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Sample records for 20th hadron collider

  1. The 20th Hadron Collider Physics Symposium in Evian

    Ludwik Dobrzynski and Emmanuel Tsesmelis

    The 20th Hadron Collider Physics Symposium took place in Evian from 16 to 20 November 2009. The Hadron Collider Physics Symposium series has been a major forum for presentations of physics at the Tevatron over the past two decades. The merger of the former Topical Conference on Hadron Collider Physics with the LHC Symposium in 2005 brought together the Tevatron and LHC communities in a single forum. The 20th Hadron Collider Physics Symposium took place in Evian, on the shores of Lake Geneva, from 16-20 November 2009, some 17 years after the historic ECFA-CERN Evian meeting in March 1992 when Expressions of Interest for LHC detectors were presented for the first time. The 2009 event was organized jointly by CERN and the French high-energy physics community (CNRS-IN2P3 and CEA-IRFU). More than 170 people registered for this symposium. This year’s symposium was held at an important time for both the Tevatron and the LHC. It stimulated the completion of analyses for a significant Tevatron data sam...

  2. Hadron hadron collider group

    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

  3. Hadron-hadron colliders

    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

  4. Hadron Colliders and Hadron Collider Physics Symposium

    Denisov D.

    2013-05-01

    Full Text Available This article summarizes main developments of the hadron colliders and physics results obtained since their inception around forty years ago. The increase in the collision energy of over two orders of magnitude and even larger increases in luminosity provided experiments with unique data samples. Developments of full acceptance detectors, particle identification and analysis methods provided fundamental discoveries and ultra-precise measurements which culminated in the completion and in depth verification of the Standard Model. Hadron Collider Physics symposium provided opportunities for those working at hadron colliders to share results of their research since 1979 and helped greatly to develop the field of particle physics.

  5. Hadron Colliders and Hadron Collider Physics Symposium

    Denisov, Dmitri

    2013-01-01

    This article summarizes main developments of the hadron colliders and physics results obtained since their inception around forty years ago. The increase in the collision energy of over two orders of magnitude and even larger increases in luminosity provided experiments with unique data samples. Developments of full acceptance detectors, particle identification and analysis methods provided fundamental discoveries and ultra-precise measurements which culminated in the completion and in depth verification of the Standard Model. Hadron Collider Physics symposium provided opportunities for those working at hadron colliders to share results of their research since 1979 and helped greatly to develop the field of particle physics.

  6. Hadron collider physics

    Hadron colliders provide an important laboratory for testing the Standard Model of strong and electroweak interactions. Because such colliders have the highest available center-of-mass energy (sq. root s), they probe the shortest accessible length scales and hence provide a unique opportunity both to study the fundamental fields of the Standard Model and to search for deviations from the predictions of the Standard Model. This paper presents recent results in the field of experimental hadron collider physics

  7. Hadron collider physics

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

  8. Large Hadron Collider

    2007-01-01

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

  9. Hadron collider physics

    Pondrom, L.

    1991-10-03

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

  10. The Large Hadron Collider

    Juettner Fernandes, Bonnie

    2014-01-01

    What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Includes glossary, websites, and bibliography for further reading. Perfect for STEM connections. Aligns to the Common Core State Standards for Language Arts. Teachers' Notes available online.

  11. Hadron therapy at the end of the 20th century

    An overview of radiotherapy methods (brachytherapy, external irradiation with X-rays, betatrons, linear accelerators, hadron therapy, neutron capture therapy) is given, including their description and basic ways of application. Improved results can be achieved through precise dosimetry, diagnostic preparation, mathematical 3D modelling, procedure simulation and conformal therapy (adaptation of the radiation field to the shape of the target volume and preparation of compensation filters). The use of accelerated protons or ions also contributes to a substantial improvement. Neutron capture therapy is a promising method; the problem of suitable chemical compounds carrying boron 10, to be captured by the neoplasm tissue, and the problem of a suitable source of thermal neutrons are being addressed. (M.D.)

  12. The Large Hadron Collider

    Evans, Lyndon

    2012-01-01

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

  13. Hadron collider physics at UCR

    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+-e- 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/2γ at PEP and the OPAL detector at LEP, as well as efforts on hadron machines

  14. Physics at Future Hadron Colliders

    U. Baur; Brock, R.; Parsons, J; Albrow, M.; Denisov, D.; Han, T.; Kotwal, A.; Olness, F.; Qian, J.; S. Belyaev

    2002-01-01

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

  15. Bottomonium production in hadron colliders

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

  16. High energy hadron colliders

    The more novel and important design considerations and features of high energy hadron colliders (pp or p anti p) are discussed. The paper does not attempt to be sufficient for making a complete design, but contains enough references to other papers necessary for doing so. Formulas are generally given without derivation, and notations are not consistent from section to section. For most formulas the derivation is transparent although the mathematics may be lengthy. Whenever obscure, an explanation of the procedure for derivation will be given in physical terms. Detailed mathematical derivations can be found in the references. 10 references

  17. Results from hadron colliders

    The present status of hadron collider physics is reviewed. The total cross section for bar p + p has been measured at 1.8 TeV: σtot = 72.1 ± 3.3 mb. New data confirm the UA2 observation of W/Z → bar qq. Precision measurements of MW by UA2 and CDF give an average value MW = 80.13 ± 0.30 GeV/c2. When combined with measurements of MZ from LEP and SLC this number gives sin2θW = 0.227 ± 0.006, or mtop = 130-60+40 GeV/c2 from the EWK radiative correction term Δr. Evidence for hadron colliders as practical sources of b quarks has been strengthened, while searches for t quarks have pushed the mass above MW: mtop > 89 GeV/c2 95% cl (CDF Preliminary). Searches beyond the standard model based on the missing ET signature have not yet produced any positive results. Future prospects for the discovery of the top quark in the range mtop 2 look promising. 80 refs., 35 figs., 7 tabs

  18. Physics at future hadron colliders

    U. Baur et al.

    2002-12-23

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

  19. Physics at Future Hadron Colliders

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

  20. Physics at future hadron colliders

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

  1. Hadron collider physics at UCR

    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.

  2. Lare Hadron Collider faces today

    Cartwright, Jon

    2007-01-01

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

  3. Physics with colliding hadron beams

    Wetherell, Alan M

    1972-01-01

    The results on p-p collisions obtained with the CERN ISR will be reviewed and the current experimental programme described. Future possibilities for colliding hadron beams, other than proton-proton, will be briefly discussed. (0 refs).

  4. Large Hadron Collider nears completion

    2008-01-01

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

  5. Experimental prospects of hadron colliders

    The main subject of this report is to take a general view on the experiment with several tens of TeV hadron colliders. Intensive studies have been carried out about the physics and the detectors for such hadron machines. The experimental prospect of hadron colliders based on the studies and the view of the author are presented. To obtain a fundamental knowledge on the experiment with hadron colliders, the general properties of hadron scattering should be investigated. First, the total cross sections and charged particle multiplicity are estimated, and hard scattering process is reviewed. The cross sections for some interesting hard scattering process are summarized. The most serious problem for the experiment with hadron colliders is to pick out useful signals from enormous QCD back-ground processes, and a possibility of finding heavy Higgs bosons is discussed in detail as an example. On the basis of these studies, the requirement which general purpose detectors should satisfy is considered. Also the important machine parameters from experimental viewpoint are discussed. High energy hadron colliders have a potentiality to reveal new physics in TeV region, but the preparation for unexpected physics is necessary. (Kako, I.)

  6. Hadron collider physics at Fermilab

    Nodulman, L.J.

    1989-01-01

    The hadron collider physics program at Fermilab, Tevatron-I, has recently provided considerable data samples to two high beta experiments as well as one low beta general purpose Collider Detector at Fermilab (CDF). A brief description of the Tevatron collider and the high beta experiments is followed by a discussion of hard scattering results from CDF. The prospects for growth in this exciting physics program are outlined. 20 refs., 29 figs., 1 tab.

  7. Hadron collider physics at Fermilab

    The hadron collider physics program at Fermilab, Tevatron-I, has recently provided considerable data samples to two high beta experiments as well as one low beta general purpose Collider Detector at Fermilab (CDF). A brief description of the Tevatron collider and the high beta experiments is followed by a discussion of hard scattering results from CDF. The prospects for growth in this exciting physics program are outlined. 20 refs., 29 figs., 1 tab

  8. QCD at high-luminosity hadron colliders

    Hautmann, F

    2016-01-01

    This talk gives a brief introduction to open questions in jet physics and QCD which come to the fore in the high-luminosity regime characterizing the upcoming phase of the Large Hadron Collider and future hadron colliders.

  9. Physics at hadron colliders: Experimental view

    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.

  10. The very large hadron collider

    NONE

    1998-09-01

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

  11. Large Hadron Collider nears completion

    2008-01-01

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

  12. Hard QCD at hadron colliders

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

  13. The Large Hadron Collider

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

    2007-01-01

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

  14. Why Large Hadron Collider?

    D P Roy

    2011-05-01

    I discuss LHC physics in the historical perspective of the progress in particle physics. After a recap of the Standard Model (SM) of particle physics, I discuss the high energy colliders leading up to LHC and their role in the discovery of these SM particles. Then I discuss the two main physics issues of LHC, i.e. Higgs mechanism and supersymmetry. I briefly touch upon Higgs and SUSY searches at LHC along with their cosmological implications.

  15. Detectors and luminosity for hadron colliders

    Diebold, R.

    1982-01-01

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

  16. Top production at hadron colliders

    Albert De Roeck

    2012-10-01

    New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including top quarks. The results are based on data samples of up to 5.4 fb-1 for the Tevatron experiments and 1.1 fb−1 for the LHC experiments.

  17. High Energy Hadron Colliders - Report of the Snowmass 2013 Frontier Capabilities Hadron Collider Study Group

    Barletta, William; Battaglia, Marco; Klute, Markus; Mangano, Michelangelo; Prestemon, Soren; Rossi, Lucio; Skands, Peter

    2013-01-01

    High energy hadron colliders have been the tools for discovery at the highest mass scales of the energy frontier from the SppS, to the Tevatron and now the LHC. This report reviews future hadron collider projects from the high luminosity LHC upgrade to a 100 TeV hadron collider in a large tunnel, the underlying technology challenges and R&D directions and presents a series of recommendations for the future development of hadron collider research and technology.

  18. Very large hadron collider (VLHC)

    NONE

    1998-09-01

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

  19. Whither colliders after the Large Hadron Collider?

    Rolf-Dieter Heuer

    2012-11-01

    This paper presents 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 (luminosity and energy) and to its injectors. This may be complemented by a linear electron–positron collider, based on the technology being developed by the Compact Linear Collider and by the International Linear Collider, by a high-energy electron– proton machine, the LHeC, and/or by a muon collider. This contribution describes the various future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining the key messages for the way forward.

  20. Critical beam intensity issues in hadron colliders

    I would like to discuss how some of the issues that have been talked about at this workshop (and some that haven't) are reflected in the performance of hadron colliders. Hadron colliders, be they proton-antiproton, proton-proton, or heavy ion, are typically supported by a half-dozen other accelerators each of which has its own set of performance characteristics and limitations. As a result, when designing, building, operating, or upgrading a hadron collider choices must be made that determine not only overall performance but also the ultimate configuration of the complex. It is impossible to discuss here the full range of issues that one has to consider in projecting performance in a hadron collider. I will concentrate on a few and attempt to make some observations on how/when various effects relating to beam intensity are important. We will start with a short introduction that is intended to give the ''lay of the land'' in hadron colliders--what are the performance issues and what are the fundamental mechanisms that limit performance? We will then examine how choices in beam parameters can and have influenced performance, and how strategies are likely to change as we contemplate higher energy colliders. Finally, I will offer some opinions on what research directions are dictated for improving the luminosity delivered from hadron colliders

  1. Preparing for the Large Hadron Collider

    Appleton, Owen

    2007-01-01

    "Processing data for the Large Hadron Collider, the next-generation particle accelerator under construction at CERN, Switzerland, is one of the driving forces for development of Grid technology." (1 page)

  2. Top Quark Studies at Hadron Colliders

    Sinervo, Pekka K.

    1996-01-01

    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 DZero 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 yield...

  3. Academic Training Lecture: Jets at Hadron Colliders

    PH Department

    2011-01-01

    Regular Programme 30, 31 March and 1 April  2011 from 11:00 to 12:00 -  Bldg. 40-S2-A01 - Salle Andersson Jets at Hadron Colliders by Gavin Salam These three lectures will discuss how jets are defined at hadron colliders, the physics that is responsible for the internal structure of jets and the ways in which an understanding of jets may help in searches for new particles at the LHC.

  4. Production of exotic hadrons at hadron colliders

    Pilloni, A

    2015-01-01

    The observation of many unexpected states decaying into heavy quarkonia has challenged the usual QQbar interpretation. One of the most studied exotic states, the X(3872), happens to be copiously produced in high-energy hadron collisions. We discuss how this large prompt production cross-section disfavors a loosely-bound molecule interpretation for this particle. This is supported by Monte Carlo simulations, and by a comparison with extrapolated light nuclei data by ALICE.

  5. Optimizing integrated luminosity of future hadron colliders

    Benedikt, Michael; Schulte, Daniel; Zimmermann, Frank

    2015-10-01

    The integrated luminosity, a key figure of merit for any particle-physics collider, is closely linked to the peak luminosity and to the beam lifetime. The instantaneous peak luminosity of a collider is constrained by a number of boundary conditions, such as the available beam current, the maximum beam-beam tune shift with acceptable beam stability and reasonable luminosity lifetime (i.e., the empirical "beam-beam limit"), or the event pileup in the physics detectors. The beam lifetime at high-luminosity hadron colliders is largely determined by particle burn off in the collisions. In future highest-energy circular colliders synchrotron radiation provides a natural damping mechanism, which can be exploited for maximizing the integrated luminosity. In this article, we derive analytical expressions describing the optimized integrated luminosity, the corresponding optimum store length, and the time evolution of relevant beam parameters, without or with radiation damping, while respecting a fixed maximum value for the total beam-beam tune shift or for the event pileup in the detector. Our results are illustrated by examples for the proton-proton luminosity of the existing Large Hadron Collider (LHC) at its design parameters, of the High-Luminosity Large Hadron Collider (HL-LHC), and of the Future Circular Collider (FCC-hh).

  6. Forward physics of hadronic colliders

    These lectures were given at the Baikal Summer School on Physics of Elementary Particles and Astrophysics in July 2012. They can be viewed as a concise introduction to hadronic diffraction, to the physics of the pomeron and related topics

  7. Single sneutrino production at hadron colliders

    Chaichian, Masud; Huitu, K; Roy, S; Yu, Z; Chaichian, Masud; Datta, Anindya; Huitu, Katri; Roy, Sourov; Yu, Zenghui

    2004-01-01

    We study the production of a single sneutrino in association with one or two $b$-quarks at hadron colliders, in the framework of an R-parity violating supersymmetric model. We find that at the Large Hadron Collider (LHC) four $b$ final states are promising with efficient b-tagging. $l^+l'^-$ decay modes of the sneutrino can also be viable for detection at the LHC. However, the branching ratio for rare $\\gamma\\gamma$ decay channel is too small to be seen.

  8. Top quark studies at hadron colliders

    Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

    1997-01-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  9. Supersymmetric particle production at hadron colliders

    Krämer, Michael

    1998-01-01

    The theoretical status of MSSM particle production at the hadron colliders Tevatron and LHC is reviewed, including next-to-leading order supersymmetric QCD corrections. The higher-order corrections significantly reduce the theoretical uncertainty and lead to a rise of the lower bounds on supersymmetric particle masses, as demonstrated for the case of top-squark and gaugino pair production at the Tevatron.

  10. Black Holes and the Large Hadron Collider

    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…

  11. Introduction to quantum chromodynamics at hadron colliders

    William B Kilgore

    2011-05-01

    A basic introduction to the application of QCD at hadron colliders is presented. I briefly review the phenomenological and theoretical origins of QCD, and then discuss factorization and infrared safety, parton distributions, the computation of hard scattering amplitudes and applications of perturbative QCD.

  12. Experiments at future hadron colliders

    This report summarizes signatures and backgrounds for processes in high-energy hadronic collisions, particularly at the SSC. It includes both signatures for new particles -- t quarks, Higgs bosons, new Ζ' bosons, supersymmetric particles, and technicolor particles -- and other experiments which might be done. It is based on the 1990 Snowmass Workshop and on work contained in the Expressions of Interest submitted to the SSC. 46 refs., 19 figs., 1 tab

  13. B Physics Theory for Hadron Colliders

    Buchalla, G. , Cata, O. , Rahn, R.

    2008-01-01

    A short overview of theoretical methods for B physics at hadron colliders is presented. The main emphasis is on the theory of two-body hadronic B decays, which provide a rich field of investigation in particular for the Tevatron and the LHC. The subject holds both interesting theoretical challenges as well as many opportunities for flavor studies and new physics tests. A brief review of the current status and recent developments is given. A few additional topics in B physics are also mentioned.

  14. The Large Hadron electron Collider at CERN

    Polini Alessandro

    2014-06-01

    Full Text Available The Large Hadron electron Collider (LHeC is a proposed facility which will exploit the new world of energy and intensity offered by the LHC through collisions with a new 60 GeV electron beam. Designed for synchronous operation with the other LHC experiments, the LHeC will be a high luminosity ep and eA collider with a wide ranging physics program on high precision deep inelastic scattering and new physics. Highlights from the physics program will be illustrated along with details from the accelerator, interaction region and detector design.

  15. The Large Hadron electron Collider at CERN

    Polini Alessandro

    2014-01-01

    The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC through collisions with a new 60 GeV electron beam. Designed for synchronous operation with the other LHC experiments, the LHeC will be a high luminosity ep and eA collider with a wide ranging physics program on high precision deep inelastic scattering and new physics. Highlights from the physics program will be illustrated along with details from the ac...

  16. Physics results at Large Hadron Collider

    A brief review of physics results of 2011 from experiments at the Large Hadron Collider is presented, first of all -- results of a search for the Standard Model Higgs boson. Measurements of W and Z bosons, t quark and a search for rare B-meson decays are in a good agreement with the Standard Model predictions in next-to-next-to-leading order (NNLO)

  17. Big Science and the Large Hadron Collider

    Giudice, Gian Francesco

    2011-01-01

    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 here by first reviewing the process that led to the emergence of Big Science and the role of large projects in the development o...

  18. Really large hadron collider working group summary

    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

  19. String Resonances at Hadron Colliders

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

    2014-01-01

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

  20. The Tevatron Hadron Collider: A short history

    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

  1. String resonances at hadron colliders

    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

  2. Ntuples for NLO Events at Hadron Colliders

    Bern, Z; Cordero, F Febres; Hoeche, S; Ita, H; Kosower, D A; Maitre, D

    2014-01-01

    We present an event-file format for the dissemination of next-to-leading-order (NLO) predictions for QCD processes at hadron colliders. The files contain all information required to compute generic jet-based infrared-safe observables at fixed order (without showering or hadronization), and to recompute observables with different factorization and renormalization scales. The files also make it possible to evaluate cross sections and distributions with different parton distribution functions. This in turn makes it possible to estimate uncertainties in NLO predictions of a wide variety of observables without recomputing the short-distance matrix elements. The event files allow a user to choose among a wide range of commonly-used jet algorithms and jet-size parameters. We provide event files for a $W$ or $Z$ boson accompanied by up to four jets, and for pure-jet events with up to four jets. The files are for the Large Hadron Collider with a center of mass energy of 7 or 8 TeV. A C++ library along with a Python in...

  3. The Large Hadron Collider, A Megascience Project

    Lebrun, P

    2001-01-01

    The Large Hadron Collider (LHC) will be the next particle accelerator built to serve the world's high-energy physics community at CERN, the European Organisation for Nuclear Research. Reusing the 26.7-km circumference tunnel and infrastructure of the existing LEP collider, the LHC will make use of advanced technology - high-field superconducting magnets operated in superfluid helium - to push the energy frontier up by an order of magnitude, while remaining economically feasible. The LHC demonstrates on a grand scale several typical features of megascience projects, such as the need for international funding, world-wide co-operation and integration in the local environment, which we review in the following.

  4. B--Physics in Hadron Colliders

    Hill, Christopher T.(Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL, 60510, USA)

    1993-01-01

    The possibility of exploring the systematics of the spectroscopy, strong dynamics, and the weak and rare decay modes of b--quark systems at hadron colliders such as Fermilab, LHC and SSC, is discussed. A copious yield of $10^{10}$ detected $B$--mesons is readily accessible in a dedicated Fermilab program, and implies a vast array of accessible decay modes, including second order weak processes and $CP$--violation, which will be unavailable elsewhere until the commissioning of LHC or SSC. Kine...

  5. Hadron collider physics at the CERN SPS

    The results of the experiments of the CERN antiproton-proton collider, collected during the 1988 and 1989 runs, are summarized. The results of the W and Z hadronic decays are discussed. The results obtained from samples of W → e ν and Z → e+e- events for the W and Z production cross section times branching ratio and for pT are in good agreement with theoretical expectations. The measurements of W and Z mass are discussed. Lower limits of 61 GeV/c2 (UA1) and of 67 GeV/c2 (UA2) are reported for the mass of the top quark

  6. Geneva University - Kinematics at Hadron Colliders - POSTPONED!!!

    2007-01-01

    The seminar is postponed.Ecole de physique - Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet 1211 GENEVE 4 Tél: (022) 379 62 73 - Fax: (022) 379 69 92 Wednesday 12 décembre 2007 PARTICLE PHYSICS SEMINAR at 17:00 – Stückelberg Auditorium Kinematics at Hadron Colliders by Prof. Drew Baden, University of Maryland Information: http://dpnc.unige.ch/seminaire/annonce.html Organizer: J.-S. Graulich

  7. Black holes at the Large Hadron Collider.

    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. PMID:11690198

  8. Light-Gravitino Production at Hadron Colliders

    Kim, J; Nanopoulos, Dimitri V; Rangarajan, R; Zichichi, Antonino; Kim, Jaewan; Lopez, Jorge L.; Rangarajan, Raghavan

    1998-01-01

    We consider the production of gravitinos ($\\widetilde G$) in association with gluinos ($\\tilde g$) or squarks ($\\tilde q$) at hadron colliders, including the three main sub-processes: $q \\bar q -> \\tilde g\\widetilde G$, $qg -> \\tilde enhanced to the point of being observable for sufficiently light gravitino masses ($m_{\\widetilde G} \\tilde g\\tilde g$. Searches for such events at the Tevatron can impose lower limits on the gravitino mass. In the Appendix, we provide a complete set of Feynman rules for gravitino interactions used in our calculation.

  9. Higgs physics at the Large Hadron Collider

    Rohini M Godbole

    2011-05-01

    In this talk I shall begin by summarizing the importance of the Higgs physics studies at the Large Hadron Collider (LHC). I shall then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with prospects in the near future at the LHC. I have added to the writeup, recent experimental results from the LHC which have become available since the time of the workshop.

  10. Measuring supersymmetry at the large hadron collider

    B C Allanach

    2003-02-01

    The large hadron collider (LHC) should have the ability to detect supersymmetric particles if low-energy supersymmetry solves the hierarchy problem. Studies of the LHC detection reach, and the ability to measure properties of supersymmetric particles are currently underway. We highlight some of these, such as the reach in minimal supergravity space and correlation with a fine-tuning parameter, precision measurements of edge variables, anomaly- or gauge-mediated supersymmetry breaking. Supersymmetry with baryon-number violation seems at first glance more difficult to detect, but proves to be possible by using leptons from cascade decays.

  11. Large hadron collider workshop. Proceedings. Vol. 3

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentaiton and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  12. Large hadron collider workshop. Proceedings. Vol. 1

    The aim of the LCH workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

  13. Large hadron collider workshop. Proceedings. Vol. 2

    The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol.1 of these proceedings contains the papers presented at the plenary sessions, Vol.2 the individual contributions to the physics sessions, and Vol.3 those to the instrumentation sessions. (orig.)

  14. Mass reach scaling for future hadron colliders

    The primary goal of any future hadron collider is to discover new physics (NP) associated with a high mass scale, M, beyond the range of the LHC. In order to maintain the same relative mass reach for rate-limited NP, M / √(s), as √(s) increases, Richter recently reminded us that the required integrated luminosity obtainable at future hadron colliders (FHC) must grow rapidly, ∝s, 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 √(s) = 100 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, αs, 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. (orig.)

  15. Searching for Top Squark at Hadron Colliders

    YANG Jin-Min(杨金民); Young Bing-Lin

    2002-01-01

    In this talk we briefly summarise our recent study (hep-ph/0007165) on searching for top squark at hadron colliders. The light top-squark (stop) if produced in hadron colliders in the form of the t1t1 pair and decaying through the likely decay chain t1→X+b followed by X→X0ff′, can mimic closely a top quark event when the mass of the stop is close to that of the top quark. Because of the much lower production rate, the stop event can be buried under the top quark event sample. In order to uncover the stop event, specific selection cuts need to be applied. Through Monte Carlo simulation with suitable kinematic cuts, we found that such stop event can be extracted from the top quark sample and detected by the top counting experiments in the upcoming upgraded Tevatron and LHC. However, because of the small statistics of the Run 1 of the Tevatron, the stop signal remains hidden at Run 1.

  16. A Large Hadron Electron Collider at CERN

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

    2012-01-01

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

  17. QCD and jets at hadron colliders

    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.

  18. QCD and Jets at Hadron Colliders

    Sapeta, Sebastian

    2015-01-01

    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.

  19. Weak mixing angle measurements at hadron colliders

    Di Simone, Andrea; The ATLAS collaboration

    2015-01-01

    The Talk will cover weak mixing angle measurements at hadron colliders ATLAS and CMS in particular. ATLAS has measured the forward-backward asymmetry for the neutral current Drell Yan process in a wide mass range around the Z resonance region using dielectron and dimuon final states with $\\sqrt{s}$ =7 TeV data. For the dielectron channel, the measurement includes electrons detected in the forward calorimeter which extends the covered phase space. The result is then used to extract a measurement of the effective weak mixing angle. Uncertainties from the limited knowledge on the parton distribution functions in the proton constitute a significant part of the uncertainty and a dedicated study is performed to obtain a PDF set describing W and Z data measured previously by ATLAS. Similar studies from CMS will be reported.

  20. Illuminating New Electroweak States at Hadron Colliders

    Ismail, Ahmed; Shuve, Brian

    2016-01-01

    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.

  1. Triplet Higgs boson at hadron colliders

    The novel feature of a Higgs-triplet representation is a nonzero tree-level coupling of H+W-Z, which is absent in all Higgs-doublet models. We study the associated production of a singly-charged Higgs boson of the Higgs-triplet representation with a W or Z boson at hadron colliders, followed by the H+→W+Z decay. We find that the 2l+4j final state gives an interesting level of signal with a negligible background, plus it allows a full mass reconstruction of the charged-Higgs boson. The cover range of the charged-Higgs mass is between 110 and 200 GeV. (author)

  2. Meeting of the Large Hadron Collider Committee

    2012-01-01

    Provisional Agenda for the 111th meeting of the Large Hadron Collider Committee to be held on Wednesday and Thursday, 26-27 September 2012. Open Session: Wednesday, 26 September at 9 a.m. in the Main Auditorium (Bldg. 500-1-001)  09.00 - 09.20    LHC Machine Status Report  09.30 - 10.00    ATLAS Status Report  10.10 - 10.40    CMS Status Report  10.50 - 11.10    COFFEE BREAK 11.10 - 11.40    LHCb Status Report 11.50 - 12.20   ALICE Status Report 12.30 - 12.50   TOTEM Status Report 13.00 - 13.20   LHCf Status Report

  3. The Large Hadron Collider, a personal recollection

    Evans, L

    2014-01-01

    The construction of the Large Hadron Collider (LHC) has been a massive endeavor spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing LEP tunnel of 27 km circumference and with a tunnel diameter of only 3.8m has required considerable innovation. The first was the development of an idea first proposed by Bob Palmer at Brookhaven National Laboratory in 1978, where the two rings are integrated into a single magnetic structure. This compact 2-in-1 structure was essential for the LHC due to both the limited space available in the existing Large Electron-Positron collider tunnel and the cost. The second innovation was the bold move to use 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. In this article, no attempt is made to give a comprehensive review of the machine design. This can be found in the LHC Design Report {[}1], w...

  4. Prospects for heavy flavor physics at hadron colliders

    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 Bs 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

  5. Prospects for heavy flavor physics at hadron colliders

    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.

  6. Large Hadron Collider slideshow shows future of physics

    Kramer, S E

    2007-01-01

    "The European organization for Nuclear Research (CERN) has been building the Large Hadron Collider for many years, but it's finally taking shape and prepping to operate at full power in 2008." (1/2 page)

  7. The ATLAS experiment at the CERN large hadron collider

    Çetin, Serkant Ali; ATLAS Collaboration

    2008-01-01

    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.

  8. Large Hadron Collider sets proton-acceleration record

    2009-01-01

    "The Large Hadron Collider, the largest atom smasher in the world, broke the record for proton acceleration Monday, sending beams of the particles at 1.18 trillion electron volts, scientists said" (1 paragraph)

  9. Higgs Boson and the Large Hadron Collider

    The Standard Model of particle physics has been extremely successful in explaining all the precision data collected during the past few decades. The model, however, was incomplete with one of the key particles still not experimentally observed till 2012. This particle is predicted by the theory in the context of providing mass to the fundamental constituents as well as the exchange particles W and Z bosons. In the recent past, two experiments, ATLAS and CMS operating at the Large Hadron Collider, CERN have observed the evidence of a new state. Search signal of this object has been motivated by the Higgs boson within the Standard Model. These results have been consolidated with newer data and some attempt has gone to determine some of the properties of this newly observed state. Some of the most important recent results in this context are presented in this lecture. Several groups from India have participated in the LHC program and contributed to various aspects like the machine, computing grid and the experiments. In particular, 3 institutes and 2 University groups have been a member of the CMS collaboration and took part in the discovery of the new state. The participation of the Indian groups are also highlighted. (author)

  10. Tune variations in the Large Hadron Collider

    The horizontal and vertical betatron tunes of the Large Hadron Collider (LHC) mainly depend on the strength of the quadrupole magnets, but are also affected by the quadrupole component in the main dipoles. In case of systematic misalignments, the sextupole component from the main dipoles and sextupole corrector magnets also affect the tunes due to the feed down effect. During the first years of operation of the LHC, the tunes have been routinely measured and corrected through either a feedback or a feed forward system. In this paper, the evolution of the tunes during injection, ramp and flat top are reconstructed from the beam measurements and the settings of the tune feedback loop and of the feed forward corrections. This gives the obtained precision of the magnetic model of the machine with respect to quadrupole and sextupole components. Measurements at the injection plateau show an unexpected large decay whose origin is not understood. This data is discussed together with the time constants and the dependence on previous cycles. We present results of dedicated experiments that show that this effect does not originate from the decay of the main dipole component. During the ramp, the tunes drift by about 0.022. It is shown that this is related to the precision of tracking the quadrupole field in the machine and this effect is reduced to about 0.01 tune units during flat top

  11. Tune variations in the Large Hadron Collider

    Aquilina, N. [CERN, Geneva (Switzerland); University of Malta, Msida (Malta); Giovannozzi, M.; Lamont, M. [CERN, Geneva (Switzerland); Sammut, N. [University of Malta, Msida (Malta); Steinhagen, R. [CERN, Geneva (Switzerland); Todesco, E., E-mail: ezio.todesco@cern.ch [CERN, Geneva (Switzerland); Wenninger, J. [CERN, Geneva (Switzerland)

    2015-04-01

    The horizontal and vertical betatron tunes of the Large Hadron Collider (LHC) mainly depend on the strength of the quadrupole magnets, but are also affected by the quadrupole component in the main dipoles. In case of systematic misalignments, the sextupole component from the main dipoles and sextupole corrector magnets also affect the tunes due to the feed down effect. During the first years of operation of the LHC, the tunes have been routinely measured and corrected through either a feedback or a feed forward system. In this paper, the evolution of the tunes during injection, ramp and flat top are reconstructed from the beam measurements and the settings of the tune feedback loop and of the feed forward corrections. This gives the obtained precision of the magnetic model of the machine with respect to quadrupole and sextupole components. Measurements at the injection plateau show an unexpected large decay whose origin is not understood. This data is discussed together with the time constants and the dependence on previous cycles. We present results of dedicated experiments that show that this effect does not originate from the decay of the main dipole component. During the ramp, the tunes drift by about 0.022. It is shown that this is related to the precision of tracking the quadrupole field in the machine and this effect is reduced to about 0.01 tune units during flat top.

  12. Large hadron collider project in CERN

    The Large Hadron Collider (LHC) is the latest scientific project in the world of particle physics launched by European Organization for Nuclear Research (CERN) nearby Geneva. The construction of the main components of this complex synchrotron ring where two proton beams will be accelerated up to energies of 7.7 TeV and then brought into collision, is well underway and the first installation of these components is expected to take place by the end of 2000. As a successor of the existing LEP machine and taking over a significant part of its infrastructure, when completed and commissioned in 2005, the LHG complex represent the most sophisticated and the largest project ever undertaken in the world of science. This machine has an ambitious task to offer the most contemporary and highest quality programmes in particle physics for scientists from all over the world. Its design and construction make use of the latest achievements in modern technologies, material sciences, engineering, computers, electronics and employing world wide experts and specialists of various profiles. At the same time, the LHC project ought to enable CERN and European scientists to maintain the world leading role in the field of particle physics in the next century. (author)

  13. Cryogenics for the Large Hadron Collider

    Lebrun, P

    2000-01-01

    The Large Hadron Collider (LHC), a 26.7 km circumference superconducting accelerator equipped with high-field magnets operating in superfluid helium below 1.9 K, has now fully entered construction at CERN, the European Laboratory for Particle Physics. The heart of the LHC cryogenic system is the quasi-isothermal magnet cooling scheme, in which flowing two-phase saturated superfluid helium removes the heat load from the 36000 ton cold mass, immersed in some 400 m/sup 3/ static pressurised superfluid helium. The LHC also makes use of supercritical helium for nonisothermal cooling of the beam screens which intercept most of the dynamic heat loads at higher temperature. Although not used in normal operation, liquid nitrogen will provide the source of refrigeration for precooling the machine. Refrigeration for the LHC is produced in eight large refrigerators, each with an equivalent capacity of about 18 kW at 4.5 K, completed by 1.8 K refrigeration units making use of several stages of hydrodynamic cold compressor...

  14. Recent results from the Large Hadron Collider

    We present an overview of the physics results obtained by experiments at the Large Hadron Collider (LHC) in 2009-2010, for an integrated luminosity of L ≈ 40 pb-1, collected mostly at a centre-of-mass energy of √s = 7 TeV. After an introduction to the physics environment at the LHC and the current performance of the accelerator and detectors, we will discuss quantum chromodynamics and B-physics analyses, W and Z production, the first results in the top sector, and searches for new physics, with particular emphasis on supersymmetry and Higgs studies. While most of the presented results are in remarkable agreement with Standard Model predictions, the excellent performance of the LHC machine and experiments, the prompt analysis of all data within just a few months after the end of data taking, and the high quality of the results obtained constitute an encouraging step towards unique measurements and exciting discoveries in the 2011-2012 period and beyond. (author)

  15. CP violation in the B mesons at hadron colliders

    CP violation measurements are a good way to test the validity of the Standard Model where CP violation phenomena are described by the CKM mechanism. A selection of recent measurements of CP violating observables in the decays of beauty hadrons performed at the hadronic colliders is presented.

  16. Tolerable systematic errors in Really Large Hadron Collider dipoles

    Peggs, S.; Dell, F.

    1996-12-01

    Maximum allowable systematic harmonics for arc dipoles in a Really Large Hadron Collider are derived. The possibility of half cell lengths much greater than 100 meters is justified. A convenient analytical model evaluating horizontal tune shifts is developed, and tested against a sample high field collider.

  17. Supersymmetry status and phenomenology at the Large Hadron Collider

    Alexander Belyaev

    2009-01-01

    Large Hadron Collider (LHC) has a great chance to finally reveal supersymmetry which remains a compelling theory for over 30 years in spite of lack of its discovery. It might be around the corner the present LHC era with sensitive dark matter search experiments and international linear collider hopefully coming up in the near future.

  18. Academic Training Lecture: Higgs Boson Searches at Hadron Colliders

    HR Department

    2010-01-01

    Regular Programme 21, 22, 23 & 24 June 2010 from 11:00 to 12:00 - Main Auditorium, Bldg. 500-1-001 Higgs Boson Searches at Hadron Colliders by Dr. Karl Jakobs (University of Freiburg) 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 ...

  19. FCC Based Lepton-Hadron and Photon-Hadron Colliders: Luminosity and Physics

    Acar, Y C; Beser, S; Karadeniz, H; Kaya, U; Oner, B B; Sultansoy, S

    2016-01-01

    Construction of future electron-positron colliders (or dedicated electron linac) and muon colliders (or dedicated muon ring) tangential to Future Circular Collider (FCC) will give opportunity to utilize highest energy proton and nucleus beams for lepton-hadron and photon-hadron collisions. Luminosity values of FCC based ep, \\mup, eA, \\muA, \\gammap and \\gammaA colliders are estimated. Multi-TeV center of mass energy ep colliders based on the FCC and linear colliders (LC) are considered in detail. Parameters of upgraded versions of the FCC proton beam are determined to optimize luminosity of electron-proton collisions keeping beam-beam effects in mind. Numerical calculations are performed using a currently being developed collision point simulator. It is shown that L_{ep}\\sim10^{32}\\,cm^{-2}s^{-1} can be achieved with LHeC-like upgrade of the FCC parameters.

  20. Production of electroweak bosons at hadron colliders: theoretical aspects

    Mangano, Michelangelo L

    2015-01-01

    Since the W and Z 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.

  1. The Higgs boson discovery at the Large Hadron Collider

    Wolf, Roger

    2015-01-01

    This book provides a comprehensive overview of the field of Higgs boson physics. It offers the first in-depth review of the complete results in connection with the discovery of the Higgs boson at CERN’s Large Hadron Collider and based on the full dataset for the years 2011 to 2012. The fundamental concepts and principles of Higgs physics are introduced and the important searches prior to the advent of the Large Hadron Collider are briefly summarized. Lastly, the discovery and first mensuration of the observed particle in the course of the CMS experiment are discussed in detail and compared to the results obtained in the ATLAS experiment.

  2. Four-Lepton Resonance at the Large Hadron Collider

    Barger, Vernon; Lee, Hye-Sung

    2011-01-01

    A spin-1 weakly interacting vector boson, Z', is predicted by many new physics theories. Searches at colliders for such a Z' resonance typically focus on lepton-antilepton or top-antitop events. Here we present a novel channel with a Z' resonance that decays to 4 leptons, but not to 2 leptons, and discuss its possible discovery at the Large Hadron Collider. This baryonic gauge boson is well motivated in a supersymmetry framework.

  3. Jet Reconstruction and Spectroscopy at Hadron Colliders

    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

  4. Resummed Results for Hadron Collider Observables

    McAslan, Heather

    2016-07-01

    Event shapes are invaluable QCD tools for theoretical calculations and experimental measurements. We revise the definition of these observables in e+e- annihilation and in hadron collisions, and give a review of the state-of-the-art results for their resummation. Then we detail how recent work on the re-summation of event shapes in electron-positron annihilation can provide us with the tools to extend resummation of generic hadronic event shapes to NNLL accuracy. We match our findings to fixed-order results at NNLO accuracy, showing the sizeable effects of resummation in the relevant regions of phase space.

  5. TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

    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.

  6. Large Hadron Collider project to study the origins of matter

    2007-01-01

    "The Scientific Information Port (PIC), a technological centre located on the campus of the UAB, recently started work on the first stage of the European project Large Hadron Collider (LHC), the largest particle accelerator in the world, which has the aim of reproducing conditions similar to those produced during the Big Bang in order to study the origins of matter." (1/2 page)

  7. CERN completes magnet set for Large Hadron Collider

    2006-01-01

    "CERN, the European Oganization for Nuclear Research, took delivery of the last superconducting main magnet for the Large Hadron Collider (LHC) on Monday, completint the full set of 1624 main magnets required to build the world's largest and most powerful particle accelerator."

  8. Model independent spin determination at hadron colliders

    Edelhaeuser, Lisa

    2012-04-25

    By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass s{sub ff} of the adjacent particles. In this thesis

  9. Model independent spin determination at hadron colliders

    By the end of the year 2011, both the CMS and ATLAS experiments at the Large Hadron Collider have recorded around 5 inverse femtobarns of data at an energy of 7 TeV. There are only vague hints from the already analysed data towards new physics at the TeV scale. However, one knows that around this scale, new physics should show up so that theoretical issues of the standard model of particle physics can be cured. During the last decades, extensions to the standard model that are supposed to solve its problems have been constructed, and the corresponding phenomenology has been worked out. As soon as new physics is discovered, one has to deal with the problem of determining the nature of the underlying model. A first hint is of course given by the mass spectrum and quantum numbers such as electric and colour charges of the new particles. However, there are two popular model classes, supersymmetric models and extradimensional models, which can exhibit almost equal properties at the accessible energy range. Both introduce partners to the standard model particles with the same charges and thus one needs an extended discrimination method. From the origin of these partners arises a relevant difference: The partners constructed in extradimensional models have the same spin as their standard model partners while in Supersymmetry they differ by spin 1/2. These different spins have an impact on the phenomenology of the two models. For example, one can exploit the fact that the total cross sections are affected, but this requires a very good knowledge of the couplings and masses involved. Another approach uses angular distributions depending on the particle spins. A prevailing method based on this idea uses the invariant mass distribution of the visible particles in decay chains. One can relate these distributions to the spin of the particle mediating the decay since it reflects itself in the highest power of the invariant mass sff of the adjacent particles. In this thesis we

  10. High-brightness injectors for hadron colliders

    The counterrotating beams in collider rings consist of trains of beam bunches with NB particles per bunch, spaced a distance SB 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 βc, the luminosity is given by L = NB2βc/4πσ2SB, where σ 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 β is the Courant-Synder betatron amplitude function at the interaction point, a characteristic of the focusing lattice and γ is the relativistic Lorentz factor. Achieving high luminosity at a given energy, and at practical values of β and SB, requires a large value for the ratio NB2/var-epsilon 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 NB, the luminosity can be increased if var-epsilon 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

  11. High-brightness injectors for hadron colliders

    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.

  12. Large Hadron Collider The Discovery Machine

    2008-01-01

    The mammoth machine, after a nine-year construction period, is scheduled (touch wood) to begin producing its beams of particles later this year. The commissioning process is planned to proceed from one beam to two beams to colliding beams; from lower energies to the terascale; from weaker test intensities to stronger ones suitable for producing data at useful rates but more difficult to control.

  13. CERN-Fermilab Hadron Collider Physics Summer School

    2007-01-01

    Applications are now open for the 2nd CERN-Fermilab Hadron Collider Physics Summer School, which will take place at CERN from 6 to 15 June 2007. The school web site is http://cern.ch/hcpss with links to the academic program and application procedure. The application deadline is 9 March 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be given on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be  supported by in-depth discussion sess...

  14. Physics at the Large Hadron Collider

    Mukhopadhyaya, Biswarup; Raychaudhari, Amitava

    2009-01-01

    In an epoch when particle physics is awaiting a major step forward, the Large Hydron Collider (LHC) at CERN, Geneva will soon be operational. It will collide a beam of high energy protons with another similar beam circulation in the same 27 km tunnel but in the opposite direction, resulting in the production of many elementary particles some never created in the laboratory before. It is widely expected that the LHC will discover the Higgs boson, the particle which supposedly lends masses to all other fundamental particles. In addition, the question as to whether there is some new law of physics at such high energy is likely to be answered through this experiment. The present volume contains a collection of articles written by international experts, both theoreticians and experimentalists, from India and abroad, which aims to acquaint a non-specialist with some basic issues related to the LHC. At the same time, it is expected to be a useful, rudimentary companion of introductory exposition and technical expert...

  15. Main Parameters of Ilc-Tevatron Based Lepton-Hadron and Photon-Hadron Colliders

    Sultansoy, Saleh; Ciftci, Abbas K; Recepoglu, Erdal; Yavas, Omer

    2005-01-01

    The construction of the ILC tangential to Tevatron ring will give opportunity to investigate electron-proton, positron-proton, electron-antiproton, positron-antiproton interactions at 1 TeV center of mass energy. The analysis of the lepton-hadron collisions in these energy region is very important both for understanding of strong interaction dynamics and for adequate interpretation of future LHC and VLHC data. In addition, ILC-Tevatron collider will provide a possibility to realize photon-hadron collisions in the same energy region using Compton backscattered laser photon off ILC electron beam. Main parameters of these colliders are estimated and their physics search potential is briefly discussed.

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

    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.

  17. Monotop phenomenology at the Large Hadron Collider

    Agram, Jean-Laurent; Buttignol, Michael; Conte, Eric; Fuks, Benjamin

    2014-01-01

    We investigate new physics scenarios where systems comprised of a single top quark accompanied by missing transverse energy, dubbed monotops, can be produced at the LHC. Following a simplified model approach, we describe all possible monotop production modes via an effective theory and estimate the sensitivity of the LHC, assuming 20 fb$^{-1}$ of collisions at a center-of-mass energy of 8 TeV, to the observation of a monotop state. Considering both leptonic and hadronic top quark decays, we show that large fractions of the parameter space are reachable and that new physics particles with masses ranging up to 1.5 TeV can leave hints within the 2012 LHC dataset, assuming moderate new physics coupling strengths.

  18. Lepton Flavor Violation at the Large Hadron Collider

    Allahverdi, Rouzbeh; Kamon, Teruki; Krislock, Abram

    2012-01-01

    We investigate a potential of discovering lepton flavor violation (LFV) at the Large Hadron Collider. A sizeable LFV in low energy supersymmetry can be induced by massive right handed neutrinos, which can explain neutrino oscillations via the seesaw mechanism. We investigate a scenario where the distribution of an invariant mass of two hadronically decaying taus ($\\tauh\\tauh$) from $\\schizero{2}$ decays is the same in events with or without LFV. We first develop a transfer function using this ditau massdistribution to model the shape of the non-LFV $\\tauh\\mu$ invariant mass. We then show the feasibility of extracting the LFV $\\tauh\\mu$ signal.

  19. B-quark production at hadron colliders

    Studying B-physics at hadron accelerators requires a good understanding of the total and differential cross sections for b-quark production. This knowledge gives those involved in B bar B mixing, rare B decays, and those trying to determine the CKM angles α, β, and γ an idea of how many events they can expect, given the luminosity and the branching ratios. It is particularly important for those studying rare B decays as they set limits on where we can hope to see new physics. For these reasons and others, the complete Ο(αs3) corrections to heavy-quark production at hadron accelerators were calculated in. Also three groups have attempted to calculate heavy-quark production using resummation techniques in the small-x kinematic region. These resummation techniques are necessary since the b-quark mass mb is small relative to the center-of-mass energies √S of the TeVatron and the SSC. While these techniques offer some hope of obtaining reasonable predictions for b-production at these machines, the current results can best be considered as preliminary. Thus we must turn to fixed-order perturbative QCD for guidance, as we have no other real choice at this point. However, let us submit a caveat here: fixed-order perturbative QCD works best when all the scales are roughly comparable, i.e. √s ∼ mb ∼ pt, √s being the partonic center-of-mass energy. When we are not in this regime, for example at the TeVatron and the SSC, our predictions will then be less reliable. Bearing this in mind, let use continue to the results section

  20. Tracking study of hadron collider boosters

    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.

  1. The Structure of Jets at Hadron Colliders

    Larkoski, Andrew James [Stanford Univ., CA (United States)

    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.

  2. Working group report: Physics at the Large Hadron Collider

    D K Ghosh; A Nyffeler; V Ravindran

    2011-05-01

    This is a summary of the activities of the Physics at the LHC working group in the XIth Workshop on High Energy Physics Phenomenology (WHEPP-XI) held at the Physical Research Laboratory, Ahmedabad, India in January 2010. We discuss the activities of each sub-working group on physics issues at colliders such as Tevatron and Large Hadron Collider (LHC). The main issues discussed involve (1) results on W mass measurement and associated QCD uncertainties, (2) an attempt to understand the asymmetry measured at Tevatron in the top quark production, and (3) phenomenology of warped space dimension model.

  3. The standard model Higgs search at the large hadron collider

    Satyaki Bhattacharya; on behalf of the CMS and the ATLAS Collaborations

    2007-11-01

    The experiments at the large hadron collider (LHC) will probe for Higgs boson in the mass range between the lower bound on the Higgs mass set by the experiments at the large electron positron collider (LEP) and the unitarity bound (∼ 1 TeV). Strategies are being developed to look for signatures of Higgs boson and measure its properties. In this paper results from full detector simulation-based studies on Higgs discovery from both ATLAS and CMS experiments at the LHC will be presented. Results of simulation studies on Higgs coupling measurement at LHC will be discussed.

  4. Bi-Event Subtraction Technique at hadron colliders

    Dutta, Bhaskar [Department of Physics and Astronomy, Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Kamon, Teruki [Department of Physics and Astronomy, Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States); Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kolev, Nikolay [Department of Physics, University of Regina, Regina, SK S4S 0A2 (Canada); Krislock, Abram, E-mail: crysanthemus@gmail.com [Department of Physics and Astronomy, Mitchell Institute for Fundamental Physics, Texas A and M University, College Station, TX 77843 (United States)

    2011-09-20

    We propose the Bi-Event Subtraction Technique (BEST) as a method of modeling and subtracting large portions of the combinatoric background during reconstruction of particle decay chains at hadron colliders. The combinatoric background arises when it is impossible to know experimentally which observed particles come from the decay chain of interest. The background shape can be modeled by combining observed particles from different collision events and be subtracted away, greatly reducing the overall background. This idea has been demonstrated in various experiments in the past. We generalize it by showing how to apply BEST multiple times in a row to fully reconstruct a cascade decay. We show the power of BEST with two simulated examples of its application towards reconstruction of the top quark and a supersymmetric decay chain at the Large Hadron Collider.

  5. Large hadron collider in the LEP tunnel. Proceedings. Vol. 2

    A Workshop, jointly organized by ECFA and CERN, took place at Lausanne and at CERN in March 1984 to study various options for a pp (or panti p) collider which might be installed at a later data alongside LEP in the LEP tunnel. Following the exploration of e+e- physics up to the highest energy now foreseeable, this would open up the opportunity to investigate hadron collisions in the new energy range of 10 to 20 TeV in the centre of mass. These proceedings put together the documents prepared in connection with this Workshop. They cover possible options for a Large Hadron Collider (LHC) in the LEP tunnel, the physics case as it stands at present, and studies of experimental possibilities in this energy range with luminosities as now considered. See hints under the relevant topics. (orig./HSI)

  6. The ALICE experiment at the large hadron collider

    Munhoz, Marcelo Gameiro [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica

    2012-07-01

    Full text: ALICE (A Large Ion Collider Experiment) is the only experiment form the Large Hadron Collider (LHC) at CERN (European Organization for Nuclear Research) dedicated mainly to study relativistic heavy ion collisions. The experiment was optimized to measure a great variety of observables that allow us to study the properties of the Quark Gluon Plasma, a new state of nuclear matter where quarks and gluons are deconfined from hadrons. The enlightenment of such properties will provide great insight in the understanding of the strong interaction described by QCD. In this talk, I will present the ALICE experiment, the latest results obtained by the collaboration in the last 2 years and discuss the Brazilian participation in this very interesting and important international project. (author)

  7. Large hadron collider in the LEP tunnel. Proceedings. Vol. 1

    A Workshop, jointly organized by ECFA and CERN, took place at Lausanne and at CERN in March 1984 to study various options for a pp (or panti p) collider which might be installed at a later date alongside LEP in the LEP tunnel. Following the exploration of e+e- physics up to the highest energy now foreseeable, this would open up the opportunity to investigate hadron collisions in the new energy range of 10 to 20 TeV in the centre of mass. These proceedings put together the documents prepared in connection with this Workshop. They cover possible options for a Large Hadron Collider (LHC= in the LEP tunnel, the physics case at it stands at present, and studies of experimental possibilities in this energy range with luminosities as now considered. See hints under the relevant topics. (orig.)

  8. Beyond the Large Hadron Collider: a first look at cryogenics for CERN future circular colliders

    Lebrun, Ph

    2015-01-01

    Following the first experimental discoveries at the Large Hadron Collider (LHC) and the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. The study, conducted with the collaborative participation of interested institutes world-wide, considers several options for very high energy hadron-hadron, electron-positron and hadron-electron colliders to be installed in a quasi-circular underground tunnel in the Geneva basin, with a circumference of 80 km to 100 km. All these machines would make intensive use of advanced superconducting devices, i.e. high-field bending and focusing magnets and/or accelerating RF cavities, thus requiring large helium cryogenic systems operating at 4.5 K or below. Based on preliminary sets of parameters and layouts for the particle colliders under study, we discuss the main challenges of their cryogenic systems and present first estimates of the cryogenic refrigeration capacities req...

  9. Learning to See at the Large Hadron Collider

    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.

  10. Next to leading order three jet production at hadron colliders

    I present results from a next-to-leading order event generator of purely gluonic jet production. This calculation is the first step in the construction of a full next-to-leading order calculation of three jet production at hadron colliders. Several jet algorithms commonly used in experiments are implemented and their numerical stability is investigated. A numerical instability is found in the iterative cone algorithm which makes it inappropriate for use in fixed order calculations beyond leading order

  11. Theory overview of electroweak physics at hadron colliders

    Campbell, John M

    2016-01-01

    This contribution summarizes some of the important theoretical progress that has been made in the arena of electroweak physics at hadron colliders. The focus is on developments that have sharpened theoretical predictions for final states produced through electroweak processes. Special attention is paid to new results that have been presented in the last year, since LHCP2015, as well as on key issues for future measurements at the LHC.

  12. Discriminating Supersymmetry and Black Holes at the Large Hadron Collider

    Roy, Arunava

    2008-01-01

    We show how to differentiate the minimal supersymmetric extension of the standard model from black hole events at the Large Hadron Collider. Black holes are simulated with the CATFISH generator. Supersymmetry simulations use a combination of PYTHIA and ISAJET. Our study, based on event shape variables, visible and missing momenta, and analysis of dilepton events, demonstrates that supersymmetry and black hole events at the LHC can be easily discriminated.

  13. Learning to See at the Large Hadron Collider

    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.

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

    Long arc cells would lead to major cost savings in a high field high Tc 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

  15. Hadron and jet production at collider energies in perturbative QCD

    Large psub(T) production of hadrons and jets at collider and ISR energies is studied in conventional perturbative QCD. Recently determined gluon and other parton distributions are used and higher order vertical strokeO(αsub(s)3)] perturbative corrections (K-factors) are taken into account. Good description of the data is found. The possible role of gluinos and other particles of supersymmetric theories is briefly discussed. (orig.)

  16. High-dimensional Z' phenomenology at hadron colliders

    Fuks, B.; van der Bij, J. J.; Q. Xu

    2008-01-01

    We study the phenomenology of a Z'-boson field coupled to hypercharge. The Z' propagator has a non-trivial K\\"all\\'en-Lehmann spectral density due to the mixing with a higher dimensional inert vector field. As a consequence detection possibilities at hadron colliders are reduced. We determine the range of parameters where this field can be studied at the Tevatron and the LHC through its production cross section via the Drell-Yan mechanism.

  17. Forward-Central Jet Correlations at the Large Hadron Collider

    Deak, M; Hautmann, F.(Dept. of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, United Kingdom); Jung, H; Kutak, K.

    2010-01-01

    For high-pT forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forwa...

  18. Electron lenses for the large hadron collider

    Stancari†, G; Bruce, R; Redaelli, S; Rossi, A; Salvachua Ferrando, B

    2014-01-01

    Electron lenses are pulsed, magnetically confined electron beamswhose 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-bybunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beamcompensation, and for the demonstration of halo scrapingwith 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. A conceptual design was recently completed, and the project is moving towards a technical design in 2014–2015 for construction in 2015–2017, if needed, after resuming LHC operations and re-assessing collimation needs and requirements at 6.5 TeV. Because of the...

  19. 2nd CERN-Fermilab Hadron Collider Physics Summer School

    2007-01-01

    June 6-15, 2007, CERN The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007 The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, extensively covered the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis t...

  20. 3rd CERN-Fermilab Hadron Collider Physics Summer School

    2008-01-01

    August 12-22, 2008, Fermilab The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 29 FEBRUARY 2008. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high-energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The third session of the summer school will focus on exposing young post-docs and advanced graduate students to broader theories and real data beyond what they’ve learned at their home institutions. Experts from across the globe will lecture on the theoretical and experimental foundations of hadron collider physics, host parallel discussion sessions and answer students’ questions. This year’s school will also have a greater focus on physics beyond the Standard Model, as well as more time for questions at the end of each lecture. The 2008 School will be held at ...

  1. Disambiguating Seesaw Models using Invariant Mass Variables at Hadron Colliders

    Dev, P S Bhupal; Mohapatra, Rabindra N

    2015-01-01

    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 dis...

  2. The Large Hadron Collider in the LEP tunnel

    The status of the studies for the CERN Large Hadron Collider (LHC) is described. This collider will provide proton-proton collisions with 16 TeV centre-of-mass energy and a luminosity exceeding 1033 cm-2 s-1 per interaction point. It can be installed in the tunnel of the Large Electron-Positron Storage Ring (LEP) above the LEP elements. It will use superconducting magnets of a novel, compact design, having two horizontally separated channels for the two counter-rotating bunched proton beams, which can collide in a maximum of seven interaction points. Collisions between protons of the LHC and electrons of LEP are also possible with a centre-of-mass energy of up to 1.8 TeV and a luminosity of up to 2 x 1032 cm-2 s-1. (orig.)

  3. Dark Matter Searches at the Large Hadron Collider

    Hoh, Siew Yan; Abdullah, Wan Ahmad Tajuddin Bin Wan

    2015-01-01

    Dark Matter is a hypothetical particle proposed to explain the missing matter expected from the cosmological observation. The motivation of Dark Matter is overwhelming however as it is mainly deduced from its gravitational interaction, for it does little to pinpoint what Dark Matter really is. In WIMPs Miracle, weakly interactive massive particle being the Dark Matter candidate is correctly producing the current thermal relic density at weak scale, implying the possibility of producing and detecting it in Large Hadron Collider. Assuming WIMPs being the maverick particle within collider, it is expected to be pair produced in association with a Standard Model particle. The presence of the WIMPs pair is inferred from the Missing Transverse Energy (MET) which is the vector sum of the imbalance in the transverse momentum plane recoils a Standard Model Particle. The collider is able to produce light mass Dark Matter which the traditional detection fail to detect due to the small momentum transfer involved in the in...

  4. Hadronic interactions in the energy region of future hadron colliders, dual topological unitarization of hard and soft hadronic cross sections

    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 pperpendicular) 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 predictions of the model for TeV colliders are presented. Interesting changes of the produced multiparticle system are found when selecting classes of events with and without hard jets or minijets. (author)

  5. Online track reconstruction at hadron colliders

    Real time event reconstruction plays a fundamental role in High Energy Physics experiments. Reducing the rate of data to be saved on tape from millions to hundreds per second is critical. In order to increase the purity of the collected samples, rate reduction has to be coupled with the capability to simultaneously perform a first selection of the most interesting events. A fast and efficient online track reconstruction is important to effectively trigger on leptons and/or displaced tracks from b-quark decays. This talk will be an overview of online tracking techniques in different HEP environments: we will show how H1 experiment at HERA faced the challenges of online track reconstruction implementing pattern matching and track linking algorithms on CAMs and FPGAs in the Fast Track Processor (FTT). The pattern recognition technique is also at the basis of the Silicon Vertex Trigger (SVT) at the CDF experiment at Tevatron: coupled to a very fast fitting phase, SVT allows to trigger on displaced tracks, thus greatly increasing the efficiency for the hadronic B decay modes. A recent upgrade of the SVT track fitter, the Giga-fitter, can perform more than 1 fit/ns and further improves the CDF online trigger capabilities at high luminosity. At SLHC, where luminosities will be 2 orders of magnitude greater than Tevatron, online tracking will be much more challenging: we will describe CMS future plans for a Level-1 track trigger and the Fast Tracker (FTK) processor at the ATLAS experiment, based on the Giga-fitter architecture and designed to provide high quality tracks reconstructed over the entire detector in time for a Level-2 trigger decision.luminosity. At SLHC, where luminosities will be 2 orders of magnitude greater than Tevatron, online tracking will be much more challenging: we will describe CMS future plans for a Level-1 track trigger and the Fast Tracker (FTK) processor at the Atlas experiment, based on the Giga-fitter architecture and designed to provide high

  6. Dark matter searches at the large hadron collider

    Hoh, S. Y.; Komaragiri, J. R.; Wan Abdullah, W. A. T.

    2016-01-01

    Dark Matter is a hypothetical particle proposed to explain the missing matter expected from the cosmological observation. The motivation of Dark Matter is overwhelming however as it is mainly deduced from its gravitational interaction, for it does little to pinpoint what Dark Matter really is. In WIMPs Miracle, weakly interactive massive particle being the Dark Matter candidate is correctly producing the current thermal relic density at weak scale, implying the possibility of producing and detecting it in Large Hadron Collider. Assuming WIMPs being the maverick particle within collider, it is expected to be pair produced in association with a Standard Model particle. The presence of the WIMPs pair is inferred from the Missing Transverse Energy (MET) which is the vector sum of the imbalance in the transverse momentum plane recoils a Standard Model Particle. The collider is able to produce light mass Dark Matter which the traditional detection fail to detect due to the small momentum transfer involved in the interaction; on the other hand, the traditional detection is robust in detecting a higher Dark matter masses but the collider is suffered from the parton distribution function suppression. Topologically the processes are similar to the scattering processes in the direct detection thus complementary to the traditional Dark Matter detection. The collider searches are strongly motivated as the results are usually translated to the annihilation and scattering rates at more traditional Dark Matter-oriented experiments, thus a concordance approach is adapted. An overview of Dark Matter searches at the Large Hadron Collider will be covered in this paper.

  7. Transverse beams stability studies at the Large Hadron Collider

    Buffat, Xavier; Pieloni, Tatiana

    2015-01-30

    A charged particle beam travelling at the speed of light produces large electromagnetic wake fields which, through interactions with its surroundings, act back on the particles in the beam. This coupled system may become unstable, resulting in a deterioration of the beam quality. Such effects play a major role in most existing storage rings, as they limit the maximum performance achievable. In a collider, the presence of a second beam significantly changes the dynamics, as the electromagnetic interactions of the two beams on each other are usually very strong and may, also, limit the collider performances. This thesis treats the coherent stability of the two beams in a circular collider, including the effects of the electromagnetic wake fields and of the beam-beam interactions, with particular emphasis on CERN's Large Hadron Collider. As opposed to other colliders, this machine features a large number of bunches per beam each experiencing multiple long-range and head-on beam-beam interactions. Existing models...

  8. A 233 km Tunnel for Lepton and Hadron Colliders

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

    2012-01-01

    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 $e^+e^-$, $p \\bar{p}$, and $\\mu^+ \\mu^-$ collider rings in this tunnel using recent technological innovations. The 240 and 500 GeV $e^+e^-$ 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 $e^+ e^-$ collider and 1.75 TeV muon accelerator in a Fermilab site filler tunnel. The 40 TeV $p \\bar{p}$ collider uses the high intensity Fermilab $\\bar{p}$ source, exploits high cross sections for $p \\bar{p}$ 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 superconduct...

  9. A 233 km tunnel for lepton and hadron colliders

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

    2012-12-21

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

  10. Complementarity of the CERN Large Hadron Collider and the $e^+e^-$ International Linear Collider

    Choi, S Y

    2008-01-01

    The next-generation high-energy facilities, the CERN Large Hadron Collider (LHC) and the prospective $e^+e^-$ International Linear Collider (ILC), are expected to unravel new structures of matter and forces from the electroweak scale to the TeV scale. In this report we review the complementary role of LHC and ILC in drawing a comprehensive and high-precision picture of the mechanism breaking the electroweak symmetries and generating mass, and the unification of forces in the frame of supersymmetry.

  11. Signatures for black hole production from hadronic observables at the Large Hadron Collider

    The concept of Large Extra Dimensions (LED) provides a way of solving the Hierarchy Problem which concerns the weakness of gravity compared with the strong and electro-weak forces. A consequence of LED is that miniature Black Holes (mini-BHs) may be produced at the Large Hadron Collider in p + p collisions. The present work uses the CHARYBDIS mini-BH generator code to simulate the hadronic signal which might be expected in a mid-rapidity particle tracking detector from the decay of these exotic objects if indeed they are produced. An estimate is also given for Pb+Pb collisions. (author)

  12. Gluon fusion contribution to VHj production at hadron colliders

    Pankaj Agrawal

    2015-02-01

    Full Text Available We study the associated production of an electroweak vector boson and the Higgs boson with a jet via gluon–gluon fusion. At the leading order, these processes occur at one-loop level. The amplitudes of these one-loop processes are gauge invariant and finite. Therefore, their contributions towards the corresponding hadronic cross sections and kinematic distributions can be calculated separately. We present results for the Large Hadron Collider and its discussed upgrades. We find that the gluon–gluon one-loop process gives dominant contribution to the γHj production. We observe a destructive interference effect in the gg→ZHj amplitude. We also find that in the high transverse momentum and central rapidity region, the ZHj production cross section via gluon–gluon fusion becomes comparable to the cross section contributions coming from quark–quark and quark–gluon channels.

  13. The phenomenology of central exclusive production at hadron colliders

    Harland-Lang, L A; Ryskin, M G; Stirling, W J

    2012-01-01

    Central exclusive production (CEP) processes in high-energy hadron-hadron collisions provide an especially clean environment in which to measure the nature and quantum numbers (in particular, the spin and parity) of new resonance states. Encouraged by the broad agreement between experimental measurements and theoretical predictions based on the Durham approach, we perform a detailed phenomenological analysis of diphoton and meson pair CEP final states, paying particular attention to the theoretical uncertainties in the predictions, including those from parton distribution functions, higher-order perturbative corrections, and non-perturbative and proton dissociation contributions. We present quantitative cross-section predictions for these CEP final states at the RHIC, Tevatron and LHC colliders.

  14. Large Hadron Collider (LHC) phenomenology, operational challenges and theoretical predictions

    Gilles, Abelin R

    2013-01-01

    The Large Hadron Collider (LHC) is the highest-energy particle collider ever constructed and is considered "one of the great engineering milestones of mankind." It was built by the European Organization for Nuclear Research (CERN) from 1998 to 2008, with the aim of allowing physicists to test the predictions of different theories of particle physics and high-energy physics, and particularly prove or disprove the existence of the theorized Higgs boson and of the large family of new particles predicted by supersymmetric theories. In this book, the authors study the phenomenology, operational challenges and theoretical predictions of LHC. Topics discussed include neutral and charged black hole remnants at the LHC; the modified statistics approach for the thermodynamical model of multiparticle production; and astroparticle physics and cosmology in the LHC era.

  15. Report on the workshop on ion sources for hadron colliders

    Alessi, J.G.

    1997-11-01

    A workshop on Ion Sources for Hadron Colliders was held September 4--5, 1997 in Gelnhausen, Germany. This workshop, organized by the WE-Heraeus-Stiftung Foundation, the University of Frankfurt, Brookhaven National Laboratory, and CERN, directly followed the 7th Symposium on Electron Beam Ion Sources and Traps. Various options were reviewed for the development of a high current, intermediate charge state heavy ion source for use on colliders such as RHIC and LHC. In addition to status reports on ECR, EBIS, and laser sources, there was also discussion of issues relevant to the scaling of these sources to intensities as required by RHIC and LHC. The presentations and discussions from this workshop are summarized.

  16. Hadron Collider Tests of Neutrino Mass-Generating Mechanisms

    Ruiz, Richard E

    2015-01-01

    The Standard Model of particle physics (SM) is presently the best description of nature at small distances and high energies. However, with tiny but nonzero neutrino masses, a Higgs boson mass unstable under radiative corrections, and little guidance on understanding the hierarchy of fermion masses, the SM remains an unsatisfactory description of nature. Well-motivated scenarios that resolve these issues exist but also predict extended gauge (e.g., Left-Right Symmetric Models), scalar (e.g., Supersymmetry), and/or fermion sectors (e.g., Seesaw Models). Hence, discovering such new states would have far-reaching implications. After reviewing basic tenets of the SM and collider physics, several beyond the SM (BSM) scenarios that alleviate these shortcomings are investigated. Emphasis is placed on the production of a heavy Majorana neutrinos at hadron colliders in the context of low-energy, effective theories that simultaneously explain the origin of neutrino masses and their smallness compared to other elementar...

  17. The Large Hadron Collider Present Status and Prospects

    Evans, Lyndon R

    2001-01-01

    The Large Hadron Collider (LHC), due to be commissioned in 2005, will provide particle physics with the first laboratory tool to access the energy frontier above 1 TeV. In order to achieve this , protons must be accelerated and stored at 7 TeV, colliding with an unprecedented luminosity of 1034 cm-2 s-1. The 8.3 Tesla guide field is obtained using conventional NbTi technology cooled to below the lambda point of helium. Considerable modification of the infrastructure around the existing LEP tunnel is needed to house the LHC machine and detectors. The project is advancing according to schedule with most of the major hardware systems including cryogenics and magnets under construction. A brief status report is given and future prospects are discussed.

  18. Report on the workshop on ion sources for hadron colliders

    A workshop on Ion Sources for Hadron Colliders was held September 4--5, 1997 in Gelnhausen, Germany. This workshop, organized by the WE-Heraeus-Stiftung Foundation, the University of Frankfurt, Brookhaven National Laboratory, and CERN, directly followed the 7th Symposium on Electron Beam Ion Sources and Traps. Various options were reviewed for the development of a high current, intermediate charge state heavy ion source for use on colliders such as RHIC and LHC. In addition to status reports on ECR, EBIS, and laser sources, there was also discussion of issues relevant to the scaling of these sources to intensities as required by RHIC and LHC. The presentations and discussions from this workshop are summarized

  19. An Application for Research: the Large Hadron Collider

    Bailey, R

    2014-01-01

    The Large Hadron Collider (LHC) machine at CERN was designed and built primarily to find or exclude the existence of the Higgs boson, for which a large amount of data is needed by the LHC experiments. This requires operation at high luminosity, which in turn requires running with thousands of high-intensity proton bunches in the machine. After quantifying the data required by the experiments and elucidating the LHC parameters needed to achieve this, this paper explains how the LHC beams are f...

  20. Charged heavy vector boson production at the Large Hadron Collider

    Oh, Dal Soo; Reno, M. H.

    1998-01-01

    We evaluate the sensitivity of the Large Hadron Collider (LHC) to charged heavy vector boson production followed by their decays to $W^\\pm Z^0$. We include the correlated decays of the gauge bosons to leptonic final states. With an integrated luminosity of $10^5$ pb$^{-1}$, charged technirhos in the minimal SU(N)$_{TC}$ model for $N\\geq 7$ yield signals with a significance larger than 5. In more general models, we explore the range of parameter space to which LHC experiments will be sensitive...

  1. The Online Model for the Large Hadron Collider

    Redaelli, Stefano; Buffat, Xavier

    2010-01-01

    The control of the high intensity beams of the CERN Large Hadron Collider is particular challenging and requires a good modeling of the machine. In recent years efforts were devoted to the design of a software infrastructure aimed at mimicking the behavior of the LHC. An online model of the machine, based on the accelerator design tool MAD-X, has been developed to support the commissioning and the operation of the LHC. This model is integrated into the Java-based LHC development framework and...

  2. ZZ production at hadron colliders in NNLO QCD

    Cascioli, F; Grazzini, M; Kallweit, S; Maierhöfer, P; von Manteuffel, A; Pozzorini, S; Rathlev, D; Tancredi, L; Weihs, E

    2014-01-01

    We report on the first calculation of next-to-next-to-leading order (NNLO) QCD corrections to the inclusive production of ZZ pairs at hadron colliders. Numerical results are presented for pp collisions with centre-of-mass energy ($\\sqrt{s}$) ranging from 7 to 14 TeV. The NNLO corrections increase the NLO result by an amount varying from $11\\%$ to $17\\%$ as $\\sqrt{s}$ goes from 7 to 14 TeV. The loop-induced gluon fusion contribution provides about $60\\%$ of the total NNLO effect. When going from NLO to NNLO the scale uncertainties do not decrease and remain at the $\\pm 3\\%$ level.

  3. nPDF constraints from the Large Hadron Electron Collider

    Helenius, Ilkka; Armesto, Nestor

    2016-01-01

    An updated analysis regarding the expected nuclear PDF constraints from the future Large Hadron Electron Collider (LHeC) experiment is presented. The new study is based on a more flexible small-$x$ parametrization which provides less biased uncertainty estimates in the region where there are currently no data constraints. The effect of the LHeC is quantified by directly including a sample of pseudodata according to the expected precision of this planned experiment. As a result, a significant reduction of the small-$x$ uncertainties in sea quarks and gluons is observed.

  4. W±πt干 Associated Production at Large Hadron Collider

    HUANGJin-Shu; PANQun-Na

    2004-01-01

    In this paper we calculate the production of a charged top pion in association with a W boson at the CERN Large Hadron Collider (LHC) in the context of the topcolor assisted technicolor model. We find that the cross section of pp → bb- → W±πt干 is roughly corresponding to the result of the process pp → bb- → W±πt干= in the minimal supersymmetric standard model, and for reasonable ranges of the parameters, the cross section can reach a few hundred fb. The W±πt干 signal should be clearly visible at LHC unless π t± is very heavy.

  5. Determination of the Higgs CP property in Hadron Colliders

    Matsuzaki, Akihiro; Tanaka, Hidekazu

    2011-01-01

    We propose three ways to determine the CP eigenvalue of the Higgs boson at the hadron collider as follows: 1. We determine the Higgs CP eigenvalue from the production cross section which is affected by the CP eigenvalue of the Higgs boson. 2. We adopt the CP selection rules to determine the Higgs CP eigenvalue. 3. We determine the CP property by the momentum distribution of the decay products of the Higgs boson. Our methods can be applied for a wide range of the Higgs mass.

  6. A high field magnet design for a future hadron collider

    Gupta, R; Dietderich, D R; Gourlay, S A; Millos, G; McInturff, A D; Scanlan, R M; Ramberger, S; Russenschuck, Stephan

    1999-01-01

    US high energy physics community is exploring the possibilities of building a Very Large Hadron Collider (VLHC) after the completion of LHC. This paper presents a high field magnet design option based on Nb/sub 3/Sn technology. A preliminary magnetic and mechanical design of a 14-16 T, 2-in-1 dipole based on the "common coil design" approach is presented. The computer code ROXIE has been upgraded to perform the field quality optimization of magnets based on the racetrack coil geometry. A magnet R&D program to investigate the issues related to high field magnet designs is also outlined. (10 refs).

  7. Top-quark physics at the Large Hadron Collider

    Cristinziani, Markus

    2016-01-01

    This experimental review gives an overview of top-quark measurements performed by the two general purpose-detectors ATLAS and CMS during the first few years of running of the Large Hadron Collider. In the years 2010 - 2012 each experiment collected 5/fb of pp collision data at $\\sqrt{s} = 7$ TeV and 20/fb at $\\sqrt{s} = 8$ TeV, allowing detailed studies of top-quark production and decays, and measurements of the properties of the top quark with unprecedented precision.

  8. Single Top Quark Production via FCNC Couplings at Hadron Colliders

    Han, T.; Hosch, M.; Whisnant, K.; Young, Bing-Lin; Zhang, X

    1998-01-01

    We calculate single top-quark production at hadron colliders via the chromo-magnetic flavor-changing neutral current couplings $\\bar tcg$ and $\\bar tug$. We find that the strength for the anomalous $\\bar tcg$ ($\\bar tug$) coupling may be probed to $\\kappa_c / \\Lambda = 0.092 {TeV}^{-1}$ ($\\kappa_u / \\Lambda = 0.026 {TeV}^{-1}$) at the Tevatron with $2 {fb}^{-1}$ of data and $\\kappa_c / \\Lambda = 0.013 {TeV}^{-1}$ ($\\kappa_u / \\Lambda = 0.0061 {TeV}^{-1}$) at the LHC with $10 {fb}^{-1}$ of dat...

  9. Single Top Quark Production via FCNC Couplings at Hadron Colliders

    Han, T; Whisnant, K; Young Bing Lin; Zhang, X; Young, Bing-Lin

    1998-01-01

    We calculate single top-quark production at hadron colliders via the chromo-magnetic flavor-changing neutral current couplings $\\bar tcg$ and $\\bar tug$. We find that the strength for the anomalous $\\bar tcg$ ($\\bar tug$) coupling may be probed to $\\kappa_c / \\Lambda = 0.092 {TeV}^{-1}$ ($\\kappa_u / {TeV}^{-1}$) at the LHC with $10 {fb}^{-1}$ of data. The two couplings may be distinguished by a comparision of the single top signal with the direct top and top decay signals for these couplings.

  10. Detector Development for the High Luminosity Large Hadron Collider

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

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

  11. QCD physics in Atlas at the large hadron collider

    The Large Hadron Collider (LHC) is a proton-proton collider with a 14 TeV center of mass energy. The design luminosity is 1034 cm-1s-1 with beam collisions separated by 25 ns. The initial operation for physics will take place at a luminosity of 1033cm-1s-1 and it is expected that the integrated luminosity delivered in the first year will be 10 fb-1. This integrated luminosity will result in very large event samples for most processes, for example: ∼108 leptonic W decays, 104 γ's with Et > 500GeV and 104 jets with Et > 1TeV. As a result of the high statistics event samples, the understanding of most QCD processes at 14TeV will be systematics limited after the first year of running. The Atlas detector [1] is a general purpose detector designed to be sensitive to the many physics processes which are expected at the LHC. It contains high performance tracking using silicon detectors and a transition radiation tracker in a 2 Tesla solenoidal magnetic field, a high resolution electromagnetic calorimeter based on lead-liquid argon, a hadron calorimeter based on steel-scintillator and Cu/W-liquid argon, and a large instrumented air-core toroid magnet system for muon measurement. The basic performance characteristics of these systems are given in Table 1

  12. High luminosity electron-hadron collider eRHIC

    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.

  13. The higgsino-singlino world at the large hadron collider

    Kim, Jong Soo [Universidad Autonoma de Madrid, Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Ray, Tirtha Sankar [University of Melbourne, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Melbourne, VIC (Australia)

    2015-02-01

    We consider light higgsinos and singlinos in the next-to-minimal supersymmetric standard model at the large hadron collider. We assume that the singlino is the lightest supersymmetric particle and that the higgsino is the next-to-lightest supersymmetric particle with the remaining supersymmetric particles in the multi-TeV range. This scenario, which is motivated by the flavor and CP issues, provides a phenomenologically viable dark matter candidate and improved electroweak fit consistent with the measured Higgs mass. Here, the higgsinos decay into on (off)-shell gauge boson and the singlino. We consider the leptonic decay modes and the resulting signature is three isolated leptons and missing transverse energy which is known as the trilepton signal. We simulate the signal and the Standard Model backgrounds and present the exclusion region in the higgsino-singlino mass plane at the large hadron collider at √(s) = 14 TeV for an integrated luminosity of 300 fb{sup -1}. (orig.)

  14. FCC-hh Hadron Collider - Parameter Scenarios and Staging Options

    Benedikt, Michael; Schulte, Daniel; Zimmermann, F; Syphers, M J

    2015-01-01

    FCC-hh is a proposed future energy-frontier hadron collider, based on dipole magnets with a field around 16 T installed in a new tunnel with a circumference of about 100 km, which would provide proton collisions at a centre-of-mass energy of 100 TeV, as well as heavy-ion collisions at the equivalent energy. The FCC-hh should deliver a high integrated proton-proton luminosity at the level of several 100 fb−1 per year, or more. The challenges for operating FCC-hh with high beam current and at high luminosity include the heat load from synchrotron radiation in a cold environment, the radiation from collision debris around the interaction region, and machine protection. In this paper, starting from the FCC-hh design baseline parameters we explore different approaches for increasing the integrated luminosity, and discuss the impact of key individual pa- rameters, such as the turnaround time. We also present some injector considerations and options for early hadron-collider operation.

  15. The higgsino-singlino world at the large hadron collider

    We consider light higgsinos and singlinos in the next-to-minimal supersymmetric standard model at the large hadron collider. We assume that the singlino is the lightest supersymmetric particle and that the higgsino is the next-to-lightest supersymmetric particle with the remaining supersymmetric particles in the multi-TeV range. This scenario, which is motivated by the flavor and CP issues, provides a phenomenologically viable dark matter candidate and improved electroweak fit consistent with the measured Higgs mass. Here, the higgsinos decay into on (off)-shell gauge boson and the singlino. We consider the leptonic decay modes and the resulting signature is three isolated leptons and missing transverse energy which is known as the trilepton signal. We simulate the signal and the Standard Model backgrounds and present the exclusion region in the higgsino-singlino mass plane at the large hadron collider at √(s) = 14 TeV for an integrated luminosity of 300 fb-1. (orig.)

  16. Improving Identification of Dijet Resonances at Hadron Colliders

    Izaguirre, Eder; Shuve, Brian; Yavin, Itay

    2015-01-01

    The experimental detection of resonances has played a vital role in the development of subatomic physics. The overwhelming multijet backgrounds at the Large Hadron Collider (LHC) necessitate the invention of new techniques to identify resonances decaying into a pair of partons. In this Letter we introduce an observable that achieves a significant improvement in several key measurements at the LHC: the Higgs boson decay to a pair of b quarks; W±/Z0 vector-boson hadronic decay; and extensions of the standard model (SM) with a new hadronic resonance. Measuring the Higgs decay to b quarks is a central test of the fermion mass generation mechanism in the SM, whereas the W±/Z0 production rates are important observables of the electroweak sector. Our technique is effective in large parts of phase space where the resonance is mildly boosted and is particularly well suited for experimental searches dominated by systematic uncertainties, which is true of many analyses in the high-luminosity running of the LHC.

  17. Parton Distributions at a 100 TeV Hadron Collider

    Rojo, Juan

    2016-01-01

    The determination of the parton distribution functions (PDFs) of the proton will be an essential input for the physics program of a future 100 TeV hadron collider. The unprecedented center-of-mass energy will require knowledge of PDFs in currently unexplored kinematical regions such as the ultra low-x region or the region of multi-TeV momentum transfers. In this contribution we briefly summarise the studies presented in the PDF section of the upcoming report on "Physics at a 100 TeV pp collider: Standard Model processes". First we map the PDF kinematical coverage in the $(x,Q^2)$ plane, quantify PDF uncertainties, and compute ratios of PDF luminosities between 100 TeV and 14 TeV. Then we show how the extreme kinematics of such collider lead to a number of remarkable PDF-related phenomena such as the top quark as a massless parton, an increased role of photon-initiated processes and the possible need of PDFs with high-energy resummation.

  18. Summary of the Very Large Hadron Collider Physics and Detector Workshop

    G. Anderson; U. Baur; Berger, M.; Borcherding, F; Brandt, A; Denisov, D.; Eno, S.; Han, T.; Keller, S; Khazins, D.; LeCompte, T.(High Energy Physics Division, Argonne National Laboratory, Argonne, IL, USA); Lykken, J; Olness, F.; Paige, F.; R. Scalise

    1997-01-01

    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.

  19. Threshold resummation for slepton-pair production at hadron colliders

    Bozzi, Giuseppe [Institut fuer Theoretische Physik, Universitaet Karlsruhe, Postfach 6980, D-76128 Karlsruhe (Germany); Fuks, Benjamin; Klasen, Michael [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier / CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

    2007-07-01

    We present a first and extensive study of threshold resummation effects for supersymmetric (SUSY) particle production at hadron colliders, focusing on Drell-Yan like slepton-pair and slepton-sneutrino associated production. After confirming the known next-to-leading order (NLO) QCD corrections and generalizing the NLO SUSY-QCD corrections to the case of mixing squarks in the virtual loop contributions, we employ the usual Mellin N-space resummation formalism with the minimal prescription for the inverse Mellin-transform and improve it by re-summing 1/N-suppressed and a class of N-independent universal contributions. Numerically, our results increase the theoretical cross sections by 5 to 15% with respect to the NLO predictions and stabilize them by reducing the scale dependence from up to 20% at NLO to less than 10% with threshold resummation. (authors)

  20. Forward-central jet correlations at the Large Hadron Collider

    For high-pT forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forward and one central jet. By computing jet correlations in rapidity and azimuth, we analyze the role of corrections to the parton-showering chain from large-angle gluon radiation, and discuss this in relationship with Monte Carlo results modeling interactions due to multiple parton chains. (orig.)

  1. Forward-central jet correlations at the Large Hadron Collider

    Deak, M. [Univ. Autonoma de Madrid, Cantoblanco (Spain). Inst. de Fisica Teorica UAM/CSIC; Hautmann, F. [Oxford Univ. (United Kingdom). Theoretical Physics Dept.; Jung, H. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysics; Kutak, K. [Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysics

    2010-12-15

    For high-p{sub T} forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forward and one central jet. By computing jet correlations in rapidity and azimuth, we analyze the role of corrections to the parton-showering chain from large-angle gluon radiation, and discuss this in relationship with Monte Carlo results modeling interactions due to multiple parton chains. (orig.)

  2. Detecting invisible Higgs bosons at the CERN Large Hadron Collider

    In some extensions of the standard model the (lightest) Higgs boson can have mainly invisible decays, decaying to a pair of the lightest supersymmetric partners, or to Goldstone bosons, or to Majorons, none of which interact in the detector. Thus it is not clear how such a Higgs boson can be detected. We show that associated production of such Higgs bosons with Z's at high-luminosity hadron colliders can provide a detectable signal for the mass region of most interest, Mh≤150 GeV. If a Higgs boson is detected another way, so that Mh is known, this method may allow a measurement of the branching ratio (B) (h→invisible), and may also allow measurement of other branching ratios

  3. Exclusive Higgs Boson Production with bottom quarks at Hadron Colliders

    Dawson, S; Reina, L; Wackeroth, D; 10.1103/PhysRevD.69.074027

    2004-01-01

    We present the next-to-leading order QCD corrected rate for the production of a scalar Higgs boson with a pair of high p_T bottom and anti-bottom quarks at the Tevatron and at the Large Hadron Collider. Results are given for both the Standard Model and the Minimal Supersymmetric Standard Model. The exclusive b-bbar-h production rate is small in the Standard Model, but it can be greatly enhanced in the Minimal Supersymmetric Standard Model for large tan(beta), making b-bbar-h an important discovery mode. We find that the next-to-leading order QCD results are much less sensitive to the renormalization and factorization scales than the lowest order results, but have a significant dependence on the choice of the renormalization scheme for the bottom quark Yukawa coupling.

  4. Precision Muon Tracking Detectors for High-Energy Hadron Colliders

    Gadow, Philipp; Kroha, Hubert; Richter, Robert

    2016-01-01

    Small-diameter muon drift tube (sMDT) chambers with 15 mm tube diameter are a cost-effective technology for high-precision muon tracking over large areas at high background rates as expected at future high-energy hadron colliders including HL-LHC. The chamber design and construction procedures have been optimized for mass production and provide sense wire positioning accuracy of better than 10 ?m. The rate capability of the sMDT chambers has been extensively tested at the CERN Gamma Irradiation Facility. It exceeds the one of the ATLAS muon drift tube (MDT) chambers, which are operated at unprecedentedly high background rates of neutrons and gamma-rays, by an order of magnitude, which is sufficient for almost the whole muon detector acceptance at FCC-hh at maximum luminosity. sMDT operational and construction experience exists from ATLAS muon spectrometer upgrades which are in progress or under preparation for LHC Phase 1 and 2.

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

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

    2012-01-01

    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 sqrt{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.

  6. Advances in Cryogenics at the Large Hadron Collider

    Lebrun, P

    1998-01-01

    After a decade of intensive R&D in the key technologies of high-field superconducting accelerator magnets and superfluid helium cryogenics, the Large Hadron Collider (LHC) has now fully entered its co nstruction phase, with the adjudication of major procurement contracts to industry. As concerns cryogenic engineering, this R&D program has resulted in significant developments in several fields, amon g which thermo-hydraulics of two-phase saturated superfluid helium, efficient cycles and machinery for large-capacity refrigeration at 1.8 K, insulation techniques for series-produced cryostats and mu lti-kilometre long distribution lines, large-current leads using high-temperature superconductors, industrial precision thermometry below 4 K, and novel control techniques applied to strongly non-line ar processes. We review the most salient advances in these domains.

  7. Phenomenology of supersymmetric Z' decays at the Large Hadron Collider

    Corcella, Gennaro

    2014-01-01

    I study the phenomenology of heavy neutral bosons Z', predicted in GUT-inspired U(1)' models, at the Large Hadron Collider. In particular, I investigate possible signatures due to Z' decays into superymmetric particles, such as chargino, neutralino and sneutrino pairs, leading to final states with charged leptons and missing energy. The analysis is carried out at sqrt{s}=14 TeV, for a few representative points of the parameter space of the Minimal Supersymmetric Standard Model, suitably modified to accommodate the extra Z' boson and consistent with the discovery of a Higgs-like boson with mass around 125 GeV. Results are presented for several observables and compared with those obtained for direct Z' decays into lepton pairs. For the sake of comparison, Z' production in the Sequential Standard Model and its supersymmetric decays are also investigated.

  8. The fast tracker processor for hadron collider triggers

    Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, E; Pietri, M; Varotto, G

    2001-01-01

    Perspectives for precise and fast track reconstruction in future hadron collider experiments are addressed. We discuss the feasibility of a pipelined highly parallel processor dedicated to the implementation of a very fast tracking algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points, called patterns, for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at an input rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution tracks with transverse momentum above a few GeV and search for secondary vertices within typical level-2 times. (15 refs).

  9. Doubly-charged particles at the Large Hadron Collider

    Alloul, Adam; Fuks, Benjamin; de Traubenberg, Michel Rausch

    2013-01-01

    In this work we investigate the production and signatures of doubly-charged particles at the Large Hadron Collider. We start with the Standard Model particle content and representations and add generic doubly-charged exotic particles. We classify these doubly-charged states according to their spin, considering scalar, fermionic and vectorial fields, and according to their SU(2)L representation, being chosen to be either trivial, fundamental, or adjoint. We write the most general interactions between them and the Standard Model sector and study their production modes and possible decay channels. We then probe how they can most likely be observed and how particles with different spin and SU(2)L representations could be possibly distinguished.

  10. In the loop Large Hadron Collider project - UK engineering firms

    Wilks, N

    2004-01-01

    This paper presents the latest measures being taken to boost the level of UK engineering firms' involvement in research at CERN (Centre for Nuclear Research), including its 27 km circular Large Hadron Collider (LHC) project. Virtually all of the components on this complex project have had to be custom-made, usually in the form of collaboration. It is part of these collaborations that some UK firms have proved they can shine. However, despite the proven capabilities, the financial return continues to be less than the government's funding. Each of the 20 CERN member states provides funds in proportion to its GDP and the UK is the second largest financial contributor. UK firms become price-competitive where a contract calls for a degree of customisation or product development, project management and tight quality control. Development of the Particle Physics Grid, for dissemination and analysis of data from the LHC, continues to provide major supply opportunities for UK manufacturers.

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

    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. PMID:22253243

  12. Effective models of new physics at the Large Hadron Collider

    With the start of the Large Hadron Collider runs, in 2010, particle physicists will be soon able to have a better understanding of the electroweak symmetry breaking. They might also answer to many experimental and theoretical open questions raised by the Standard Model. Surfing on this really favorable situation, we will first present in this thesis a highly model-independent parametrization in order to characterize the new physics effects on mechanisms of production and decay of the Higgs boson. This original tool will be easily and directly usable in data analysis of CMS and ATLAS, the huge generalist experiments of LHC. It will help indeed to exclude or validate significantly some new theories beyond the Standard Model. In another approach, based on model-building, we considered a scenario of new physics, where the Standard Model fields can propagate in a flat six-dimensional space. The new spatial extra-dimensions will be compactified on a Real Projective Plane. This orbifold is the unique six-dimensional geometry which possesses chiral fermions and a natural Dark Matter candidate. The scalar photon, which is the lightest particle of the first Kaluza-Klein tier, is stabilized by a symmetry relic of the six dimension Lorentz invariance. Using the current constraints from cosmological observations and our first analytical calculation, we derived a characteristic mass range around few hundred GeV for the Kaluza-Klein scalar photon. Therefore the new states of our Universal Extra-Dimension model are light enough to be produced through clear signatures at the Large Hadron Collider. So we used a more sophisticated analysis of particle mass spectrum and couplings, including radiative corrections at one-loop, in order to establish our first predictions and constraints on the expected LHC phenomenology. (author)

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

    Goncalves, V P; Navarra, F S

    2016-01-01

    In this paper we study double vector meson production in photon -- hadron ($\\gamma h$) interactions at $pp/pA/AA$ collisions and present predictions for $\\rho\\rho$, $J/\\Psi J/\\Psi$ and $\\rho J/\\Psi$ production considering the double scattering mechanism. We compute the total cross sections and rapidity distributions at LHC energies and compare our results with the predictions for double vector meson production in $\\gamma \\gamma$ 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 $\\rho\\rho$ and $J/\\Psi J/\\Psi$ 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 $\\rho J/\\Psi$ production at LHC can be useful to constrain the double scattering mechanism.

  14. Physics with a multi-TeV hadron collider

    A large hadron collider (LHC) has always seemed an obvious option to follow LEP and it is clearly becoming time to start R and D on suitable magnets. It is less clear that it is sensible to discuss the physics which might be studied with such a machine without more complete results from the SPS collider, let alone data from LEP, SLC and HERA. All we can do is identify the questions which seem most pressing now and ask how they could be addressed by experiments at an LHC, whose centre of mass energy we take to be 10 to 20 TeV. Theoretically it has long been clear that the standard model is not complete. It simply does explain enough. By now there is a fairly standard list of its deficiencies, some of the most obvious items which it fails to explain being the origin of mass, the origin of flavour, the origin of CP violation and the connection between the electroweak, strong and gravitational forces. It is becoming increasingly obvious that the most glaring of these defects is the failure to explain the origin of the masses of the W and Z and of fermions. I therefore discuss this question in some detail. As we shall see, it seems likely that the answer involves departures from the standard model in the TeV energy range. (orig./HSI)

  15. Heavy ions: Results from the Large Hadron Collider

    Tapan K Nayak

    2012-10-01

    On November 8, 2010 the Large Hadron Collider (LHC) at CERN collided the first stable beams of heavy ions (Pb on Pb) at the centre-of-mass energy of 2.76 TeV/nucleon. The LHC worked exceedingly well during its one month of operation with heavy ions, delivering about 10 −1 of data, with peak luminosity reaching to $L_{O} = 2 × 10^{25}$ cm-2 s-1 towards the end of the run. Three experiments, ALICE, ATLAS and CMS, recorded their first heavy-ion data, which were analysed in a record time. The results of the multiplicity, flow, fluctuations and Bose–Einstein correlations indicate that the fireball formed in nuclear collisions at the LHC is hotter, lives longer, and expands to a larger size at freeze-out as compared to lower energies. We give an overview of these as well as new results on quarkonia and heavy flavour suppression, and jet energy loss.

  16. Department of Energy assessment of the Large Hadron Collider

    This report summarizes the conclusions of the committee that assessed the cost estimate for the Large Hadron Collider (LHC). This proton-proton collider will be built at CERN, the European Laboratory for Particle Physics near Geneva, Switzerland. The committee found the accelerator-project cost estimate of 2.3 billion in 1995 Swiss francs, or about $2 billion US, to be adequate and reasonable. The planned project completion date of 2005 also appears achievable, assuming the resources are available when needed. The cost estimate was made using established European accounting procedures. In particular, the cost estimate does not include R and D, prototyping and testing, spare parts, and most of the engineering labor. Also excluded are costs for decommissioning the Large Electron-Positron collider (LEP) that now occupies the tunnel, modifications to the injector system, the experimental areas, preoperations costs, and CERN manpower. All these items are assumed by CERN to be included in the normal annual operations budget rather than the construction budget. Finally, contingency is built into the base estimate, in contrast to Department of Energy (DOE) estimates that explicitly identify contingency. The committee's charge, given by Dr. James F. Decker, Deputy Directory of the DOE Office of Energy Research, was to understand the basis for the LHC cost estimate, identify uncertainties, and judge the overall validity of the estimate, proposed schedule, and related issues. The committee met at CERN April 22--26, 1996. The assessment was based on the October 1995 LHC Conceptual Design Report or ''Yellow Book,'' cost estimates and formal presentations made by the CERN staff, site inspection, detailed discussions with LHC technical experts, and the committee members' considerable experience

  17. Two-photon production of leptons at hadron colliders in semielastic and elastic cases

    Manko, A. Yu.; Shulyakovsky, R. G.

    2016-03-01

    The mechanism of two-photon dilepton production is studied in the equivalent-photon (Weizsäcker-Williams) approximation. This approximation is shown to describe well experimental data from hadron accelerators. The respective total and differential cross sections were obtained for the LHC and for the Tevatron collider at various energies of colliding hadrons. The differential cross sections were studied versus the dilepton invariant mass, transverse momentum, and emission angle in the reference frame comoving with the center of mass of colliding hadrons. The cases of semielastic and inelastic collisions were examined.

  18. EPOS LHC: Test of collective hadronization with data measured at the CERN Large Hadron Collider

    Pierog, T.; Karpenko, Iu.; Katzy, J. M.; Yatsenko, E.; Werner, K.

    2015-09-01

    Epos is a Monte Carlo event generator for minimum bias hadronic interactions, used for both heavy ion interactions and cosmic ray air shower simulations. Since the last public release in 2009, the Large Hadron Collider (LHC) experiments have provided a number of very interesting data sets comprising minimum bias p -p ,p -Pb, and Pb-Pb interactions. We describe the changes required to the model to reproduce in detail the new data available from the LHC and the consequences in the interpretation of these data. In particular we discuss the effect of the collective hadronization in p -p scattering. A different parametrization of flow has been introduced in the case of a small volume with high density of thermalized matter (core) reached in p -p compared to large volume produced in heavy ion collisions. Both parametrizations depend only on the geometry and the amount of secondary particles entering in the core and not on the beam mass or energy. The transition between the two flow regimes can be tested with p -Pb data. Epos LHC is able to reproduce all minimum bias results for all particles with transverse momentum from pt=0 to a few GeV/c .

  19. Resummation for supersymmetric particle production at hadron colliders

    Brensing, Silja Christine

    2011-05-10

    The search for supersymmetry is among the most important tasks at current and future colliders. Especially the production of coloured supersymmetric particles would occur copiously in hadronic collisions. Since these production processes are of high relevance for experimental searches accurate theoretical predictions are needed. Higher-order corrections in quantum chromodynamics (QCD) to these processes are dominated by large logarithmic terms due to the emission of soft gluons from initial-state and final-state particles. A systematic treatment of these logarithms to all orders in perturbation theory is provided by resummation methods. We perform the resummation of soft gluons at next-to-leading-logarithmic (NLL) accuracy for all possible production processes in the framework of the Minimal Supersymmetric Standard Model. In particular we consider pair production processes of mass-degenerate light-flavour squarks and gluinos as well as the pair production of top squarks and non-mass-degenerate bottom squarks. We present analytical results for all considered processes including the soft anomalous dimensions. Moreover numerical predictions for total cross sections and transverse-momentum distributions for both the Large Hadron Collider (LHC) and the Tevatron are presented. We provide an estimate of the theoretical uncertainty due to scale variation and the parton distribution functions. The inclusion of NLL corrections leads to a considerable reduction of the theoretical uncertainty due to scale variation and to an enhancement of the next-to-leading order (NLO) cross section predictions. The size of the soft-gluon corrections and the reduction in the scale uncertainty are most significant for processes involving gluino production. At the LHC, where the sensitivity to squark and gluino masses ranges up to 3 TeV, the corrections due to NLL resummation over and above the NLO predictions can be as high as 35 % in the case of gluino-pair production, whereas at the

  20. NLO corrections to production of heavy particles at hadron colliders

    In this thesis we study specific aspects of the production of heavy particles at hadron colliders, with emphasis on precision predictions including next-to-leading order (NLO) corrections from the strong and electroweak interactions. In the first part of the thesis we consider the top quark charge asymmetry. In particular, we discuss in detail the calculation of the electroweak contributions from the asymmetric part of the top quark pair production cross section at O(α2sα) and O(α2) and their numerical impact on predictions for the asymmetry measurements at the Tevatron. These electroweak contributions provide a non-negligible addition to the QCD-induced asymmetry with the same overall sign and, in general, enlarge the Standard Model predictions by a factor around 1.2, diminishing the deviations from experimental measurements. In the second part of the thesis we consider the production of squarks, the supersymmetric partners of quarks, at the Large Hadron Collider (LHC). We discuss the calculation of the contribution of factorizable NLO QCD corrections to the production of squark-squark pairs combined at fully differential level with squark decays. Combining the production process with two different configurations for the squark decays, our calculation is used to provide precise phenomenological predictions for two different experimental signatures that are important for the search of supersymmetry at the LHC. We focus, for one signature, on the impact of our results on important physical differential distributions and on cut-and-count searches performed by the ATLAS and CMS collaborations. Considering the other signature, we analyze the effects from NLO QCD corrections and from the combination of production and decays on distributions relevant for parameter determination. In general, factorizable NLO QCD corrections have to be taken into account to obtain precise phenomenological predictions for the analyzed distributions and inclusive quantities. Moreover

  1. Large hadron collider (LHC) project quality assurance plan

    Gullo, Lisa; Karpenko, Victor; Robinson, Kem; Turner, William; Wong, Otis

    2002-09-30

    The LHC Quality Assurance Plan is a set of operating principles, requirements, and practices used to support Berkeley Lab's participation in the Large Hadron Collider Project. The LHC/QAP is intended to achieve reliable, safe, and quality performance in the LHC project activities. The LHC/QAP is also designed to fulfill the following objectives: (1) The LHC/QAP is Berkeley Lab's QA program document that describes the elements necessary to integrate quality assurance, safety management, and conduct of operations into the Berkeley Lab's portion of the LHC operations. (2) The LHC/QAP provides the framework for Berkeley Lab LHC Project administrators, managers, supervisors, and staff to plan, manage, perform, and assess their Laboratory work. (3) The LHC/QAP is the compliance document that conforms to the requirements of the Laboratory's Work Smart Standards for quality assurance (DOE O 414.1, 10 CFR 830.120), facility operations (DOE O 5480.19), and safety management (DOE P 450.4).

  2. Sextupole correction magnets for the Large Hadron Collider

    Meinke, R B; Senti, M; Op de Beeck, W J; De Ryck, C; MacKay, W W

    1999-01-01

    About 2500 superconducting sextupole corrector magnets (MCS) are needed for the Large Hadron Collider (LHC) at CERN to compensate persistent current sextupole fields of the main dipoles. The MCS is a cold bore magnet with iron yoke. The coils are made from a NbTi conductor, which is cooled to 1.9 K. In the original CERN design 6 individual sub-coils, made from a monolithic composite conductor, are assembled and spliced together to form the sextupole. The coils are individually wound around precision-machined central islands and stabilized with matching saddle pieces at both ends. The Advanced Magnet Lab, Inc. (AML) has produced an alternative design, which gives improved performance and reliability at reduced manufacturing cost. In the AML design, the magnet consists of three splice-free sub-coils, which are placed with an automated winding process into pockets of prefabricated G-11 support cylinders. Any assembly process of sub-coils with potential misalignment is eliminated. The AML magnet uses a Kapton-wra...

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

    Azatov, Aleksandr; Paul, Ayan; Salvioni, Ennio

    2016-01-01

    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 $t\\bar{t}h$ 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 $t\\bar{t}Z$ 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.

  4. Commissioning and First Operation of the Large Hadron Collider (LHC)

    Lebrun, Ph

    2010-01-01

    After some fifteen years of construction, the Large Hadron Collider (LHC) was commissioned at CERN, the European Organization for Nuclear Research in 2008. This high-energy particle accelerator of 26.7 km circumference – the largest scientific instrument ever built – brings into collision intense beams of protons and ions to probe the structure of matter and study the forces acting on its elementary components at the TeV scale, an order of magnitude higher than the previous stateof-the-art. To guide and focus its particle beams, the LHC uses several thousands high-field superconducting magnets operating in superfluid helium at 1.9 K. The project therefore constitutes a technological feat: all its components were developed, industrialized and series produced by industrial companies according to demanding specifications. Started as a CERN undertaking – by decision of the CERN Council and its twenty European member states – the project soon became global with special contributions from Canada, India, Jap...

  5. The lattice of the CERN Large Hadron Collider

    Scandale, Walter; Koutchouk, Jean-Pierre; Luo, X; Méot, F; Ostojic, R; Risselada, Thys; Rufer, C E; Taylor, T; Trenkler, T; Weisz, S

    1996-01-01

    The lattice of the CERN Large Hadron Collider is designed with 23 regular cells per arc, each containing 6 tightly packed 14.2 m long dipoles. This allows to reach 7 TeV per beam with a dipole field of 8.4 Tesla. There are four experimental insertions, two of which are devoted to high luminosity experiments with ± 23 m of free space for the detector. The other two experimental insertions are combined with injection. The value of ß* at the interaction points is tunable from 6 m at injection to 0.5 m in collision. The energy deposition in the inner triplets is carefully reduced to sustain the nominal luminosity of 1034 cm-2s-1. Two insertions are devoted to collect the halo particles with large emittance and momentum spread surrounding the beam core: escaping rates of the protons are estimated to be less than 4·106 sec-1m-1. Finally, one insertion is used to extract the particles in the vertical direction with a minimized deflecting strength.

  6. The Large Hadron Collider: lessons learned and summary

    Llewellyn Smith, Chris

    2012-01-01

    The Large Hadron Collider (LHC) machine and detectors are now working superbly. There are good reasons to hope and expect that the new domain that the LHC is already exploring, operating at 7 TeV with a luminosity of 1033 cm−2 s−1, or the much bigger domain that will be opened up as the luminosity increases to over 1034 and the energy to 14 TeV, will provide clues that will usher in a new era in particle physics. The arguments that new phenomena will be found in the energy range that will be explored by the LHC have become stronger since they were first seriously analysed in 1984, although their essence has changed little. I will review the evolution of these arguments in a historical context, the development of the LHC project since 1984, and the outlook in the light of reports on the performance of the machine and detectors presented at this meeting.

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

    Dominguez, O; Arduini, G; Metral, E; Rumolo, G; Zimmermann, F; Maury Cuna, H

    2013-01-01

    During the beam commissioning of the Large Hadron Collider (LHC) 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 electr...

  8. Large hadron collider (LHC) project quality assurance plan

    The LHC Quality Assurance Plan is a set of operating principles, requirements, and practices used to support Berkeley Lab's participation in the Large Hadron Collider Project. The LHC/QAP is intended to achieve reliable, safe, and quality performance in the LHC project activities. The LHC/QAP is also designed to fulfill the following objectives: (1) The LHC/QAP is Berkeley Lab's QA program document that describes the elements necessary to integrate quality assurance, safety management, and conduct of operations into the Berkeley Lab's portion of the LHC operations. (2) The LHC/QAP provides the framework for Berkeley Lab LHC Project administrators, managers, supervisors, and staff to plan, manage, perform, and assess their Laboratory work. (3) The LHC/QAP is the compliance document that conforms to the requirements of the Laboratory's Work Smart Standards for quality assurance (DOE O 414.1, 10 CFR 830.120), facility operations (DOE O 5480.19), and safety management (DOE P 450.4)

  9. Beam tube vacuum in 100 TeV hadron colliders

    Bounds on the beam tube gas pressure and the required pumping speed are estimated for ∼ 2 T low field (LF) and ∼ 12 T high field (HF) 100 TeV center-of-mass hadron colliders. In both cases photodesorption by synchrotron radiation is the dominant source of gas. Assuming beam-gas scattering limited luminosity lifetime five times the IP scattering lifetime, the required CO equivalent beam tube pressure is 0.25 nTorr for LF and 1.8 nTorr for HF, ambient room temperature equivalent. The CO equivalent pumping speeds required to achieve this pressure within a reasonable beam conditioning time (a few tenths of an operational year at design intensity) are estimated to be ∼ 300 l/s-m for LF and ∼ 40 l/s-m for HF. For the LF case with a superferric warm iron magnet, the beam tube is at ambient room temperature and a distributed NEG plus lumped ion or cryo pump system is considered. The size of antechamber needed, ID ∼ 6 cm, requires that it be located outside the ∼ 2 cm C-coil magnet gap. Lumped pumps for pumping CH4 need to be spaced at ∼ 20 m intervals on the antechamber. For the HF case the likely beam tube temperature is 15--20 K and cryopumping with a beam screen system is considered. The necessary pumping speed can be achieved with slots covering ∼ 2% of the beam screen surface

  10. Mirror mesons at the Large Hadron Collider (LHC)

    Triantaphyllou, George

    2016-01-01

    The existence of mirror partners of Standard-Model fermions offers a viable alternative to a fundamental BEH mechanism, with the coupling corresponding to the gauged mirror generation symmetry becoming naturally strong at energies around 1 TeV. The resulting non-perturbative processes produce dynamical katoptron masses which might range from 0.1 to 1.15 TeV in a way circumventing usual problems with the S parameter. Moreover, they create mirror mesons belonging in two main groups, with masses differing from each other approximately by a factor of six and which might range approximately from 0.1 to 2.8 TeV. Since the corresponding phenomenology expected at hadron colliders is particularly rich, some interesting mirror-meson cross-sections are presented, something that might also lead to a deeper understanding of the underlying mirror fermion structure. Among other findings, results in principle compatible with indications from LHC concerning decays of new particles to two photons are analyzed.

  11. Search for invisibly decaying Higgs boson at Large Hadron Collider

    S Bansal; K Mazumdar; J B Singh

    2010-02-01

    In several scenarios of Beyond Standard Model physics, the invisible decay mode of the Higgs boson is an interesting possibility. The search strategy for an invisible Higgs boson at the Large Hadron Collider (LHC), using weak boson fusion process, has been studied in detail, by taking into account all possible backgrounds. Realistic simulations have been used in the context of CMS experiment to devise a set of event selection criteria which eventually enhances the signal contribution compared to the background processes in characteristic distributions. In cut-based analysis, multi-jet background is found to overwhelm the signal in the finally selected sample. With an integrated luminosity of 10 fb-1, an upper limit of 36% on the branching ratio can be obtained for Higgs boson with a mass of 120 GeV/c2 for LHC energy of 14 TeV. Since the analysis essentially depends on the background estimation, detailed studies have been done to determine the background rates from real data.

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

    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.

  13. Overview of the Large Hadron Collider cryo-magnets logistics

    Capatina, O; Bihery, R; Brunero, P; Chevalley, JM; Dauvergne, LP; Feniet, T; Foraz, K; Francey, J; Grenard, JL; Kershaw, K; Pelletier, S; Prodon, S; Rühl, Ingo; Uwumarogie, J; Valbuena, R; Vellut, G; Weisz, S

    2006-01-01

    More than 1700 superconducting cryo-magnets have to be installed in the Large Hadron Collider tunnel. The long, heavy and fragile LHC cryo-magnets are difficult to handle and transport in particular in the LEP tunnel environment originally designed for smaller, lighter LEP magnets. An installation rate of more than 20 cryo-magnets per week is needed to cope with the foreseen LHC installation end date. The paper gives an overview of the transport and installation sequence complexity, from the storage area at the surface to the cryo-magnet final position in the tunnel. The success of this task depends on a series of independent factors that have to be considered at the same time. The equipment needed for the transport and tunnel installation of the LHC cryo-magnets is briefly described. The manpower and equipment organisation as well as the challenges of logistics are then detailed. The paper includes conclusions and some of the lessons learned during the first phase of the LHC cryo-magnets installation.

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

    Ballarino, A

    2014-01-01

    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 MgB 2 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.

  15. Anisotropic flow and flow fluctuations at the large hadron collider

    Zhou, You

    One of the fundamental questions in the phenomenology of Quantum Chromodynamics (QCD) is what the properties of matter are at the extreme densities and temperatures where quarks and gluons are in a new state of matter, the so-called Quark Gluon Plasma (QGP). Collisions of high-energy heavy-ions at the CERN Large Hadron Collider (LHC), allow us to create and study the properties of such a system in the laboratory. Anisotropic flow (vn) is strong evidence for the existence of QGP, and has been described as one of the most important observations measured in the ultra-relativistic heavy-ion collisions. In this thesis, the anisotropic flow of not only charged particles but also identified particles are presented. In addition, the investigations of correlations and fluctuations of both flow angle (symmetry plane) and magnitude were discussed. The main goal of this thesis is to understand the nature of anisotropic flow and its response to the initial geometry of the created system as well as its fluctuations.

  16. Theoretical progress for the associated production of a Higgs boson with heavy quarks at hadron colliders

    The production of a Higgs boson in association with a pair of t anti t or b anti 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 introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider. (orig.)

  17. THEORETICAL PROGRESS FOR THE ASSOCIATED PRODUCTION OF A HIGGS BOSON WITH HEAVY QUARKS AT HADRON COLLIDERS

    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 introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider

  18. Theoretical progress for the associated production of a Higgs boson with heavy quarks at hadron colliders

    Dawson, S; Orr, L H; Reina, L; Wackeroth, D

    2004-01-01

    The production of a Higgs boson in association with a pair of top-antitop or bottom-antibottom 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 introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider.

  19. Extra dimension searches at hadron colliders to next-to-leading order-QCD

    M C Kumar; Prakash Mathewes; V Ravindran

    2007-11-01

    The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton distribution functions are studied. Uncertainties arising from the error on experimental data are estimated using the MRST parton distribution functions.

  20. Measuring masses of semi-invisibly decaying particles pair produced at hadron colliders

    Lester, Christopher G; Summers, D. J.

    1999-01-01

    We introduce a variable useful for measuring masses of particles pair produced at hadron colliders, where each particle decays to one particle that is directly observable and another particle whose existence can only be inferred from missing transverse momenta. This variable is closely related to the transverse mass variable commonly used for measuring the $W$ mass at hadron colliders, and like the transverse mass our variable extracts masses in a reasonably model independent way. Without con...

  1. On Large Hadron Collider's High-Energy Physics Research (brief review)

    In this review Large Hadron Collider (LHC) - the most advanced collider commissioned at CERN is described in brief, and present status of high-energy physics research at the LHC, including mathematics (software) Scientific Linux (SL6) based applications for the experiment are summarized. (authors)

  2. Signatures of the anomalous $Z\\gamma$ and $ZZ$ production at the lepton and hadron Colliders

    Gounaris, George J; Renard, F M

    2000-01-01

    The possible form of the ZZZ, ZZ$\\gamma$ and $Z\\gamma \\gamma$ vertices which may be induced from some New Physics interactions is critically examined. Their signatures and the possibilities to study them, through ZZ and $Z\\gamma$ production, at the e^-e^+ Colliders LEP and LC and at the hadronic Colliders Tevatron and LHC, are investigated.

  3. The CDF SVX: A silicon vertex detector for a hadron collider

    A silicon microstrip vertex detector is being constructed as an upgrade to the CDF detector at the Fermilab Tevatron-1 anti pp collider. This device, which is designed to operate in the hadron collider environment, should allow the tagging of long-lived heavy flavors produced in anti pp collisions. The mechanical and electronic design of this device are described in this paper. (orig.)

  4. Destination Universe: The Incredible Journey of a Proton in the Large Hadron Collider (English version)

    Lefevre, C

    2008-01-01

    This brochure illustrates the incredible journey of a proton as he winds his way through the CERN accelerator chain and ends up inside the Large Hadron Collider (LHC). The LHC is CERN's flagship particle accelerator which can collide protons together at close to the speed of light, creating circumstances like those just seconds after the Big Bang.

  5. Destination Universe: The Incredible Journey of a Proton in the Large Hadron Collider

    Lefevre, C

    2008-01-01

    This brochure illustrates the incredible journey of a proton as he winds his way through the CERN accelerator chain and ends up inside the Large Hadron Collider (LHC). The LHC is CERN's flagship particle accelerator which can collide protons together at close to the speed of light, creating circumstances like those just seconds after the Big Bang.

  6. A search for technicolor at the large hadron collider

    Love, Jeremy R.

    The Standard Model of particle physics provides an accurate description of all experimental data to date. The only unobserved piece of the Standard Model is the Higgs boson, a consequence of the spontaneous breaking of electroweak symmetry by the Higgs mechanism. An alternative to the Higgs mechanism is proposed by Technicolor theories which break electroweak symmetry dynamically through a new force. Technicolor predicts many new particles, called Technihadrons, that could be observed by experiments at hadron colliders. This thesis presents a search for two of the lightest Technihadrons, the rhoT and oT. The Low-Scale Technicolor model predicts the phenomenology of these new states. The rhoT and oT are produced through qq annihilation and couple to Standard Model fermions through the Drell-Yan process, which can result in the dimuon final state. The rhoT and oT preferentially decay to the piT and a Standard Model gauge boson if kinematically allowed. Changing the mass of the piT relative to that of the rhoT and o T affects the cross section times branching fraction to dimuons. The rhoT and oT are expected to have masses below about 1 TeV. The Large Hadron Collider (LHC) at CERN outside of Geneva, Switzerland, produces proton-proton collisions with a center of mass energy of 7 TeV. A general purpose high energy physics detector ATLAS has been used in this analysis to search for Technihadrons decaying to two muons. We use the ATLAS detector to reconstruct the tracks of muons with high transverse momentum coming from these proton-proton collisions. The dimuon invariant mass spectrum is analyzed above 130 GeV to test the consistency of the observed data with the Standard Model prediction. We observe excellent agreement between our data and the background only hypothesis, and proceed to set limits on the cross section times branching ratio of the rhoT and oT as a function of their mass using the Low-Scale Technicolor model. We combine the dielectron and dimuon channels

  7. CERN Library | Mario Campanelli presents "Inside CERN's Large Hadron Collider" | 16 March

    CERN Library

    2016-01-01

    "Inside CERN's Large Hadron Collider" by Mario Campanelli. Presentation on Wednesday, 16 March at 4 p.m. in the Library (bldg 52-1-052) The book aims to explain the historical development of particle physics, with special emphasis on CERN and collider physics. It describes in detail the LHC accelerator and its detectors, describing the science involved as well as the sociology of big collaborations, culminating with the discovery of the Higgs boson.  Inside CERN's Large Hadron Collider  Mario Campanelli World Scientific Publishing, 2015  ISBN 9789814656641​

  8. Phenomenology of Little Higgs Models at the Large Hadron Collider

    Moats, Kenneth Paul

    Little Higgs models provide an elegant solution to the hierarchy problem of the Standard Model, introducing new particles at the TeV scale to cancel the quadratic divergences to the square of the Higgs boson mass. The research carried out in this thesis focuses on the Large Hadron Collider (LHC) phenomenology of two such Little Higgs models: the Littlest Higgs model and the Bestest Little Higgs model. Firstly, the results of a study of Higgs triplet boson production in the Littlest Higgs model are presented in the W+/- W+/-, W +/-Z, W+ W--, and ZZ channels at the LHC for a centre of mass energy of s = 14 TeV, comparing these results with the predictions of two additional Higgs triplet models: the Georgi-Machacek model and the Left-Right Symmetric model. It is found that, given the constraints on the triplet vacuum expectation value (vev), considerable luminosity is required to observe Higgs triplet bosons in vector boson scattering. Observing a Higgs triplet at the LHC is most promising in the Georgi-Machacek model due to a weaker constraint on the triplet vev. In this model, a Higgs triplet boson with a mass of 1.0 (1.5) TeV can be observed at the LHC with an integrated luminosity as low as 41 (119) fb--1 in the W+/- W+/- channel and as low as 171 (474) fb --1 in the W+/- Z channel. The structure of the Bestest Little Higgs model is then described, including the procedure for deriving the Feynman rules of this model. The results of a study of heavy quark production in the Bestest Little Higgs model at the LHC are presented, focusing on associated single production of the exotic charge 5/3 heavy quark, T5/3b , at s = 14 TeV for two scenarios of Yukawa couplings. Applying stringent kinematic cuts to reduce the backgrounds, it is found that, in the two scenarios considered, the T5/3b heavy quark with a mass of 400, 600 and 800 GeV could be discovered in the same-sign dilepton channel at the LHC with an integrated luminosity as low as 43, 149 and 797 fb--1

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

    Shiltsev, Vladimir D.

    2015-08-01

    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 paper 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.

  10. Diffractive Physics at the CERN Large Hadron Collider

    Revol, Jean-Pierre [Physics Department, CERN, Geneva (Switzerland)

    2011-07-15

    After a short introduction on diffraction, I briefly review the framework used to describe non-perturbative QCD phenomena in hadron-hadron interactions. Then I explain why diffractive processes cannot be ignored at LHC and how ALICE, ATLAS, CMS, LHCb and TOTEM study diffraction, with emphasis on how inclusive particle production measurements are normalised to non-single diffractive and inelastic event classes.

  11. Precision predictions for electroweak superpartner production at hadron colliders with Resummino

    Fuks, Benjamin; Lamprea, David R; Rothering, Marcel

    2013-01-01

    We describe the Resummino package, a C++ and Fortran program dedicated to precision calculations in the framework of gaugino and slepton pair production at hadron colliders. This code allows to calculate transverse-momentum and invariant-mass distributions as well as total cross sections by combining the next-to-leading order predictions obtained by means of perturbative QCD with the resummation of the large logarithmic contributions arising in the small transverse-momentum region and close to the production threshold. The results computed in this way benefit from reduced theoretical uncertainties, compared to a pure next-to-leading order approach as currently employed in the experimental analyses searching for sleptons and gauginos at hadron colliders. This is illustrated by using of Resummino in the context of a typical supersymmetric benchmark point dedicated to superpartner searches at the Large Hadron Collider.

  12. Quantum chromodynamics at high energy, theory and phenomenology at hadron colliders

    When probing small distances inside a hadron, one can resolve its partonic constituents: quarks and gluons that obey the laws of perturbative Quantum Chromodynamics (QCD). This substructure reveals itself in hadronic collisions characterized by a large momentum transfer: in such collisions, a hadron acts like a collection of partons whose interactions can be described in QCD. In a collision at moderate energy, a hadron looks dilute and the partons interact incoherently. As the collision energy increases, the parton density inside the hadron grows. Eventually, at some energy much bigger than the momentum transfer, one enters the saturation regime of QCD: the gluon density has become so large that collective effects are important. We introduce a formalism suitable to study hadronic collisions in the high-energy limit in QCD, and the transition to the saturation regime. In this framework, we derive known results that are needed to present our personal contributions and we compute different cross-sections in the context of hard diffraction and particle production. We study the transition to the saturation regime as given by the Balitsky-Kovchegov equation. In particular we derive properties of its solutions.We apply our results to deep inelastic scattering and show that, in the energy range of the HERA collider, the predictions of high-energy QCD are in good agreement with the data. We also consider jet production in hadronic collisions and discuss the possibility to test saturation at the Large Hadron Collider. (author)

  13. Bottomonium production with statistical hadronization in heavy-ion collisions at collider energies

    Byungsik, Hong

    2004-01-01

    We present the bottomonium production estimated by using the hybrid model that combines direct bb pair creation in hard scattering and a statistical hadronization of the deconfined quark-gluon plasma. Complete color screening and full equilibration of the deconfined quark matter is assumed in the quark-gluon plasma phase. An enhanced production of the Upsilon (1S) state is predicted at collider energies. However, a significant, difference between the RHIC (Relativistic Heavy Ion Collider) and the LHC (Large Hadron Collider) is expected in the centrality dependence of the Upsilon (1S) production. Normalizing the Upsilon (1S) production by the average number of binary collisions, we expect about a factor of five decrease from half-overlap to central collisions at the RHIC, but almost no change at the LHC. Plans for measuring the bottomonium production cross-sections in future collider experiments are summarized. (28 refs).

  14. Top-quark pair production at hadron colliders

    Ahrens, Valentin

    2011-12-08

    In this thesis we investigate several phenomenologically important properties of top-quark pair production at hadron colliders. We calculate double differential cross sections in two different kinematical setups, pair invariant-mass (PIM) and single-particle inclusive (1PI) kinematics. In pair invariant-mass kinematics we are able to present results for the double differential cross section with respect to the invariant mass of the top-quark pair and the top-quark scattering angle. Working in the threshold region, where the pair invariant mass M is close to the partonic center-of-mass energy {radical}(s), we are able to factorize the partonic cross section into different energy regions. We use renormalization-group (RG) methods to resum large threshold logarithms to next-to-next-to-leading-logarithmic (NNLL) accuracy. On a technical level this is done using effective field theories, such as heavy-quark effective theory (HQET) and soft-collinear effective theory (SCET). The same techniques are applied when working in 1PI kinematics, leading to a calculation of the double differential cross section with respect to transverse-momentum pT and the rapidity of the top quark. We restrict the phase-space such that only soft emission of gluons is possible, and perform a NNLL resummation of threshold logarithms. The obtained analytical expressions enable us to precisely predict several observables, and a substantial part of this thesis is devoted to their detailed phenomenological analysis. Matching our results in the threshold regions to the exact ones at next-to-leading order (NLO) in fixed-order perturbation theory, allows us to make predictions at NLO+NNLL order in RG-improved, and at approximate next-to-next-to-leading order (NNLO) in fixed order perturbation theory. We give numerical results for the invariant mass distribution of the top-quark pair, and for the top-quark transverse-momentum and rapidity spectrum. We predict the total cross section, separately for both

  15. Top-quark pair production at hadron colliders

    In this thesis we investigate several phenomenologically important properties of top-quark pair production at hadron colliders. We calculate double differential cross sections in two different kinematical setups, pair invariant-mass (PIM) and single-particle inclusive (1PI) kinematics. In pair invariant-mass kinematics we are able to present results for the double differential cross section with respect to the invariant mass of the top-quark pair and the top-quark scattering angle. Working in the threshold region, where the pair invariant mass M is close to the partonic center-of-mass energy √(s), we are able to factorize the partonic cross section into different energy regions. We use renormalization-group (RG) methods to resum large threshold logarithms to next-to-next-to-leading-logarithmic (NNLL) accuracy. On a technical level this is done using effective field theories, such as heavy-quark effective theory (HQET) and soft-collinear effective theory (SCET). The same techniques are applied when working in 1PI kinematics, leading to a calculation of the double differential cross section with respect to transverse-momentum pT and the rapidity of the top quark. We restrict the phase-space such that only soft emission of gluons is possible, and perform a NNLL resummation of threshold logarithms. The obtained analytical expressions enable us to precisely predict several observables, and a substantial part of this thesis is devoted to their detailed phenomenological analysis. Matching our results in the threshold regions to the exact ones at next-to-leading order (NLO) in fixed-order perturbation theory, allows us to make predictions at NLO+NNLL order in RG-improved, and at approximate next-to-next-to-leading order (NNLO) in fixed order perturbation theory. We give numerical results for the invariant mass distribution of the top-quark pair, and for the top-quark transverse-momentum and rapidity spectrum. We predict the total cross section, separately for both

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

    Gingrich, Douglas M.

    2010-01-01

    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 Collide...

  17. Long term stability in hadron colliders in presence of synchrotron oscillations and tune ripple

    Scandale, Walter

    1998-01-01

    The problem of long-term losses in hadron colliders such as the Large Hadron Collider (LHC) is considered. A previous formula that provides the reduction of dynamic aperture with the number of turns is generalized to include also the relevant cases of off-momentum and tune ripple. The dynamic aperture turns out to shrink with a power of the inverse logarithm of the number of turns. Long-term tracking data of the LHC are analysed in this framework. The formula proves to hold in all cases, and the possibility of using its extrapolation to predict long-term losses are explored.

  18. Hangout With CERN: The Large Hadron Collider (S01E02)

    Kahle, Kate

    2012-01-01

    In this second Hangout with CERN "The Large Hadron Collider" ATLAS physicist Steven Goldfarb is joined by Giulia Papotti and Laurette Ponce from the CERN Control Centre, Despina Hatzifotiadou and Ken Read from the ALICE experiment, Achintya Rao and Roberto Rossin from the CMS experiment and Patrick Koppenburg from the LHCb experiment, as well as Jaana Nystrom from Finland and Liz Krane from the USA. This hangout answers questions about the Large Hadron Collider (LHC) received via #askCERN on Twitter and Google+ and via YouTube and Facebook comments. Recorded live on 8th November 2012.

  19. Quantitative Calculations for Black Hole Production at the Large Hadron Collider

    Bock, Nicolas

    2008-01-01

    The framework of Large Extra Dimensions provides a way to explain why gravity is weaker compared to the other forces in nature. A consequence of this model is the possible production of D-dimensional Black Holes in high energy p-p collisions at the Large Hadron Collider. The present work uses the CATFISH Black Hole generator to study quantitatively how these events could be observed in the hadronic channel at mid-rapidity using a particle tracking detector.

  20. Design considerations and expectations of a very large hadron collider

    The ELOISATRON Project is a proton-proton collider at very high energy and very large luminosity. The main goal is to determine the ultimate performance that is possible to achieve with reasonable extrapolation of the present accelerator technology. A complete study and design of the collider requires that several steps of investigations are undertaken. The authors count five of such steps as outlined in the report

  1. Future hadron colliders: From physics perspectives to technology R&D

    Battaglia, Marco; Klute, Markus; Mangano, Michelangelo; Prestemon, Soren; Rossi, Lucio; Skands, Peter; Barletta, William A.

    2014-01-01

    High energy hadron colliders have been instrumental to discoveries in particle physics at the energy frontier and their role as discovery machines will remain unchallenged for the foreseeable future. The full exploitation of the LHC is now the highest priority of the energy frontier collider program. This includes the high luminosity LHC project which is made possible by a successful technology-readiness program for Nb[subscript 3]Sn superconductor and magnet engineering based on long-term hi...

  2. Pomeron as quark-gluon strings and multiple hadron production at SPS-collider energies

    Multiple hadron production at high energy is considered as the result of the creation and breaking of quark-gluon strings in hadron-hadron collision. It is shown that this approach, together with the general results of the supercritical Pomeron theory (αsub(p)(0) > 1), yields the natural fit of all high energy multiple production data, including those obtained at SPS-Collider. In the present form (without small contribution of the so-called enhanced graphs) theory leads to the strong violation of KNO scaling in high energy limit

  3. Computer simulation of the emittance growth due to noise in large hadron colliders

    The problem of emittance growth due to random fluctuations of the magnetic field in a hadron collider is considered. The results of computer simulations are compared with the analytical theory developed earlier. A good agreement was found between the analytical theory predictions and the computer simulations for the collider tunes located far enough from high order betatron resonances. The dependencies of the emittance growth rate on noise spectral density, beam separation at the Interaction Point (IP) and value of beam separation at long range collisions are studied. The results are applicable to the Superconducting Super Collider (SSC)

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

    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 Tc superconductors operating at liquid N2 or liquid H2 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

  5. Recognizing Critical Behavior amidst Minijets at the Large Hadron Collider

    The transition from quarks to hadrons in a heavy-ion collision at high energy is usually studied in two different contexts that involve very different transverse scales: local and nonlocal. Models that are concerned with the pT spectra and azimuthal anisotropy belong to the former, that is, hadronization at a local point in (η,ϕ) space, such as the recombination model. The nonlocal problem has to do with quark-hadron phase transition where collective behavior through near-neighbor interaction can generate patterns of varying sizes in the (η,ϕ) space. The two types of problems are put together in this paper both as brief reviews separately and to discuss how they are related to each other. In particular, we ask how minijets produced at LHC can affect the investigation of multiplicity fluctuations as signals of critical behavior. It is suggested that the existing data from LHC have sufficient multiplicities in small pT intervals to make the observation of distinctive features of clustering of soft particles, as well as voids, feasible that characterize the critical behavior at phase transition from quarks to hadrons, without any ambiguity posed by the clustering of jet particles

  6. Top-Anti-top Production at Hadron Colliders

    We review the status of the theoretical predictions for the top-anti top production in hadronic collisions, paying particular attention to the pair production at the LHC. We stress the need for a complete theoretical analysis that includes higher-order quantum corrections and we discuss recent theoretical calculations at the level of NNLO. (author)

  7. Recognizing Critical Behavior amidst Minijets at the Large Hadron Collider

    Rudolph C. Hwa

    2015-01-01

    Full Text Available The transition from quarks to hadrons in a heavy-ion collision at high energy is usually studied in two different contexts that involve very different transverse scales: local and nonlocal. Models that are concerned with the pT spectra and azimuthal anisotropy belong to the former, that is, hadronization at a local point in (η,ϕ space, such as the recombination model. The nonlocal problem has to do with quark-hadron phase transition where collective behavior through near-neighbor interaction can generate patterns of varying sizes in the (η,ϕ space. The two types of problems are put together in this paper both as brief reviews separately and to discuss how they are related to each other. In particular, we ask how minijets produced at LHC can affect the investigation of multiplicity fluctuations as signals of critical behavior. It is suggested that the existing data from LHC have sufficient multiplicities in small pT intervals to make the observation of distinctive features of clustering of soft particles, as well as voids, feasible that characterize the critical behavior at phase transition from quarks to hadrons, without any ambiguity posed by the clustering of jet particles.

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

    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

  9. 1 Go/s pour la grille de calcul du Large hadron collider

    Prevéraud, Jean-François

    2006-01-01

    The worldwide collaboration "Worldwide LHC computing grid (WLCG)", in which IN2P3 take part, has just announced a new record in the implementation of a computing grid for the Large Hadron Collider of CERN: a continuous flow of scientific data has been transferred on a worldwide infrastructure grid, with a flow up to sometimes 1 gigaoctet per second (1 page)

  10. CERN celebrating the Lowering of the final detector element for large Hadron Collider

    2008-01-01

    In the early hours of the morning the final element of the Compact Muon Solenoid (CMS) detector began the descent into its underground experimental cavern in preparation for the start-up of CERNs Large Hadron Collider (LHC) this summer. This is a pivotal moment for the CMS collaboration.