effect leads to an unrealistically low source radius, about 2 times smaller than the corresponding value for p -Λ ⊕p ¯-Λ ¯ case, when one fits the experimental correlation function within Lednický-Lyuboshitz analytical model. Recently an approach that accounts effectively for residual correlations for the baryon-antibaryon correlation function was proposed, and a good RHIC data description was reached with the source radius extracted from the hydrokinetic model (HKM). The p ¯-Λ scattering length, as well as the parameters characterizing the residual correlation effect—annihilation dip amplitude and its inverse width—were extracted from the corresponding fit. In this paper we use these extracted values and simulated in HKM source functions for Pb+Pb collisions at the LHC energy √{sNN}=2.76 TeV to predict the corresponding p Λ and p Λ ¯ correlation functions.

  3. Hadron colliders as the {open_quotes}neutralino factory{close_quotes}: Search for a slow decay of the lightest neutralino at the CERN LHC

    SciTech Connect

    Maki, K.; Orito, S.

    1998-01-01

    The prospects are examined for the detection of a slow decay of the lightest neutralino (or any other long-lived particles) at the CERN LHC and at the Very Large Hadron Collider (VLHC). We first point out that such hadron colliders will become the {open_quotes}neutralino factory{close_quotes} producing 10{sup 6}{endash}10{sup 9}neutralinos/yr, if gluinos and/or squarks actually exist below O(1) TeV. The lightest neutralino ({tilde {chi}}{sub 1}{sup 0}), usually assumed to be stable, will be unstable if lighter superparticles such as the gravitino ({tilde G}) or axino ({tilde a}) exist, or R-parity is not conserved. The decay signal would, however, be missed in usual collider experiments, particularly when the decay mostly occurs outside the detector. In order to search for such a slow decay of {tilde {chi}}{sub 1}{sup 0}, we propose a dedicated experiment where the collision products are dumped by a thick shield, which is followed by a long decay tunnel. The decay product of {tilde {chi}}{sub 1}{sup 0} can be detected by a detector located at the end of the tunnel. The slow arrival time and the large off angle (to the direction of the interaction point) of the decay product will provide a clear signature of slowly decaying {tilde {chi}}{sub 1}{sup 0}{close_quote}s. One can explore the decay length (c{tau}) in a wide range, i.e., 0.2 m to 1{times}10{sup 5}km for m{sub {tilde {chi}}{sub 1}{sup 0}}=25GeV and 1 m to 2 km for m{sub {tilde {chi}}{sub 1}{sup 0}}=200GeV at the LHC. This corresponds to the range of the SUSY breaking scale {radical} (F) =2{times}10{sup 5} to 2{times}10{sup 7}GeV in case of the {tilde {chi}}{sub 1}{sup 0}{r_arrow}{gamma}{tilde G} decay predicted in gauge-mediated SUSY breaking models. At VLHC, one can extend the explorable range of m{sub {tilde {chi}}{sub 1}{sup 0}} up to {approximately}1000GeV, and that of {radical} (F) up to {approximately}1{times}10{sup 8}GeV. In the case of the {tilde {chi}}{sub 1}{sup 0}{r_arrow}{gamma}{tilde a} decay

  4. Towards future circular colliders

    NASA Astrophysics Data System (ADS)

    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.

  5. Ion colliders

    SciTech Connect

    Fischer, W.

    2011-12-01

    Ion colliders are research tools for high-energy nuclear physics, and are used to test the theory of Quantum Chromo Dynamics (QCD). The collisions of fully stripped high-energy ions create matter of a temperature and density that existed only microseconds after the Big Bang. Ion colliders can reach higher densities and temperatures than fixed target experiments although at a much lower luminosity. The first ion collider was the CERN Intersecting Storage Ring (ISR), which collided light ions [77Asb1, 81Bou1]. The BNL Relativistic Heavy Ion Collider (RHIC) is in operation since 2000 and has collided a number of species at numerous energies. The CERN Large Hadron Collider (LHC) started the heavy ion program in 2010. Table 1 shows all previous and the currently planned running modes for ISR, RHIC, and LHC. All three machines also collide protons, which are spin-polarized in RHIC. Ion colliders differ from proton or antiproton colliders in a number of ways: the preparation of the ions in the source and the pre-injector chain is limited by other effects than for protons; frequent changes in the collision energy and particle species, including asymmetric species, are typical; and the interaction of ions with each other and accelerator components is different from protons, which has implications for collision products, collimation, the beam dump, and intercepting instrumentation devices such a profile monitors. In the preparation for the collider use the charge state Z of the ions is successively increased to minimize the effects of space charge, intrabeam scattering (IBS), charge change effects (electron capture and stripping), and ion-impact desorption after beam loss. Low charge states reduce space charge, intrabeam scattering, and electron capture effects. High charge states reduce electron stripping, and make bending and acceleration more effective. Electron stripping at higher energies is generally more efficient. Table 2 shows the charge states and energies in the

  6. High luminosity muon collider design

    SciTech Connect

    Palmer, R.; Gallardo, J.

    1996-10-01

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

  7. Reco level Smin and subsystem Smin: improved global inclusive variables for measuring the new physics mass scale in MET events at hadron colliders

    SciTech Connect

    Konar, Partha; Kong, Kyoungchul; Matchev, Konstantin T.; Park, Myeonghun; /Florida U.

    2011-08-11

    The variable {radical}s{sub min} was originally proposed in [1] as a model-independent, global and fully inclusive measure of the new physics mass scale in missing energy events at hadron colliders. In the original incarnation of {radical}s{sub min}, however, the connection to the new physics mass scale was blurred by the effects of the underlying event, most notably initial state radiation and multiple parton interactions. In this paper we advertize two improved variants of the {radical}s{sub min} variable, which overcome this problem. First we show that by evaluating the {radical}s{sub min} variable at the RECO level, in terms of the reconstructed objects in the event, the effects from the underlying event are significantly diminished and the nice correlation between the peak in the {radical}s{sub min}{sup (reco)} distribution and the new physics mass scale is restored. Secondly, the underlying event problem can be avoided altogether when the {radical}s{sub min} concept is applied to a subsystem of the event which does not involve any QCD jets. We supply an analytic formula for the resulting subsystem {radical}s{sub min}{sup (sub)} variable and show that its peak exhibits the usual correlation with the mass scale of the particles produced in the subsystem. Finally, we contrast {radical}s{sub min} to other popular inclusive variables such as H{sub T}, M{sub Tgen} and M{sub TTgen}. We illustrate our discussion with several examples from supersymmetry, and with dilepton events from top quark pair production.

  8. Optimization of a closed-loop gas system for the operation of Resistive Plate Chambers at the Large Hadron Collider experiments

    NASA Astrophysics Data System (ADS)

    Capeans, M.; Glushkov, I.; Guida, R.; Hahn, F.; Haider, S.

    2012-01-01

    Resistive Plate Chambers (RPCs), thanks to their fast time resolution (˜1 ns), suitable space resolution (˜1 cm) and low production cost (˜50 €/m2), are widely employed for the muon trigger systems at the Large Hadron Collider (LHC). Their large detector volume (they cover a surface of about 4000 m2 equivalent to 16 m3 of gas volume both in ATLAS and CMS) and the use of a relatively expensive Freon-based gas mixture make a closed-loop gas circulation unavoidable. It has been observed that the return gas of RPCs operated in conditions similar to the difficult experimental background foreseen at LHC contains a large amount of impurities potentially dangerous for long-term operation. Several gas-cleaning agents are currently in use in order to avoid accumulation of impurities in the closed-loop circuits. We present the results of a systematic study characterizing each of these cleaning agents. During the test, several RPCs were operated at the CERN Gamma Irradiation Facility (GIF) in a high radiation environment in order to observe the production of typical impurities: mainly fluoride ions, molecules of the Freon group and hydrocarbons. The polluted return gas was sent to several cartridges, each containing a different cleaning agent. The effectiveness of each material was studied using gas chromatography and mass-spectrometry techniques. Results of this test have revealed an optimized configuration of filters that is now under long-term validation.Gas optimization studies are complemented with a finite element simulation of gas flow distribution in the RPCs, aiming at its eventual optimization in terms of distribution and flow rate.

  9. Physics at the Large Hadron Collider. Higgs boson (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 26 February 2014)

    NASA Astrophysics Data System (ADS)

    2014-09-01

    A scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) "Physics at the Large Hadron Collider. Higgs boson" was held in the conference hall of the Lebedev Physical Institute, RAS, on 26 February 2014. The agenda of the session, announced on the website http://www.gpad.ac.ru of the Physical Sciences Division, RAS, listed the following reports: (1) Boos E E (Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow) "Standard Model and predictions for the Higgs boson"; (2) Zaytsev A M (National Research Center Kurchatov Institute, Moscow) "ATLAS experiment. The Higgs boson and the Standard Model"; (3) Lanyov A V (Joint Institute for Nuclear Research, Dubna, Moscow region) "CMS collaboration results: Higgs boson and search for new physics"; (4) Kazakov D I (Joint Institute for Nuclear Research, Dubna, Moscow region) "The Higgs boson has been found: what is next?" Papers written on the basis of oral reports 1, 3, and 4 are published below. An extensive review of the topic in item 2 will be published in an upcoming issue of Physics-Uspekhi. • Standard Model and predictions for the Higgs boson, E E Boos Physics-Uspekhi, 2014, Volume 57, Number 9, Pages 912-923 • CMS collaboration results: Higgs boson and search for new physics, A V Lanyov Physics-Uspekhi, 2014, Volume 57, Number 9, Pages 923-930 • The Higgs boson is found: what is next?, D I Kazakov Physics-Uspekhi, 2014, Volume 57, Number 9, Pages 930-942

  10. Charged-particle (pseudo-)rapidity distributions in p+p/p+p and Pb+Pb/Au+Au collisions from UrQMD calculations at energies available at the CERN Super Proton Synchrotron to the Large Hadron Collider

    SciTech Connect

    Mitrovski, Michael; Petersen, Hannah; Schuster, Tim; Graef, Gunnar; Bleicher, Marcus

    2009-04-15

    We present results for final state charged-particle (pseudo-)rapidity distributions in p+p/p+p and Pb+Pb/Au+Au at ultra high energies (17.3 GeV{<=}{radical}(s{sub NN}){<=}14 TeV) from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD-v2.3) model. In addition, excitation functions of produced charged-particle multiplicities (N{sub ch}) and pseudorapidity spectra are investigated up to CERN Large Hadron Collider energies. Good agreement is observed between UrQMD and measured pseudorapidity distributions of charged particles up to the highest Tevatron and SppS energies.

  11. Luminosity measurements at hadron colliders

    SciTech Connect

    Papadimitriou, Vaia; /Fermilab

    2008-04-01

    In this paper we discuss luminosity measurements at Tevatron and HERA as well as plans for luminosity measurements at LHC. We discuss luminosity measurements using the luminosity detectors of the experiments as well as measurements by the machine. We address uncertainties of the measurements, challenges and lessons learned.

  12. Triphoton production at hadron colliders

    SciTech Connect

    Campbell, John M.; Williams, Ciaran

    2014-06-01

    We present next-to-leading order predictions for the production of triphoton final states at the LHC and the Tevatron. Our results include the effect of photon fragmentation for the first time and we are able to quantify the impact of different isolation prescriptions. We find that calculations accounting for fragmentation effects at leading order, and those employing a smooth cone isolation where no fragmentation contribution is required, are in reasonable agreement with one another. However, larger differences in the predicted rates arise when higher order corrections to the fragmentation functions are included. In addition we present full analytic results for the $\\gamma\\gamma\\gamma$ and $\\gamma\\gamma+$jet one-loop amplitudes. These amplitudes, which are particularly compact, may be useful to future higher-order calculations. Our results are available in the Monte Carlo code MCFM.

  13. hc production at hadron colliders

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Xiong; Zhang, Hong-Fei

    2015-02-01

    In this paper, we present the study of the hadroproduction rate of hc at next-to-leading order in {{α }s} under the nonrelativisitic QCD (NRQCD) factorization framework, using color-octet long-distance matrix elements obtained from a global fit of experimental measurements on {{χ }c} yield and the ratio dσ ({{χ }c2})/dσ ({{χ }c1}) from the CDF, LHCb, CMS, and ATLAS Collaborations. This paper considers the problem of NRQCD scale dependence for the first time, and finds that, for some experimental conditions, the choice of this scale can significantly affect the final results, which indicates that, for these conditions, theoretical evaluation up to next-to-leading order cannot provide sufficiently precise predictions. We also present a brief analysis on the NRQCD scale dependence problem, and provide a criterion to determine in which case next-to-leading order prediction would be ruined by the scale dependence.

  14. Hadron Colliders Working Group Report

    SciTech Connect

    S. Peggs and M.J. Syphers

    2001-11-08

    The ''point design'' studied this year shows that a staged VLHC (40, {approx} 200 TeV) is feasible, with no insurmountable challenges. Further work can provide a more optimized design, by studying various alternative field strengths (e.g., superferric magnets for Stage 1) for improvements to vacuum, wall impedance, and other major performance parameters. It may be that a ''single-stage'' scenario for accessing higher energies sooner is the correct approach. A next-step design study should be considered to look at the two cases near to and complementary to the 2001 VLHC Design Study. The effectiveness of photon stops and their engineering design need to be addressed in the near future to truly determine if these devices can lead this effort to even higher luminosities and energies. The superbunch approach should continue to be studied, as well as IR designs, new instrumentation and diagnostics, and beam dynamics issues. Finally, a well organized VLHC-motivated beam studies effort should become part of the national program.

  15. High energy colliders

    SciTech Connect

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

    1997-02-01

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

  16. Two- and three-pion quantum statistics correlations in Pb-Pb collisions at √sNN =2.76 TeV at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Aggarwal, M. M.; Rinella, G. Aglieri; Agnello, M.; Agocs, A. G.; Agostinelli, A.; Agrawal, N.; Ahammed, Z.; Ahmad, N.; Masoodi, A. Ahmad; Ahmed, I.; Ahn, S. U.; Ahn, S. A.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Prado, C. Alves Garcia; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bairathi, V.; Bala, R.; Baldisseri, A.; Pedrosa, F. Baltasar Dos Santos; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Batzing, P. C.; Baumann, C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Berger, M. E.; Bergognon, A. A. E.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Boehmer, F. V.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bornschein, J.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Caffarri, D.; Cai, X.; Caines, H.; Caliva, A.; Villar, E. Calvo; Camerini, P.; Roman, V. Canoa; Carena, F.; Carena, W.; Carminati, F.; Díaz, A. Casanova; Castellanos, J. Castillo; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Sanchez, C. Ceballos; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Barroso, V. Chibante; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Balbastre, G. Conesa; Conesa Del Valle, Z.; Connors, M. E.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Morales, Y. Corrales; Cortese, P.; Maldonado, I. Cortés; Cosentino, M. R.; Costa, F.; Crochet, P.; Albino, R. Cruz; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dang, R.; Danu, A.; Das, D.; Das, I.; Das, K.; Das, S.; Dash, A.; Dash, S.; de, S.; Delagrange, H.; Deloff, A.; Dénes, E.; D'Erasmo, G.; de Barros, G. O. V.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; de Rooij, R.; Corchero, M. A. Diaz; Dietel, T.; Divià, R.; Bari, D. Di; Liberto, S. Di; Mauro, A. Di; Nezza, P. Di; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Gimenez, D. Domenicis; Dönigus, B.; Dordic, O.; Dorheim, S.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Majumdar, A. K. Dutta; Elia, D.; Engel, H.; Erazmus, B.; Erdal, H. A.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fehlker, D.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Téllez, A. Fernández; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floratos, E.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Girard, M. Fusco; Gaardhøje, J. J.; Gagliardi, M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Garishvili, I.; Gerhard, J.; Germain, M.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Khan, K. H.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Hayrapetyan, A.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Corral, G. Herrera; Hess, B. A.; Hetland, K. F.; Hicks, B.; Hippolyte, B.; Hladky, J.; Hristov, P.; Huang, M.; Humanic, T. J.; Hutter, D.; Hwang, D. S.; Ianigro, J.-C.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G. M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Ivanytskyi, O.; Jachołkowski, A.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, S.; Bustamante, R. T. Jimenez; Jones, P. G.; Jung, H.; Jusko, A.; Kalcher, S.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Uysal, A. Karasu; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Ketzer, B.; Khan, M. Mohisin.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobdaj, C.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Kovalenko, V.; Kowalski, M.; Kox, S.; Meethaleveedu, G. Koyithatta; Kral, J.; Králik, I.; Kramer, F.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kushpil, V.; Kweon, M. J.; Kwon, Y.; de Guevara, P. Ladron; Fernandes, C. Lagana; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Pointe, S. L. La; Rocca, P. La; Lea, R.; Lee, G. R.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenhardt, M.; Lenti, V.; Leogrande, E.; Leoncino, M.; Monzón, I. León; Lévai, P.; Li, S.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohner, D.; Loizides, C.; Lopez, X.; Torres, E. López; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luo, J.; Luparello, G.; Luzzi, C.; Gago, A. M.; Jacobs, P. M.; Ma, R.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Malaev, M.; Cervantes, I. Maldonado; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martinengo, P.; Martínez, M. I.; García, G. Martínez; Blanco, J. Martin; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazumder, R.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Pérez, J. Mercado; Meres, M.; Miake, Y.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitu, C. M.; Mlynarz, J.; Mohanty, B.; Molnar, L.; Zetina, L. Montaño; Montes, E.; Morando, M.; de Godoy, D. A. Moreira; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nicassio, M.; Niculescu, M.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Nyanin, A.; Nyatha, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Okatan, A.; Olah, L.; Oleniacz, J.; da Silva, A. C. Oliveira; Onderwaater, J.; Oppedisano, C.; Velasquez, A. Ortiz; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Pachmayer, Y.; Pachr, M.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S. K.; Palmeri, A.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Passfeld, A.; Patalakha, D. I.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; da Costa, H. Pereira; Filho, E. Pereira De Oliveira; Peresunko, D.; Lara, C. E. Pérez; Peryt, W.; Pesci, A.; Pestov, Y.; Petráček, V.; Petran, M.; Petris, M.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Planinic, M.; Płoskoń, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Pohjoisaho, E. H. O.; Polichtchouk, B.; Poljak, N.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, V.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Rauf, A. W.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rivetti, A.; Rocco, E.; Cahuantzi, M. Rodríguez; Manso, A. Rodriguez; Røed, K.; Rogochaya, E.; Rohni, S.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roy, A.; Roy, C.; Roy, P.; Montero, A. J. Rubio; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, R.; Sahu, P. K.; Saini, J.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Castro, X. Sanchez; Rodríguez, F. J. Sánchez; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, P. A.; Scott, R.; Segato, G.; Seger, J. E.; Selyuzhenkov, I.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Shangaraev, A.; Sharma, N.; Sharma, S.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R. J. M.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Soramel, F.; Sorensen, S.; Spacek, M.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strmen, P.; Suaide, A. A. P.; Vasquez, M. A. Subieta; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Susa, T.; Symons, T. J. M.; de Toledo, A. Szanto; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tangaro, M. A.; Takaki, J. D. Tapia; Peloni, A. Tarantola; Martinez, A. Tarazona; Tauro, A.; Muñoz, G. Tejeda; Telesca, A.; Terrevoli, C.; Minasyan, A. Ter; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Torii, H.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ulery, J.; Ullaland, K.; Ulrich, J.; Uras, A.; Usai, G. L.; Vajzer, M.; Vala, M.; Palomo, L. Valencia; Vallero, S.; Vyvre, P. Vande; Vannucci, L.; van Hoorne, J. W.; van Leeuwen, M.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Venaruzzo, M.; Vercellin, E.; Limón, S. Vergara; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Baillie, O. Villalobos; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wagner, V.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Xiang, C.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yang, S.; Yano, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I.-K.; Yushmanov, I.; Zaccolo, V.; Zach, C.; Zaman, A.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, F.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhou, D.; Zhou, F.; Zhou, Y.; Zhu, H.; Zhu, J.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.; Alice Collaboration

    2014-02-01

    Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two- and three-pion correlations of same and mixed charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at √sNN =2.76 TeV at the CERN Large Hadron Collider with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission. The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged-pion emission of 23%±8%.

  17. Measurement of the Inclusive $Z \\to ee$ Production Cross Section in Proton-Proton Collisions at $\\sqrt{s}$ = 7TeV and $Z \\to ee$ Decays as Standard Candles for Luminosity at the Large Hadron Collider

    SciTech Connect

    Werner, Jeremy

    2011-01-01

    This thesis comprises a precision measurement of the inclusive \\Zee production cross section in proton-proton collisions provided by the Large Hadron Collider (LHC) at a center-of-mass energy of $\\sqrt{s}=7$~TeV and the absolute luminosity based on \\Zee decays. The data was collected by the Compact Muon Solenoid (CMS) detector near Geneva, Switzerland during the year of 2010 and corresponds to an integrated luminosity of $\\int\\mathcal{L}dt = 35.9\\pm 1.4$~pb$^{-1}$. Electronic decays of $Z$ bosons allow one of the first electroweak measurements at the LHC, making the cross section measurement a benchmark of physics performance after the first year of CMS detector and LHC machine operations. It is the first systematic uncertainty limited \\Zee cross section measurement performed at $\\sqrt{s}=7$~TeV. The measured cross section pertaining to the invariant mass window $M_{ee}\\in (60,120)$~GeV is reported as: $\\sigma(pp\\to Z+X) \\times \\mathcal{B}( Z\\to ee ) = 997 \\pm 11 \\mathrm{(sta t)} \\pm 19 \\mathrm{(syst)} \\pm 40 \\mathrm{(lumi)} \\textrm{ pb}$, which agrees with the theoretical prediction calculated to NNLO in QCD. Leveraging \\Zee decays as ``standard candles'' for measuring the absolute luminosity at the LHC is examined; they are produced copiously, are well understood, and have clean detector signatures. Thus the consistency of the inclusive \\Zee production cross section measurement with the theoretical prediction motivates inverting the measurement to instead use the \\Zee signal yield to measure the luminosity. The result, which agrees with the primary relative CMS luminosity measurement calibrated using Van der Meer separation scans, is not only the most precise absolute luminosity measurement performed to date at a hadron collider, but also the first one based on a physics signal at the LHC.

  18. Hadronization of partons

    SciTech Connect

    Albino, S.

    2010-07-15

    The description of inclusive production of single unpolarized light hadrons using fragmentation functions in the framework of the factorization theorem is reviewed. The factorization of observables into perturbatively calculable quantities and these universal fragmentation functions are summarized and some improvements beyond the standard fixed order approach are discussed. The extraction of fragmentation functions for light charged ({pi}{sup {+-}}, K{sup {+-}}, and p/p) and neutral (K{sub S}{sup 0} and {Lambda}/{Lambda}) hadrons using these theoretical tools is discussed through global fits to experimental data from reactions at various colliders, in particular from accurate e{sup +}e{sup -} reactions at the Large Electron-Position Collider (LEP), and the subsequent successful predictions of other experimental data, such as data gathered at Hadron Electron Ring Accelerator (HERA), the Tevatron, and the Relativistic Heavy Ion Collider (RHIC), from these fitted fragmentation functions as allowed by factorization universality. These global fits also impose competitive constraints on {alpha}{sub s}(M{sub Z}). Emphasis is placed on the need for accurate data from pp(p) and ep reactions in which the hadron species is identified in order to constrain the separate fragmentation functions of the gluon and each quark flavor for each hadron species.

  19. Status and future directions for advanced accelerator research - conventional and non-conventional collider concepts

    SciTech Connect

    Siemann, R.H.

    1997-01-01

    The relationship between advanced accelerator research and future directions for particle physics is discussed. Comments are made about accelerator research trends in hadron colliders, muon colliders, and e{sup +}3{sup {minus}} linear colliders.

  20. Tau physics at p{bar p} colliders

    SciTech Connect

    Konigsberg, J.

    1993-01-01

    Tau detection techniques in hadron colliders are discussed together with the measurements and searches performed so far. We also underline the importance tau physics has in present and future collider experiments.

  1. P{bar P} collider physics

    SciTech Connect

    Demarteau, M.

    1992-04-01

    A brief introduction to {bar p}p collider physics is given. Selected results from the collider experiments at the CERN S{bar p}pS and the Tevatron collider are described. The emphasis is on experimental aspects of {bar p}p collisions. Minimum bias physics and the production of jets, Intermediate Vector Bosons and heavy flavors is reviewed. The outlook for physics at hadron colliders for the near future is briefly discussed.

  2. Triangular flow of thermal photons from an event-by-event hydrodynamic model for 2.76 A TeV Pb + Pb collisions at the CERN Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Chatterjee, Rupa; Srivastava, Dinesh K.; Renk, Thorsten

    2016-07-01

    We calculate the triangular flow parameter v3 of thermal photons from an event-by-event ideal hydrodynamic model for 0-40% central collisions of Pb nuclei at √{sN N}=2.76 TeV at the CERN Large Hadron Collider. v3 determined with respect to the participant plane (PP) is found to be nonzero and positive, and its pT dependence is qualitatively similar to the elliptic flow parameter v2(PP) of thermal photons in the range 1 ≤pT≤6 GeV/c . In the range pT≤ 3 GeV/c , v3(PP) is found to be about 50-75% of v2(PP) and for pT> 3 GeV/c the two anisotropy parameters become comparable. The value of v3 is driven by local density fluctuations both directly via the creation of triangular geometry and indirectly via additional flow. As expected, the triangular flow parameter calculated with respect to the reaction plane v3(RP) is found to be close to zero. We show that v3(PP) strongly depends on the spatial size of fluctuations, especially in the higher pT(≥3 GeV /c ) region where a larger value of σ results in a smaller v3(PP ) . In addition, v3(PP ) is found to increase with the assumed formation time of the thermalized system.

  3. Impact of parton distribution function and {alpha}{sub s} uncertainties on Higgs boson production in gluon fusion at hadron colliders

    SciTech Connect

    Demartin, Federico; Mariani, Elisa; Forte, Stefano; Vicini, Alessandro; Rojo, Juan

    2010-07-01

    We present a systematic study of uncertainties due to parton distributions (PDFs) and the strong coupling on the gluon-fusion production cross section of the standard model Higgs at the Tevatron and LHC colliders. We compare procedures and results when three recent sets of PDFs are used, CTEQ6.6, MSTW08, and NNPDF1.2, and we discuss specifically the way PDF and strong coupling uncertainties are combined. We find that results obtained from different PDF sets are in reasonable agreement if a common value of the strong coupling is adopted. We show that the addition in quadrature of PDF and {alpha}{sub s} uncertainties provides an adequate approximation to the full result with exact error propagation. We discuss a simple recipe to determine a conservative PDF+{alpha}{sub s} uncertainty from available global parton sets, and we use it to estimate this uncertainty on the given process to be about 10% at the Tevatron and 5% at the LHC for a light Higgs.

  4. 750 GeV diphoton resonance in a vector-like extension of Hill model at a 100 TeV hadron collider

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Wang, Wenyu; Zhang, Mengchao; Zheng, Rui

    2016-09-01

    In this paper, we study the recent 750 GeV diphoton excess in the Hill model with vector-like fermions. The singlet-like Hill boson is chosen as the 750 GeV diphoton resonance. Such a scalar is mainly produced by gluon fusion via vector-like top and bottom quark loops and decays to diphoton via the vector-like quark and lepton loops. Under the current experimental and theoretical constraints, we find that the mixing angle of the singlet and doublet Higgs bosons lies within |sin 𝜃|≲ 0.03 and the 750 GeV diphoton cross-section can be maximally enhanced to about 6 fb at 13 TeV LHC. Moreover, we find that the Hill boson pair production in jjγγ channel can be probed at 3σ significance if 375GeV < mF < 1500GeV and 1.4 < yF < 3 at a 100 TeV collider with 3000 fb‑1 luminosity.

  5. 750 GeV diphoton resonance in a vector-like extension of Hill model at a 100 TeV hadron collider

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Wang, Wenyu; Zhang, Mengchao; Zheng, Rui

    2016-09-01

    In this paper, we study the recent 750 GeV diphoton excess in the Hill model with vector-like fermions. The singlet-like Hill boson is chosen as the 750 GeV diphoton resonance. Such a scalar is mainly produced by gluon fusion via vector-like top and bottom quark loops and decays to diphoton via the vector-like quark and lepton loops. Under the current experimental and theoretical constraints, we find that the mixing angle of the singlet and doublet Higgs bosons lies within |sin 𝜃|≲ 0.03 and the 750 GeV diphoton cross-section can be maximally enhanced to about 6 fb at 13 TeV LHC. Moreover, we find that the Hill boson pair production in jjγγ channel can be probed at 3σ significance if 375GeV < mF < 1500GeV and 1.4 < yF < 3 at a 100 TeV collider with 3000 fb-1 luminosity.

  6. Exotic colliders

    SciTech Connect

    Chattopadhyay, S.

    1994-11-01

    The motivation, feasibility and potential for two unconventional collider concepts - the Gamma-Gamma Collider and the Muon Collider - are described. The importance of the development of associated technologies such as high average power, high repetition rate lasers and ultrafast phase-space techniques are outlined.

  7. Accessing the Distribution of Linearly Polarized Gluons in Unpolarized Hadrons

    SciTech Connect

    Boer, Daniel; Brodsky, Stanley J.; Mulders, Piet J.; Pisano, Cristian; /Cagliari U. /INFN, Cagliari

    2011-08-19

    Gluons inside unpolarized hadrons can be linearly polarized provided they have a nonzero transverse momentum. The simplest and theoretically safest way to probe this distribution of linearly polarized gluons is through cos2{phi} asymmetries in heavy quark pair or dijet production in electron-hadron collisions. Future Electron-Ion Collider (EIC) or Large Hadron electron Collider (LHeC) experiments are ideally suited for this purpose. Here we estimate the maximum asymmetries for EIC kinematics.

  8. Direct probes of linearly polarized gluons inside unpolarized hadrons.

    PubMed

    Boer, Daniël; Brodsky, Stanley J; Mulders, Piet J; Pisano, Cristian

    2011-04-01

    We show that linearly polarized gluons inside unpolarized hadrons can be directly probed in jet or heavy quark pair production in electron-hadron collisions. We discuss the simplest cos2ϕ asymmetries and estimate their maximal value, concluding that measurements of the unknown linearly polarized gluon distribution in the proton should be feasible in future Electron-Ion Collider or Large Hadron electron Collider experiments. Analogous asymmetries in hadron-hadron collisions suffer from factorization breaking contributions and would allow us to quantify the importance of initial- and final-state interactions.

  9. Linear Colliders

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akira; Yokoya, Kaoru

    2015-02-01

    An overview of linear collider programs is given. The history and technical challenges are described and the pioneering electron-positron linear collider, the SLC, is first introduced. For future energy frontier linear collider projects, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are introduced and their technical features are discussed. The ILC is based on superconducting RF technology and the CLIC is based on two-beam acceleration technology. The ILC collaboration completed the Technical Design Report in 2013, and has come to the stage of "Design to Reality." The CLIC collaboration published the Conceptual Design Report in 2012, and the key technology demonstration is in progress. The prospects for further advanced acceleration technology are briefly discussed for possible long-term future linear colliders.

  10. Linear Colliders

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akira; Yokoya, Kaoru

    An overview of linear collider programs is given. The history and technical challenges are described and the pioneering electron-positron linear collider, the SLC, is first introduced. For future energy frontier linear collider projects, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are introduced and their technical features are discussed. The ILC is based on superconducting RF technology and the CLIC is based on two-beam acceleration technology. The ILC collaboration completed the Technical Design Report in 2013, and has come to the stage of "Design to Reality." The CLIC collaboration published the Conceptual Design Report in 2012, and the key technology demonstration is in progress. The prospects for further advanced acceleration technology are briefly discussed for possible long-term future linear colliders.

  11. PHENIX Measurement of High-pT Hadron-Hadron and Photon-Hadron Azimuthal Correlations

    SciTech Connect

    Jin, J.; Awes, Terry C; Batsouli, Sotiria; Cianciolo, Vince; Efremenko, Yuri; Read Jr, Kenneth F; Silvermyr, David O; Sorensen, Soren P; Stankus, Paul W; Young, Glenn R; Zhang, Chun; PHENIX, Collaboration

    2007-01-01

    High-p{sub T} hadron-hadron correlations have been measured with the PHENIX experiment in Cu and pp collisions at {radical}s{sub NN}=200 GeV. A comparison of the jet widths and yields between the two colliding systems allows us to study the medium effect on jets. We also present a first measurement of direct photon-hadron correlations in Au and pp collisions. We find that the near-side yields are consistent with zero in both systems. By comparing the jet yields on the away side, we observe a suggestion of the expected suppression of hadrons associated with photons in Au collisions.

  12. Theoretical study of the effect of the size of a high-energy proton beam of the Large Hadron Collider on the formation and propagation of shock waves in copper irradiated by 450-GeV proton beams

    NASA Astrophysics Data System (ADS)

    Ryazanov, A. I.; Stepakov, A. V.; Vasilyev, Ya. S.; Ferrari, A.

    2014-02-01

    The interaction of 450-GeV protons with copper, which is the material of the collimators of the Large Hadron Collider, has been theoretically studied. A theoretical model for the formation and propagation of shock waves has been proposed on the basis of the analysis of the energy released by a proton beam in the electronic subsystem of the material owing to the deceleration of secondary particles appearing in nuclear reactions induced by this beam on the electronic subsystem of the material. The subsequent transfer of the energy from the excited electronic subsystem to the crystal lattice through the electron-phonon interaction has been described within the thermal spike model [I.M. Lifshitz, M.I. Kaganov, and L.V. Tanatarov, Sov. Phys. JETP 4, 173 (1957); I.M. Lifshitz, M.I. Kaganov, and L.V. Tanatarov, At. Energ. 6, 391 (1959); K. Yasui, Nucl. Instrum. Methods Phys. Res., Sect. B 90, 409 (1994)]. The model of the formation of shock waves involves energy exchange processes between excited electronic and ionic subsystems of the irradiated material and is based on the hydrodynamic approximation proposed by Zel'dovich [Ya.B. Zel'dovich and Yu.P. Raizer, Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena (Nauka, Moscow, 1966; Dover, New York, 2002)]. This model makes it possible to obtain the space-time distributions of the main physical characteristics (temperatures of the ionic and electronic subsystems, density, pressure, etc.) in materials irradiated by high-energy proton beams and to analyze the formation and propagation of shock waves in them. The nonlinear differential equations describing the conservation laws of mass, energy, and momentum of electrons and ions in the Euler variables in the case of the propagation of shock waves has been solved with the Godunov scheme [S. K. Godunov, A.V. Zabrodin, M.Ya. Ivanov, A.N. Kraiko, and G.P. Prokopov, Numerical Solution of Multidimensional Problems in Gas Dynamics (Nauka, Moscow, 1976) [in Russian

  13. Quarks and gluons at hadron colliders

    SciTech Connect

    Bodek, A.; CDF Collaboration

    1996-08-01

    Data from proton-antiproton collisions at high energy provide important information on constraining the quark and gluon distributions in the nucleon and place limits on quark substructure. The S asymmetry data constrains the slope of the d/u quark distributions and significantly reduces the systematic error on the extracted value of the W mass. Drell-Yan data at high invariant mass provides strong limits on quark substructure. Information on {alpha}{sub s} and the gluon distributions can be extracted from high P{sub T} jet data and direct photons.

  14. Higgs friends and counterfeits at hadron colliders

    SciTech Connect

    Fox, Patrick J.; Tucker-Smith, David; Weiner, Neal; /New York U., CCPP /New York U. /Princeton, Inst. Advanced Study

    2011-04-01

    We consider the possibility of 'Higgs counterfeits' - scalars that can be produced with cross sections comparable to the SM Higgs, and which decay with identical relative observable branching ratios, but which are nonetheless not responsible for electroweak symmetry breaking. We also consider a related scenario involving 'Higgs friends,' fields similarly produced through gg fusion processes, which would be discovered through diboson channels WW,ZZ,{gamma}{gamma}, or even {gamma}Z, potentially with larger cross sections times branching ratios than for the Higgs. The discovery of either a Higgs friend or a Higgs counterfeit, rather than directly pointing towards the origin of the weak scale, would indicate the presence of new colored fields necessary for the sizable production cross section (and possibly new colorless but electroweakly charged states as well, in the case of the diboson decays of a Higgs friend). These particles could easily be confused for an ordinary Higgs, perhaps with an additional generation to explain the different cross section, and we emphasize the importance of vector boson fusion as a channel to distinguish a Higgs counterfeit from a true Higgs. Such fields would naturally be expected in scenarios with 'effective Z's,' where heavy states charged under the SM produce effective charges for SM fields under a new gauge force. We discuss the prospects for discovery of Higgs counterfeits, Higgs friends, and associated charged fields at the LHC.

  15. The large hadron computer

    NASA Astrophysics Data System (ADS)

    Hirstius, Andreas

    2008-11-01

    In the mid-1990s, when CERN physicists made their first cautious estimates of the amount of data that experiments at the Large Hadron Collider (LHC) would produce, the microcomputer component manufacturer Intel had just released the Pentium Pro processor. Windows was the dominant operating system, although Linux was gaining momentum. CERN had recently made the World Wide Web public, but the system was still a long way from the all-encompassing network it is today. And a single gigabyte (109 bytes) of disk space cost several hundred dollars.

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

    SciTech Connect

    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.

  17. High Energy Accelerator and Colliding Beam User Group

    SciTech Connect

    Snow, G.A.; Skuja, A.

    1992-05-01

    This report discusses research in the following areas: the study of e{sup +}e{sup {minus}} interactions; Hadron collider physics at Fermilab; fixed target physics and particle physics of general interest; and, the solenoidal detector collaboration at SSCL.

  18. Signatures of doubly-charged Higgsinos at colliders

    SciTech Connect

    Demir, D. A.; Frank, M.; Turan, I.; Huitu, K.; Rai, S. K.

    2008-11-23

    Several supersymmetric models with extended gauge structures predict light doubly-charged Higgsinos. Their distinctive signature at the large hadron collider is highlighted by studying its production and decay characteristics.

  19. World lays groundwork for future linear collider

    SciTech Connect

    Feder, Toni

    2010-07-15

    With the Large Hadron Collider at CERN finally working, the particle-physics community can now afford to divide its attention between achieving LHC results and preparing for the next machine on its wish list, an electron-positron linear collider. The preparations involve developing and deciding on the technology for such a machine, the mode of its governance, and how to balance regional and global particle- and accelerator-physics programs.

  20. Physics at Future Circular Colliders

    NASA Astrophysics Data System (ADS)

    Kotwal, Ashutosh

    2016-03-01

    The Large Hadron Collider has been a grand success with the discovery of the Higgs boson, with bright prospects for additional discoveries since the recent increase in collider energy and the anticipated large datasets. Big open questions such as the nature of dark matter, the origin of the matter-antimatter asymmetry in the Universe, and the theoretical puzzle of the finely-tuned parameters in the Higgs sector, demand new physics principles that extend the established Standard Model paradigm. Future circular colliders in a substantially larger tunnel can house both a high luminosity electron-positron collider for precision measurements of Higgs and electroweak parameters, as well as a very high energy proton-proton collider which can directly manifest particles associated with these new physics principles. We discuss the physics goals of these future circular colliders, and the prospects for elucidating fundamental new laws of nature that will significantly extend our understanding of the Universe. Detailed studies of the discovery potential in specific benchmark models will be presented, with implications for detector design.

  1. Charmless Hadronic B Decays at BaBar

    SciTech Connect

    Burke, James P.; /Liverpool U.

    2007-12-04

    We report recent measurements for the branching fractions of charmless hadronic B decays obtained from data collected by the BABAR detector at the PEP-II asymmetric-energy collider at the Stanford Linear Accelerator Center.

  2. Muon Collider

    SciTech Connect

    Palmer, R.

    2009-10-19

    Parameters are given of muon colliders with center of mass energies of 1.5 and 3 TeV. Pion production is from protons on a mercury target. Capture, decay, and phase rotation yields bunch trains of both muon signs. Six dimensional cooling reduces the emittances until the trains are merged into single bunches, one of each sign. Further cooling in 6 dimensions is then applied, followed by final transverse cooling in 50 T solenoids. After acceleration the muons enter the collider ring. Ongoing R&D is discussed.

  3. On the Future High Energy Colliders

    SciTech Connect

    Shiltsev, Vladimir

    2015-09-28

    High energy particle colliders have been in the forefront of particle physics for more than three decades. 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). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

  4. QCD and Hadron Physics

    SciTech Connect

    Brodsky, Stanley J.; Deshpande, Abhay L.; Gao, Haiyan; McKeown, Robert D.; Meyer, Curtis A.; Meziani, Zein-Eddine; Milner, Richard G.; Qiu, Jianwei; Richards, David G.; Roberts, Craig D.

    2015-02-26

    This White Paper presents the recommendations and scientific conclusions from the Town Meeting on QCD and Hadronic Physics that took place in the period 13-15 September 2014 at Temple University as part of the NSAC 2014 Long Range Planning process. The meeting was held in coordination with the Town Meeting on Phases of QCD and included a full day of joint plenary sessions of the two meetings. The goals of the meeting were to report and highlight progress in hadron physics in the seven years since the 2007 Long Range Plan (LRP07), and present a vision for the future by identifying the key questions and plausible paths to solutions which should define the next decade. The introductory summary details the recommendations and their supporting rationales, as determined at the Town Meeting on QCD and Hadron Physics, and the endorsements that were voted upon. The larger document is organized as follows. Section 2 highlights major progress since the 2007 LRP. It is followed, in Section 3, by a brief overview of the physics program planned for the immediate future. Finally, Section 4 provides an overview of the physics motivations and goals associated with the next QCD frontier: the Electron-Ion-Collider.

  5. Hadron interactions

    SciTech Connect

    K. Orginos

    2011-12-01

    In this talk I am reviewing recent calculations of properties of multi-hadron systems in lattice QCD. In particular, I am reviewing results of elastic scattering phase shifts in meson-meson, meson-baryon and baryon-baryon systems, as well as discussing results indicating possible existence of bound states in two baryon systems. Finally, calculations of properties of systems with more than two hadrons are presented.

  6. Future hadron physics at Fermilab

    SciTech Connect

    Appel, Jeffrey A.; /Fermilab

    2005-09-01

    Today, hadron physics research occurs at Fermilab as parts of broader experimental programs. This is very likely to be the case in the future. Thus, much of this presentation focuses on our vision of that future--a future aimed at making Fermilab the host laboratory for the International Linear Collider (ILC). Given the uncertainties associated with the ILC--the level of needed R&D, the ILC costs, and the timing--Fermilab is also preparing for other program choices. I will describe these latter efforts, efforts focused on a Proton Driver to increase the numbers of protons available for experiments. As examples of the hadron physics which will be coming from Fermilab, I summarize three experiments: MIPP/E907 which is running currently, and MINERvA and Drell-Yan/E906 which are scheduled for future running periods. Hadron physics coming from the Tevatron Collider program will be summarized by Arthur Maciel in another talk at Hadron05.

  7. Operational experience with the CMS hadronic calorimeter system

    NASA Astrophysics Data System (ADS)

    Yetkin, Taylan; CMS Collaboration

    2011-04-01

    The hadronic calorimeter (HCAL) of CMS was commissioned before and during the initial proton collisions in Large Hadron Collider. Various phases of HCAL commissioning were used to gain operational experience and prepare the detector for physics. In this note we briefly summarize the activities and outcomes from the the commissioning studies.

  8. Seismic studies for Fermilab future collider projects

    SciTech Connect

    Lauh, J.; Shiltsev, V.

    1997-11-01

    Ground motion can cause significant beam emittance growth and orbit oscillations in large hadron colliders due to a vibration of numerous focusing magnets. Larger accelerator ring circumference leads to smaller revolution frequency and, e.g. for the Fermilab Very Large Hadron Collider(VLHC) 50-150 Hz vibrations are of particular interest as they are resonant with the beam betatron frequency. Seismic measurements at an existing large accelerator under operation can help to estimate the vibrations generated by the technical systems in future machines. Comparison of noisy and quiet microseismic conditions might be useful for proper choice of technical solutions for future colliders. This article presents results of wide-band seismic measurements at the Fermilab site, namely, in the tunnel of the Tevatron and on the surface nearby, and in two deep tunnels in the Illinois dolomite which is though to be a possible geological environment of the future accelerators.

  9. Collider and detector protection at beam accidents

    SciTech Connect

    I. L. Rakhno; N. V. Mokhov; A. I. Drozhdin

    2003-12-10

    Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section.

  10. Measurement of the Masses and Lifetimes of B Hadrons at the Tevatron

    SciTech Connect

    Catastini, Pierluigi; /Pisa U. /INFN, Pisa

    2006-05-01

    The latest results for the B Hadron sector at the Tevatron Collider are summarized. The properties of B hadrons can be precisely measured at the Tevatron. In particularly they will focus on the masses and lifetimes. The new Tevatron results for the CP violation in B Hadrons are also discussed.

  11. Status of the Future Circular Collider Study

    NASA Astrophysics Data System (ADS)

    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.

  12. PERFORMANCE LIMITATIONS IN HIGH-ENERGY ION COLLIDERS

    SciTech Connect

    FISCHER, W.

    2005-05-16

    High-energy ion colliders (hadron colliders operating with ions other than protons) are premier research tools for nuclear physics. The collision energy and high luminosity are important design and operations considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species, including asymmetric collisions. For the creation, acceleration, and storage of bright intense ion beams limits are set by space charge, charge exchange, and intrabeam scattering effects. The latter leads to luminosity lifetimes of only a few hours for intense heavy ions beams. Currently, the Relativistic Heavy Ion Collider (RHIC) at BNL is the only operating high-energy ion collider. Later this decade the Large Hadron Collider (LHC), under construction at CERN, will also run with heavy ions.

  13. Collider physics

    SciTech Connect

    Not Available

    1991-01-01

    This past year our group participated in both the D0 experiment at Fermilab and the SDC experiment at the SSC. Most of our effort was concentrated on the D0 project, where we contributed as much manpower as possible to the commissioning of the detector in preparation for the coming collider run. Our SDC work consisted of the investigation of one of the candidate technologies for the forward calorimeter. On the D0 experiment, our primary responsibilities have been in the areas of electronics commissioning and in the establishment of triggers for the coming collider run. We have also actively participated in the physics studies and have contributed to the upgrade effort as much as time has permitted. Our group has also participated in the cosmic ray run and in the D0 test beam. In view of our contributions, James White was selected as a member of the D0 Trigger board, and Jay Wightman is being trained as one of the global experts'' who are responsible for keeping the detector operational during the run. In addition, Amber Boehnlein has played a major role in the Level-2 trigger commissioning. A more detailed description of these activities is given in this paper.

  14. Magnet R&D for future colliders

    SciTech Connect

    Sabbi, Gian Luca

    2001-06-14

    High-energy colliders complementing and expanding the physics reach of LHC are presently under study in the United States, Europe and Japan. The magnet system is a major cost driver for hadron colliders at the energy frontier, and critical to the successful operation of muon colliders. Under most scenarios, magnet design as well as vacuum and cryogenic systems are complicated by high radiation loads. Magnet R&D programs are underway worldwide to take advantage of new developments in superconducting materials, achieve higher efficiency and simplify fabrication while preserving accelerator-class field quality. A review of recent progress in magnet technology for future colliders is presented, with emphasis on the most innovative design concepts and fabrication techniques.

  15. Klystron switching power supplies for the Internation Linear Collider

    SciTech Connect

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  16. Elastic scattering of hadrons

    NASA Astrophysics Data System (ADS)

    Dremin, I. M.

    2013-01-01

    Colliding high-energy hadrons either produce new particles or scatter elastically with their quantum numbers conserved and no other particles produced. We consider the latter case here. Although inelastic processes dominate at high energies, elastic scattering contributes considerably (18-25%) to the total cross section. Its share first decreases and then increases at higher energies. Small-angle scattering prevails at all energies. Some characteristic features can be seen that provide information on the geometrical structure of the colliding particles and the relevant dynamical mechanisms. The steep Gaussian peak at small angles is followed by the exponential (Orear) regime with some shoulders and dips, and then by a power-law decrease. Results from various theoretical approaches are compared with experimental data. Phenomenological models claiming to describe this process are reviewed. The unitarity condition predicts an exponential fall for the differential cross section with an additional substructure to occur exactly between the low momentum transfer diffraction cone and a power-law, hard parton scattering regime under high momentum transfer. Data on the interference of the Coulomb and nuclear parts of amplitudes at extremely small angles provide the value of the real part of the forward scattering amplitude. The real part of the elastic scattering amplitude and the contribution of inelastic processes to the imaginary part of this amplitude (the so-called overlap function) are also discussed. Problems related to the scaling behavior of the differential cross section are considered. The power-law regime at highest momentum transfer is briefly described.

  17. Muon Muon Collider: Feasibility Study

    SciTech Connect

    Gallardo, J.C.; Palmer, R.B.; Tollestrup, A.V.; Sessler, A.M.; Skrinsky, A.N.; 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

  18. Energy-range relations for hadrons in nuclear matter

    NASA Technical Reports Server (NTRS)

    Strugalski, Z.

    1985-01-01

    Range-energy relations for hadrons in nuclear matter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclear matter in nucleons on which the incident hadrons are stopped.

  19. Suppressing Electron Cloud in Future Linear Colliders

    SciTech Connect

    Pivi, M; Kirby, R.E.; Raubenheimer, T.O.; Le Pimpec, F.; /PSI, Villigen

    2005-05-27

    Any accelerator circulating positively charged beams can suffer from a build-up of an electron cloud (EC) in the beam pipe. The cloud develops through ionization of residual gases, synchrotron radiation and secondary electron emission and, when severe, can cause instability, emittance blow-up or loss of the circulating beam. The electron cloud is potentially a luminosity limiting effect for both the Large Hadron Collider (LHC) and the International Linear Collider (ILC). For the ILC positron damping ring, the development of the electron cloud must be suppressed. This paper discusses the state-of-the-art of the ongoing SLAC and international R&D program to study potential remedies.

  20. A high energy e{sup +}e{sup {minus}} collider in a ``really large`` tunnel

    SciTech Connect

    Norem, J.; Keil, E.

    1996-12-31

    Recent developments in tunneling technology imply that it is possible to consider much larger tunnels for high energy circular colliders in the future. Tunnels with diameters of 200 km are being considered for a low field hadron collider called the Really Large Hadron Collider (RLHC). This tunnel might be produced for a cost of about 1000 $/m. An e{sup +}e{sup -} collider in this tunnel could perhaps study {ital t{anti t}} production at threshold with good resolution, Higgs production and e/p collisions at high energy. This note considers some of the parameters and issues of such a machine.

  1. Hadron physics

    SciTech Connect

    Bunce, G.

    1984-05-30

    Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain.

  2. CDF (Collider Detector at Fermilab) calorimetry

    SciTech Connect

    Jensen, H.B.

    1987-03-01

    The Collider Detector at Fermilab (CDF) is a large detector built to study 2 TeV anti p p collisions at the Fermilab Tevatron. The calorimetry, which has polar angle coverage from 2 to 178, and complete azimuthal coverage within this region, forms the subject of this paper. It consists of both electromagnetic shower counters (EM calorimeters) and hadron calorimeters, and is segmented into about 5000 ''towers'' or solid angle elements.

  3. High Energy Accelerator and Colliding Beam User Group. Progress report, March 1, 1992--October 31, 1992

    SciTech Connect

    Snow, G.A.; Skuja, A.

    1992-05-01

    This report discusses research in the following areas: the study of e{sup +}e{sup {minus}} interactions; Hadron collider physics at Fermilab; fixed target physics and particle physics of general interest; and, the solenoidal detector collaboration at SSCL.

  4. The Emergence of Hadrons from QCD Color

    NASA Astrophysics Data System (ADS)

    Brooks, Will

    2013-10-01

    The propagation of colored quarks through strongly interacting systems, and their subsequent evolution into color-singlet hadrons, are phenomena that showcase unique facets of Quantum Chromodynamics (QCD). Medium-stimulated gluon bremsstrahlung, a fundamental QCD process, induces broadening of the transverse momentum of the parton, and creates partonic energy loss manifesting itself in experimental observables that are accessible in high energy interactions in hot and cold systems. The formation of hadrons, which is the dynamical enforcement of the QCD confinement principle, is very poorly understood on the basis of fundamental theory, although detailed models such as the Lund string model or cluster hadronization models can generally be tuned to capture the main features of hadronic final states. With the advent of the technical capability to study hadronic final states with good particle identification and at high luminosity, a new opportunity has appeared. Study of the characteristics of parton propagation and hadron formation as they unfold within atomic nuclei are now being used to understand the coherence and spatial features of these processes and to refine new experimental tools that will be used in future experiments. Fixed-target data on nuclei with lepton and hadron beams, and collider experiments involving nuclei, all make essential contact with these topics and they elucidate different aspects of these same themes. In this talk, a survey of the most relevant recent data and its potential interpretation will be followed by descriptions of feasible experiments at an electron-ion collider, in the context of existing measurements as well as the experiments performed following the upgrade of Jefferson Lab to 12 GeV.

  5. Antiparticle to particle production ratios in hadron-hadron and d-Au collisions in the DPMJET-III Monte Carlo model

    SciTech Connect

    Bopp, F. W.; Ranft, J.; Engel, R.; Roesler, S.

    2008-01-15

    To understand baryon stopping we analyze new Relativistic Heavy Ion Collider and Fermilab data within the framework of the multichain Monte Carlo DPMJET-III. The present consideration is restricted to hadron-hadron and d-Au collisions, where the present version of the model can be trusted.

  6. NLO QCD CORRECTIONS TO HADRONIC HIGGS PRODUCTION WITH HEAVY QUARKS.

    SciTech Connect

    DAWSON,S.; JACKSON,C.; ORR,L.; REINA,L.; WACHEROTH,D.

    2003-07-02

    The production of a Higgs boson in association with a pair of t{bar t} or b{bar b} quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief description of the most relevant technical aspects of the calculation, we review the results obtained for both the Tevatron and the Large Hadron Collider.

  7. Proton-Proton and Proton-Antiproton Colliders

    NASA Astrophysics Data System (ADS)

    Scandale, Walter

    2015-02-01

    In the last five decades, proton-proton and proton-antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion-ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

  8. Measurement of the radiation field surrounding the Collider Detector at Fermilab

    SciTech Connect

    K. Kordas et al.

    2004-01-28

    We present here the first direct and detailed measurements of the spatial distribution of the ionizing radiation surrounding a hadron collider experiment. Using data from two different exposures we measure the effect of additional shielding on the radiation field around the Collider Detector at Fermilab (CDF). Employing a simple model we parameterize the ionizing radiation field surrounding the detector.

  9. Radiative return capabilities of a high-energy, high-luminositye+e-collider

    DOE PAGES

    Karliner, Marek; Low, Matthew; Rosner, Jonathan L.; Wang, Lian-Tao

    2015-08-14

    An electron-positron collider operating at a center-of-mass energy ECM can collect events at all lower energies through initial-state radiation (ISR or radiative return). We explore the capabilities for radiative return studies by a proposed high-luminosity collider at ECM = 250 or 90 GeV, to fill in gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These capabilities are compared with those of the lower-energy e+e- colliders as well as hadron colliders such as the Tevatron and the CERN Large Hadron Collider (LHC). Some examples of accessible questions in dark photon searches and heavy flavor spectroscopy are given.

  10. Radiative return capabilities of a high-energy, high-luminosity e+e- collider

    NASA Astrophysics Data System (ADS)

    Karliner, Marek; Low, Matthew; Rosner, Jonathan L.; Wang, Lian-Tao

    2015-08-01

    An electron-positron collider operating at a center-of-mass energy ECM can collect events at all lower energies through initial-state radiation (ISR or radiative return). We explore the capabilities for radiative return studies by a proposed high-luminosity collider at ECM=250 or 90 GeV, to fill in gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These capabilities are compared with those of the lower-energy e+e- colliders as well as hadron colliders such as the Tevatron and the CERN Large Hadron Collider (LHC). Some examples of accessible questions in dark photon searches and heavy flavor spectroscopy are given.

  11. Searches for new gauge bosons at future colliders

    SciTech Connect

    Rizzo, T.G.

    1996-09-01

    The search reaches for new gauge bosons at future hadron and lepton colliders are summarized for a variety of extended gauge models. Experiments at these energies will vastly improve over present limits and will easily discover a Z` and/or W` in the multi-TeV range.

  12. Overview of a high luminosity {mu}{sup +}{mu}{sup {minus}} collider

    SciTech Connect

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

    1997-03-01

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

  13. Photon collider Higgs factories

    NASA Astrophysics Data System (ADS)

    Telnov, V. I.

    2014-09-01

    The discovery of the Higgs boson (and still nothing else) have triggered appearance of many proposals of Higgs factories for precision measurement of the Higgs properties. Among them there are several projects of photon colliders (PC) without e+e- in addition to PLC based on e+e- linear colliders ILC and CLIC. In this paper, following a brief discussion of Higgs factories physics program I give an overview of photon colliders based on linear colliders ILC and CLIC, and of the recently proposed photon-collider Higgs factories with no e+e- collision option based on recirculation linacs in ring tunnels.

  14. Gamma-gamma colliders

    SciTech Connect

    Kim, K.J.; Sessler, A.

    1996-06-01

    Gamma-gamma colliders make intense beams of gamma rays and have them collide so as to make elementary particles. The authors show, in this article, that constructing a gamma-gamma collider as an add-on to an electron-positron linear collider is possible with present technology and that it does not require much additional cost. Furthermore, they show that the resulting capability is very interesting from a particle physics point of view. An overview of a linear collider, with a second interaction region devoted to {gamma}{gamma} collisions is shown.

  15. Hadronic Production of Colored SUSY Particles with Electroweak NLO Contributions

    SciTech Connect

    Hollik, Wolfgang; Mirabella, Edoardo; Kollar, Monika; Trenkel, Maike K.

    2008-11-23

    We consider the production of squarks and gluinos at hadronic colliders. An overview over the class of processes is given. We investigate in detail the tree-level and higher order EW contributions to the cross sections. Special care has to be taken to obtain infrared finite observables. We study numerically stop--anti-stop and squark-gluino production at the LHC.

  16. QCD in hadron-hadron collisions

    SciTech Connect

    Albrow, M.

    1997-03-01

    Quantum Chromodynamics provides a good description of many aspects of high energy hadron-hadron collisions, and this will be described, along with some aspects that are not yet understood in QCD. Topics include high E{sub T} jet production, direct photon, W, Z and heavy flavor production, rapidity gaps and hard diffraction.

  17. Crystal Ball: On the Future High Energy Colliders

    SciTech Connect

    Shiltsev, Vladimir

    2015-09-20

    High energy particle colliders have been in the forefront of particle physics for more than three decades. 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). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

  18. Updated measurements of hadronic B decays at CDF

    SciTech Connect

    Morello, Michael J.

    2012-01-01

    The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides a rich, and highly rewarding program that has currently reached full maturity. In the following I report some recent results on hadronic decays: the evidence for the charmless annihilation decay mode B{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}, and the first reconstruction in hadron collisions of the suppressed decays B{sup -} {yields} D({yields} K{sup +}{pi}{sup 0})K{sup -} and B{sup -} {yields} D({yields} K{sup +} {pi}{sup -}){pi}{sup -}.

  19. Drell-Yan production at collider energies

    SciTech Connect

    Neerven, W.L. Van

    1995-07-01

    We present some results of the Drell-Yan cross sections d{sigma}/dm and {sigma}{sub tot} which includes the O ({alpha}{sub s}{sup 2}) contribution to the coefficient function. In particular we study the total cross section {sigma}{sub tot} for vector boson production and d{sigma}/dm for low invariant masses m of the lepton pairs at large hadron collider energies. This study includes a detailed discussion of the dependence of the cross sections on the chosen scheme ({bar M}S versus DIS) and the factorization scale.

  20. International linear collider reference design report

    SciTech Connect

    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.

  1. The development of colliders

    SciTech Connect

    Sessler, A.M.

    1997-03-01

    During the period of the 50`s and the 60`s colliders were developed. Prior to that time there were no colliders, and by 1965 a number of small devices had worked, good understanding had been achieved, and one could speculate, as Gersh Budker did, that in a few years 20% of high energy physics would come from colliders. His estimate was an under-estimate, for now essentially all of high energy physics comes from colliders. The author presents a brief review of that history: sketching the development of the concepts, the experiments, and the technological advances which made it all possible.

  2. Future Accelerators, Muon Colliders, and Neutrino Factories

    SciTech Connect

    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.

  3. Detecting gluinos at hadron supercolliders

    SciTech Connect

    Baer, H.; Barger, V.; Karatas, D.; Tata, X.

    1987-07-01

    If the gluino mass exceeds 150--200 GeV, searches for gluinos will likely have to be made at multi-TeV hadron colliders. Unlike the case of light gluinos (m approx. <60 GeV), which dominantly decay via g-tilde..-->..qq-bargamma-tilde, heavy-gluino decays proceed via g-tilde..-->..qq-barW-tilde/sub i/ and g-tilde..-->..qq-barZ-tilde/sub j/ where W-tilde/sub i/ and Z-tilde/sub j/ are charged and neutral mass eigenstates in the gauge-Higgs-fermion sector. The usual missing-p/sub T/ signatures are altered and new strategies may be required for gluino detection. We analyze heavy-gluino and scalar-quark decays and estimate the production rates for W-tilde/sub i/W-tilde/sub j/, W-tilde/sub i/Z-tilde/sub j/, and Z-tilde/sub i/Z-tilde/sub j/ pairs at a 40-TeV pp collider. Since a heavy gluino decays dominantly into jets and the heavy chargino, which in turn decays into a Z/sup 0/ or W boson plus a lighter chargino or neutralino, a typical gluino-pair event contains several leptons and/or jets in the final state.

  4. Collider-independent tt forward-backward asymmetries.

    PubMed

    Aguilar-Saavedra, J A; Juste, A

    2012-11-21

    We introduce the forward-backward asymmetries A(u), A(d) corresponding to uū, dd → tt production, respectively, at hadron colliders. These are collider and center-of-mass independent observables, directly related to the forward-backward and charge asymmetries measured at the Tevatron and the LHC, respectively. We discuss how to extract these asymmetries from data. Because these asymmetries are collider independent, their measurement at these two colliders could elucidate the nature of the anomalous forward-backward asymmetry measured at the Tevatron. Our framework also shows in a model independent fashion that a positive Tevatron asymmetry exceeding the standard model expectation is compatible with the small asymmetry measured at the LHC.

  5. Science and Technology of the TESLA Electron-Positron Linear Collider

    NASA Astrophysics Data System (ADS)

    Wagner, Albrecht

    2002-07-01

    Recent analyses of the long term future of particles physics in Asia, Europe, and the U.S.A. have led to the consensus that the next major facility to be built to unravel the secrets of the micro-cosmos is an electron-positron linear collider in the energy range of 500 to 1000 GeV. This collider should be constructed in an as timely fashion as possible to overlap with the Large Hadron Collider, under construction at CERN. Here, the scientific potential and the technological aspects of the TESLA projects, a superconducting collider with an integrated X-ray laser laboratory, are summarised.

  6. Measurement of the Oscillation Frequency of Bs Mesons in the Hadronic Decay Mode Bs→ π Ds(Φ π)X with the D0 Detector at the Fermilab Tevatron Collider

    SciTech Connect

    Weber, Gernot August

    2009-03-01

    The standard model (SM) of particle physics is a theory, describing three out of four fundamental forces. In this model the Cabibbo-Kobayashi-Maskawa (CKM) matrix describes the transformation between the mass and weak eigenstates of quarks. The matrix properties can be visualized as triangles in the complex plane. A precise measurement of all triangle parameters can be used to verify the validity of the SM. The least precisely measured parameter of the triangle is related to the CKM element |Vtd|, accessible through the mixing frequency (oscillation) of neutral B mesons, where mixing is the transition of a neutral meson into its anti-particle and vice versa. It is possible to calculate the CKM element |Vtd| and a related element |Vts| by measuring the mass differences Δmd(Δms) between neutral Bd and $\\bar{B}$d (Bs and $\\bar{B}$s) meson mass eigenstates. This measurement is accomplished by tagging the initial and final state of decaying B mesons and determining their lifetime. Currently the Fermilab Tevatron Collider (providing p$\\bar{p}$ collisions at {radical}s = 1.96 TeV) is the only place, where Bs oscillations can be studied. The first selection of the 'golden', fully hadronic decay mode Bs → πDs(Φπ)X at D0 is presented in this thesis. All data, taken between April 2002 and August 2007 with the D0 detector, corresponding to an integrated luminosity of integral Ldt = 2.8 fb-1 is used. The oscillation frequency Δms and the ratio |Vtd|/|Vts| are determined as Δms = (16.6-0.4+0.5(stat)-0.3+0.4(sys)) ps-1, |Vtd|/|Vts| = 0.213-0.003+0.004(exp) ± 0.008(theor). These results are consistent with the standard model expectations and no evidence for new physics is observable.

  7. SLAC Linear Collider

    SciTech Connect

    Richter, B.

    1985-12-01

    A report is given on the goals and progress of the SLAC Linear Collider. The status of the machine and the detectors are discussed and an overview is given of the physics which can be done at this new facility. Some ideas on how (and why) large linear colliders of the future should be built are given.

  8. Composite weak bosons at the large hadronic collider

    NASA Astrophysics Data System (ADS)

    Fritzsch, Harald

    2016-06-01

    In a composite model of the weak bosons the p-wave bosons are studied. The state with the lowest mass is identified with the boson, which has been discovered at the LHC. Specific properties of the excited bosons are discussed, in particular their decays into weak bosons and photons. Recently a two-photon signal has been observed, which might come from the decay of a neutral heavy boson with a mass of about 0.75 TeV. This particle could be an excited weak tensor boson.

  9. W±Z production at hadron colliders in NNLO QCD

    NASA Astrophysics Data System (ADS)

    Grazzini, Massimiliano; Kallweit, Stefan; Rathlev, Dirk; Wiesemann, Marius

    2016-10-01

    We report on the first computation of the next-to-next-to-leading order (NNLO) QCD corrections to W± Z production in proton collisions. We consider both the inclusive production of on-shell W± Z pairs at LHC energies and the total W± Z rates including off-shell effects of the W and Z bosons. In the off-shell computation, the invariant mass of the lepton pairs from the Z boson decay is required to be in a given mass window, and the results are compared with the corresponding measurements obtained by the ATLAS and CMS collaborations. The NNLO corrections range from 8% at √{ s} = 7TeV to 11% at √{ s} = 14TeV and significantly improve the agreement with the LHC data at √{ s} = 7 and 8TeV.

  10. Rf system considerations for a large hadron collider

    SciTech Connect

    Raka, E.

    1988-01-01

    In this paper, we shall discuss how we arrive at a particular choice of voltage and frequency; the type of acceleration structure that would be suitable for obtaining the required voltage and resonant impedance; static beam loading including a simplified beam stability criterion involving the beam current and total rf system shunt impedance; the basic principle of rf phase and frequency control loops; and the effect of rf noise and its interaction with these loops. Finally, we shall consider the need for and design of rf systems to damp independently coherent oscillations of individual bunches or groups of bunches. 30 refs., 17 figs., 2 tabs.

  11. Six-lepton Z' resonance at the Large Hadron Collider.

    PubMed

    Barger, Vernon; Langacker, Paul; Lee, Hye-Sung

    2009-12-18

    New physics models admit the interesting possibility of a Z' weak boson associated with an extra U(1) gauge symmetry and a Higgs boson that is heavy enough to decay into a pair of Z bosons. Then Z' production and decay via Z' --> ZH --> ZZZ has a distinctive LHC signal that is nearly background-free and reconstructs the H and Z' masses and widths. The Z' decay to 3 pairs of leptons is especially distinctive. The ZH decay mode exists even if the Z' is decoupled from leptons, which motivates an independent 6-lepton resonance search regardless of the dilepton search results. PMID:20366250

  12. Color sextet scalars at the CERN Large Hadron Collider

    SciTech Connect

    Chen, C.-R.; Klemm, William; Rentala, Vikram; Wang Kai

    2009-03-01

    Taking a phenomenological approach, we study a color sextet scalar at the LHC. We focus on the QCD production of a color sextet pair {phi}{sub 6}{phi}{sub 6} through gg fusion and qq annihilation. Its unique coupling to {psi}{sup c}{psi} allows the color sextet scalar to decay into same-sign diquark states, such as {phi}{sub 6}{yields}tt/tt*. We propose a new reconstruction in the multijet plus same-sign dilepton with missing transverse energy samples (bb+l{sup {+-}}l{sup {+-}}+Ee{sub T}+Nj, N{>=}6) to search for on-shell tttt final states from sextet scalar pair production. Thanks to the large QCD production, the search covers the sextet mass range up to 1 TeV for 100 fb{sup -1} integrated luminosity.

  13. Dijet Searches for Supersymmetry at the Large Hadron Collider

    SciTech Connect

    Randall, Lisa; Tucker-Smith, David

    2008-11-28

    We present several strategies for searching for supersymmetry in dijet channels, using the two leading jets' momenta alone rather than the full missing transverse energy. Preliminary investigations suggest that signal-to-background ratios of at least 4-5 should be achievable at the LHC, with discovery possible for squarks as heavy as {approx}1.7 TeV.

  14. Non-Large Hadron Collider Physics Program at CERN

    SciTech Connect

    Rondio, Ewa

    2011-08-17

    CERN has a diversified program at the chain of accelerators also used as LHC injectors. Selected examples of recent results will be used to illustrate the depth and the breadth of the overall physics program. Starting from lowest energies – the only decelerator at CERN (AD) is looking at antimatter production and trapping. First trapped anti-hydrogen were reported in 2010. Interdisciplinary team is working in the CLOUD experiment, where systematic studies on condensation have just started with the unique equipment allowing control of contamination, temperature and radiation dose. They may affect our understanding of climate changes. At SPS, results from Compass on the studies of nucleon spin structure bring the conclusion on how much gluons contribute to the nucleon spin. These results will be presented in more details. SPS beam is also used to produce high energy neutrinos which are sent towards Gran Sasso underground laboratory where OPERA and ICARUS detectors are waiting to register them. First observation of tau neutrino interaction was reported by OPERA last year. It is expected that the broad and evolving physics program will be supported at CERN to complement the research at the energy frontier.

  15. Six-Lepton Z' Resonance at the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Barger, Vernon; Langacker, Paul; Lee, Hye-Sung

    2009-12-01

    New physics models admit the interesting possibility of a Z' weak boson associated with an extra U(1) gauge symmetry and a Higgs boson that is heavy enough to decay into a pair of Z bosons. Then Z' production and decay via Z'→ZH→ZZZ has a distinctive LHC signal that is nearly background-free and reconstructs the H and Z' masses and widths. The Z' decay to 3 pairs of leptons is especially distinctive. The ZH decay mode exists even if the Z' is decoupled from leptons, which motivates an independent 6-lepton resonance search regardless of the dilepton search results.

  16. Hadron multiplicity in pp and AA collisions at LHC from the color glass condensate

    NASA Astrophysics Data System (ADS)

    Levin, Eugene; Rezaeian, Amir H.

    2010-09-01

    We provide quantitative predictions for the rapidity, centrality and energy dependencies of inclusive charged-hadron productions for the forthcoming LHC measurements in nucleus-nucleus collisions based on the idea of gluon saturation in the color-glass condensate framework. Our formulation gives very good descriptions of the first data from the LHC for the inclusive charged-hadron production in proton-proton collisions, the deep inelastic scattering at the Hadron-Elektron-Ring-Anlage at small Bjorken x, and the hadron multiplicities in nucleus-nucleus collisions at the Relativistic Heavy Ion Collider.

  17. Prospects for and tests of hadron calorimetry with silicon

    SciTech Connect

    Brau, James E.; Gabriel, Tony A.; Rancoita, P. G.

    1989-03-01

    Hadron calorimetry with silicon may provide crucial capabilities in experiments at the high luminosity, high energy colliders of the future, particularly due to silicon's fast intrinsic speed and absolute calibration. The important underlying processes of our understanding of hadron calorimeters are reviewed to set the framework for the presentation of recent calculations of the expected performance of silicon detector based hadron calorimeters. Such devices employing uranium are expected to achieve the compensation condition (that is, the ratio of the most probable electron signal to hadron signal (e/h) is approx.1.0) based on the understanding that has been derived from the uranium-liquid argon and uranium-plastic scintillator systems. In fact, even lead-silicon calorimeters are found to achieve the attractive value for the e/h ratio of 1.16 at 10 GeV. An experimental test of these predictions is underway at CERN by the SICAPO Collaboration. 64 refs., 19 figs.

  18. Containment and resolution of hadronic showers at the FCC

    NASA Astrophysics Data System (ADS)

    Carli, T.; Helsens, C.; Henriques Correia, A.; Solans Sánchez, C.

    2016-09-01

    The particles produced at a potential Future Circular Collider with √s = 100 TeV are of unprecented energies. In this document we present the hadronic shower containment and resolution parametrizations based on Geant4 simulations for the Hadronic calorimetry needed for conceptual detector design at this energy. The Geant4 toolkit along with FTFP_BERT physics list are used in this study. Comparisons are made with test-beam data from the ATLAS Tile hadronic calorimeter. These simulations motivate a 12 λ calorimeter in order to contain at 98% level TeV single hadron showers and multi-TeV jets and keep a pion energy resolution constant term of approximately 3%.

  19. GARLIC: GAmma Reconstruction at a LInear Collider experiment

    NASA Astrophysics Data System (ADS)

    Jeans, D.; Brient, J.-C.; Reinhard, M.

    2012-06-01

    The precise measurement of hadronic jet energy is crucial to maximise the physics reach of a future Linear Collider. An important ingredient required to achieve this is the efficient identification of photons within hadronic showers. One configuration of the ILD detector concept employs a highly granular silicon-tungsten sampling calorimeter to identify and measure photons, and the GARLIC algorithm described in this paper has been developed to identify photons in such a calorimeter. We describe the algorithm and characterise its performance using events fully simulated in a model of the ILD detector.

  20. Non-Diagonal Flavour Observables in B and Collider Physics

    SciTech Connect

    Hurth, Tobias

    2003-11-11

    Until now the focus within the direct search for supersymmetry has mainly been on flavour diagonal observables. Recently lepton flavour violating signals at future electron positron colliders have been studied. There is now an opportunity to analyze the relations between collider observables and low-energy observables in the hadronic sector. In a first work in this direction, we study flavour violation in the squark decays of the second and third generations taking into account results from B physics, in particular from the rare decay b {yields} s gamma. Correlations between various squark decay modes can be used to get more precise information on various flavour violating parameters.

  1. High Energy Colliders as Tools to Understand the Early Universe

    SciTech Connect

    Tait, Tim

    2008-08-16

    Cosmological observations have reached a new era of precision, and reveal many interesting and puzzling features of the Universe. I will briefly review two of the most exciting mysteries: the nature of the dark components of the Universe, and the origin of the asymmetry between matter and anti-matter. I will argue that our best hope of unraveling these questions will need to combine information from the heavens with measurements in the lab at high energy particle accelerators. The end of run II of the Tevatron, the up-coming Large Hadron Collider and proposed International Linear Collider all have great potential to help us answer these questions in the near future.

  2. Unparticle self-interactions and their collider implications

    NASA Astrophysics Data System (ADS)

    Feng, Jonathan L.; Rajaraman, Arvind; Tu, Huitzu

    2008-04-01

    In unparticle physics, operators of the conformal sector have self-interactions, and these are unsuppressed for strong coupling. The 3-point interactions are completely determined by conformal symmetry, up to a constant. We do not know of any theoretical upper bounds on this constant. Imposing current experimental constraints, we find that these interactions mediate spectacular collider signals, such as pp→U→UU→γγγγ, γγZZ, ZZZZ, γγl+l-, ZZl+l-, and 4l, with cross sections of picobarns or larger at the large hadron collider. Self-interactions may therefore provide the leading discovery prospects for unparticle physics.

  3. Linear Collider Physics Resource Book Snowmass 2001

    SciTech Connect

    Ronan , 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

  4. QCD SPIN PHYSICS IN HADRONIC INTERACTIONS.

    SciTech Connect

    VOGELSANG,W.

    2007-06-19

    We discuss spin phenomena in high-energy hadronic scattering, with a particular emphasis on the spin physics program now underway at the first polarized proton-proton collider, RHIC. Experiments at RHIC unravel the spin structure of the nucleon in new ways. Prime goals are to determine the contribution of gluon spins to the proton spin, to elucidate the flavor structure of quark and antiquark polarizations in the nucleon, and to help clarify the origin of transverse-spin phenomena in QCD. These lectures describe some aspects of this program and of the associated physics.

  5. Holographic model of hadronization.

    PubMed

    Evans, Nick; Tedder, Andrew

    2008-04-25

    We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e(+)e(-) collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well. PMID:18518189

  6. Holographic Model of Hadronization

    SciTech Connect

    Evans, Nick; Tedder, Andrew

    2008-04-25

    We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e{sup +}e{sup -} collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well.

  7. Holographic model of hadronization.

    PubMed

    Evans, Nick; Tedder, Andrew

    2008-04-25

    We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e(+)e(-) collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well.

  8. Towards resolving strongly-interacting dark sectors at colliders

    NASA Astrophysics Data System (ADS)

    Englert, Christoph; Nordström, Karl; Spannowsky, Michael

    2016-09-01

    Dark sectors with strong interactions have received considerable interest. Assuming the existence of a minimally coupled dark sector which runs to strong interactions in the infrared, we address the question whether the scaling behavior of this dark sector can be observed in missing energy signatures at present and future hadron colliders. We compare these findings to the concrete case of self-interacting dark matter and demonstrate that the energy dependence of high-momentum transfer final states can in principle be used to gain information about the UV structure of hidden sectors at future hadron colliders, subject to large improvements in systematic uncertainties, which could complement proof-of-principle lattice investigations. We also comment on the case of dark Abelian U (1 ) theories.

  9. Threshold hadronic event shapes with effective field theory

    SciTech Connect

    Kelley, Randall; Schwartz, Matthew D.

    2011-02-01

    Hadronic event shapes, that is, event shapes at hadron colliders, could provide a great way to test both standard and nonstandard theoretical models. However, they are significantly more complicated than event shapes at e{sup +}e{sup -} colliders, involving multiple hard directions, multiple channels, and multiple color structures. In this paper, hadronic event shapes are examined with soft-collinear effective theory (SCET) by expanding around the dijet limit. A simple event shape, threshold thrust, is defined. This observable is global and has no free parameters, making it ideal for clarifying how resummation of hadronic event shapes can be done in SCET. Threshold thrust is calculated at next-to-leading fixed order (NLO) in SCET and resummed to next-to-next-to-leading logarithmic (NNLL) accuracy. The scale-dependent parts of the soft function are shown to agree with what is expected from general observations, and the factorization formula is explicitly shown to be renormalization group invariant to 1-loop. Although threshold thrust is not itself expected to be phenomenologically interesting, it can be modified into a related observable which allows the jet p{sub T} distribution to be calculated and resummed to NNLL+NLO accuracy. As in other processes, one expects resummation to be important even for moderate jet momenta due to dynamical threshold enhancement. A general discussion of threshold enhancement and nonglobal logs in hadronic event shapes is also included.

  10. Proton-antiproton collider physics

    SciTech Connect

    Shochet, M.J.

    1995-07-01

    The 9th {anti p}p Workshop was held in Tsukuba, Japan in October, 1993. A number of important issues remained after that meeting: Does QCD adequately describe the large cross section observed by CDF for {gamma} production below 30 GeV? Do the CDF and D0 b-production cross sections agree? Will the Tevatron live up to its billing as a world-class b-physics facility? How small will the uncertainty in the W mass be? Is there anything beyond the Minimal Standard Model? And finally, where is the top quark? Presentations at this workshop addressed all of these issues. Most of them are now resolved, but new questions have arisen. This summary focuses on the experimental results presented at the meeting by CDF and D0 physicists. Reviews of LEP and HERA results, future plans for hadron colliders and their experiments, as well as important theoretical presentations are summarized elsewhere in this volume. Section 1 reviews physics beyond the Minimal Standard Model. Issues in b and c physics are addressed in section 3. Section 4 focuses on the top quark. Electroweak physics is reviewed in section 5, followed by QCD studies in section 6. Conclusions are drawn in section 7.

  11. Nonglobal correlations in collider physics

    DOE PAGES

    Moult, Ian; Larkoski, Andrew J.

    2016-01-13

    Despite their importance for precision QCD calculations, correlations between in- and out-of-jet regions of phase space have never directly been observed. These so-called non-global effects are present generically whenever a collider physics measurement is not explicitly dependent on radiation throughout the entire phase space. In this paper, we introduce a novel procedure based on mutual information, which allows us to isolate these non-global correlations between measurements made in different regions of phase space. We study this procedure both analytically and in Monte Carlo simulations in the context of observables measured on hadronic final states produced in e+e- collisions, though itmore » is more widely applicable.The procedure exploits the sensitivity of soft radiation at large angles to non-global correlations, and we calculate these correlations through next-to-leading logarithmic accuracy. The bulk of these non-global correlations are found to be described in Monte Carlo simulation. They increase by the inclusion of non-perturbative effects, which we show can be incorporated in our calculation through the use of a model shape function. As a result, this procedure illuminates the source of non-global correlations and has connections more broadly to fundamental quantities in quantum field theory.« less

  12. Linear collider: a preview

    SciTech Connect

    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.

  13. Accelerator physics in ERL based polarized electron ion collider

    SciTech Connect

    Hao, Yue

    2015-05-03

    This talk will present the current accelerator physics challenges and solutions in designing ERL-based polarized electron-hadron colliders, and illustrate them with examples from eRHIC and LHeC designs. These challenges include multi-pass ERL design, highly HOM-damped SRF linacs, cost effective FFAG arcs, suppression of kink instability due to beam-beam effect, and control of ion accumulation and fast ion instabilities.

  14. High luminosity {mu}{sup +} {mu}{sup {minus}} collider: Report of a feasibility study

    SciTech Connect

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

    1996-12-01

    Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity {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 analyzed. Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. We briefly mention the luminosity requirements of hadrons and lepton machines and their high-energy-physics advantages and disadvantages in reference to their effective center of mass energy. Finally, we present an R & D plan to determine whether such machines are practical.

  15. Photon collider at TESLA

    NASA Astrophysics Data System (ADS)

    Telnov, Valery

    2001-10-01

    High energy photon colliders ( γγ, γe) based on backward Compton scattering of laser light is a very natural addition to e +e - linear colliders. In this report, we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case, the γγ luminosity in the high energy part of spectrum can reach about (1/3) Le +e -. Typical cross-sections of interesting processes in γγ collisions are higher than those in e +e - collisions by about one order of magnitude, so the number of events in γγ collisions will be more than that in e +e - collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is "an optical storage ring (optical trap)" with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems.

  16. An Electron-Ion Collider at CEBAF

    SciTech Connect

    Kees de Jager; Lia Merminga; Ya. Derbenev

    2002-10-01

    Electron-ion colliders with a center of mass energy between 15 and 100 GeV, a luminosity of at least 10{sup 33}cm{sup -1}s{sup -1}, and a polarization of both beams at or above 80% have been proposed for future studies of hadronic structure. The scheme proposed here would accelerate the electron beam using the CEBAF recirculating linac with energy recovery. If all accelerating structures presently installed in the CEBAF tunnel are replaced by ones with a {approx}20 MV/m gradient, then a single recirculation results in an electron beam energy of about 5 GeV. After colliding with protons/light ions circulating in a figure-of-eight storage ring (for flexibility of spin manipulation) at an energy of up to 100 GeV, the electrons are re-injected into the CEBAF accelerator for deceleration and energy recovery. In this report several lay-out options and their respective feasibilities will be presented and discussed, together with parameters which would provide a luminosity of up to 1 x 10{sup 35} cm{sup -2}s{sup -1}. The feasibility of combining such a collider at a center-of-mass energy [sq rt] s of up to 43 GeV with a fixed target facility of 25 GeV is also explored.

  17. Comparing multiparticle production within a two-component dual parton model with collider data

    SciTech Connect

    Hahn, K.; Ranft, J. )

    1990-03-01

    The dual parton model (DPM) is very successful in describing hadronic multiparticle production. The version of DPM presented includes both soft and hard mechanisms. The hard component is described according to the lowest-order perturbative QCD--parton-model cross section. The model is formulated in the form of a Monte Carlo event generator. Results obtained with this event generator are compared with data on inclusive reactions in the TeV energy range of the CERN and Fermilab hadron colliders.

  18. Virtual hadronic and leptonic contributions to Bhabha scattering.

    PubMed

    Actis, Stefano; Czakon, Michał; Gluza, Janusz; Riemann, Tord

    2008-04-01

    Using dispersion relations, we derive the complete virtual QED contributions to Bhabha scattering due to vacuum polarization effects. We apply our result to hadronic corrections and to heavy lepton and top quark loop insertions. We give the first complete estimate of their net numerical effects for both small and large angle scattering at typical beam energies of meson factories, the CERN Large Electron-Positron Collider, and the International Linear Collider. With a typical amount of 1-3 per mil they are of relevance for precision experiments. PMID:18517933

  19. B physics at CDF - the Beauty of hadron collisions

    SciTech Connect

    Tonelli, Diego

    2010-11-01

    The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides an unique, rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in B{sub s}{sup 0} mixing, and b {yields} s penguin decays.

  20. Single event effects and their mitigation for the Collider Detector at Fermilab

    SciTech Connect

    Tesarek, Richard J.; D'Auria, Saverio; Dong, Peter; Hocker, Andy; Kordas, Kostas; McGimpsey, Susan; Nicolas, Ludovic; Wallny, Rainer; Schmitt, Wayne; Worm, Steven; /Fermilab /Toronto U. /Glasgow U. /Rutherford /UCLA

    2005-11-01

    We present an overview of radiation induced failures and operational experiences from the Collider Detector at Fermilab (CDF). In our summary, we examine single event effects (SEE) in electronics located in and around the detector. We present results of experiments to identify the sources and composition of the radiation and steps to reduce the rate of SEEs in our electronics. Our studies have led to a better, more complete understanding of the radiation environment in a modern hadron collider experiment.

  1. Extended gauge sectors at future colliders: Report of the New Gauge Boson Subgroup

    SciTech Connect

    Rizzo, T.G.

    1996-12-01

    The author summarizes the results of the New Gauge Boson Subgroup on the physics of extended gauge sectors at future colliders as presented at the 1996 Snowmass workshop. He discusses the direct and indirect search reaches for new gauge bosons at both hadron and lepton colliders as well as the ability of such machines to extract detailed information on the couplings of these particles to the fermions and gauge bosons of the Standard Model. 41 refs., 18 figs., 5 tabs.

  2. Rapidity dependence of the average transverse momentum in hadronic collisions

    NASA Astrophysics Data System (ADS)

    Durães, F. O.; Giannini, A. V.; Gonçalves, V. P.; Navarra, F. S.

    2016-08-01

    The energy and rapidity dependence of the average transverse momentum in p p and p A collisions at energies currently available at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) are estimated using the color glass condensate (CGC) formalism. We update previous predictions for the pT spectra using the hybrid formalism of the CGC approach and two phenomenological models for the dipole-target scattering amplitude. We demonstrate that these models are able to describe the RHIC and LHC data for hadron production in p p , d Au , and p Pb collisions at pT≤20 GeV. Moreover, we present our predictions for and demonstrate that the ratio / decreases with the rapidity and has a behavior similar to that predicted by hydrodynamical calculations.

  3. Hadron supercolliders: The 1-TeV scale and beyond

    SciTech Connect

    Quigg, C.

    1990-08-10

    Greater understanding of the connection between the weak and electromagnetic interactions is central to progress in elementary-particle physics. A definitive exploration of the mechanism for electroweak symmetry breaking will require collisions between fundamental constituents at energies on the order of 1 TeV. This goal drives the design of high-energy, high-luminosity hadron colliders that will be commissioned during the next decade, but by no means completely defines their scientific potential. These three lectures are devoted to a review of the standard-model issues that motivated an experimental assault on the 1-TeV scale, an introduction to the machines and the experimental environment they will present, and a survey of possibilities for measurement and discovery with a multi-TeV hadron collider. 72 refs., 29 figs.

  4. Searches for supersymmetry at high-energy colliders

    SciTech Connect

    Feng, Jonathan L.; Grivaz, Jean-Francois; Nachtman, Jane

    2010-01-15

    This review summarizes the state of the art in searches for supersymmetry at colliders on the eve of the Large Hadron Collider era. Supersymmetry is unique among extensions of the standard model in being motivated by naturalness, dark matter, and force unification, both with and without gravity. At the same time, weak-scale supersymmetry encompasses a wide range of experimental signals that are also found in many other frameworks. Motivations for supersymmetry are recalled and the various models and their distinctive features are reviewed. Searches for neutral and charged Higgs bosons and standard-model superpartners at the high energy frontier are summarized comprehensively, considering both canonical and noncanonical supersymmetric models, and including results from the LEP collider at CERN, HERA at DESY, and the Fermilab Tevatron.

  5. Muon-muon and other high energy colliders

    SciTech Connect

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

    1997-02-01

    The first section looks at the high energy physics advantages, disadvantages and luminosity requirements of hadron, of lepton and photon-photon colliders for comparison. The second section discusses the physics considerations for the muon collider. The third section covers muon collider components. The fourth section is about the intersection region and detectors. In the fifth section, the authors discuss modifications to enhance the muon polarization`s operating parameters with very small momentum spreads, operations at energies other than the maximum for which the machine is designed, and designs of machines for different maximum energies. The final section discusses a Research and Development plan aimed at the operation of a 0.5 TeV demonstration machine by the year 2010, and of the 4 TeV machine by the year 2020.

  6. Azimuthal Asymmetric Distribution of Hadrons Inside a Jet atHadron Collider

    SciTech Connect

    Yuan, Feng

    2007-09-20

    We study the azimuthal asymmetric distribution of hadronsinside a high energy jet in the single transverse polarized proton protonscattering, coming from the Collins effect multiplied by the quarktransversity distribution. We argue that the Collins function in thisprocess is the same as that in the semi-inclusive deep inelasticscattering. The experimental study of this process will provide usimportant information on the quark transversity distribution and test theuniversality of the fragmentation functions.

  7. Photon-photon colliders

    SciTech Connect

    Sessler, Andrew M.

    1996-01-01

    Since the seminal work by Ginsburg, et al., the subject of giving the Next Linear Collider photon-photon capability, as well as electron-positron capability, has drawn much attention [1]. A 1990 article by V.I. Telnov describes the situation at that time [2]. In March 1994, the first workshop on this subject was held [3]. 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.

  8. Photon-photon colliders

    SciTech Connect

    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.

  9. Observation of exclusive electron-positron production in hadron-hadron collisions.

    PubMed

    Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Ambrose, D; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arguin, J-F; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Bedeschi, F; Behari, S; Belforte, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Budroni, S; Burkett, K; Busetto, G; Bussey, P; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Caron, B; Carosi, R; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciljak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; Cyr, D; Daronco, S; D'Auria, S; Davies, T; D'Onofrio, M; Dagenhart, D; de Barbaro, P; Cecco, S De; Deisher, A; Lentdecker, G De; Dell'orso, M; Paoli, F Delli; Demortier, L; Deng, J; Deninno, M; Pedis, D De; Derwent, P F; Giovanni, G P Di; Dionisi, C; Ruzza, B Di; Dittmann, J R; Dituro, P; Dörr, C; Donati, S; Donega, M; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Foland, A; Forrester, S; Foster, G W; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, A; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Griffiths, M; Grinstein, S; Grosso-Pilcher, C; Grundler, U; da Costa, J Guimaraes; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ishizawa, Y; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jensen, H; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kovalev, A; Kraan, A C; Kraus, J; Kravchenko, I; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Loverre, P; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Manca, G; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Nachtman, J; Nagano, A; Naganoma, J; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nigmanov, T; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pinfold, J; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ranjan, N; Rappoccio, S; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Sabik, S; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Saltzberg, D; Sánchez, C; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Sjolin, J; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Denis, R St; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Takikawa, K; Tanaka, M; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuchiya, R; Tsuno, S; Turini, N; Ukegawa, F; Unverhau, T; Uozumi, S; Usynin, D; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Veramendi, G; Veszpremi, V; Vidal, R; Vila, I; Vilar, R; Vine, T; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waschke, S; Waters, D; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-03-16

    We present the first observation of exclusive e(+)e(-) production in hadron-hadron collisions, using pp[over] collision data at (square root) s = 1.96 TeV taken by the run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb(-1). We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy E(T) > 5 GeV and pseudorapidity |eta| < 2. With these criteria, 16 events are observed compared to a background expectation of 1.9+/-0.3 events. These events are consistent in cross section and properties with the QED process pp[over] --> p + e(+)e(-) + p[over] through two-photon exchange. The measured cross section is 1.6(-0.3)(+0.5)(stat) +/- 0.3(syst) pb. This agrees with the theoretical prediction of 1.71+/-0.01 pb.

  10. Single particle momentum and angular distributions in hadron-hadron collisions at ultrahigh energies

    NASA Technical Reports Server (NTRS)

    Chou, T. T.; Chen, N. Y.

    1985-01-01

    The forward-backward charged multiplicity distribution (P n sub F, n sub B) of events in the 540 GeV antiproton-proton collider has been extensively studied by the UA5 Collaboration. It was pointed out that the distribution with respect to n = n sub F + n sub B satisfies approximate KNO scaling and that with respect to Z = n sub F - n sub B is binomial. The geometrical model of hadron-hadron collision interprets the large multiplicity fluctuation as due to the widely different nature of collisions at different impact parameters b. For a single impact parameter b, the collision in the geometrical model should exhibit stochastic behavior. This separation of the stochastic and nonstochastic (KNO) aspects of multiparticle production processes gives conceptually a lucid and attractive picture of such collisions, leading to the concept of partition temperature T sub p and the single particle momentum spectrum to be discussed in detail.

  11. Forward hadronic scattering at 7 TeV: An update on predictions for the LHC

    SciTech Connect

    Block, Martin M.; Halzen, Francis

    2011-04-01

    The Large Hadron Collider (LHC) has successfully run for a long period at half energy, 7 TeV. In this note, we update earlier full-energy LHC forward hadronic scattering predictions [M. M. Block, Phys. Rep. 436, 71 (2006).], giving new predictions, including errors, for the pp total and inelastic cross sections, the {rho} value, the nuclear slope parameter B, d{sigma}{sub el}/dt, and the large gap survival probability at the current 7 TeV energy.

  12. Development of GEM-Based Digital Hadron Calorimetry Using the SLAC KPiX Chip

    SciTech Connect

    White, A.; /Texas U., Arlington /Washington U., Seattle /Unlisted /SLAC

    2012-04-12

    The development of Digital Hadron Calorimetry for the SiD detector Concept for the International Linear Collider is described. The jet energy requirements of the ILC physics program are discussed. The concept of GEM-based digital hadron calorimetry is presented, followed by a description of, and results from, prototype detectors. Plans are described for the construction of 1m{sup 2} GEM-DHCAL planes to be tested as part of a future calorimeter stack.

  13. Erratum: Photon isolation effects at NLO in γγ + jet final states in hadronic collisions

    NASA Astrophysics Data System (ADS)

    Gehrmann, T.; Greiner, N.; Heinrich, G.

    2014-06-01

    We present the NLO QCD corrections to pp → γγj production at hadron colliders. Our calculation includes contributions from the fragmentation of a hadronic jet into a highly energetic photon, and consequently allows the implementation of arbitrary infrared-safe photon isolation definitions. We compare different photon isolation criteria and perform a detailed study of the dependence of the γγj cross section on the photon isolation parameters.

  14. Photon isolation effects at NLO in γγ+jet final states in hadronic collisions

    NASA Astrophysics Data System (ADS)

    Gehrmann, T.; Greiner, N.; Heinrich, G.

    2013-06-01

    We present the NLO QCD corrections to pp → γγj production at hadron colliders. Our calculation includes contributions from the fragmentation of a hadronic jet into a highly energetic photon, and consequently allows the implementation of arbitrary infrared-safe photon isolation definitions. We compare different photon isolation criteria and perform a detailed study of the dependence of the γγj cross section on the photon isolation parameters.

  15. Topics in Hadronic Physics

    SciTech Connect

    Alfred Tang

    2002-08-01

    Hadron production cross sections are calculated in the perturbative QCD frame work. Parton distribution functions are obtained from a strip-soliton model. The fragmentation functions are derived from the Lund model of string breaking.

  16. Hadron spectroscopy at RHIC

    SciTech Connect

    Chung, S.U.; Kern, W.; Willutzki, H.J.

    1990-08-01

    A description is given of the physics opportunities at RHIC regarding quark-gluon spectroscopy. The basic idea is to isolate with appropriate triggers the subprocesses pomeron + pomeron {yields} hadrons and {gamma}* + {gamma}* {yields} hadrons with the net effective mass of hadrons in the range of 1.0 to 3.0 GeV, in order to study the hadronic states composed of u, d, and s and gluons. The double-pomeron interactions are expected to produce glueballs and hybrids preferentially, while the two-offshell-photon initial states should couple predominantly to quarkonia and multiquark states. A plethora of J{sup PC}-exotic mesons can be produced either directly in both types of interactions or in association with a single recoil photon in the final state. 8 refs., 2 figs.

  17. The Muon Collider

    SciTech Connect

    Zisman, Michael S

    2010-05-17

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  18. The Muon Collider

    SciTech Connect

    Zisman, Michael S.

    2011-01-05

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  19. Muon collider design

    SciTech Connect

    Palmer, R. |; Sessler, A.; Skrinsky, A.

    1996-03-01

    The possibility of muon colliders was introduced by Skrinsky et al., Neuffer, and others. More recently, several workshops and collaboration meetings have greatly increased the level of discussion. In this paper we present scenarios for 4 TeV and 0.5 TeV colliders based on an optimally designed proton source, and for a lower luminosity 0.5 TeV demonstration based on an upgraded version of the AGS. It is assumed that a demonstration version based on upgrades of the FERMILAB machines would also be possible. 53 refs., 25 figs., 8 tabs.

  20. B Hadron properties measured in the D0 experiment

    SciTech Connect

    Fisk, H.Eugene; /Fermilab

    2008-12-01

    The study of charm and beauty mesons and baryons provides many opportunities to not only measure and classify their spectroscopic states, but also it serves as a testing ground for aspects of flavor QCD such as heavy quark effective theory and lattice gauge calculations, that are used in precise calculations of masses, lifetimes and cross sections. The Fermilab Tevatron has provided both fixed target and proton--antiproton collider facilities that not only account for the discovery of b-quarks but also have dovetailed well with the b-factories to answer a variety of b-physics questions, some of which were not readily explored at existing e{sup +} e{sup -} and electron-positron colliders. An added feature of the hadron colliders is their large cross-section and high luminosity for production of b-quark states that compliments the high luminosities of the b-factories. We report on the observation of b-hadron states reconstructed using the D0 detector data at the Tevatron Collider. Measurements of the mass and relative rates of neutral excited B{sub d} and B{sub s} mesons, and the discovery of the {Xi}{sub b} baryon are described.

  1. The Stanford Linear Collider

    SciTech Connect

    Rees, J.R.

    1989-10-01

    April, 1989, the first Z zero particle was observed at the Stanford Linear Collider (SLC). The SLC collides high-energy beams of electrons and positrons into each other. In break with tradition the SLC aims two linear beams at each other. Strong motives impelled the Stanford team to choose the route of innovation. One reason being that linear colliders promise to be less expensive to build and operate than storage ring colliders. An equally powerful motive was the desire to build an Z zero factory, a facility at which the Z zero particle can be studied in detail. More than 200 Z zero particles have been detected at the SLC and more continue to be churned out regularly. It is in measuring the properties of the Z zero that the SLC has a seminal contribution to make. One of the primary goals of the SLC experimental program is to determine the mass of the Z zero as precisely as possible.In the end, the SLC's greatest significance will be in having proved a new accelerator technology. 7 figs.

  2. Status report of a high luminosity muon collider and future research and development plans

    SciTech Connect

    Palmer, R.B.; Tollestrup, A.; Sessler, A.

    1996-11-01

    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 (c-of-m) 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 analyzed. Finally, we present an R & D plan to determine whether such machines are practical, and, if they are, lead to the construction of a 0.5 TeV demonstration by 2010, and to a 4 TeV collider by the year 2020.

  3. Overview of results from the Fermilab fixed target and collider experiments

    SciTech Connect

    Montgomery, H.E.

    1997-06-01

    In this paper we present a review of recent QCD related results from Fermilab fixed target and collider experiments. Topics covered range from structure functions through W/Z production, heavy quark production and jet angular distributions. We also include the current state of knowledge about leptoquark pair production in hadronic collisions.

  4. Lectures on perturbative QCD, jets and the standard model: collider phenomenology

    SciTech Connect

    Ellis, S.D.

    1988-01-01

    Applications of the Standard Model to the description of physics at hadron colliders are discussed. Particular attention is paid to the use of jets to characterize this physics. The issue of identifying physics beyond the Standard Model is also discussed. 59 refs., 6 figs., 4 tabs.

  5. Hadron Resonances from QCD

    NASA Astrophysics Data System (ADS)

    Dudek, Jozef J.

    2016-03-01

    I describe how hadron-hadron scattering amplitudes are related to the eigenstates of QCD in a finite cubic volume. The discrete spectrum of such eigenstates can be determined from correlation functions computed using lattice QCD, and the corresponding scattering amplitudes extracted. I review results from the Hadron Spectrum Collaboration who have used these finite volume methods to study ππ elastic scattering, including the ρ resonance, as well as coupled-channel πK, ηK scattering. The very recent extension to the case where an external current acts is also presented, considering the reaction πγ* → ππ, from which the unstable ρ → πγ transition form factor is extracted. Ongoing calculations are advertised and the outlook for finite volume approaches is presented.

  6. J. J. Sakurai Prize for Theoretical Particle Physics Talk: Collider Physics: Yesterday, Today and Tomorrow

    NASA Astrophysics Data System (ADS)

    Eichten, Estia

    2011-04-01

    More than a quarter century ago, theoretical issues with the Standard Model scalar boson sector inspired theorists to develop alternative models of electroweak symmetry breaking. The goal of the EHLQ study of hadron collider physics was to help determine the basic parameters of a supercollider that could distinguish these alternatives. Now we await data from the CMS and ATLAS experiments at CERN's Large Hadron Collider to solve this mystery. Does the Standard Model survive or, as theorists generally expect, does new physics appear (Strong Dynamics, SUSY, Extra Dimensions,...)? Even well into the LHC era it is likely that questions about the origin of fermion mass and mixings will remain and new physics will bring new puzzles. This time, the associated new scales are unknown. The opportunity to address new physics at a future multi-TeV lepton collider is briefly addressed.

  7. Proceedings of the 2005 International Linear Collider Workshop (LCWS05)

    SciTech Connect

    Hewett, JoAnne,; /SLAC

    2006-12-18

    Exploration of physics at the TeV scale holds the promise of addressing some of our most basic questions about the nature of matter, space, time, and energy. Discoveries of the Electroweak Symmetry Breaking mechanism, Supersymmetry, Extra Dimensions of space, Dark Matter particles, and new forces of nature are all possible. We have been waiting and planning for this exploration for over 20 years. In 2007 the Large Hadron Collider at CERN will begin its operation and will break into this new energy frontier. A new era of understanding will emerge as the LHC data maps out the Terascale. With the LHC discoveries, new compelling questions will arise. Responding to these questions will call for a new tool with greater sensitivity--the International Linear Collider. Historically, the most striking progress in the exploration of new energy frontiers has been made from combining results from hadron and electron-positron colliders. The precision measurements possible at the ILC will reveal the underlying theory which gave rise to the particles discovered at the LHC and will open the window to even higher energies. The world High Energy Physics community has reached an accord that an e+e- linear collider operating at 0.5-1.0 TeV would provide both unique and essential scientific opportunities; the community has endorsed with highest priority the construction of such a machine. A major milestone toward this goal was reached in August 2004 when the International Committee on Future Accelerators approved a recommendation for the technology of the future International Linear Collider. A global research and design effort is now underway to construct a global design report for the ILC. This endeavor is directed by Barry Barrish of the California Institute of Technology. The offer, made by Jonathan Dorfan on the behalf of ICFA, and acceptance of this directorship took place during the opening plenary session of this workshop. The 2005 International Linear Collider Workshop was held

  8. Flavourful hadronic physics.

    SciTech Connect

    El-Bennich, B.; Ivanov, M. A.; Roberts, C. D.

    2010-02-01

    We review theoretical approaches to form factors that arise in heavy-meson decays and are hadronic expressions of non-perturbative QCD. After motivating their origin in QCD factorisation, we retrace their evolution from quark-model calculations to non-perturbative QCD techniques with an emphasis on formulations of truncated heavy-light amplitudes based upon Dyson-Schwinger equations. We compare model predictions exemplarily for the F{sup B {yields} {pi}}(q{sup 2}) transition form factor and discuss new results for the g{sub D*D{pi}}coupling in the hadronic D* decay.

  9. Bouncing and Colliding Branes

    SciTech Connect

    Lehners, Jean-Luc

    2007-11-20

    In a braneworld description of our universe, we must allow for the possibility of having dynamical branes around the time of the big bang. Some properties of such domain walls in motion are discussed here, for example the ability of negative-tension domain walls to bounce off spacetime singularities and the consequences for cosmological perturbations. In this context, we will also review a colliding branes solution of heterotic M-theory that has been proposed as a model for early universe cosmology.

  10. Muon Collider Progress: Accelerators

    SciTech Connect

    Zisman, Michael S.

    2011-09-10

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 × 10{sup 34} cm{sup –2}s{sup –1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (“cooling”). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

  11. The dark penguin shines light at colliders

    NASA Astrophysics Data System (ADS)

    Primulando, Reinard; Salvioni, Ennio; Tsai, Yuhsin

    2015-07-01

    Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For several types of DM-Standard Model couplings, a meaningful interpretation of the results requires to go beyond effective field theory, considering simplified models with light mediators. This is especially important in the case of loop-mediated interactions. In this paper we perform the first simplified model study of the magnetic dipole interacting DM, by including the one-loop momentum-dependent form factors that mediate the coupling — given by the Dark Penguin — in collider processes. We compute bounds from the monojet, monophoton, and diphoton searches at the 8 and 14 TeV LHC, and compare the results to those of direct and indirect detection experiments. Future searches at the 100 TeV hadron collider and at the ILC are also addressed. We find that the optimal search strategy requires loose cuts on the missing transverse energy, to capture the enhancement of the form factors near the threshold for on-shell production of the mediators. We consider both minimal models and models where an additional state beyond the DM is accessible. In the latter case, under the assumption of anarchic flavor structure in the dark sector, the LHC monophoton and diphoton searches will be able to set much stronger bounds than in the minimal scenario. A determination of the mass of the heavier dark fermion might be feasible using the M T2 variable. In addition, if the Dark Penguin flavor structure is almost aligned with that of the DM mass, a displaced signal from the decay of the heavier dark fermion into the DM and photon can be observed. This allows us to set constraints on the mixings and couplings of the model from an existing search for non-pointing photons.

  12. Hadron Therapy for Cancer Treatment

    SciTech Connect

    Lennox, Arlene

    2003-09-10

    The biological and physical rationale for hadron therapy is well understood by the research community, but hadron therapy is not well established in mainstream medicine. This talk will describe the biological advantage of neutron therapy and the dose distribution advantage of proton therapy, followed by a discussion of the challenges to be met before hadron therapy can play a significant role in treating cancer. A proposal for a new research-oriented hadron clinic will be presented.

  13. Genetic characterization of interleukins (IL-1α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12A, IL-12B, IL-15 and IL-18) with relevant biological roles in lagomorphs

    PubMed Central

    Neves, Fabiana; Abrantes, Joana; Almeida, Tereza; de Matos, Ana Lemos; Costa, Paulo P

    2015-01-01

    ILs, as essential innate immune modulators, are involved in an array of biological processes. In the European rabbit (Oryctolagus cuniculus) IL-1α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12A, IL-12B, IL-15 and IL-18 have been implicated in inflammatory processes and in the immune response against rabbit hemorrhagic disease virus and myxoma virus infections. In this study we characterized these ILs in six Lagomorpha species (European rabbit, pygmy rabbit, two cottontail rabbit species, European brown hare and American pika). Overall, these ILs are conserved between lagomorphs, including in their exon/intron structure. Most differences were observed between leporids and American pika. Indeed, when comparing both, some relevant differences were observed in American pika, such as the location of the stop codon in IL-1α and IL-2, the existence of a different transcript in IL8 and the number of cysteine residues in IL-1β. Changes at N-glycosylation motifs were also detected in IL-1, IL-10, IL-12B and IL-15. IL-1α is the protein that presents the highest evolutionary distances, which is in contrast to IL-12A where the distances between lagomorphs are the lowest. For all these ILs, sequences of human and European rabbit are more closely related than between human and mouse or European rabbit and mouse. PMID:26395994

  14. Genetic characterization of interleukins (IL-1α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12A, IL-12B, IL-15 and IL-18) with relevant biological roles in lagomorphs.

    PubMed

    Neves, Fabiana; Abrantes, Joana; Almeida, Tereza; de Matos, Ana Lemos; Costa, Paulo P; Esteves, Pedro J

    2015-11-01

    ILs, as essential innate immune modulators, are involved in an array of biological processes. In the European rabbit (Oryctolagus cuniculus) IL-1α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12A, IL-12B, IL-15 and IL-18 have been implicated in inflammatory processes and in the immune response against rabbit hemorrhagic disease virus and myxoma virus infections. In this study we characterized these ILs in six Lagomorpha species (European rabbit, pygmy rabbit, two cottontail rabbit species, European brown hare and American pika). Overall, these ILs are conserved between lagomorphs, including in their exon/intron structure. Most differences were observed between leporids and American pika. Indeed, when comparing both, some relevant differences were observed in American pika, such as the location of the stop codon in IL-1α and IL-2, the existence of a different transcript in IL8 and the number of cysteine residues in IL-1β. Changes at N-glycosylation motifs were also detected in IL-1, IL-10, IL-12B and IL-15. IL-1α is the protein that presents the highest evolutionary distances, which is in contrast to IL-12A where the distances between lagomorphs are the lowest. For all these ILs, sequences of human and European rabbit are more closely related than between human and mouse or European rabbit and mouse. PMID:26395994

  15. Electroweak and hadron studies

    SciTech Connect

    Rau, R.R.

    1988-01-01

    Some final results are presented on ..mu mu.., /tau//tau/, and hadron production, obtained by the MARK J collaboration at PETRA, over the cm energy band 22 GeV to 46.8 GeV. The MARK J results agree with world averaged data. They constitute powerful tests of the predictions of the Standard Model. 29 refs., 8 figs., 3 tabs.

  16. Proceedings of the workshop on future hadron facilities in the US

    SciTech Connect

    Not Available

    1994-12-31

    This report discusses the following topics on future hadron facilities: Workshop on future hadron facilities in the US; 30 {times} 30 TeV-summary report; A high luminosity, 2 {times} 2 TeV collider in the tevatron tunnel; magnets working group; cryogenics discussion; vacuum report; antiproton source production; injector working group; interaction region working group; lattice/beam dynamics working group; LEBT for high-luminosity colliders; some notes on long-range beam-beam effects for the 2TeV collider; synchrotron radiation masks for high energy proton accelerators. Emittance preservation in a proton synchrotron; beam-beam interaction effects on betatron tunes; analytic solutions for phase trombone modules; and chromatic corrections of RHIC when one or two insertions is at {Beta}* = 0.5m.

  17. Extracting hadron-neutron scattering amplitudes from hadron-proton and hadron-deuteron measurements

    NASA Technical Reports Server (NTRS)

    Franco, V.

    1977-01-01

    A method is presented for extracting hadron-neutron scattering amplitudes from hadron-proton and hadron-deuteron measurements within the framework of the Glauber approximation. This method, which involves the solution of a linear integral equation, is applied to pn collisions between 15 and 275 GeV/c. Effects arising from inelastic intermediate states are estimated.

  18. sPHENIX Hadronic Calorimeter Scintillator Studies

    NASA Astrophysics Data System (ADS)

    Byrd, Reuben; Sphenix Collaboration

    2015-10-01

    A new form of matter called the Quark-Gluon Plasma (QGP) was discovered with the Relativistic Heavy Ion Collider (RHIC). PHENIX is an experiment at RHIC that helped with this discovery, but plans are being made to replace it with a new spectrometer with different capabilities. The sPHENIX detector will consist of a superconducting solenoid magnet, hadronic and electromagnetic calorimetry and charged particle tracking. sPHENIX will enable a rich jet physics program that will address fundamental questions about of the nature of the QGP. The new detector will provide full azimuthal coverage and +/- 1.1 in pseudorapidity. The Hadronic Calorimeter is a major subsystem in this detector. It is made of alternating layers of scintillating tiles and steel plates. In the current prototype the tiles are covered with a reflective coating and contain wavelength shifting fibers. As the second round of prototypes are developed for an upcoming beam test, special care is being taken to provide uniform light collection efficiency across the detector. Studies are being conducted to ensure this by careful alignment of the silicon photomultipliers to the fibers and varying coatings on the tiles. The effects of the coating will be presented along with the current status and ongoing plans.

  19. The super collider revisited

    SciTech Connect

    Hussein, M.S.; Pato, M.P. )

    1992-05-20

    In this paper, the authors suggest a revised version of the Superconducting Super Collider (SSC) that employs the planned SSC first stage machine as an injector of 0.5 TeV protons into a power laser accelerator. The recently developed Non-linear Amplification of Inverse Bremsstrahlung Acceleration (NAIBA) concept dictates the scenario of the next stage of acceleration. Post Star Wars lasers, available at several laboratories, can be used for the purpose. The 40 TeV CM energy, a target of the SSC, can be obtained with a new machine which can be 20 times smaller than the planned SSC.

  20. Muon Colliders and Neutrino Factories *

    NASA Astrophysics Data System (ADS)

    Geer, Steve

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate O(1021) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  1. Muon Colliders and Neutrino Factories

    SciTech Connect

    Geer, Steve; /Fermilab

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate {Omicron}(10{sup 21}) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  2. Muon colliders and neutrino factories

    SciTech Connect

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

  3. Physics with the collider detectors at RHIC and the LHC

    SciTech Connect

    Thomas, J.; Hallman, T.

    1995-07-15

    On January 8, 1995, over 180 participants gathered to hear the QM95 preconference workshop on `Physics with the Collider Detectors at RHIC and the LHC`. The goal was to bring together the experimentalists from a wide community of hadron and heavy ion collider detector collaborations. The speakers were encouraged to present the current status of their detectors, with all the blemishes, and the audience was encouraged to share their successes and failures in approaching similar detector design issues. The presentations were excellent and the discussions were lively and stimulating. The editors hope that the reader will find these proceedings to be equally stimulating. Separate abstracts have been submitted to the energy database from articles in this report.

  4. Unparticle self-interactions and their collider implications

    SciTech Connect

    Feng, Jonathan L.; Rajaraman, Arvind; Tu Huitzu

    2008-04-01

    In unparticle physics, operators of the conformal sector have self-interactions, and these are unsuppressed for strong coupling. The 3-point interactions are completely determined by conformal symmetry, up to a constant. We do not know of any theoretical upper bounds on this constant. Imposing current experimental constraints, we find that these interactions mediate spectacular collider signals, such as pp{yields}U{yields}UU{yields}{gamma}{gamma}{gamma}{gamma}, {gamma}{gamma}ZZ, ZZZZ, {gamma}{gamma}l{sup +}l{sup -}, ZZl{sup +}l{sup -}, and 4l, with cross sections of picobarns or larger at the large hadron collider. Self-interactions may therefore provide the leading discovery prospects for unparticle physics.

  5. Collider searches for nonperturbative low-scale gravity states

    NASA Astrophysics Data System (ADS)

    Gingrich, Douglas M.

    2015-12-01

    The possibility of producing nonperturbative low-scale gravity states in collider experiments was first discussed in about 1998. The ATLAS and CMS experiments have searched for nonperturbative low-scale gravity states using the Large Hadron Collider with a proton-proton center-of-mass energy of 8 TeV. These experiments have now seriously confronted the possibility of producing nonperturbative low-scale gravity states which were proposed over 17 years ago. I will summarize the results of the searches, give a personal view of what they mean, and make some predictions for 13 TeV center-of-mass energy. I will also discuss early ATLAS 13 TeV center-of-mass energy results.

  6. Experiments and detectors for high energy heavy ion colliders

    SciTech Connect

    Ludlam, T.

    1984-01-01

    Problems and possibilities are discussed for experiments at the highest collision energies achievable in man-made accelerators; i.e., colliding beams of heavy nuclei at cm energies greater than or equal to 100 GeV/amu, well beyond the threshold of nuclear transparency. Here the final state consists of two hot, dense, baryon-rich fireballs flying away from each other at large rapidity (the fragmentation regions), and thermally-produced particles with near-zero net baryon number populating the central rapidity range. The matter produced at central rapidity (the lab frame for a collider) may reach extremely high temperatures and energy densities, and it is here that one expects to produce thermodynamic conditions similar to those which existed when the early universe condensed from a plasma of quarks and gluons to a gas of hadrons. The problem of tracking, lepton measurements, and calorimeters are discussed. (WHK)

  7. Quantum chromodynamics and the statistical hydrodynamical model of hadron production

    NASA Astrophysics Data System (ADS)

    Carruthers, P.; Duong-van, Minh

    1983-07-01

    We analyze the Fermi-Landau statistical hydrodynamical model of hadron-hadron multiplicities in the framework of QCD, using the Pokorski-Van Hove model wherein the collision of preexisting glue dominates the multiplicity. It is noted that previous dismissal of the possibility of thermalization in the basis of nuclear "transparency" is circumvented in this picture because the valence quarks pass through, whereas the gluon clouds interact strongly. Assuming that the gluons equilibrate to a thermalized plasmoid within the Fermi-Landau (FL) Lorentz-contracted initial volume, we derive a simple formula for the multiplicity with the form Nch~2.5f14Whad12 (three flavors excited), where 1-f is the fraction of energy carried away by the leading particles and Whad=fW is the energy left behind. If f were fixed at a constant value of 1/2 , the formula would agree extremely well with data up to and including p¯p collider energies. (The widely held belief that collider multiplicities rule out the Fermi power law was based on the use of W rather than Whad.) However, using the data of Basile et al., in which multiplicities are broken down as a function of Whad for different W values, we find that the f14 dependence is ruled out. We conclude that thermalization of the colliding gluon clouds in the FL volume is also ruled out, although thermalization in the gluon fragmentation and central regions remains a possibility.

  8. Introducing the Hyper Hadrons, Hyper Mesons, Heavy Leptons and Massive Neutrinos of Kazuo Kondo's Mass Quantum Cascade

    NASA Astrophysics Data System (ADS)

    Croll, Grenville J.

    The late Professor Kazuo Kondo (Department of Mathematics, Tokyo University, Japan) l a hitherto unknown a priori particle theory which provides predictions of massive particles which may be detected by the Large Hadron Collider (LHC) and related apparatus. This article briefly introduces Kondo's work and documents the derivation and masses of his expected hyper-mesons, hyper-hadrons, heavy leptons and massive neutrinos. Several particles in these classes may have already been detected.

  9. Prospects in CP violation measurements at the Tevatron Collider

    SciTech Connect

    Diego Tonelli

    2004-06-22

    The Fermilab Tevatron Collider is currently the most copious source of b-hadrons, thanks to the large b{bar b} production cross-section in 1.96 TeV p{bar p} collisions. Recent detector upgrades allow for a wide range of CP violation and flavor-mixing measurements that are fully competitive (direct asymmetries in self-tagging modes) or complementary (asymmetries of B{sub s} and b-baryons decays) with B-factories. In this paper we review some recent CP violation results from the D0 and CDF II Collaborations and we discuss the prospects for future measurements.

  10. Signatures and possible evidence for supersymmetry at the CERN collider

    NASA Astrophysics Data System (ADS)

    Haber, Howard E.; Kane, G. L.

    1984-07-01

    For certain ranges of masses of the supersymmetric partners of the gluons, quarks and W-bosons, it is expected that a few events of production and decay of the partners could be observed at the CERN pp¯ collider. The characteristic signatures are events with ℓ± j?, ℓ± jj?, jjj?, jj?and j? where ℓ ± is an isolated charged lepton, j is a hadron jet and ? stands for missing pT. Some recently reported events are of this type.

  11. Tracking studies of the Compact Linear Collider collimation system

    SciTech Connect

    Agapov, I.; Burkhardt, H.; Schulte, D.; Latina, A.; Blair, G.A.; Malton, S.; Resta-Lopez, J.; /Oxford U., JAI

    2009-08-01

    A collimation system performance study includes several types of computations performed by different codes. Optics calculations are performed with codes such as MADX, tracking studies including additional effects such as wakefields, halo and tail generation, and dynamical machine alignment are done with codes such as PLACET, and energy deposition can be studied with BDSIM. More detailed studies of hadron production in the beam halo interaction with collimators are better performed with GEANT4 and FLUKA. A procedure has been developed that allows one to perform a single tracking study using several codes simultaneously. In this paper we study the performance of the Compact Linear Collider collimation system using such a procedure.

  12. Linear collider development at SLAC

    SciTech Connect

    Irwin, J.

    1993-08-01

    Linear collider R&D at SLAC comprises work on the present Stanford Linear Collider (SLC) and work toward the next linear collider (NLC). Recent SLC developments are summarized. NLC studies are divided into hardware-based and theoretical. We report on the status of the NLC Test Accelerator (NLCTA) and the final focus test beam (FFTB), describe plans for ASSET, an installation to measure accelerator structure wakefields, and mention IR design developments. Finally we review recent NLC theoretical studies, ending with the author`s view of next linear collider parameter sets.

  13. Hadron Physics at J-PARC —Exotic Hadrons and Hadrons in Nuclei—

    NASA Astrophysics Data System (ADS)

    Jido, Daisuke

    A personal view of hadron physics being developed at J-PARC is presented in this article. Hadrons are particles interacting each other with the strong interaction, being composed of quarks and gluons, of which dynamics governs quantum chromodynamics (QCD). Although the fundamental theory of the strong interaction is written beautifully in a simple way, its dynamical consequence is very complicated and makes hadron physics rich. In this paper, I select two topics, exotic hadrons which are not explained by conventional quark models and hadron in nucleus which will be a tool to investigate the vacuum property of QCD.

  14. Proposal for Research and Development: Vertexing, Tracking, and Data Acquisition for the Bottom Collider Detector

    SciTech Connect

    Castro, H.; Gomez, B.; Rivera, F.; Sanabria, J.-C.; Yager, P.; Barsotti, E.; Bowden, M.; Childress, S.; Lebrun, P.; Morfin, J.; Roberts, L.A.; /Fermilab /Florida U. /Houston U. /IIT /Iowa U. /Northeastern U. /Northern Illinois U. /Ohio State U. /Oklahoma U. /Pennsylvania U.

    1989-01-01

    The authors propose a program of research and development into the detector systems needed for a B-physics experiment at the Fermilab p-{bar p} Collider. The initial emphasis is on the critical issues of vertexting, tracking, and data acquisition in the high-multiplicity, high-rate collider environment. R and D for the particle-identification systems (RICH counters, TRD's, and EM calorimeter) will be covered in a subsequent proposal. To help focus their efforts in a timely manner, they propose the first phase of the R and D should culminate in a system test at the C0 collider intersect during the 1990-1991 run: a small fraction of the eventual vertex detector would be used to demonstrate that secondary-decay vertices can be found at a hadron collider. The proposed budget for the r and D program is $800k in 1989, $1.5M in 1990, and $1.6M in 1991.

  15. Charmed Hadron Interactions

    SciTech Connect

    Liu, Liuming

    2009-07-01

    We calculate the scattering lengths of the scattering processes where one or both hadrons contain charm quarks in full lattice QCD. We use relativistic Fermilab formulation for the charm quark. For the light quark, we use domain-wall fermions in the valence sector and improved Kogut- Susskind sea quarks. In J = Psi - N and D - K channels, we observe attractive interactions. In D - D* channel, the sign of the scattering length changes, which suggests a bound state.

  16. Optimization of a muon collider interaction region with respect to detector backgrounds and the heat load to the cryogenic systems

    SciTech Connect

    Johnstone, C.J.; Mokhov, N.V.

    1996-10-16

    In a 2 X 2 TeV {mu}{sup +}{mu}{sup -} Collider almost 15 MW of power is deposited in the machine and detector components due to the unavoidable {mu}{r_arrow}{ital e{nu}{nu}{anti {nu}}} decays. The resulting heat load to the cryogenic systems and the background levels in the collider detectors significantly exceed those in any existing or designed hadron and {ital e}{sup +}{ital e}{sup -} colliders. This paper shows that by carefully designing the final focus system, by embedding shielding and by taking other protective measures the heat load and backgrounds can be mitigated by several orders of magnitude.

  17. Positrons for linear colliders

    SciTech Connect

    Ecklund, S.

    1987-11-01

    The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. Photons from synchrotron radiation and from channeling are also mentioned briefly, as well as positron collection, transverse focusing techniques, and longitudinal capture. Computer ray tracing is then briefly discussed, followed by space-charge effects and thermal heating and stress due to showers. (LEW)

  18. Collider Signal I :. Resonance

    NASA Astrophysics Data System (ADS)

    Tait, Tim M. P.

    2010-08-01

    These TASI lectures were part of the summer school in 2008 and cover the collider signal associated with resonances in models of physics beyond the Standard Model. I begin with a review of the Z boson, one of the best-studied resonances in particle physics, and review how the Breit-Wigner form of the propagator emerges in perturbation theory and discuss the narrow width approximation. I review how the LEP and SLAC experiments could use the kinematics of Z events to learn about fermion couplings to the Z. I then make a brief survey of models of physics beyond the Standard Model which predict resonances, and discuss some of the LHC observables which we can use to discover and identify the nature of the BSM physics. I finish up with a discussion of the linear moose that one can use for an effective theory description of a massive color octet vector particle.

  19. ALPs at colliders

    NASA Astrophysics Data System (ADS)

    Mimasu, Ken; Sanz, Verónica

    2015-06-01

    New pseudo-scalars, often called axion-like particles (ALPs), abound in model-building and are often associated with the breaking of a new symmetry. Traditional searches and indirect bounds are limited to light axions, typically in or below the KeV range for ALPs coupled to photons. We present collider bounds on ALPs from mono-γ, tri-γ and mono-jet searches in a model independent fashion, as well as the prospects for the LHC and future machines. We find that they are complementary to existing searches, as they are sensitive to heavier ALPs and have the capability to cover an otherwise inaccessible region of parameter space. We also show that, assuming certain model dependent correlations between the ALP coupling to photons and gluons as well as considering the validity of the effective description of ALP interactions, mono-jet searches are in fact more suitable and effective in indirectly constraining ALP scenarios.

  20. Muon Collider design status

    SciTech Connect

    Alexahin, Y.; /Fermilab

    2010-09-01

    Muon Collider (MC) - proposed by G.I. Budker and A.N. Skrinsky a few decades ago - is now considered as the most exciting option for the energy frontier machine in the post-LHC era. A national Muon Accelerator Program (MAP) is being formed in the USA with the ultimate goal of building a MC at the Fermilab site with c.o.m. energy in the range 1.5-3 TeV and luminosity of {approx} 1.5 {center_dot} 10{sup 34} cm{sup -2} s{sup -1}. As the first step on the way to MC it envisages construction of a Neutrino Factory (NF) for high-precision neutrino experiments. The baseline scheme of the NF-MC complex is presented and possible options for its main components are discussed.