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Sample records for hadron collider lhc

  1. LHC: The Large Hadron Collider

    SciTech Connect (OSTI)

    Lincoln, Don

    2015-03-04

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

  2. B physics at hadron colliders

    SciTech Connect (OSTI)

    Butler, J.N.; /Fermilab

    2005-09-01

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

  3. v{sub 4} from ideal and viscous hydrodynamic simulations of nuclear collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC)

    SciTech Connect (OSTI)

    Luzum, Matthew; Gombeaud, Clement; Ollitrault, Jean-Yves

    2010-05-15

    We compute v{sub 4}/(v{sub 2}){sup 2} in ideal and viscous hydrodynamics. We investigate its sensitivity to details of the hydrodynamic model and compare the results to experimental data from the BNL Relativistic Heavy Ion Collider (RHIC). Whereas v{sub 2} has a significant sensitivity only to initial eccentricity and viscosity while being insensitive to freeze-out temperature, we find that v{sub 4}/(v{sub 2}){sup 2} is quite insensitive to initial eccentricity. On the other hand, it can still be sensitive to shear viscosity in addition to freeze-out temperature, although viscous effects do not universally increase v{sub 4}/(v{sub 2}){sup 2} as originally predicted. Consistent with data, we find no dependence on particle species. We also make a prediction for v{sub 4}/(v{sub 2}){sup 2} in heavy ion collisions at the CERN Large Hadron Collider (LHC).

  4. Tomography of quark gluon plasma at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC)

    SciTech Connect (OSTI)

    Gossiaux, P. B.; Bierkandt, R.; Aichelin, J.

    2009-04-15

    Using the recently published model [Gossiaux and Aichelin, Phys. Rev. C 78, 014904 (2008)] for the collisional energy loss of heavy quarks in a quark gluon plasma (QGP), based on perturbative QCD (pQCD) with a running coupling constant, we study the interaction between heavy quarks and plasma particles in detail. We discuss correlations between the simultaneously produced c and c quarks, study how central collisions can be experimentally selected, predict observable correlations, and extend our model to the energy domain of the Large Hadron Collider (LHC). We finally compare the predictions of our model with that of other approaches such as anti-de Sitter/conformal field theory (AdS/CFT)

  5. Beam collimation at hadron colliders

    SciTech Connect (OSTI)

    Nikolai V. Mokhov

    2003-08-12

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

  6. June 30, 2008: US portion of Large Hadron Collider completed

    Broader source: Energy.gov [DOE]

    June 30, 2008The Department and the National Science Foundation announce that the U.S. contribution to the Large Hadron Collider (LHC) has been completed on budget and ahead of schedule. The LHC,...

  7. Early Hadron Physics at the LHC

    SciTech Connect (OSTI)

    Askew, A.

    2010-08-05

    The Large Hadron Collider (LHC) is presently undergoing beam commissioning in preparation for physics running in 2010 at a center of mass energy of 7 TeV. I will briefly describe the hadron physics capabilities of the ATLAS, CMS, and LHCb detectors, their performance with cosmic ray and early collision data, as well as their plans for physics with the first data.

  8. Hadron calorimeters for future hadron colliders

    SciTech Connect (OSTI)

    Jim Freeman

    2004-01-27

    Hadron calorimeters are essential for jet and neutrino physics at collider experiments. Current hadron calorimeters for the ATLAS and CMS detectors are described. Increased energy and luminosity of future hadron colliders place constraints on detector technology. Difficulties for operation of the current detectors in future hadron collider environments are discussed. New experiments for future colliders should take notice of physics processes during jet evolution that place fundamental limits on performance of the calorimeter to reconstruct jets. A technique of incorporating tracking information to improve jet resolution is described. Future detectors should be designed with these constraints in mind. Possible avenues of exploration for future technology are described.

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

    SciTech Connect (OSTI)

    David Rainwater; Michael Spira; Dieter Zeppenfeld

    2004-01-12

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

  10. Director's colloquium March 18 large hadron collider

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Director's colloquium large hadron collider Director's colloquium March 18 large hadron collider Lyndon Evans of CERN will talk about the most complex scientific instrument ever ...

  11. Photoproduction of {rho}{sup 0} mesons in ultraperipheral heavy ion collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC)

    SciTech Connect (OSTI)

    Goncalves, V. P.; Machado, M. V. T.

    2009-11-15

    We investigate the photoproduction of {rho} mesons in ultraperipheral heavy ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) energies in the dipole approach and within two phenomenological models based on the color glass condensate (CGC) formalism. We estimate the integrated cross section and rapidity distribution for meson production and compare our predictions with the data from the STAR Collaboration. In particular, we demonstrate that the total cross section at RHIC is strongly dependent on the energy behavior of the dipole-target cross section at low energies, which is not well determined in the dipole approach. In contrast, the predictions at midrapidities at RHIC and in the full rapidity at LHC are under theoretical control and can be used to test QCD dynamics at high energies.

  12. Hadron colliders working group report (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Hadron colliders working group report Citation Details In-Document Search Title: Hadron colliders working group report Authors: Peggs, Stephen G. ; Syphers, M.J. Publication Date: ...

  13. A large hadron electron collider at CERN

    SciTech Connect (OSTI)

    Abelleira Fernandez, J. L.

    2015-04-06

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

  14. A large hadron electron collider at CERN

    SciTech Connect (OSTI)

    Abelleira Fernandez, J. L.

    2015-04-06

    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and eletron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100)fb1. 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.

  15. A large hadron electron collider at CERN

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abelleira Fernandez, J. L.

    2015-04-06

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

  16. Vector meson production in coherent hadronic interactions: Update on predictions for energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

    SciTech Connect (OSTI)

    Goncalves, V. P.; Machado, M. V. T.

    2011-07-15

    In this Rapid Communication we update our predictions for the photoproduction of vector mesons in coherent pp and AA collisions at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies using the color dipole approach and the Color Glass Condensate formalism. In particular, we present our predictions for the first run of the LHC at half energy and for the rapidity dependence of the ratio between the J/{Psi} and {rho} cross sections at RHIC energies.

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

    SciTech Connect (OSTI)

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

    2010-05-26

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

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

    SciTech Connect (OSTI)

    2010-06-21

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

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

    ScienceCinema (OSTI)

    None

    2011-10-06

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

  20. Non-Large Hadron Collider Physics Program at CERN (Conference...

    Office of Scientific and Technical Information (OSTI)

    Non-Large Hadron Collider Physics Program at CERN Citation Details In-Document Search Title: Non-Large Hadron Collider Physics Program at CERN You are accessing a document from...

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

    SciTech Connect (OSTI)

    Chung Kao

    2007-09-05

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

  2. Triphoton production at hadron colliders

    SciTech Connect (OSTI)

    Campbell, John M.; Williams, Ciaran

    2014-06-01

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

  3. Strange quark suppression and strange hadron production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider

    SciTech Connect (OSTI)

    Long Haiyan; Feng Shengqin; Zhou Daimei; Yan Yuliang; Ma Hailiang; Sa Benhao

    2011-09-15

    The parton and hadron cascade model PACIAE based on PYTHIA is utilized to systematically investigate strange particle production in pp collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). Globally speaking, the PACIAE results of the strange particle rapidity density at midrapidity and the transverse momentum distribution are better than those of PYTHIA (default) in comparison with STAR and ALICE experimental data. This may represent the importance of the parton and hadron rescatterings, as well as the reduction mechanism of strange quark suppression, added in the PACIAE model. The K/{pi} ratios as a function of reaction energy in pp collisions from CERN Super Proton Synchrotron (SPS) to LHC energies are also analyzed in this paper.

  4. Electron Lenses for the Large Hadron Collider

    SciTech Connect (OSTI)

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

    2014-07-01

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

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

    SciTech Connect (OSTI)

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

    2008-10-31

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

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shiltsev, Vladimir D.

    2015-08-20

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

  7. OSTIblog Articles in the large hadron collider Topic | OSTI, US Dept of

    Office of Scientific and Technical Information (OSTI)

    Energy Office of Scientific and Technical Information large hadron collider Topic The Higgs boson - a turning point in history by Kathy Chambers 19 Aug, 2013 in Products and Content 8105 cern_lhc_tunnel.jpg The Higgs boson - a turning point in history Read more about 8105 Turning points in history - things or events that define lasting change in the world we know. The industrial revolution, Henry Ford's automobile, penicillin, Einstein's theory of relativity, firsts in aviation and space,

  8. SCIENCE ON SATURDAY- "The Large Hadron Collider: big science...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    January 5, 2013, 9:30am Science On Saturday MBG Auditorium SCIENCE ON SATURDAY- "The Large Hadron Collider: big science for big questions" Professor James Olsen Department of ...

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

    SciTech Connect (OSTI)

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

    2014-05-08

    Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. Within the US LHC Accelerator Research Program (LARP) and the European FP7 HiLumi LHC Design Study, we are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were checked to ensure that undesired effects were suppressed. Hardware specifications were based on the Tevatron devices and on preliminary engineering integration studies in the LHC machine. Required resources and a possible timeline were also outlined, together with a brief discussion of alternative halo-removal schemes and of other possible uses of electron lenses to improve the performance of the LHC.

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

    SciTech Connect (OSTI)

    Quigg, Chris; /Fermilab /CERN

    2007-02-01

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

  11. First Beam Measurements with the LHC Synchrotron Light Monitors...

    Office of Scientific and Technical Information (OSTI)

    Title: First Beam Measurements with the LHC Synchrotron Light Monitors The continuous monitoring of the transverse sizes of the beams in the Large Hadron Collider (LHC) relies on ...

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

    SciTech Connect (OSTI)

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

    2009-01-15

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

  13. TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

    SciTech Connect (OSTI)

    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.

  14. Higgs Hunting at the Large Hadron Collider

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sinjini Sengupta Saturday Morning Physics Texas A&M University 26 th Jan 2013  Introduction to the Standard Model  What is the Higgs really?  Hunting grounds: LHC and the detectors  How do we hunt for particles?  How would we know we see a Higgs?  What have we found so far?  What"s next? SMP 1/26/2013 2 Sinjini Sengupta  The idea that all matter is composed of elementary particles dates as far back as the 6 th century BC. ◦ Most of these were philosophical

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

    SciTech Connect (OSTI)

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

    2010-09-07

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

  16. Single and multiple intrabeam scattering in hadron colliders

    SciTech Connect (OSTI)

    Lebedev, V.; /Fermilab

    2005-01-01

    Single and multiple intra-beam scattering are usually considered separately. Such separation works well for electron-positron colliders but usually yields only coarse description in the case of hadron colliders. Boltzmann type integro-differential equation is used to describe evolution of longitudinal distribution due to IBS. The finite size of the longitudinal potential well, its non-linearity and x-y coupling are taken into account. The model predictions for longitudinal and transverse distributions are compared to the experimental measurements.

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

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

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

  18. Radio Frequency Noise Effects on the CERN Large Hadron Collider Beam Diffusion

    SciTech Connect (OSTI)

    Mastoridis, T.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; Rivetta, C.; Fox, J.D.; /SLAC

    2012-04-30

    Radio frequency (rf) accelerating system noise can have a detrimental impact on the Large Hadron Collider (LHC) performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and rf station dynamics with the bunch length growth. Measurements were conducted at LHC to determine the performance limiting rf components and validate the formalism through studies of the beam diffusion dependence on rf noise. As a result, a noise threshold was established for acceptable performance which provides the foundation for beam diffusion estimates for higher energies and intensities. Measurements were also conducted to determine the low level rf noise spectrum and its major contributions, as well as to validate models and simulations of this system.

  19. Higgs friends and counterfeits at hadron colliders

    SciTech Connect (OSTI)

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

    2011-04-01

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

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

    ScienceCinema (OSTI)

    None

    2011-10-06

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

  1. A 233 km tunnel for lepton and hadron colliders

    SciTech Connect (OSTI)

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

    2012-12-21

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

  2. Natural h{yields}4g in supersymmetric models and R-hadrons at the LHC

    SciTech Connect (OSTI)

    Luty, Markus A.; Phalen, Daniel J.; Pierce, Aaron

    2011-04-01

    We construct a simple and natural supersymmetric model where the dominant Higgs decay is h{yields}aa followed by a{yields}gg. In this case m{sub h}LHC. If these particles are stable on collider time scales, they will appear as R-hadrons, a signal visible in early LHC running. A smoking-gun signal that the stable colored particles are mediators of h{yields}4j is R-hadron production in association with an a. We show that this signal with a{yields}{gamma}{gamma} is observable at the LHC with as little as 10 fb{sup -1} of integrated luminosity. Observation of R-hadrons plus missing energy would show that the superpartner of the R-hadron is R-parity odd, and therefore not an ordinary quark or gluon.

  3. The PDF4LHC report on PDFs and LHC data: results from Run I and...

    Office of Scientific and Technical Information (OSTI)

    Hadron Collider (LHC) program. PDF uncertainties impact a wide range of processes, from Higgs boson characterization and precision Standard Model measurements to New Physics...

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

    SciTech Connect (OSTI)

    Hartanto, Heribertus Bayu

    2013-01-01

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

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

    SciTech Connect (OSTI)

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

    2010-09-14

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

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

    SciTech Connect (OSTI)

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

    2011-12-09

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

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

    SciTech Connect (OSTI)

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

    2009-07-01

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

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

    SciTech Connect (OSTI)

    Bruce, R.; et al.,

    2013-11-21

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

  9. The Very Large Hadron Collider: The farthest energy frontier...

    Office of Scientific and Technical Information (OSTI)

    would cost more than what is presently politically acceptable. This talk summarizes the strategies of collider design including staged deployment, comparison with...

  10. The Very Large Hadron Collider: The farthest energy frontier...

    Office of Scientific and Technical Information (OSTI)

    cost more than what is presently politically acceptable. This talk summarizes the strategies of collider design including staged deployment, comparison with electron-positron...

  11. The fate of long-lived superparticles with hadronic decays after LHC Run 1

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zhen; Tweedie, Brock

    2015-06-08

    Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation,more » and mini-split SUSY. We then explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final-state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMS’s tracker-based displaced dijet search and heavy stable charged particle searches. By adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.« less

  12. The fate of long-lived superparticles with hadronic decays after LHC Run 1

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Zhen; Tweedie, Brock

    2015-06-08

    Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation,moreand mini-split SUSY. We explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final-state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMSs tracker-based displaced dijet search and heavy stable charged particle searches. Adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.less

  13. The fate of long-lived superparticles with hadronic decays after LHC Run 1

    SciTech Connect (OSTI)

    Liu, Zhen; Tweedie, Brock

    2015-06-08

    Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation, and mini-split SUSY. We explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final-state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMSs tracker-based displaced dijet search and heavy stable charged particle searches. Adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.

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

    SciTech Connect (OSTI)

    Miller, David Wilkins

    2012-03-20

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

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

    ScienceCinema (OSTI)

    None

    2011-10-06

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

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

    SciTech Connect (OSTI)

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

    2012-06-27

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

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

    SciTech Connect (OSTI)

    2010-01-20

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

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

    SciTech Connect (OSTI)

    Yost, Scott A

    2014-04-02

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

  19. Color sextet scalars at the CERN Large Hadron Collider

    SciTech Connect (OSTI)

    Chen, C.-R.; Klemm, William; Rentala, Vikram; Wang Kai

    2009-03-01

    Taking a phenomenological approach, we study a color sextet scalar at the LHC. We focus on the QCD production of a color sextet pair {phi}{sub 6}{phi}{sub 6} through gg fusion and qq annihilation. Its unique coupling to {psi}{sup c}{psi} allows the color sextet scalar to decay into same-sign diquark states, such as {phi}{sub 6}{yields}tt/tt*. We propose a new reconstruction in the multijet plus same-sign dilepton with missing transverse energy samples (bb+l{sup {+-}}l{sup {+-}}+Ee{sub T}+Nj, N{>=}6) to search for on-shell tttt final states from sextet scalar pair production. Thanks to the large QCD production, the search covers the sextet mass range up to 1 TeV for 100 fb{sup -1} integrated luminosity.

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

    SciTech Connect (OSTI)

    Quigg, Chris

    2015-08-24

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

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Quigg, Chris

    2015-08-24

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

  2. PHOBOS in the LHC era

    SciTech Connect (OSTI)

    Steinberg, Peter

    2015-01-15

    The PHOBOS experiment ran at the RHIC collider from 2000 to 2005, under the leadership of Wit Busza. These proceedings summarize selected PHOBOS results, highlighting their continuing relevance amidst the wealth of new results from the lead–lead program at the Large Hadron Collider (LHC)

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2016-02-18

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

  4. SCIENCE ON SATURDAY- "The Large Hadron Collider: big science for big

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    questions" | Princeton Plasma Physics Lab January 5, 2013, 9:30am Science On Saturday MBG Auditorium SCIENCE ON SATURDAY- "The Large Hadron Collider: big science for big questions" Professor James Olsen Department of Physics, Princeton University Science on Saturday is a series of lectures given by scientists, mathematicians, and other professionals involved in cutting-edge research. Held on Saturday mornings throughout winter, the lectures are geared toward high school

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

    SciTech Connect (OSTI)

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

    2013-07-29

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

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

    ScienceCinema (OSTI)

    None

    2011-10-06

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

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

    SciTech Connect (OSTI)

    Nadolsky, Pavel M.

    2015-08-31

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

  8. The LHC Experiments

    SciTech Connect (OSTI)

    Lincoln, Don

    2015-03-11

    The Large Hadron Collider or LHC is the world’s biggest particle accelerator, but it can only get particles moving very quickly. To make measurements, scientists must employ particle detectors. There are four big detectors at the LHC: ALICE, ATLAS, CMS, and LHCb. In this video, Fermilab’s Dr. Don Lincoln introduces us to these detectors and gives us an idea of each one’s capabilities.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    LeCompte, Thomas J.; Martin, Stephen P.

    2012-02-22

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

  10. K (transverse) jet algorithms in hadron colliders: The D0 experience

    SciTech Connect (OSTI)

    V. Daniel Elvira

    2002-12-05

    D0 has implemented and studied a k{sub {perpendicular}} jet algorithm for the first time in a hadron collider. The authors have submitted two physics results for publication: the subjet multiplicity in quark and gluon jets and the central inclusive jet cross section measurements. A third result, a measurement of thrust distributions in jet events, is underway. A combination of measurements using several types of algorithms and samples taken at different center-of-mass energies is desirable to understand and distinguish with higher accuracy between instrumentation and physics effects.

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

    SciTech Connect (OSTI)

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

    2011-04-01

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

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

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

    2016-01-11

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

  13. Supersymmetry At LHC

    SciTech Connect (OSTI)

    Khalil, Shaaban

    2008-04-21

    One of the main motivation of the experiments at the Large Hadron Collider (LHC), scheduled to start around 2006, is to search for supersymmetric particles. The region of the parameter space of the minimal supersymmetric standard model, where supersymmetry can be discovered is investigated. We show that if supersymmetry exists at electroweak scale, it would be easy to find signals for it at the LHC. If the LHC does find supersymmetry, this would be one of the greatest achievements in the history of theoretical physics.

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

    SciTech Connect (OSTI)

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

    2015-06-01

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

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

    SciTech Connect (OSTI)

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

    2015-02-03

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

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

    SciTech Connect (OSTI)

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

    2008-10-01

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

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

    SciTech Connect (OSTI)

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

    2013-11-15

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

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

    SciTech Connect (OSTI)

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

    2010-12-01

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

  19. Comparison of LHC and ILC Capabilities for Higgs Boson Coupling

    Office of Scientific and Technical Information (OSTI)

    Measurements (Journal Article) | SciTech Connect Journal Article: Comparison of LHC and ILC Capabilities for Higgs Boson Coupling Measurements Citation Details In-Document Search Title: Comparison of LHC and ILC Capabilities for Higgs Boson Coupling Measurements I estimate the accuracies on Higgs boson coupling constants that experiments at the Large Hadron Collider and the International Linear Collider are capable of reaching over the long term. Authors: Peskin, Michael E. ; /SLAC

  20. Single and double photonuclear excitations in Pb+Pb collisions at {radical}(s{sub NN})=2.76 TeV at the CERN Large Hadron Collider

    SciTech Connect (OSTI)

    Djuvsland, Oystein; Nystrand, Joakim

    2011-04-15

    Cross sections are calculated for single and double photon exchange in ultraperipheral Pb+Pb collisions at the CERN Large Hadron Collider. The particle production is simulated with the DPMJET event generator. Large cross sections are found for particle production around midrapidity, making these processes an important background to hadronic nuclear interactions at both the trigger and analysis levels.

  1. DOE's Office of Science Launches Website for U.S. Role at Large Hadron

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Collider | Department of Energy Launches Website for U.S. Role at Large Hadron Collider DOE's Office of Science Launches Website for U.S. Role at Large Hadron Collider September 12, 2007 - 2:32pm Addthis U.S. scientists join international colleagues to explore universe's mysteries at world's largest scientific experiments WASHINGTON, DC - The U.S. Department of Energy's Office of Science today launched a new website to tell the story of the U.S. role in the Large Hadron Collider (LHC), a

  2. Tevatron-for-LHC Report of the QCD Working Group

    SciTech Connect (OSTI)

    Albrow, Michael G.; Begel, M.; Bourilkov, D.; Campanelli, M.; Chlebana, F.; De Roeck, A.; Dittmann, J.R.; Ellis, S.D.; Field, B.; Field, R.; Gallinaro, M.; /Fermilab /Rochester U. /Florida U. /Geneva U. /CERN /Baylor U. /Washington U., Seattle /Florida State U. /Rockefeller U. /Prague, Tech. U. /Michigan State U.

    2006-10-01

    The experiments at Run 2 of the Tevatron have each accumulated over 1 fb{sup -1} of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focused on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.

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

    SciTech Connect (OSTI)

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

    2010-07-01

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

  4. Large Hadron Collider Probe of Supersymmetric Neutrinoless Double-Beta-Decay Mechanism

    SciTech Connect (OSTI)

    Allanach, B. C.; Kom, C. H.; Paes, H. [DAMTP, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom); Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Fakultaet fuer Physik, Technische Universitaet Dortmund, D-44221, Dortmund (Germany)

    2009-08-28

    In the minimal supersymmetric extension to the standard model, a nonzero lepton number violating coupling {lambda}{sub 111}{sup '} predicts both neutrinoless double-beta-decay and resonant single slepton production at the LHC. We show that, in this case, if neutrinoless double beta decay is discovered in the next generation of experiments, there exist good prospects to observe single slepton production at the LHC. Neutrinoless double beta decay could otherwise result from a different source (such as a nonzero Majorana neutrino mass). Resonant single slepton production at the LHC can therefore discriminate between the {lambda}{sub 111}{sup '} neutrinoless double-beta-decay mechanism and others.

  5. Catching Collisions in the LHC

    SciTech Connect (OSTI)

    Fruguiele, Claudia; Hirschauer, Jim

    2015-06-16

    Now that the Large Hadron Collider has officially turned back on for its second run, within every proton collision could emerge the next new discovery in particle physics. Learn how the detectors on the Compact Muon Solenoid, or CMS, experiment capture and track particles as they are expelled from a collision. Talking us through these collisions are Claudia Fruguiele and Jim Hirschauer of Fermi National Accelerator Laboratory, the largest U.S. institution collaborating on the LHC.

  6. ATLAS at the LHC | Argonne National Laboratory

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ATLAS at the LHC ATLAS at the LHC The Large Hadron Collider in Geneva, Switzerland is the largest physics machine on Earth, and involves a collaboration of thousands of scientists who have used it to investigate the structure and properties of the tiniest building blocks of matter. At one of the experiments being performed on the LHC, called ATLAS, more than 3,000 scientists have undertaken the search for new discoveries based upon the head-on collisions of protons of extraordinarily high

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

    SciTech Connect (OSTI)

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

    2004-03-01

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

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

    SciTech Connect (OSTI)

    Dobbs, M.A

    2004-08-24

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

  9. Selected experimental results from heavy-ion collisions at LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singh, Ranbir; Kumar, Lokesh; Netrakanti, Pawan Kumar; Mohanty, Bedangadas

    2013-01-01

    We reviewmore » a subset of experimental results from the heavy-ion collisions at the Large Hadron Collider (LHC) facility at CERN. Excellent consistency is observed across all the experiments at the LHC (at center of mass energysNN=2.76 TeV) for the measurements such as charged particle multiplicity density, azimuthal anisotropy coefficients, and nuclear modification factor of charged hadrons. Comparison to similar measurements from the Relativistic Heavy Ion Collider (RHIC) at lower energy (sNN=200 GeV) suggests that the system formed at LHC has a higher energy density and larger system size and lives for a longer time. These measurements are compared to model calculations to obtain physical insights on the properties of matter created at the RHIC and LHC.« less

  10. Klystron switching power supplies for the Internation Linear Collider

    SciTech Connect (OSTI)

    Fraioli, Andrea; /Cassino U. /INFN, Pisa

    2009-12-01

    The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

  11. Fermilab | Science | Particle Accelerators | LHC and Future Accelerators

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    LHC, LCLS-II and future accelerators photo Fermilab is actively involved in the research and development of future particle accelerators around the world, contributing to the next generation of machines. These accelerators, each with its own specialty, would open new windows into our universe, allowing us to view it from as yet unexplored vantages. Upgrades to the Large Hadron Collider thumb Through its participation in the LHC Accelerator Research Program, called US LARP, Fermilab contributes

  12. CERN and LHC - their place in global science

    ScienceCinema (OSTI)

    None

    2011-10-06

    The Large Hadron Collider (LHC) is the largest scientific instrument in the world. It brings into collision intense beams of protons and ions to explore the structure of matter and investigate the forces of nature at an unprecedented energy scale, thus serving a community of some 7,000 particle physicists from all over the world.

  13. Indications of Conical Emission of Charged Hadrons at the BNL Relativistic Heavy Ion Collider

    SciTech Connect (OSTI)

    Abelev, B. I.; Barannikova, O.; Betts, R. R.; Callner, J.; Garcia-Solis, E.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Suarez, M. C.; Aggarwal, M. M.; Bhati, A. K.; Kumar, L.; Pruthi, N. K.; Ahammed, Z.; Chattopadhyay, S.; Dutta Mazumdar, M. R.; Ganti, M. S.; Ghosh, P.; Mohanty, B.; Nayak, T. K.

    2009-02-06

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

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

    SciTech Connect (OSTI)

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

    2009-01-01

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

  15. Indications of Conical Emission of Charged Hadrons at the BNL Relativistic HeavyIon Collider

    SciTech Connect (OSTI)

    STAR Coll

    2009-02-09

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

  16. Lepton number violating processes mediated by Majorana neutrinos at hadron colliders

    SciTech Connect (OSTI)

    Kovalenko, Sergey; Lu Zhun; Schmidt, Ivan [Departamento de Fisica, Universidad Tecnica Federico, Santa Maria, Casilla 110-V, Valparaiso (Chile) and Center of Subatomic Physics, Valparaiso (Chile)

    2009-10-01

    We study the lepton number violating like-sign dilepton processes h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}jjX and h{sub 1}h{sub 2}{yields}l{sup {+-}}l{sup '{+-}}W{sup {+-}}X, mediated by heavy GeV scale Majorana neutrinos. We focus on the resonantly enhanced contributions with a nearly on-mass-shell Majorana neutrino in the s channel. We study the constraints on like-sign dilepton production at the Tevatron and the LHC on the basis of the existing experimental limits on the masses of heavy neutrinos and their mixings U{sub {alpha}}{sub N} with {alpha}={nu}{sub e}, {nu}{sub {mu}}, {nu}{sub {tau}}. Special attention is paid to the constraints from neutrinoless double beta decay. We note that searches for like-sign e{sup {+-}}e{sup {+-}} events at Tevatron and LHC may provide evidence of CP violation in the neutrino sector. We also discuss the conditions under which it is possible to extract individual constraints on the mixing matrix elements in a model independent way.

  17. RF system models for the CERN Large Hadron Collider with application to longitudinal dynamics

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Winkle, D.Van; Baudrenghien, P.; /CERN

    2011-03-03

    The LHC RF station-beam interaction strongly influences the longitudinal beam dynamics, both single bunch and collective effects. Non-linearities and noise generated within the Radio Frequency (RF) accelerating system interact with the beam and contribute to beam motion and longitudinal emittance blowup. Thus, the noise power spectrum of the RF accelerating voltage strongly affects the longitudinal beam distribution. Furthermore, the coupled-bunch instabilities are also directly affected by the RF components and the configuration of the Low Level RF (LLRF) feedback loops. In this work we present a formalism relating the longitudinal beam dynamics with the RF system configurations, an estimation of collective effects stability margins, and an evaluation of longitudinal sensitivity to various LLRF parameters and configurations.

  18. Search for signatures of extra dimensions in the diphoton mass spectrum at the Large Hadron Collider

    SciTech Connect (OSTI)

    Chatrchyan, Serguei; Khachatryan, Vardan; Sirunyan, Albert M.; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; /Yerevan Phys. Inst. /Vienna, OAW /Minsk, High Energy Phys. Ctr. /Antwerp U., WISINF /Vrije U., Brussels /Brussels U. /Gent U. /Louvain U. /UMH, Mons /Rio de Janeiro, CBPF /Rio de Janeiro State U.

    2011-12-01

    A search for signatures of extra dimensions in the diphoton invariant-mass spectrum has been performed with the CMS detector at the LHC. No excess of events above the standard model expectation is observed using a data sample collected in proton-proton collisions at {radical}s = 7 TeV corresponding to an integrated luminosity of 2.2 fb{sup -1}. In the context of the large-extra-dimensions model, lower limits are set on the effective Planck scale in the range of 2.3-3.8 TeV at the 95% confidence level. These limits are the most restrictive bounds on virtual-graviton exchange to date. The most restrictive lower limits to date are also set on the mass of the first graviton excitation in the Randall-Sundrum model in the range of 0.86-1.84 TeV, for values of the associated coupling parameter between 0.01 and 0.10.

  19. Reliability of Beam Loss Monitor Systems for the Large Hadron Collider

    SciTech Connect (OSTI)

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

    2005-06-08

    The increase of beam energy and beam intensity, together with the use of super conducting magnets, opens new failure scenarios and brings new criticalities for the whole accelerator protection system. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system, and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses at 7 TeV and assisted by the Fast Beam Current Decay Monitors at 450 GeV. At medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standard databases. All the data has been processed by reliability software (Isograph). The analysis spaces from the components data to the system configuration.

  20. The ATLAS Experiment: Getting Ready for the LHC

    SciTech Connect (OSTI)

    Jenni, Peter

    2006-05-15

    At CERN the Large Hadron Collider (LHC) project is well advanced. First proton-proton collisions at the high-energy frontier are expected for the second half of 2007. In parallel to the collider construction the powerful general-purpose ATLAS detector is being assembled in its underground cavern by a world-wide collaboration. ATLAS will explore new domains of particle physics. After briefly overviewing the LHC construction and installation progress, the status of the ATLAS experiment will be presented, including examples of the exciting prospects for new physics.

  1. Jet energy loss, photon production, and photon-hadron correlations at energies available at the BNL Relativistic Heavy Ion Collider (RHIC)

    SciTech Connect (OSTI)

    Qin Guangyou; Ruppert, Joerg; Gale, Charles; Jeon, Sangyong; Moore, Guy D.

    2009-11-15

    Jet energy loss, photon production, and photon-hadron correlations are studied together at high transverse momentum in relativistic heavy-ion collisions at Relativistic Heavy Ion Collider (RHIC) energies. The modification of hard jets traversing a hot and dense nuclear medium is evaluated by consistently taking into account induced gluon radiation and elastic collisions. The production of high-transverse-momentum photons in Au+Au collisions at RHIC is calculated by incorporating a complete set of photon-production channels. Comparison with experimental photon production and photon-hadron correlation data is performed, using a (3+1)-dimensional relativistic hydrodynamic description of the thermalized medium created in these collisions. Our results demonstrate that the interaction between the hard jets and the soft medium is important for the study of photon production and of photon-hadron correlation at RHIC.

  2. Crystal Ball: On the Future High Energy Colliders

    SciTech Connect (OSTI)

    Shiltsev, Vladimir

    2015-09-20

    High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

  3. Radiative return capabilities of a high-energy, high-luminositye+e-collider

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Karliner, Marek; Low, Matthew; Rosner, Jonathan L.; Wang, Lian-Tao

    2015-08-14

    An electron-positron collider operating at a center-of-mass energy ECM can collect events at all lower energies through initial-state radiation (ISR or radiative return). We explore the capabilities for radiative return studies by a proposed high-luminosity collider at ECM = 250 or 90 GeV, to fill in gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These capabilities are compared with those of the lower-energy e+e- colliders as well as hadron colliders such as the Tevatron and the CERN Large Hadron Collider (LHC). Some examples of accessible questions in dark photon searches and heavy flavor spectroscopy are given.

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

    SciTech Connect (OSTI)

    Yeh, G.P.; /Fermilab

    2010-01-01

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

  5. Higher order mode filter design for double quarter wave crab cavity for the LHC high luminosity upgrade

    SciTech Connect (OSTI)

    Xiao, B.; Belomestnykh, S.; Ben-Zvi, I.; Burt, G.; Calaga, R.; Capatina, O.; Hall, B.; Jones, T.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Double Quarter Wave Crab Cavity (DQWCC) was designed for the Large Hadron Collider (LHC) luminosity upgrade. A compact Higher Order Mode (HOM) filter with wide stop band at the deflecting mode is developed for this cavity. Multiphysics finite element simulation results are presented. The integration of this design to the cavity cryomodule is described.

  6. Fermilab | Newsroom | Press Releases | LHC experiments eliminate more Higgs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    hiding spots 5 August 22, 2011 Media Contact: Elizabeth Clements, +1-630-840-2326, lizzie@fnal.gov LHC experiments eliminate more Higgs hiding spots August 22, 2011 - Two experimental collaborations at the Large Hadron Collider, located at CERN laboratory near Geneva, Switzerland, announced today that they have significantly narrowed the mass region in which the Higgs boson could be hiding. The ATLAS and CMS experiments excluded with 95 percent certainty the existence of a Higgs over most of

  7. LHC RF System Time-Domain Simulation

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.

    2010-09-14

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  8. First Experiences with LHC Grid Computing and Distributed Analysis

    SciTech Connect (OSTI)

    Fisk, Ian

    2010-12-01

    In this presentation the experiences of the LHC experiments using grid computing were presented with a focus on experience with distributed analysis. After many years of development, preparation, exercises, and validation the LHC (Large Hadron Collider) experiments are in operations. The computing infrastructure has been heavily utilized in the first 6 months of data collection. The general experience of exploiting the grid infrastructure for organized processing and preparation is described, as well as the successes employing the infrastructure for distributed analysis. At the end the expected evolution and future plans are outlined.

  9. Fermilab | Science | Particle Physics | Fermilab and the LHC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Fermilab and the LHC photo The Large Hadron Collider is the largest, most powerful particle accelerator in the world. It steers beams of particles on a collision course around a 17-mile ring located 300 feet beneath the border of Switzerland and France. Experiments at the LHC seek a greater understanding of nature by searching for new phenomena and particles-such as the recently discovered Higgs boson-and by investigating the properties of the particles and forces we know. For almost two

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

    SciTech Connect (OSTI)

    Demartin, Federico; Mariani, Elisa [Dipartimento di Fisica, Universita di Milano, Via Celoria 16, I-20133 Milano (Italy); Forte, Stefano; Vicini, Alessandro [Dipartimento di Fisica, Universita di Milano, Via Celoria 16, I-20133 Milano (Italy); INFN, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Rojo, Juan [INFN, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy)

    2010-07-01

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

  11. Measurement of identified charged hadron spectra in proton-proton collisions using the Inner Tracking System of the ALICE experiment at the LHC

    SciTech Connect (OSTI)

    Biolcati, Emanuele

    2011-05-23

    The measurement of the identified charged hadron p{sub t} spectra using the ITS energy loss signal in the pp data at {radical}(s) = 900 GeV collected by the ALICE experiment at LHC will be discussed. It is performed using the Inner Tracking System (ITS) in stand-alone mode, both for track reconstruction and particle identification, allowing one to detect low momentum particles with p{sub t} below 200 MeV/c. A second method using the tracks reconstructed by both the ITS and the Time Projection Chamber (TPC) has also been developed. The obtained results will be compared with the ones obtained from the TPC and from the Time Of Flight detector and used to extract the mean p{sub t} value.

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

    SciTech Connect (OSTI)

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

    2015-09-16

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

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rojo, Juan; Accardi, Alberto; Ball, Richard D.; Cooper-Sarkar, Amanda; de Roeck, Albert; Farry, Stephen; Ferrando, James; Forte, Stefano; Gao, Jun; Harland-Lang, Lucian; et al

    2015-09-16

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

  14. Linear Collider Physics Resource Book Snowmass 2001

    SciTech Connect (OSTI)

    Ronan , M.T.

    2001-06-01

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup -} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup -} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup -} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup -} experiments can provide. This last point merits further emphasis. If a new accelerator could be designed and

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vogt, R.

    2015-09-17

    Proton-nucleus collisions have been used as a intermediate baseline for the determination of cold medium effects. They lie between proton-proton collisions in vacuum and nucleus-nucleus collisions which are expected to be dominated by hot matter effects. Modifications of the quark densities in nuclei relative to those of the proton are well established although those of the gluons in the nucleus are not well understood. We focus on the effect of these on quarkonium production in proton-lead collisions at the LHC at a center of mass energy of 5.02 TeV.

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

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bzdak, Adam; Skokov, Vladimir; Bathe, Stefan

    2016-04-08

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

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

    SciTech Connect (OSTI)

    Yu, Jaehoon; White, Andrew

    2014-09-25

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

  18. Cryogenic test of double quarter wave crab cavity for the LHC High luminosity upgrade

    SciTech Connect (OSTI)

    Xiao, B.; Alberty, L.; Belomestnykh, S.; Ben-Zvi, I.; Calaga, R.; Cullen, C.; Capatina, O.; Hammons, L.; Li, Z.; Marques, C.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Proof-of-Principle (PoP) Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. A vertical cryogenic test has been done at Brookhaven National Lab (BNL). The cavity achieved 4.5 MV deflecting voltage with a quality factor above 3×109. We report the test results of this design.

  19. Jet energy calibration at the LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Schwartzman, Ariel

    2015-11-10

    In this study, jets are one of the most prominent physics signatures of high energy proton–proton (p–p) collisions at the Large Hadron Collider (LHC). They are key physics objects for precision measurements and searches for new phenomena. This review provides an overview of the reconstruction and calibration of jets at the LHC during its first Run. ATLAS and CMS developed different approaches for the reconstruction of jets, but use similar methods for the energy calibration. ATLAS reconstructs jets utilizing input signals from their calorimeters and use charged particle tracks to refine their energy measurement and suppress the effects of multiplemore » p–p interactions (pileup). CMS, instead, combines calorimeter and tracking information to build jets from particle flow objects. Jets are calibrated using Monte Carlo (MC) simulations and a residual in situ calibration derived from collision data is applied to correct for the differences in jet response between data and Monte Carlo.« less

  20. Probing top-Z dipole moments at the LHC and ILC

    SciTech Connect (OSTI)

    Röntsch, Raoul; Schulze, Markus

    2015-08-11

    We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirect constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. Furthermore, we find that LHC experiments will soon be able to probe weak dipole moments for the first time.

  1. Summary of the Mini BNL/LARP/CARE-HHH Workshop on Crab Cavities for the LHC (LHC-CC08)

    SciTech Connect (OSTI)

    Ben-Zvi,I.; Calaga, R.; Zimmermann, F.

    2008-05-01

    The first mini-workshop on crab compensation for the LHC luminosity upgrade (LHC-CC08) was held February 24-25, 2008 at the Brookhaven National Laboratory. A total of 35 participants from 3 continents and 15 institutions from around the world participated to discuss the exciting prospect of a crab scheme for the LHC. If realized it will be the first demonstration in hadron colliders. The workshop is organized by joint collaboration of BNL, US-LARP and CARE-HHH. The enormous interest in the subject of crab cavities for the international linear collider and future light sources has resulted in a large international collaboration to exchange aspects of synergy and expertise. A central repository for this exchange of information documenting the latest design effort for LHC crab cavities is consolidated in a wiki page: https://twiki.cern.ch/twiki/bin/view/Main/LHCCrabCavities. The main goal of this workshop was to define a road-map for a prototype crab cavity to be installed in the LHC and to discuss the associated R&D and beam dynamics challenges. The diverse subject of implementing the crab scheme resulted in a scientific program with a wide range of subtopics which were divided into 8 sessions. Each session was given a list of fundamental questions to be addressed and used as a guideline to steer the discussions.

  2. LHC Physics Potential versus Energy

    SciTech Connect (OSTI)

    Quigg, Chris; /Fermilab

    2009-08-01

    Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u{bar d}, and qq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes.

  3. Radiative return capabilities of a high-energy, high-luminositye+e-collider

    SciTech Connect (OSTI)

    Karliner, Marek; Low, Matthew; Rosner, Jonathan L.; Wang, Lian-Tao

    2015-08-14

    An electron-positron collider operating at a center-of-mass energy ECM can collect events at all lower energies through initial-state radiation (ISR or radiative return). We explore the capabilities for radiative return studies by a proposed high-luminosity collider at ECM = 250 or 90 GeV, to fill in gaps left by lower-energy colliders such as PEP, PETRA, TRISTAN, and LEP. These capabilities are compared with those of the lower-energy e+e- colliders as well as hadron colliders such as the Tevatron and the CERN Large Hadron Collider (LHC). Some examples of accessible questions in dark photon searches and heavy flavor spectroscopy are given.

  4. The versatile link, a common project for super-LHC

    SciTech Connect (OSTI)

    Amaral, Luis; Dris, Stefanos; Gerardin, Alexandre; Huffman, Todd; Issever, Cigdem; Pacheco, Alberto Jimenez; Jones, Mark; Kwan, Simon; Lee, Shih-Chang; Lian, Zhijun; Liu, Tiankuan; /CERN /Oxford U. /Fermilab /Taipei, Computing Ctr. /Southern Methodist U.

    2009-07-01

    Radiation tolerant, high speed optoelectronic data transmission links are fundamental building blocks in today's large scale High Energy Physics (HEP) detectors, as exemplified by the four experiments currently under commissioning at the Large Hadron Collider (LHC), see for example. New experiments or upgrades will impose even more stringent demands on these systems from the point of view of performance and radiation tolerance. This can already be seen from the developments underway for the Super Large Hadron Collider (SLHC) project, a proposed upgrade to the LHC aiming at increasing the luminosity of the machine by factor of 10 to 10{sup 35} cm{sup -2}s{sup -1}, and thus providing a better chance to see rare processes and improving statistically marginal measurements. In the past, specific data transmission links have been independently developed by each LHC experiment for data acquisition (DAQ), detector control as well as trigger and timing distribution (TTC). This was justified by the different types of applications being targeted as well as by technological limitations preventing one single solution from fitting all requirements. However with today's maturity of optoelectronic and CMOS technologies it is possible to envisage the development of a general purpose optical link which can cover most transmission applications: a Versatile Link. Such an approach has the clear advantage of concentrating the development effort on one single project targeting an optical link whose final functionality will only result from the topology and configuration settings adopted.

  5. COLLOQUIUM: Fundamental Physics and the LHC: A Progress Report | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab 17, 2013, 4:15pm to 5:30pm Colloquia MBG Auditorium COLLOQUIUM: Fundamental Physics and the LHC: A Progress Report Professor Nima Arkani-Hamed The Institute for Advanced Study Presentation: PDF icon WC17APR2013_NAHamed.pdf Last July's discovery of the Higgs particle at the Large Hadron Collider was a triumph for both experiment and theory in fundamental physics. But the Higgs also introduces major conceptual paradoxes that strongly suggest we are missing essential new

  6. Probing New Physics with Jets at the LHC

    ScienceCinema (OSTI)

    Harris, Robert

    2009-09-01

    The Large Hadron Collider at CERN has the potential to make a major discovery as early as 2008 from simple measurements of events with two high energy jets. This talk will present the jet trigger and analysis plans of the CMS collaboration, which were produced at the LHC Physics Center at Fermilab. Plans to search the two jet channel for generic signals of new particles and forces will be discussed. I will present the anticipated sensitivity of the CMS experiment to a variety of models of new physics, including quark compositeness, technicolor, superstrings, extra dimensions and grand unification.

  7. Hadron Colliders Working Group Report

    SciTech Connect (OSTI)

    S. Peggs and M.J. Syphers

    2001-11-08

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

  8. International linear collider reference design report

    SciTech Connect (OSTI)

    Aarons, G.

    2007-06-22

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

  9. The Interplay Between Collider Searches For Supersymmetric Higgs Bosons and Direct Dark Matter Experiments

    SciTech Connect (OSTI)

    Carena, Marcela; Hooper, Dan; Vallinotto, Alberto; /Fermilab /Chicago U. /Paris, Inst. Astrophys.

    2006-11-01

    In this article, we explore the interplay between searches for supersymmetric particles and Higgs bosons at hadron colliders (the Tevatron and the LHC) and direct dark matter searches (such as CDMS, ZEPLIN, XENON, EDELWEISS, CRESST, WARP and others). We focus on collider searches for heavy MSSM Higgs bosons (A, H, H{sup {+-}}) and how the prospects for these searches are impacted by direct dark matter limits and vice versa. We find that the prospects of these two experimental programs are highly interrelated. A positive detection of A, H or H{sup {+-}} at the Tevatron would dramatically enhance the prospects for a near future direct discovery of neutralino dark matter. Similarly, a positive direct detection of neutralino dark matter would enhance the prospects of discovering heavy MSSM Higgs bosons at the Tevatron or the LHC. Combining the information obtained from both types of experimental searches will enable us to learn more about the nature of supersymmetry.

  10. Steady State Heat Deposits Modeling in the Nb3Sn Quadrupole Magnets for the Upgrade of the LHC Inner Triplet

    SciTech Connect (OSTI)

    Bocian, D.; Ambrosio, G.; Felice, H.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidze, G.; Dietderich, D.; Feher, S.; Ferracin, P.; Hafalia, R.; /Fermilab /Lawrence Berkeley Lab /Brookhaven

    2011-09-01

    In hadron colliders such as the LHC, the energy deposited in the superconductors by the particles lost from the beams or coming from the collision debris may provoke quenches detrimental to the accelerator operation. In previous papers, a Network Model has been used to study the thermodynamic behavior of magnet coils and to calculate the quench levels in the LHC magnets for expected beam loss profiles. This model was subsequently used for thermal analysis and design optimization of Nb{sub 3}Sn quadrupole magnets, which LARP (US LHC Accelerator Research Program) is developing for possible use in the LHC luminosity upgrade. For these new magnets, the heat transport efficiency from the coil to the helium bath needs to be determined and optimized. In this paper the study of helium cooling channels and the heat evacuation scheme are presented and discussed.

  11. Polarizations of X c1 and X c2 in Prompt Production at the LHC

    SciTech Connect (OSTI)

    Sheng, Shao H.; Ma, Y.; Wang, K.; Ta Chao, K.

    2014-05-08

    Prompt χc production at hadron colliders may provide a unique test for the color-octet mechanism in nonrelativistic QCD. We present an analysis for the polarization observables of χc1 and χc2 at next-to-leading order in αS and propose to measure them at the LHC, which is expected to be important for testing the validity of nonrelativistic QCD.

  12. LINEAR COLLIDER PHYSICS RESOURCE BOOK FOR SNOWMASS 2001.

    SciTech Connect (OSTI)

    ABE,T.; DAWSON,S.; HEINEMEYER,S.; MARCIANO,W.; PAIGE,F.; TURCOT,A.S.; ET AL

    2001-05-03

    The American particle physics community can look forward to a well-conceived and vital program of experimentation for the next ten years, using both colliders and fixed target beams to study a wide variety of pressing questions. Beyond 2010, these programs will be reaching the end of their expected lives. The CERN LHC will provide an experimental program of the first importance. But beyond the LHC, the American community needs a coherent plan. The Snowmass 2001 Workshop and the deliberations of the HEPAP subpanel offer a rare opportunity to engage the full community in planning our future for the next decade or more. A major accelerator project requires a decade from the beginning of an engineering design to the receipt of the first data. So it is now time to decide whether to begin a new accelerator project that will operate in the years soon after 2010. We believe that the world high-energy physics community needs such a project. With the great promise of discovery in physics at the next energy scale, and with the opportunity for the uncovering of profound insights, we cannot allow our field to contract to a single experimental program at a single laboratory in the world. We believe that an e{sup +}e{sup {minus}} linear collider is an excellent choice for the next major project in high-energy physics. Applying experimental techniques very different from those used at hadron colliders, an e{sup +}e{sup {minus}} linear collider will allow us to build on the discoveries made at the Tevatron and the LHC, and to add a level of precision and clarity that will be necessary to understand the physics of the next energy scale. It is not necessary to anticipate specific results from the hadron collider programs to argue for constructing an e{sup +}e{sup {minus}} linear collider; in any scenario that is now discussed, physics will benefit from the new information that e{sup +}e{sup {minus}} experiments can provide.

  13. Beam-machine Interaction at the CERN LHC

    SciTech Connect (OSTI)

    Boccone, V.; Bruce, R.; Brugger, M.; Calviani, M.; Cerutti, F. Esposito, L.S.; Ferrari, A.; Lechner, A.; Mereghetti, A.; Nowak, E.; Shetty, N.V.; Skordis, E.; Versaci, R.; Vlachoudis, V.

    2014-06-15

    The radiation field generated by a high energy and intensity accelerator is of concern in terms of element functionality threat, component damage, electronics reliability, and material activation, but also provides signatures that allow actual operating conditions to be monitored. The shower initiated by an energetic hadron involves many different physical processes, down to slow neutron interactions and fragment de-excitation, which need to be accurately described for design purposes and to interpret operation events. The experience with the transport and interaction Monte Carlo code FLUKA at the Large Hadron Collider (LHC), operating at CERN with 4 TeV proton beams (and equivalent magnetic rigidity Pb beams) and approaching nominal luminosity and energy, is presented. Design, operation and upgrade challenges are reviewed in the context of beam-machine interaction account and relevant benchmarking examples based on radiation monitor measurements are shown.

  14. Physics validation studies for muon collider detector background simulations

    SciTech Connect (OSTI)

    Morris, Aaron Owen; /Northern Illinois U.

    2011-07-01

    Within the broad discipline of physics, the study of the fundamental forces of nature and the most basic constituents of the universe belongs to the field of particle physics. While frequently referred to as 'high-energy physics,' or by the acronym 'HEP,' particle physics is not driven just by the quest for ever-greater energies in particle accelerators. Rather, particle physics is seen as having three distinct areas of focus: the cosmic, intensity, and energy frontiers. These three frontiers all provide different, but complementary, views of the basic building blocks of the universe. Currently, the energy frontier is the realm of hadron colliders like the Tevatron at Fermi National Accelerator Laboratory (Fermilab) or the Large Hadron Collider (LHC) at CERN. While the LHC is expected to be adequate for explorations up to 14 TeV for the next decade, the long development lead time for modern colliders necessitates research and development efforts in the present for the next generation of colliders. This paper focuses on one such next-generation machine: a muon collider. Specifically, this paper focuses on Monte Carlo simulations of beam-induced backgrounds vis-a-vis detector region contamination. Initial validation studies of a few muon collider physics background processes using G4beamline have been undertaken and results presented. While these investigations have revealed a number of hurdles to getting G4beamline up to the level of more established simulation suites, such as MARS, the close communication between us, as users, and the G4beamline developer, Tom Roberts, has allowed for rapid implementation of user-desired features. The main example of user-desired feature implementation, as it applies to this project, is Bethe-Heitler muon production. Regarding the neutron interaction issues, we continue to study the specifics of how GEANT4 implements nuclear interactions. The GEANT4 collaboration has been contacted regarding the minor discrepancies in the neutron

  15. General-purpose event generators for LHC physics

    SciTech Connect (OSTI)

    Buckley, Andy; Butterworth, Jonathan; Gieseke, Stefan; Grellscheid, David; Hoche, Stefan; Hoeth, Hendrik; Krauss, Frank; Lonnblad, Leif; Nurse, Emily; Richardson, Peter; Schumann, Steffen; Seymour, Michael H.; Sjostrand, Torbjorn; Skands, Peter; Webber, Bryan; /Cambridge U.

    2011-03-03

    We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard-scattering matrix elements for processes of interest, at both leading and next-to-leading QCD perturbative order; their matching to approximate treatments of higher orders based on the showering approximation; the parton and dipole shower formulations; parton distribution functions for event generators; non-perturbative aspects such as soft QCD collisions, the underlying event and diffractive processes; the string and cluster models for hadron formation; the treatment of hadron and tau decays; the inclusion of QED radiation and beyond-Standard-Model processes. We describe the principal features of the Ariadne, Herwig++, Pythia 8 and Sherpa generators, together with the Rivet and Professor validation and tuning tools, and discuss the physics philosophy behind the proper use of these generators and tools. This review is aimed at phenomenologists wishing to understand better how parton-level predictions are translated into hadron-level events as well as experimentalists wanting a deeper insight into the tools available for signal and background simulation at the LHC.

  16. Collider effects of unparticle interactions in multiphoton signals

    SciTech Connect (OSTI)

    Aliev, T. M.; Frank, Mariana; Turan, Ismail

    2009-12-01

    A new model of physics, with a hidden conformal sector which manifests itself as an unparticle coupling to standard model particles effectively through higher dimensional operators, predicts strong collider signals due to unparticle self-interactions. We perform a complete analysis of the most spectacular of these signals at the hadron collider, pp(p){yields}{gamma}{gamma}{gamma}{gamma} and {gamma}{gamma}gg. These processes can go through the three-point unparticle self-interactions as well as through some s and t channel diagrams with one and/or two unparticle exchanges. We study the contributions of individual diagrams classified with respect to the number of unparticle exchanges and discuss their effect on the cross sections at the Tevatron and the LHC. We also restrict the Tevatron bound on the unknown coefficient of the three-point unparticle correlator. With the availability of data from the Tevatron, and the advent of the data emerging from the LHC, these interactions can provide a clear and strong indication of unparticle physics and distinguish this model from other beyond the standard model scenarios.

  17. Automated next-to-leading order predictions for new physics at the LHC: The case of colored scalar pair production

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Degrande, Céline; Fuks, Benjamin; Hirschi, Valentin; Proudom, Josselin; Shao, Hua -Sheng

    2015-05-05

    We present for the first time the full automation of collider predictions matched with parton showers at the next-to-leading accuracy in QCD within nontrivial extensions of the standard model. The sole inputs required from the user are the model Lagrangian and the process of interest. As an application of the above, we explore scenarios beyond the standard model where new colored scalar particles can be pair produced in hadron collisions. Using simplified models to describe the new field interactions with the standard model, we present precision predictions for the LHC within the MadGraph5_aMC@NLO framework.

  18. The standard model and colliders

    SciTech Connect (OSTI)

    Hinchliffe, I.

    1987-03-01

    Some topics in the standard model of strong and electroweak interactions are discussed, as well as how these topics are relevant for the high energy colliders which will become operational in the next few years. The radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed briefly, followed by a discussion of the Higgs boson and the searches which are relevant to hadron colliders are then discussed. Some of the problems which the standard model does not solve are discussed, and the energy ranges accessible to the new colliders are indicated. (LEW)

  19. First Operation of the Abort Gap Monitor for LHC

    SciTech Connect (OSTI)

    Lefevre, Thibaut; Bart Pedersen, Stephane; Boccardi, Andrea; Bravin, Enrico; Goldblatt, A.; Jeff, Adam; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-06

    The Large Hadron Collider (LHC) beam-dump system relies on extraction kickers that need 3 microseconds to rise to their nominal field. Since particles transiting the kickers during the rise will not be dumped properly, the proton population in this interval must always remain below quench and damage limits. A specific monitor to measure the particle population of this gap has been designed based on the detection of synchrotron radiation using a gated photomultiplier. Since the quench and damage limits change with the beam energy, the acceptable population in the abort gap and the settings of the monitor must adapt accordingly. This paper presents the design of the monitor, the calibration procedure and the detector performance with beam.

  20. First Beam Measurements with the LHC Synchrotron Light Monitors

    SciTech Connect (OSTI)

    Lefevre, Thibaut; Bravin, Enrico; Burtin, Gerard; Guerrero, Ana; Jeff, Adam; Rabiller, Aurelie; Roncarolo, Federico; Fisher, Alan; /SLAC

    2012-07-13

    The continuous monitoring of the transverse sizes of the beams in the Large Hadron Collider (LHC) relies on the use of synchrotron radiation and intensified video cameras. Depending on the beam energy, different synchrotron light sources must be used. A dedicated superconducting undulator has been built for low beam energies (450 GeV to 1.5 TeV), while edge and centre radiation from a beam-separation dipole magnet are used respectively for intermediate and high energies (up to 7 TeV). The emitted visible photons are collected using a retractable mirror, which sends the light into an optical system adapted for acquisition using intensified CCD cameras. This paper presents the design of the imaging system, and compares the expected light intensity with measurements and the calculated spatial resolution with a cross calibration performed with the wire scanners. Upgrades and future plans are also discussed.

  1. Probing top-Z dipole moments at the LHC and ILC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Röntsch, Raoul; Schulze, Markus

    2015-08-11

    We investigate the weak electric and magnetic dipole moments of top quark-Z boson interactions at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). Their vanishingly small magnitude in the Standard Model makes these couplings ideal for probing New Physics interactions and for exploring the role of top quarks in electroweak symmetry breaking. In our analysis, we consider the production of two top quarks in association with a Z boson at the LHC, and top quark pairs mediated by neutral gauge bosons at the ILC. These processes yield direct sensitivity to top quark-Z boson interactions and complement indirectmore » constraints from electroweak precision data. Our computation is accurate to next-to-leading order in QCD, we include the full decay chain of top quarks and the Z boson, and account for theoretical uncertainties in our constraints. Furthermore, we find that LHC experiments will soon be able to probe weak dipole moments for the first time.« less

  2. Heavy Ion Collisions at the LHC - Last Call for Predictions

    SciTech Connect (OSTI)

    Armesto, N; Borghini, N; Jeon, S; Wiedemann, U A; Abreu, S; Akkelin, V; Alam, J; Albacete, J L; Andronic, A; Antonuv, D; Arleo, F; Armesto, N; Arsene, I C; Barnafoldi, G G; Barrette, J; Bauchle, B; Becattini, F; Betz, B; Bleicher, M; Bluhm, M; Boer, D; Bopp, F W; Braun-Munzinger, P; Bravina, L; Busza, W; Cacciari, M; Capella, A; Casalderrey-Solana, J; Chatterjee, R; Chen, L; Cleymans, J; Cole, B A; delValle, Z C; Csernai, L P; Cunqueiro, L; Dainese, A; de Deus, J D; Ding, H; Djordjevic, M; Drescher, H; Dremin, I M; Dumitru, A; El, A; Engel, R; d'Enterria, D; Eskola, K J; Fai, G; Ferreiro, E G; Fries, R J; Frodermann, E; Fujii, H; Gale, C; Gelis, F; Goncalves, V P; Greco, V; Gyulassy, M; van Hees, H; Heinz, U; Honkanen, H; Horowitz, W A; Iancu, E; Ingelman, G; Jalilian-Marian, J; Jeon, S; Kaidalov, A B; Kampfer, B; Kang, Z; Karpenko, I A; Kestin, G; Kharzeev, D; Ko, C M; Koch, B; Kopeliovich, B; Kozlov, M; Kraus, I; Kuznetsova, I; Lee, S H; Lednicky, R; Letessier, J; Levin, E; Li, B; Lin, Z; Liu, H; Liu, W; Loizides, C; Lokhtin, I P; Machado, M T; Malinina, L V; Managadze, A M; Mangano, M L; Mannarelli, M; Manuel, C; Martinez, G; Milhano, J G; Mocsy, A; Molnar, D; Nardi, M; Nayak, J K; Niemi, H; Oeschler, H; Ollitrault, J; Paic, G; Pajares, C; Pantuev, V S; Papp, G; Peressounko, D; Petreczky, P; Petrushanko, S V; Piccinini, F; Pierog, T; Pirner, H J; Porteboeuf, S; Potashnikova, I; Qin, G Y; Qiu, J; Rafelski, J; Rajagopal, K; Ranft, J; Rapp, R; Rasanen, S S; Rathsman, J; Rau, P; Redlich, K; Renk, T; Rezaeian, A H; Rischke, D; Roesler, S; Ruppert, J; Ruuskanen, P V; Salgado, C A; Sapeta, S; Sarcevic, I; Sarkar, S; Sarycheva, L I; Schmidt, I; Shoski, A I; Sinha, B; Sinyukov, Y M; Snigirev, A M; Srivastava, D K; Stachel, J; Stasto, A; Stocker, H; Teplov, C Y; Thews, R L; Torrieri, G; Pop, V T; Triantafyllopoulos, D N; Tuchin, K L; Turbide, S; Tywoniuk, K; Utermann, A; Venugopalan, R; Vitev, I; Vogt, R; Wang, E; Wang, X N; Werner, K; Wessels, E; Wheaton, S; Wicks, S; Wiedemann, U A; Wolschin, G; Xiao, B; Xu, Z; Yasui, S; Zabrodin, E; Zapp, K; Zhang, B

    2008-02-25

    In August 2006, the CERN Theory Unit announced to restructure its visitor program and to create a 'CERN Theory Institute', where 1-3 month long specific programs can take place. The first such Institute was held from 14 May to 10 June 2007, focusing on 'Heavy Ion Collisions at the LHC - Last Call for Predictions'. It brought together close to 100 scientists working on the theory of ultra-relativistic heavy ion collisions. The aim of this workshop was to review and document the status of expectations and predictions for the heavy ion program at the Large Hadron Collider LHC before its start. LHC will explore heavy ion collisions at {approx} 30 times higher center of mass energy than explored previously at the Relativistic Heavy Ion Collider RHIC. So, on the one hand, the charge of this workshop provided a natural forum for the exchange of the most recent ideas, and allowed to monitor how the understanding of heavy ion collisions has evolved in recent years with the data from RHIC, and with the preparation of the LHC experimental program. On the other hand, the workshop aimed at a documentation which helps to distinguish pre- from post-dictions. An analogous documentation of the 'Last Call for Predictions' [1] was prepared prior to the start of the heavy-ion program at the Relativistic Heavy Ion Collider RHIC, and it proved useful in the subsequent discussion and interpretation of RHIC data. The present write-up is the documentation of predictions for the LHC heavy ion program, received or presented during the CERN TH Institute. The set-up of the CERN TH Institute allowed us to aim for the wide-most coverage of predictions. There were more than 100 presentations and discussions during the workshop. Moreover, those unable to attend could still participate by submitting predictions in written form during the workshop. This followed the spirit that everybody interested in making a prediction had the right to be heard. To arrive at a concise document, we required that

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

    SciTech Connect (OSTI)

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

    2011-08-19

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

  4. Direct Probes of Linearly Polarized Gluons inside Unpolarized Hadrons

    SciTech Connect (OSTI)

    Boer, Danieel; Brodsky, Stanley J.; Mulders, Piet J.; Pisano, Cristian

    2011-04-01

    We show that linearly polarized gluons inside unpolarized hadrons can be directly probed in jet or heavy quark pair production in electron-hadron collisions. We discuss the simplest cos2{phi} asymmetries and estimate their maximal value, concluding that measurements of the unknown linearly polarized gluon distribution in the proton should be feasible in future Electron-Ion Collider or Large Hadron electron Collider experiments. Analogous asymmetries in hadron-hadron collisions suffer from factorization breaking contributions and would allow us to quantify the importance of initial- and final-state interactions.

  5. Baseline review of the U.S. LHC Accelerator project

    SciTech Connect (OSTI)

    1998-02-01

    The Department of Energy (DOE) Review of the U.S. Large Hadron Collider (LHC) Accelerator project was conducted February 23--26, 1998, at the request of Dr. John R. O`Fallon, Director, Division of High Energy Physics, Office of Energy Research, U.S. DOE. This is the first review of the U.S. LHC Accelerator project. Overall, the Committee found that the U.S. LHC Accelerator project effort is off to a good start and that the proposed scope is very conservative for the funding available. The Committee recommends that the project be initially baselined at a total cost of $110 million, with a scheduled completion data of 2005. The U.S. LHC Accelerator project will supply high technology superconducting magnets for the interaction regions (IRs) and the radio frequency (rf) straight section of the LHC intersecting storage rings. In addition, the project provides the cryogenic support interface boxes to service the magnets and radiation absorbers to protect the IR dipoles and the inner triplet quadrupoles. US scientists will provide support in analyzing some of the detailed aspects of accelerator physics in the two rings. The three laboratories participating in this project are Brookhaven National Laboratory, Fermi National Accelerator Laboratory (Fermilab), and Lawrence Berkeley National Laboratory. The Committee was very impressed by the technical capabilities of the US LHC Accelerator project team. Cost estimates for each subsystem of the US LHC Accelerator project were presented to the Review Committee, with a total cost including contingency of $110 million (then year dollars). The cost estimates were deemed to be conservative. A re-examination of the funding profile, costs, and schedules on a centralized project basis should lead to an increased list of deliverables. The Committee concluded that the proposed scope of US deliverables to CERN can be readily accomplished with the $110 million total cost baseline for the project. The current deliverables should serve as

  6. An updated analysis of Inert Higgs Doublet Model in light of the recent results from LUX, PLANCK, AMS-02 and LHC

    SciTech Connect (OSTI)

    Arhrib, Abdesslam; Tsai, Yue-Lin Sming; Yuan, Tzu-Chiang; Yuan, Qiang E-mail: yue-lin.tsai@ipmu.jp E-mail: tcyuan@phys.sinica.edu.tw

    2014-06-01

    In light of the recent discovery by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) of a Higgs-like particle with a narrow mass range of 125126 GeV, we perform an updated analysis on one of the popular scalar dark matter models, the Inert Higgs Doublet Model (IHDM). We take into account in our likelihood analysis of various experimental constraints, including recent relic density measurement, dark matter direct and indirect detection constraints as well as the latest collider constraints on the invisible decay width of the Higgs boson and monojet search at the LHC. It is shown that if the invisible decay of the standard model Higgs boson is open, LHC as well as direct detection experiments like LUX and XENON100 could put stringent limits on the Higgs boson couplings to dark matter. We find that the most favoured parameter space for IHDM corresponds to dark matter with a mass less than 100 GeV or so. In particular, the best-fit points are at the dark matter mass around 70 GeV where the invisible Higgs decay to dark matter is closed. Scalar dark matter in the higher mass range of 0.54 TeV is also explored in our study. Projected sensitivities for the future experiments of monojet at LHC-14, XENON1T and AMS-02 one year antiproton flux are shown to put further constraints on the existing parameter space of IHDM.

  7. Measurement of the Oscillation Frequency of B_s Mesons in the Hadronic Decay Mode B_s-> pi D_s(phi pi)X$ with the D0 Detector at the Fermilab Tevatron Collider

    SciTech Connect (OSTI)

    Weber, Gernot August; /Mainz U., Inst. Phys.

    2009-03-01

    The standard model (SM) of particle physics is a theory, describing three out of four fundamental forces. In this model the Cabibbo-Kobayashi-Maskawa (CKM) matrix describes the transformation between the mass and weak eigenstates of quarks. The matrix properties can be visualized as triangles in the complex plane. A precise measurement of all triangle parameters can be used to verify the validity of the SM. The least precisely measured parameter of the triangle is related to the CKM element |V{sub td}|, accessible through the mixing frequency (oscillation) of neutral B mesons, where mixing is the transition of a neutral meson into its anti-particle and vice versa. It is possible to calculate the CKM element |V{sub td}| and a related element |V{sub ts}| by measuring the mass differences {Delta}m{sub d} ({Delta}m{sub s}) between neutral B{sub d} and {bar B}{sub d} (B{sub s} and {bar B}{sub s}) meson mass eigenstates. This measurement is accomplished by tagging the initial and final state of decaying B mesons and determining their lifetime. Currently the Fermilab Tevatron Collider (providing p{bar p} collisions at {radical}s = 1.96 TeV) is the only place, where B{sub s} oscillations can be studied. The first selection of the 'golden', fully hadronic decay mode B{sub s} {yields} {pi}D{sub s}({phi}{pi})X at D0 is presented in this thesis. All data, taken between April 2002 and August 2007 with the D0 detector, corresponding to an integrated luminosity of {integral} Ldt = 2.8 fb{sup -1} is used. The oscillation frequency {Delta}m{sub s} and the ratio |V{sub td}|/|V{sub ts}| are determined as {Delta}m{sub s} = (16.6{sub -0.4}{sup +0.5}(stat){sub -0.3}{sup +0.4}(sys)) ps{sup -1}, |V{sub td}|/|V{sub ts}| = 0.213{sub -0.003}{sup +0.004}(exp) {+-} 0.008(theor). These results are consistent with the standard model expectations and no evidence for new physics is observable.

  8. Development of MQXF: The Nb3Sn low-β quadrupole for the HiLumi LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ferracin, P.; G. Ambrosio; Anerella, M.; Ballarino, A.; Bajas, H.; Bajko, M.; Bordini, B.; Bossert, R.; Cheng, D. W.; Dietderich, D. R.; et al

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating atmore » magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. Lastly, this paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.« less

  9. Top Quark Anomalous Couplings at the International Linear Collider...

    Office of Scientific and Technical Information (OSTI)

    This process probes the elementary couplings of the top quark to the photon, the Z and the W bosons at a level of precision that is difficult to achieve at hadron colliders. ...

  10. Muon Collider Progress: Accelerators

    SciTech Connect (OSTI)

    Zisman, Michael S.

    2011-09-10

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 10{sup 34} cm{sup 2}s{sup 1}. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (cooling). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program are described.

  11. Current Lead Design for the Accelerator Project for Upgrade of LHC

    SciTech Connect (OSTI)

    Brandt, Jeffrey S.; Cheban, Sergey; Feher, Sandor; Kaducak, Marc; Nobrega, Fred; Peterson, Tom

    2010-01-01

    The Accelerator Project for Upgrade of LHC (APUL) is a U.S. project participating in and contributing to CERN's Large Hadron Collider (LHC) upgrade program. In collaboration with Brookhaven National Laboratory, Fermilab is developing sub-systems for an upgrade of the LHC final focus magnet systems. A concept of main and auxiliary helium flow was developed that allows the superconductor to remain cold while the lead body warms up to prevent upper section frosting. The auxiliary flow will subsequently cool the thermal shields of the feed box and the transmission line cryostats. A thermal analysis of the current lead central heat exchange section was performed using analytic and FEA techniques. A method of remote soldering was developed that allows the current leads to be field replaceable. The remote solder joint was designed to be made without flux or additional solder, and able to be remade up to ten full cycles. A method of upper section attachment was developed that allows high pressure sealing of the helium volume. Test fixtures for both remote soldering and upper section attachment for the 13 kA lead were produced. The cooling concept, thermal analyses, and test results from both remote soldering and upper section attachment fixtures are presented.

  12. Muon Collider

    SciTech Connect (OSTI)

    Palmer, R.

    2009-10-19

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

  13. Strongly interacting dynamics and the search for new physics at the LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Appelquist, T.; Brower, R. C.; Fleming, G. T.; Hasenfratz, A.; Jin, X. Y.; Kiskis, J.; Neil, E. T.; Osborn, J. C.; Rebbi, C.; Rinaldi, E.; et al

    2016-06-21

    We present results for the spectrum of a strongly interacting SU(3) gauge theory with Nf = 8 light fermions in the fundamental representation. Carrying out nonperturbative lattice calculations at the lightest masses and largest volumes considered to date, we confirm the existence of a remarkably light singlet scalar particle. We explore the rich resonance spectrum of the 8-flavor theory in the context of the search for new physics beyond the standard model at the Large Hadron Collider (LHC). Lastly, connecting our results to models of dynamical electroweak symmetry breaking, we estimate the vector resonance mass to be about 2 TeVmore » with a width of roughly 450 GeV, and predict additional resonances with masses below ~3 TeV.« less

  14. Early physics with the ATLAS and CMS detectors at the LHC

    SciTech Connect (OSTI)

    Holzner, A. G.

    2008-08-29

    The Large Hadron Collider (LHC) at CERN in Geneva (Switzerland) will go into operation in the coming months and will soon enable us to analyse the highest energy collisions ever produced at an accelerator. With a design integrated luminosity of up to 100 fb{sup -1} per year and a centre-of-mass energy of 14 TeV it will not only allow us to probe the Standard Model beyond the TeV scale but also search for new phenomena such as the Higgs boson, supersymmetric particles, extra spatial dimensions etc. This article summarises a few selected analyses which are foreseen to be performed with the first 0.01 to 1 fb{sup -1}.

  15. Operational results from the LHC luminosity monitors

    SciTech Connect (OSTI)

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

    2011-03-28

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

  16. QCD and Hadron Physics

    SciTech Connect (OSTI)

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

    2015-02-26

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

  17. Hadron interactions

    SciTech Connect (OSTI)

    K. Orginos

    2011-12-01

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

  18. Development of MQXF: The Nb3Sn low-β quadrupole for the HiLumi LHC

    SciTech Connect (OSTI)

    Ferracin, P.; G. Ambrosio; Anerella, M.; Ballarino, A.; Bajas, H.; Bajko, M.; Bordini, B.; Bossert, R.; Cheng, D. W.; Dietderich, D. R.; Chlachidze, G.; Cooley, L.; Felice, H.; Ghosh, A.; Hafalia, R.; Holik, E.; Bermudez, S. Izquierdo; Fessia, P.; Grosclaude, P.; Guinchard, M.; Juchno, M.; Krave, S.; Lackner, F.; Marchevsky, M.; Marinozzi, V.; Nobrega, F.; Oberli, L.; Pan, H.; Perez, J. C.; Prin, H.; Rysti, J.; Rochepault, E.; Sabbi, G.; Salmi, T.; Schmalzle, J.; Sorbi, M.; Tavares, S. Sequeira; Todesco, E.; Wanderer, P.; Wang, X.; Yu, M.

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating at magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. Lastly, this paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.

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

    SciTech Connect (OSTI)

    Catastini, Pierluigi; /Pisa U. /INFN, Pisa

    2006-05-01

    The latest results for the B Hadron sector at the Tevatron Collider are summarized. The properties of B hadrons can be precisely measured at the Tevatron. In particularly they will focus on the masses and lifetimes. The new Tevatron results for the CP violation in B Hadrons are also discussed.

  20. Tevatron instrumentation: boosting collider performance

    SciTech Connect (OSTI)

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

    2006-05-01

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

  1. hhjj production at the LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dolan, Matthew J.; Englert, Christoph; Greiner, Nicolas; Nordstrom, Karl; Spannowsky, Michael

    2015-08-25

    The search for di-Higgs production at the LHC in order to set limits on the Higgs trilinear coupling and constraints on new physics is one of the main motivations for the LHC high-luminosity phase. Recent experimental analyses suggest that such analyses will only be successful if information from a range of channels is included. We therefore investigate di-Higgs production in association with two hadronic jets and give a detailed discussion of both the gluon- and the weak boson-fusion (WBF) contributions, with a particular emphasis on the phenomenology with modified Higgs trilinear and quartic gauge couplings. We perform a detailed investigationmore » of the full hadronic final state and find that hhjj production should add sensitivity to a di-Higgs search combination at the HL-LHC with 3 ab-1. Since the WBF and GF contributions are sensitive to different sources of physics beyond the Standard Model, we devise search strategies to disentangle and isolate these production modes. In addition, while gluon fusion remains non-negligible in WBF-type selections, sizeable new physics contributions to the latter can still be constrained. As an example of the latter point we investigate the sensitivity that can be obtained for a measurement of the quartic Higgs–gauge boson couplings.« less

  2. Muon Colliders: The Next Frontier

    ScienceCinema (OSTI)

    Tourun, Yagmur [Illinois Institute of Technology, Chicago, Illinois, United States

    2010-01-08

    Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

  3. Is Particle Physics Ready for the LHC

    ScienceCinema (OSTI)

    Lykken, Joseph

    2009-09-01

    The advent of the Large Hadron Collider in 2007 entails daunting challenges to particle physicists. The first set of challenges will arise from trying to separate new physics from old. The second set of challenges will come in trying to interpret the new discoveries. I will describe a few of the scariest examples.

  4. R-parity violating effects in top quark flavor-changing neutral-current production at LHC

    SciTech Connect (OSTI)

    Cao Junjie; Heng Zhaoxia; Yang Jinmin; Wu Lei

    2009-03-01

    In the minimal supersymmetric model the R-parity violating top quark interactions, which are so far weakly constrained, can induce various flavor-changing neutral-current (FCNC) productions for the top quark at the large hadron collider (LHC). In this work we assume the presence of the B-violating couplings and examine their contributions to the FCNC productions proceeding through the parton processes cg{yields}t, gg{yields}tc, cg{yields}t{gamma}, cg{yields}tZ and cg{yields}th. We find that all these processes can be greatly enhanced relative to the R-parity preserving predictions. In the parameter space allowed by current experiments, all the production channels except cg{yields}th can reach the 3{sigma} sensitivity, in contrast to the R-parity preserving case in which only cg{yields}t can reach the 3{sigma} sensitivity.

  5. Supersymmetry Breaking, Gauge Mediation, and the LHC

    SciTech Connect (OSTI)

    Shih, David

    2015-04-14

    Gauge mediated SUSY breaking (GMSB) is a promising class of supersymmetric models that automatically satisfies the precision constraints. Prior work of Meade, Seiberg and Shih in 2008 established the full, model-independent parameter space of GMSB, which they called "General Gauge Mediation" (GGM). During the first half of 2010-2015, Shih and his collaborators thoroughly explored the parameter space of GGM and established many well-motivated benchmark models for use by the experimentalists at the LHC. Through their work, the current constraints on GGM from LEP, the Tevatron and the LHC were fully elucidated, together with the possible collider signatures of GMSB at the LHC. This ensured that the full discovery potential for GGM could be completely realized at the LHC.

  6. Progress with high-field superconducting magnets for high-energy colliders

    SciTech Connect (OSTI)

    Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

    2015-10-01

    One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ~10 T at 1.9 K. Fields above 10 T became possible with the use of Nb$_3$Sn superconductors. Nb$_3$Sn accelerator magnets can provide operating fields up to ~15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. Furthermore, this review discusses the status and main results of Nb$_3$Sn accelerator magnet research and development and work toward 20-T magnets.

  7. Progress with high-field superconducting magnets for high-energy colliders

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

    2015-10-01

    One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ~10 T at 1.9 K. Fields above 10 T became possible with the use of Nb$_3$Sn superconductors.more » Nb$_3$Sn accelerator magnets can provide operating fields up to ~15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. Furthermore, this review discusses the status and main results of Nb$_3$Sn accelerator magnet research and development and work toward 20-T magnets.« less

  8. Muon Muon Collider: Feasibility Study

    SciTech Connect (OSTI)

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

    2012-04-05

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

  9. LARP Long Quadrupole: A "Long" Step Toward an LHC

    ScienceCinema (OSTI)

    Giorgio Ambrosio

    2010-01-08

    The beginning of the development of Nb3Sn magnets for particle accelerators goes back to the 1960?s. But only very recently has this development begun to face the challenges of fabricating Nb3Sn magnets which can meet the requirements of modern particle accelerators. LARP (the LHC Accelerator Research Program) is leading this effort focusing on long models of the Interaction Region quadrupoles for a possible luminosity upgrade of the Large Hadron Collider. A major milestone in this development is to test, by the end of 2009, 4m-long quadrupole models, which will be the first Nb3Sn accelerator-type magnets approaching the length of real accelerator magnets. The Long Quadrupoles (LQ) are ?Proof-of-Principle? magnets which are to demonstrate that Nb3Sn technology is sufficiently mature for use in high energy particle accelerators. Their design is based on the LARP Technological Quadrupole (TQ) models, under development at FNAL and LBNL, which have design gradients higher than 200 T/m and an aperture of 90 mm. Several challenges must be addressed for the successful fabrication of long Nb3Sn coils and magnets. These challenges and the solutions adopted will be presented together with the main features of the LQ magnets. Several R&D lines are participating to this effort and their contributions will be also presented.

  10. High precision predictions for exclusive VH production at the LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Ye; Liu, Xiaohui

    2014-06-04

    We present a resummation-improved prediction for pp → VH + 0 jets at the Large Hadron Collider. We focus on highly-boosted final states in the presence of jet veto to suppress the tt¯ background. In this case, conventional fixed-order calculations are plagued by the existence of large Sudakov logarithms αnslogm(pvetoT/Q) for Q ~ mV + mH which lead to unreliable predictions as well as large theoretical uncertainties, and thus limit the accuracy when comparing experimental measurements to the Standard Model. In this work, we show that the resummation of Sudakov logarithms beyond the next-to-next-to-leading-log accuracy, combined with the next-to-next-to-leading ordermore » calculation, reduces the scale uncertainty and stabilizes the perturbative expansion in the region where the vector bosons carry large transverse momentum. Thus, our result improves the precision with which Higgs properties can be determined from LHC measurements using boosted Higgs techniques.« less

  11. Development of MQXF: The Nb3Sn Low- $\\beta$ Quadrupole for the HiLumi LHC

    SciTech Connect (OSTI)

    Ferracin, P.; et al.

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating at magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. This paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.

  12. Development of MQXF: The Nb3Sn Low- $$\\beta$$ Quadrupole for the HiLumi LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ferracin, P.; et al.

    2015-12-18

    The High Luminosity (HiLumi) Large Hadron Collider (LHC) project has, as the main objective, to increase the LHC peak luminosity by a factor five and the integrated luminosity by a factor ten. This goal will be achieved mainly with a new interaction region layout, which will allow a stronger focusing of the colliding beams. The target will be to reduce the beam size in the interaction points by a factor of two, which requires doubling the aperture of the low-β (or inner triplet) quadrupole magnets. The use of Nb3Sn superconducting material and, as a result, the possibility of operating atmore » magnetic field levels in the windings higher than 11 T will limit the increase in length of these quadrupoles, called MQXF, to acceptable levels. After the initial design phase, where the key parameters were chosen and the magnet's conceptual design finalized, the MQXF project, a joint effort between the U.S. LHC Accelerator Research Program and the Conseil Europeen pour la Recherche Nucleaire (CERN), has now entered the construction and test phase of the short models. Concurrently, the preparation for the development of the full-length prototypes has been initiated. This paper will provide an overview of the project status, describing and reporting on the performance of the superconducting material, the lessons learnt during the fabrication of superconducting coils and support structure, and the fine tuning of the magnet design in view of the start of the prototyping phase.« less

  13. LHC Computing

    SciTech Connect (OSTI)

    Lincoln, Don

    2015-07-28

    The LHC is the world’s highest energy particle accelerator and scientists use it to record an unprecedented amount of data. This data is recorded in electronic format and it requires an enormous computational infrastructure to convert the raw data into conclusions about the fundamental rules that govern matter. In this video, Fermilab’s Dr. Don Lincoln gives us a sense of just how much data is involved and the incredible computer resources that makes it all possible.

  14. Interim report on the Global Design Effort Global International Linear Collider (ILC) R&D

    SciTech Connect (OSTI)

    Harrison, M.

    2011-04-30

    The International Linear Collider: A Technical Progress Report marks the halfway point towards the Global Design Effort fulfilling its mandate to follow up the ILC Reference Design Report with a more optimised Technical Design Report (TDR) by the end of 2012. The TDR will be based on much of the work reported here and will contain all the elements needed to propose the ILC to collaborating governments, including a technical design and implementation plan that are realistic and have been better optimised for performance, cost and risk. We are on track to develop detailed plans for the ILC, such that once results from the Large Hadron Collider (LHC) at CERN establish the main science goals and parameters of the next machine, we will be in good position to make a strong proposal for this new major global project in particle physics. The two overriding issues for the ILC R&D programme are to demonstrate that the technical requirements for the accelerator are achievable with practical technologies, and that the ambitious physics goals can be addressed by realistic ILC detectors. This GDE interim report documents the impressive progress on the accelerator technologies that can make the ILC a reality. It highlights results of the technological demonstrations that are giving the community increased confidence that we will be ready to proceed with an ILC project following the TDR. The companion detector and physics report document likewise demonstrates how detector designs can meet the ambitious and detailed physics goals set out by the ILC Steering Committee. LHC results will likely affect the requirements for the machine design and the detectors, and we are monitoring that very closely, intending to adapt our design as those results become available.

  15. Construction and tests of a model of the LHC superconducting corrector magnet MDSBV

    SciTech Connect (OSTI)

    Ijspeert, A.; Perin, R. ); Baynham, E.; Clee, P.; Coombs, R.; Evans, D. ); Begg, M.; Landgrebe, D. )

    1992-01-01

    A full-scale model of the 1.25 m long MDSBV (Magnet Decapole Sextupole Bending Vertical) correction magnet for the Large Hadron Collider (LHC) has been constructed and is currently being tested. The model contains the desired dipole and sextupole but not the decapole which was decided upon later. The magnet was built in a very compact way by placing the dipole coil around the sextupole coil. The two coils were vacuum impregnated and prestressed by shrink-fitted aluminum rings. The design took into account the high positional accuracy requirements for the coils and incorporated manufacturing techniques which are compatible with mass production methods, as approximately 800 of these magnets will be required for the LHC. The model is being tested in liquid helium at the temperature of 4.2 K and will be tested later at 2.0 K. The paper describes the construction, the experience gained during assembly, the test conditions and gives the first test-results.

  16. Hadron physics

    SciTech Connect (OSTI)

    Bunce, G.

    1984-05-30

    Is all hadronic physics ultimately describable by QCD. Certainly, many disparate phenomena can be understood within the QCD framework. Also certainly, there are important questions which are open, both theoretically (little guidance, as yet) and experimentally, regarding confinement. Are there dibaryons, baryonium, glueballs. In addition, there are experimental results which at present do not have an explanation. This talk, after a short section on QCD successes and difficulties, will emphasize two experimental topics which have recent results - glueball spectroscopy and exclusive reactions at large momentum transfer. Both are experimentally accessible in the AGS/LAMPF II/AGS II/TRIUMF II/SIN II energy domain.

  17. Proceedings, High-Precision $\\alpha_s$ Measurements from LHC to FCC-ee

    SciTech Connect (OSTI)

    d'Enterria, David; Skands, Peter Z.

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in $e^+e^-$ collisions at the Future Circular Collider (FCC-ee) with $\\cal{O}$(1--100 ab$^{-1}$) integrated luminosities yielding 10$^{12}$ Z bosons and jets, and 10$^{8}$ W bosons and $\\tau$ leptons, are thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong coupling world-average value, $\\alpha_s(m_Z)$ = 0.1177 $\\pm$ 0.0013, is about 1\\%. Some participants believed this may be reduced by a factor of three in the near future by including novel high-precision observables, although this opinion was not universally shared. At the FCC-ee facility, a factor of ten reduction in the $\\alpha_s$ uncertainty should be possible, mostly thanks to the huge Z and W data samples available.

  18. The Next Linear Collider: NLC2001

    SciTech Connect (OSTI)

    D. Burke et al.

    2002-01-14

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

  19. LHC Physics Potential vs. Energy: Considerations for the 2011 Run

    SciTech Connect (OSTI)

    Quigg, Chris; /Fermilab /CERN

    2011-02-01

    Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I quantify the advantage of increasing the beam energy from 3.5 TeV to 4 TeV. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u {bar d}, qq, and gq interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes. This note extends the analysis presented in Ref. [1]. Full-size figures are available as pdf files at lutece.fnal.gov/PartonLum11/.

  20. Second-generation coil design of the Nb3Sn low-β quadrupole for the high luminosity LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bermudez, S. Izquierdo; Ambrosio, G.; Ballarino, A.; Cavanna, E.; Bossert, R.; Cheng, D.; Dietderich, D.; Ferracin, P.; Ghosh, A.; Hagen, P.; et al

    2016-01-18

    As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build a 150 mm aperture Nb3Sn quadrupole for the LHC interaction regions. A first series of 1.5 m long coils were fabricated and assembled in a first short model. A detailed visual inspection of the coils was carried out to investigate cable dimensional changes during heat treatment and the position of the windings in the coil straight section and in the end region. The analyses allow identifying a set of design changes which, combined with a finemore » tune of the cable geometry and a field quality optimization, were implemented in a new, second-generation, coil design. In this study, we review the main characteristics of the first generation coils, describe the modification in coil lay-out, and discuss their impact on parts design and magnet analysis.« less

  1. Assembly Tests of the First Nb 3 Sn Low-Beta Quadrupole Short Model for the Hi-Lumi LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pan, H.; Felice, H.; Cheng, D. W.; Anderssen, E.; Ambrosio, G.; Perez, J. C.; Juchno, M.; Ferracin, P.; Prestemon, S. O.

    2016-01-18

    In preparation for the high-luminosity upgrade of the Large Hadron Collider (LHC), the LHC Accelerator Research Program (LARP) in collaboration with CERN is pursuing the development of MQXF: a 150-mm-aperture high-field Nb3Sn quadrupole magnet. Moreover, the development phase starts with the fabrication and test of several short models (1.2-m magnetic length) and will continue with the development of several long prototypes. All of them are mechanically supported using a shell-based support structure, which has been extensively demonstrated on several R&D models within LARP. The first short model MQXFS-AT has been assembled at LBNL with coils fabricated by LARP and CERN.more » In our paper, we summarize the assembly process and show how it relies strongly on experience acquired during the LARP 120-mm-aperture HQ magnet series. We also present comparison between strain gauges data and finite-element model analysis. Finally, we present the implication of the MQXFS-AT experience on the design of the long prototype support structure.« less

  2. LHC detector upgrades

    SciTech Connect (OSTI)

    Dan Green

    2003-09-15

    The LHC detectors are well into their construction phase. The LHC schedule shows first beam to ATLAS and CMS in 2007. Because the LHC accelerator has begun to plan for a ten fold increase in LHC design luminosity (the SLHC or super LHC) it is none too soon to begin to think about the upgrades which will be required of the present LHC detectors. In particular, the tracking systems of ATLAS and CMS will need to be completely rebuilt. Given the time needed to do the R & D, make prototypes, and construct the new detectors and given the accelerator schedule for the SLHC, work needs to begin rather soon.

  3. LHC luminosity upgrade with large Piwinski angle scheme: a recent look

    SciTech Connect (OSTI)

    Bhat, C.M.; Zimmermann, f.; /CERN

    2011-09-01

    Luminosity upgrade at the LHC collider using longitudinally flat bunches in combination with the large crossing angle (large Piwinski angle scheme) is being studied with renewed interest in recent years. By design, the total beam-beam tune shift at the LHC is less than 0.015 for two interaction points together. But the 2010-11 3.5 TeV collider operation and dedicated studies indicated that the beam-beam tune shift is >0.015 per interaction point. In view of this development we have revisited the requirements for the Large Piwinski Angle scheme at the LHC. In this paper we present a new set of parameters and luminosity calculations for the desired upgrade by investigating: (1) current performance of the LHC injectors, (2) e-cloud issues on nearly flat bunches and (3) realistic beam particle distributions from longitudinal beam dynamics simulations. We also make some remarks on the needed upgrades on the LHC injector accelerators.

  4. High precision predictions for exclusive VH production at the LHC

    SciTech Connect (OSTI)

    Li, Ye; Liu, Xiaohui

    2014-06-04

    We present a resummation-improved prediction for pp → VH + 0 jets at the Large Hadron Collider. We focus on highly-boosted final states in the presence of jet veto to suppress the tt¯ background. In this case, conventional fixed-order calculations are plagued by the existence of large Sudakov logarithms αnslogm(pvetoT/Q) for Q ~ mV + mH which lead to unreliable predictions as well as large theoretical uncertainties, and thus limit the accuracy when comparing experimental measurements to the Standard Model. In this work, we show that the resummation of Sudakov logarithms beyond the next-to-next-to-leading-log accuracy, combined with the next-to-next-to-leading order calculation, reduces the scale uncertainty and stabilizes the perturbative expansion in the region where the vector bosons carry large transverse momentum. Thus, our result improves the precision with which Higgs properties can be determined from LHC measurements using boosted Higgs techniques.

  5. New Perspectives for QCD Physics at the LHC

    SciTech Connect (OSTI)

    Brodsky, Stanley J.; /SLAC /Stanford U. /Southern Denmark U., CP3-Origins

    2011-02-07

    I review a number of topics where conventional wisdom relevant to hadron physics at the LHC has been challenged. For example, the initial-state and final-state interactions of the quarks and gluons entering perturbative QCD hard-scattering subprocesses lead to the breakdown of traditional concepts of factorization and universality for transverse-momentum-dependent observables at leading twist. These soft-gluon rescattering effect produce single-spin asymmetries, the breakdown of the Lam-Tung relation in Drell-Yan reactions, as well as diffractive deep inelastic scattering, The antishadowing of nuclear structure functions is predicted to depend on the flavor quantum numbers of each quark and antiquark. Isolated hadrons can be produced at large transverse momentum directly within a hard higher-twist QCD subprocess, rather than from jet fragmentation, even at the LHC. Such 'direct' processes can explain the observed deviations from pQCD predictions of the power-law fall-off of inclusive hadron cross sections as well as the 'baryon anomaly' seen in high-centrality heavy-ion collisions at RHIC. The intrinsic charm contribution to the proton structure function at high x can explain the large rate for high p{sub T} photon plus charm-jet events observed at the Tevatron and imply a large production rate for charm and bottom jets at high p{sub T} at the LHC, as well as a novel mechanism for Higgs and Z{sup 0} production at high x{sub F}. The light-front wavefunctions derived in AdS/QCD can be used to calculate jet hadronization at the amplitude level. The elimination of the renormalization scale ambiguity for the QCD coupling using the scheme-independent BLM method will increase the sensitivity of searches for new physics at the LHC. The implications of 'in-hadron condensates' for the QCD contribution to the cosmological constant are also discussed.

  6. First Beam for Large Hadron Collider | Department of Energy

    Office of Environmental Management (EM)

    ... India, Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status. Media contact(s): National Science ...

  7. Non-Large Hadron Collider Physics Program at CERN (Conference...

    Office of Scientific and Technical Information (OSTI)

    at CERN (AD) is looking at antimatter production and trapping. First trapped anti-hydrogen were reported in 2010. Interdisciplinary team is working in the CLOUD experiment,...

  8. ALCF helps tackle the Large Hadron Collider's big data challenge...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Facility (ALCF), a DOE Office of Science User Facility. "Simulating the collisions ... Ultimately, this effort is helping to accelerate the science that depends on these ...

  9. Hadron colliders working group report (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    A paper copy of this document is also available for sale to the public from the National Technical Information Service, Springfield, VA at www.ntis.gov. Authors: Peggs, Stephen G. ...

  10. A Large Hadron Electron Collider at CERN (Journal Article) |...

    Office of Scientific and Technical Information (OSTI)

    M. ; Brookhaven ; Barber, D. ; Daresbury DESY Liverpool U. ; Bartels, J. ; Hamburg, Tech. U. ; Behnke, O. ; DESY ; Behr, J. ; DESY ; Belyaev, A.S. ; Rutherford...

  11. Jet vetoes for Higgs boson production at future hadron colliders...

    Office of Scientific and Technical Information (OSTI)

    Publisher: American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English Word Cloud More Like This Free Publicly Accessible Full Text ...

  12. Dark matter signals in dilepton production at hadron colliders...

    Office of Scientific and Technical Information (OSTI)

    Journal Volume: 91; Journal Issue: 11; Journal ID: ISSN 1550-7998 Publisher: American Physical Society Sponsoring Org: USDOE Country of Publication: United States Language: English ...

  13. Ion Desorption Stability in Superconducting High Energy Physics Proton Colliders

    SciTech Connect (OSTI)

    Turner, W.C.

    1995-05-29

    In this paper we extend our previous analysis of cold beam tube vacuum in a superconducting proton collider to include ion desorption in addition to thermal desorption and synchrotron radiation induced photodesorption. The new ion desorption terms introduce the possibility of vacuum instability. This is similar to the classical room temperature case but now modified by the inclusion of ion desorption coefficients for cryosorbed (physisorbed) molecules which can greatly exceed the coefficients for tightly bound molecules. The sojourn time concept for physisorbed H{sub 2} is generalized to include photodesorption and ion desorption as well as the usually considered thermal desorption. The ion desorption rate is density dependent and divergent so at the onset of instability the sojourn time goes to zero. Experimental data are used to evaluate the H{sub 2} sojourn time for the conditions of the Large Hadron Collider (LHC) and the situation is found to be stable. The sojourn time is dominated by photodesorption for surface density s(H{sub 2}) less than a monolayer and by thermal deposition for s(H{sub 2}) greater than a monolayer. For a few percent of a monolayer, characteristic of a beam screen, the photodesorption rate exceeds ion desorption rate by more than two orders of magnitude. The photodesorption rate corresponds to a sojourn time of approximately 100 sec. The paper next turns to the evaluation of stability margins and inclusion of gases heavier than H{sub 2} (CO, CO{sub 2} and CH{sub 4}), where ion desorption introduces coupling between molecular species. Stability conditions are worked out for a simple cold beam tube, a cold beam tube pumped from the ends and a cold beam tube with a co-axial perforated beam screen. In each case a simple inequality for stability of a single component is replaced by a determinant that must be greater than zero for a gas mixture. The connection with the general theory of feedback stability is made and it is shown that the gains

  14. SEARCHING FOR QUARK - GLUON PLASMA (QGP) BUBBLE EFFECTS AT RHIC / LHC.

    SciTech Connect (OSTI)

    LINDENBAUM,S.J.; LONGACRE,R.S.; KRAMER,M.

    2003-03-01

    Since the early eighties, we have shared with Leon Van Hove the view that if a QGP were produced in high energy heavy ion colliders that its hadronization products would likely come from small localized in phase space bubbles of plasma. In previous papers we have discussed the case where one to at most a few separated bubbles were produced. In this paper we develop a model based on HIJING to which we added a ring of adjoining multi bubble production, which we believe is a higher cross-section process which dominates the near central rapidity region. We have performed simulations which were designed to be tested by the expected first to become available suitable test data, namely the forthcoming RHIC STAR detector data on 65Gev/n Au colliding with 65 Gev/n Au. We took into account background effects and resonance effects so that a direct comparison with the data, and detailed test of these ideas could be made in the near future. Subsequently 100 Gev/n Au on 100 Gev/n Au forthcoming data can be tested, and of course these techniques, suitably modified by experience can be applied to it and eventually to LHC. We concluded that two charged particle correlations versus the azimuthal angle {Delta}{phi}; vs the opening angle, and vs psuedorapidity {eta}, can detect important bubble signals in the expected background, with statistical significances of 5 - 20{sigma}, provided the reasonably conservative assumptions we have made for bubble production occur. We also predicted charge fluctuation suppressions which increase with the bubble signal, and range from {approx} 5% to 27% in the simulations performed. We demonstrated reasonably that in our model, these charge suppression effects would not significantly be affected by resonances.

  15. High Energy Colliders as Tools to Understand the Early Universe

    SciTech Connect (OSTI)

    Tait, Tim

    2008-08-16

    Cosmological observations have reached a new era of precision, and reveal many interesting and puzzling features of the Universe. I will briefly review two of the most exciting mysteries: the nature of the dark components of the Universe, and the origin of the asymmetry between matter and anti-matter. I will argue that our best hope of unraveling these questions will need to combine information from the heavens with measurements in the lab at high energy particle accelerators. The end of run II of the Tevatron, the up-coming Large Hadron Collider and proposed International Linear Collider all have great potential to help us answer these questions in the near future.

  16. Detectors for Linear Colliders: Physics Requirements and Experimental Conditions (1/4)

    ScienceCinema (OSTI)

    None

    2011-10-06

    How is the anticipated physics program of a future e+e- collider shaping the R&D; for new detectors in collider particle physics ? This presentation will review the main physics requirements and experimental conditions comparing to LHC and LEP. In particular, I shall discuss how e+e- experimentation is expected to change moving from LEP-2 up to multi-TeV energies.

  17. Proton-antiproton collider physics

    SciTech Connect (OSTI)

    Shochet, M.J.

    1995-07-01

    The 9th {anti p}p Workshop was held in Tsukuba, Japan in October, 1993. A number of important issues remained after that meeting: Does QCD adequately describe the large cross section observed by CDF for {gamma} production below 30 GeV? Do the CDF and D0 b-production cross sections agree? Will the Tevatron live up to its billing as a world-class b-physics facility? How small will the uncertainty in the W mass be? Is there anything beyond the Minimal Standard Model? And finally, where is the top quark? Presentations at this workshop addressed all of these issues. Most of them are now resolved, but new questions have arisen. This summary focuses on the experimental results presented at the meeting by CDF and D0 physicists. Reviews of LEP and HERA results, future plans for hadron colliders and their experiments, as well as important theoretical presentations are summarized elsewhere in this volume. Section 1 reviews physics beyond the Minimal Standard Model. Issues in b and c physics are addressed in section 3. Section 4 focuses on the top quark. Electroweak physics is reviewed in section 5, followed by QCD studies in section 6. Conclusions are drawn in section 7.

  18. Nonglobal correlations in collider physics

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moult, Ian; Larkoski, Andrew J.

    2016-01-13

    Despite their importance for precision QCD calculations, correlations between in- and out-of-jet regions of phase space have never directly been observed. These so-called non-global effects are present generically whenever a collider physics measurement is not explicitly dependent on radiation throughout the entire phase space. In this paper, we introduce a novel procedure based on mutual information, which allows us to isolate these non-global correlations between measurements made in different regions of phase space. We study this procedure both analytically and in Monte Carlo simulations in the context of observables measured on hadronic final states produced in e+e- collisions, though itmore » is more widely applicable.The procedure exploits the sensitivity of soft radiation at large angles to non-global correlations, and we calculate these correlations through next-to-leading logarithmic accuracy. The bulk of these non-global correlations are found to be described in Monte Carlo simulation. They increase by the inclusion of non-perturbative effects, which we show can be incorporated in our calculation through the use of a model shape function. As a result, this procedure illuminates the source of non-global correlations and has connections more broadly to fundamental quantities in quantum field theory.« less

  19. Accelerator physics in ERL based polarized electron ion collider

    SciTech Connect (OSTI)

    Hao, Yue

    2015-05-03

    This talk will present the current accelerator physics challenges and solutions in designing ERL-based polarized electron-hadron colliders, and illustrate them with examples from eRHIC and LHeC designs. These challenges include multi-pass ERL design, highly HOM-damped SRF linacs, cost effective FFAG arcs, suppression of kink instability due to beam-beam effect, and control of ion accumulation and fast ion instabilities.

  20. Researchers create enormous simulation of proton collisions ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    events with transverse momentum of jets above 2.7 TeV. Such an event sample is expected to be produced by a future hadron collider that surpasses the Large Hadron Collider (LHC). ...

  1. Shooting string holography of jet quenching at RHIC and LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ficnar, Andrej; Gubser, Steven S.; Gyulassy, Miklos

    2014-10-13

    We derive a new formula for jet energy loss using finite endpoint momentum shooting strings initial conditions in SYM plasmas to overcome the difficulties of previous falling string holographic scenarios. We apply the new formula to compute the nuclear modification factor RAA and the elliptic flow parameter v2 of light hadrons at RHIC and LHC. We show furthermore that GaussBonnet quadratic curvature corrections to the AdS5 geometry improve the agreement with the recent data.

  2. Erratum to: Constraining couplings of top quarks to the Z boson in $$ t\\overline{t} $$ + Z production at the LHC

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Röntsch, Raoul; Schulze, Markus

    2015-09-21

    We study top quark pair production in association with a Z boson at the Large Hadron Collider (LHC) and investigate the prospects of measuring the couplings of top quarks to the Z boson. To date these couplings have not been constrained in direct measurements. Such a determination will be possible for the first time at the LHC. Our calculation improves previous coupling studies through the inclusion of next-to-leading order (NLO) QCD corrections in production and decays of all unstable particles. We treat top quarks in the narrow-width approximation and retain all NLO spin correlations. To determine the sensitivity of amore » coupling measurement we perform a binned log-likelihood ratio test based on normalization and shape information of the angle between the leptons from the Z boson decay. The obtained limits account for statistical uncertainties as well as leading theoretical systematics from residual scale dependence and parton distribution functions. We use current CMS data to place the first direct constraints on the ttbZ couplings. We also consider the upcoming high-energy LHC run and find that with 300 inverse fb of data at an energy of 13 TeV the vector and axial ttbZ couplings can be constrained at the 95% confidence level to C_V=0.24^{+0.39}_{-0.85} and C_A=-0.60^{+0.14}_{-0.18}, where the central values are the Standard Model predictions. This is a reduction of uncertainties by 25% and 42%, respectively, compared to an analysis based on leading-order predictions. We also translate these results into limits on dimension-six operators contributing to the ttbZ interactions beyond the Standard Model.« less

  3. Spin and diffractive physics with a fixed-target experiment at the LHC (AFTER-LHC)

    SciTech Connect (OSTI)

    Lorce, C.; Chambert, V.; Didelez, J. P.; Genolini, B.; Hadjidakis, C.; Lansberg, J. P.; Rosier, P.; Brodsky, S. J.; Ferreiro, E. G.; Fleuret, F.

    2013-04-15

    We report on the spin and diffractive physics at a future multi-purpose f xed-target experiment with proton and lead LHC beams extracted by a bent crystal. The LHC multi-TeV beams allow for the most energetic f xed-target experiments ever performed, opening new domains of particle and nuclear physics and complementing that of collider physics, in particular that of RHIC and the EIC projects. The luminosity achievable with AFTER using typical targets would surpass that of RHIC by more than 3 orders of magnitude. The f xed-target mode has the advantage to allow for measurements of single-spin asymmetries with polarized target as well as of single-diffractive processes in the target region.

  4. DOE Issues Request for Proposals Seeking a Contractor to Manage...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    the Host Laboratory for U.S. participation in the Large Hadron Collider (LHC) Compact Muon Solenoid detector, construction of certain LHC accelerator components, and the U.S. LHC...

  5. Novel QCD Phenomena at the LHC: The Ridge, Digluon-Initiated Subprocesses, Direct Reactions, Non-Universal Antishadowing, and Forward Higgs Production

    SciTech Connect (OSTI)

    Brodsky, Stanley J.; /SLAC

    2014-10-03

    I discuss a number of novel tests of QCD at the LHC, measurements which can illuminate fundamental features of hadron physics. I also review the “Principle of Maximum Conformality” (PMC) which systematically sets the renormalization scale order-by-order in pQCD, eliminating an unnecessary theoretical uncertainty. The PMC allows LHC experiments to test QCD much more precisely, and the sensitivity of LHC measurements to physics beyond the Standard Model is increased.

  6. Topics in Hadronic Physics

    SciTech Connect (OSTI)

    Alfred Tang

    2002-08-01

    Hadron production cross sections are calculated in the perturbative QCD frame work. Parton distribution functions are obtained from a strip-soliton model. The fragmentation functions are derived from the Lund model of string breaking.

  7. The Muon Collider

    SciTech Connect (OSTI)

    Zisman, Michael S.

    2011-01-05

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  8. The Muon Collider

    SciTech Connect (OSTI)

    Zisman, Michael S

    2010-05-17

    We describe the scientific motivation for a new type of accelerator, the muon collider. This accelerator would permit an energy-frontier scientific program and yet would fit on the site of an existing laboratory. Such a device is quite challenging, and requires a substantial R&D program. After describing the ingredients of the facility, the ongoing R&D activities of the Muon Accelerator Program are discussed. A possible U.S. scenario that could lead to a muon collider at Fermilab is briefly mentioned.

  9. ERL BASED ELECTRON-ION COLLIDER ERHIC.

    SciTech Connect (OSTI)

    LITVINENKO,V.N.; BEN-ZVI,I.; ANDERSON,D.; ET AL.

    2005-05-16

    In this paper we describe eRHIC design based on the RHIC hadron rings and 10-to-20 GeV energy recovery electron linac. RHIC requires a very large tunability range for c.m. energies while maintaining very high luminosity up to 10{sup 34} cm{sup -2} s{sup -1} per nucleon. The designs of this future polarized electron-hadron collider, eRHIC, based on a high current super-conducting energy-recovery linac (ERL) with energy of electrons up to 20 GeV, have a number of specific requirements on the ERL optics. Two of the most attractive features of this scheme are full spin transparency of the ERL at all operational energies and the capability to support up to four interaction points. We present two main layouts of the eRHIC, the expected beam and luminosity parameter, and discuss the potential limitation of its performance. Two of the most attractive features of this scheme are full spin transparency of the ERL at all operational energies and the capability to support up to four interaction points. We present two main layouts of the eRHIC, the expected beam and luminosity parameter, and discuss the potential limitation of its performance.

  10. Symmetry restored in dibosons at the LHC?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Brehmer, Johann; Hewett, JoAnne; Kopp, Joachim; Rizzo, Thomas; Tattersall, Jamie

    2015-10-28

    A number of LHC resonance search channels display an excess in the invariant mass region of 1.8–2.0 TeV. Among them is a 3.4σ excess in the fully hadronic decay of a pair of Standard Model electroweak gauge bosons, in addition to potential signals in the HW and dijet final states. We perform a model-independent cross-section fit to the results of all ATLAS and CMS searches sensitive to these final states. We then interpret these results in the context of the Left-Right Symmetric Model, based on the extended gauge group SU(2)L × SU(2)R × U(1)', and show that a heavy right-handedmore » gauge boson WR can naturally explain the current measurements with just a single coupling gR ~ 0.4. Thus, we discuss a possible connection to dark matter.« less

  11. The Stanford Linear Collider

    SciTech Connect (OSTI)

    Emma, P.

    1995-06-01

    The Stanford Linear Collider (SLC) is the first and only high-energy e{sup +}e{sup {minus}} linear collider in the world. Its most remarkable features are high intensity, submicron sized, polarized (e{sup {minus}}) beams at a single interaction point. The main challenges posed by these unique characteristics include machine-wide emittance preservation, consistent high intensity operation, polarized electron production and transport, and the achievement of a high degree of beam stability on all time scales. In addition to serving as an important machine for the study of Z{sup 0} boson production and decay using polarized beams, the SLC is also an indispensable source of hands-on experience for future linear colliders. Each new year of operation has been highlighted with a marked improvement in performance. The most significant improvements for the 1994-95 run include new low impedance vacuum chambers for the damping rings, an upgrade to the optics and diagnostics of the final focus systems, and a higher degree of polarization from the electron source. As a result, the average luminosity has nearly doubled over the previous year with peaks approaching 10{sup 30} cm{sup {minus}2}s{sup {minus}1} and an 80% electron polarization at the interaction point. These developments as well as the remaining identifiable performance limitations will be discussed.

  12. hhjj production at the LHC

    SciTech Connect (OSTI)

    Dolan, Matthew J.; Englert, Christoph; Greiner, Nicolas; Nordstrom, Karl; Spannowsky, Michael

    2015-08-25

    The search for di-Higgs production at the LHC in order to set limits on the Higgs trilinear coupling and constraints on new physics is one of the main motivations for the LHC high-luminosity phase. Recent experimental analyses suggest that such analyses will only be successful if information from a range of channels is included. We therefore investigate di-Higgs production in association with two hadronic jets and give a detailed discussion of both the gluon- and the weak boson-fusion (WBF) contributions, with a particular emphasis on the phenomenology with modified Higgs trilinear and quartic gauge couplings. We perform a detailed investigation of the full hadronic final state and find that hhjj production should add sensitivity to a di-Higgs search combination at the HL-LHC with 3 ab-1. Since the WBF and GF contributions are sensitive to different sources of physics beyond the Standard Model, we devise search strategies to disentangle and isolate these production modes. In addition, while gluon fusion remains non-negligible in WBF-type selections, sizeable new physics contributions to the latter can still be constrained. As an example of the latter point we investigate the sensitivity that can be obtained for a measurement of the quartic Higgs–gauge boson couplings.

  13. Jet measurements by ALICE at LHC

    SciTech Connect (OSTI)

    Sultanov, Rishat; Collaboration: ALICE Collaboration

    2015-12-15

    Jets are collimated sprays of particles originating from fragmentation of high energy partons produced in a hard collision. They are an important diagnostic tool in studies of the Quark Gluon Plasma (QGP). The modification of the jet fragmentation pattern and its structure is a signature for the influence of hot and dense matter on the parton fragmentation process. Jet measurements in proton-proton collisions provide a baseline for similar measurements in heavy-ion collisions, while studies in proton-nucleus system allow to estimate cold nuclear matter effects. Here we present jet studies in different colliding systems (p–p, p–Pb, Pb–Pb) performed by the ALICE collaboration at LHC energies. Results on jet spectra, cross sections, nuclear modification factors, jet structure and other kinematic observables will be presented.

  14. SC14 DOE Booth Presentations by NERSC, Berkeley Lab Staff

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    giving researchers at American universities and national laboratories the fastest possible access to scientific data from the Large Hadron Collider (LHC) and other sites in Europe. ...

  15. Fermilab | Newsroom | Press Releases | July 4, 2012: Search for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    that scientists, engineers and students from Fermilab have made to the LHC." Search for Higgs boson at Large Hadron Collider reveals new particle Physicists on experiments at the...

  16. Physics at the e⁺e⁻ linear collider

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moortgat-Picka, G.; Kronfeld, A. S.

    2015-08-14

    A comprehensive review of physics at an e⁺e⁻ linear collider in the energy range of √s = 92 GeV–3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focuses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

  17. Physics at the e?e? linear collider

    SciTech Connect (OSTI)

    Moortgat-Picka, G.; Kronfeld, A. S.

    2015-08-14

    A comprehensive review of physics at an e?e? linear collider in the energy range of ?s = 92 GeV3 TeV is presented in view of recent and expected LHC results, experiments from low-energy as well as astroparticle physics. The report focuses in particular on Higgs-boson, top-quark and electroweak precision physics, but also discusses several models of beyond the standard model physics such as supersymmetry, little Higgs models and extra gauge bosons. The connection to cosmology has been analysed as well.

  18. Discovering colorons at the early stage LHC

    SciTech Connect (OSTI)

    Dicus, Duane A.; Kao, Chung; Sayre, Joshua; Nandi, S.

    2011-05-01

    Prospects are investigated for the discovery of massive hypergluons using data from the early runs of the Large Hadron Collider. A center of mass energy of 7 TeV and an integrated luminosity of 1 fb{sup -1} or 5 fb{sup -1} are assumed. A phenomenological Lagrangian is adopted to evaluate the cross section of a pair of colored vector bosons (colorons, {rho}-tilde) decaying into four colored scalar resonances (hyperpions, {pi}-tilde), which then decay into eight gluons. The dominant eight-jet background from the production of 8g, 7g1q, 6g2q, and 5g3q is included. We find an abundance of signal events and that realistic cuts reduce the background enough to establish a 5{sigma} signal for the coloron mass of up to 733 GeV with 1 fb{sup -1} or 833 GeV with 5 fb{sup -1}.

  19. Muon Colliders and Neutrino Factories

    SciTech Connect (OSTI)

    Geer, Steve; /Fermilab

    2009-11-01

    Over the past decade, there has been significant progress in developing the concepts and technologies needed to produce, capture, and accelerate {Omicron}(10{sup 21}) muons per year. These developments have paved the way for a new type of neutrino source (neutrino factory) and a new type of very high energy lepton-antilepton collider (muon collider). This article reviews the motivation, design, and research and development for future neutrino factories and muon colliders.

  20. Muon colliders and neutrino factories

    SciTech Connect (OSTI)

    Geer, S.; /Fermilab

    2010-09-01

    Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture and accelerate {Omicron}(10{sup 21}) muons/year. This development prepares the way for a new type of neutrino source (Neutrino Factory) and a new type of very high energy lepton-antilepton collider (Muon Collider). This article reviews the motivation, design and R&D for Neutrino Factories and Muon Colliders.

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

    SciTech Connect (OSTI)

    Bhat, C.M.; /Fermilab

    2009-05-01

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

  2. Reconstruction and identification of $$\\tau$$ lepton decays to hadrons and $$\

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Khachatryan, Vardan

    2016-01-29

    This paper describes the algorithms used by the CMS experiment to reconstruct and identify τ→ hadrons + vt decays during Run 1 of the LHC. The performance of the algorithms is studied in proton-proton collisions recorded at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The algorithms achieve an identification efficiency of 50–60%, with misidentification rates for quark and gluon jets, electrons, and muons between per mille and per cent levels.

  3. Reconstruction and identification of $\\tau$ lepton decays to hadrons and $\

    SciTech Connect (OSTI)

    Khachatryan, Vardan

    2015-10-27

    This paper describes the algorithms used by the CMS experiment to reconstruct and identify τ→ hadrons + vt decays during Run 1 of the LHC. The performance of the algorithms is studied in proton-proton collisions recorded at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb-1. The algorithms achieve an identification efficiency of 50–60%, with misidentification rates for quark and gluon jets, electrons, and muons between per mille and per cent levels.

  4. Colliding Nuclei at High Energy

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08

    Physicist Peter Steinberg explains what happens when atomic nucleii travelling at close to the speed of light smash together in Brookhaven Lab's Relativistic Heavy Ion Collider (RHIC).

  5. The TESLA superconducting linear collider

    SciTech Connect (OSTI)

    the TESLA Collaboration

    1997-03-01

    This paper summarizes the present status of the studies for a superconducting Linear Collider (TESLA). {copyright} {ital 1997 American Institute of Physics.}

  6. Spin Physics at A Fixed-Target ExpeRiment at the LHC (AFTER@LHC...

    Office of Scientific and Technical Information (OSTI)

    Spin Physics at A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) Citation Details In-Document Search Title: Spin Physics at A Fixed-Target ExpeRiment at the LHC (AFTER@LHC) ...

  7. The PDF4LHC report on PDFs and LHC data: results from Run I and...

    Office of Scientific and Technical Information (OSTI)

    The PDF4LHC report on PDFs and LHC data: results from Run I and preparation for Run II Citation Details In-Document Search Title: The PDF4LHC report on PDFs and LHC data: results...

  8. LHC forward physics

    SciTech Connect (OSTI)

    Cartiglia, N.; Royon, C.

    2015-10-02

    The goal of this report is to give a comprehensive overview of the rich field of forward physics, with a special attention to the topics that can be studied at the LHC. The report starts presenting a selection of the Monte Carlo simulation tools currently available, chapter 2, then enters the rich phenomenology of QCD at low, chapter 3, and high, chapter 4, momentum transfer, while the unique scattering conditions of central exclusive production are analyzed in chapter 5. The last two experimental topics, Cosmic Ray and Heavy Ion physics are presented in the chapter 6 and 7 respectively. Chapter 8 is dedicated to the BFKL dynamics, multiparton interactions, and saturation. The report ends with an overview of the forward detectors at LHC. Each chapter is correlated with a comprehensive bibliography, attempting to provide to the interested reader with a wide opportunity for further studies.

  9. First Measurement of Hadronic Event Shapes in pp Collisions at sqrt(s)=7 TeV

    SciTech Connect (OSTI)

    Khachatryan, Vardan; et al.

    2011-05-01

    Hadronic event shapes have been measured in proton-proton collisions at sqrt(s)=7 TeV, with a data sample collected with the CMS detector at the LHC. The sample corresponds to an integrated luminosity of 3.2 inverse picobarns. Event-shape distributions, corrected for detector response, are compared with five models of QCD multijet production.

  10. Positrons for linear colliders

    SciTech Connect (OSTI)

    Ecklund, S.

    1987-11-01

    The requirements of a positron source for a linear collider are briefly reviewed, followed by methods of positron production and production of photons by electromagnetic cascade showers. Cross sections for the electromagnetic cascade shower processes of positron-electron pair production and Compton scattering are compared. A program used for Monte Carlo analysis of electromagnetic cascades is briefly discussed, and positron distributions obtained from several runs of the program are discussed. Photons from synchrotron radiation and from channeling are also mentioned briefly, as well as positron collection, transverse focusing techniques, and longitudinal capture. Computer ray tracing is then briefly discussed, followed by space-charge effects and thermal heating and stress due to showers. (LEW)

  11. Final Report - The Decline and Fall of the Superconducting Super Collider

    SciTech Connect (OSTI)

    RIORDAN, MICHAEL

    2011-11-29

    In October 1993 the US Congress terminated the Superconducting Super Collider — at the time the largest pure-science project ever attempted, with a total cost estimated to exceed $10 billion. It was a stunning loss for the US highenergy physics community, which until that moment had perched for decades at the pinnacle of American science. Ever since 1993, this once-dominant scientific community has been in gradual decline. With the 2010 startup of research on the CERN Large Hadron Collider and the 2011 shutdown of the Fermilab Tevatron, world leadership in elementary-particle physics has crossed the Atlantic and returned to Europe.

  12. International Linear Collider Technical Design Report - Volume...

    Office of Scientific and Technical Information (OSTI)

    International Linear Collider Technical Design Report - Volume 2: Physics Citation Details In-Document Search Title: International Linear Collider Technical Design Report - Volume ...

  13. Possibility of observing an MSSM charged Higgs boson in association with a W boson at the LHC

    SciTech Connect (OSTI)

    Hashemi, M.

    2011-03-01

    The possibility of observing associated production of the charged Higgs and W boson in the framework of the minimal supersymmetric standard model (MSSM) at LHC is studied. Both leptonic and hadronic decays of the W boson are studied while the charged Higgs boson is considered to decay to a {tau} lepton and a neutrino. Therefore two search categories are defined based on the leptonic and hadronic final states, i.e., l{tau}+E{sub T}{sup miss} and jj{tau}+E{sub T}{sup miss} where l=e or {mu} and j is a light jet from W decay. The discovery chance of the two categories is evaluated at an integrated luminosity of 300 fb{sup -1} at LHC. It is shown that both leptonic and hadronic final states have the chance of discovery at high tan{beta}. Finally 5{sigma} and 3{sigma} contours are provided for both search categories.

  14. SciDAC advances in beam dynamics simulation: from light sources to colliders

    SciTech Connect (OSTI)

    Qiang, Ji; Qiang, J.; Borland, M.; Kabel, A.; Li, R.; Ryne, R.; Stern, E.; Wang, Y.; Wasserman, H.; Zhang, Y.

    2008-06-16

    In this paper, we report on progress that has been made in beam dynamics simulation, from light sources to colliders, during the first year of SciDAC-II accelerator project,"Community Petascale Project for Accelerator Science and Simulation (ComPASS)." Several parallel computational tools for beam dynamics simulation will be described. A number of applications in current and future accelerator facilities, e.g., LCLS, RHIC, Tevatron, LHC, ELIC, are presented.

  15. Monte Carlo event generators for hadron-hadron collisions

    SciTech Connect (OSTI)

    Knowles, I.G.; Protopopescu, S.D.

    1993-06-01

    A brief review of Monte Carlo event generators for simulating hadron-hadron collisions is presented. Particular emphasis is placed on comparisons of the approaches used to describe physics elements and identifying their relative merits and weaknesses. This review summarizes a more detailed report.

  16. Observation of Exclusive Electron-Positron Production in Hadron-Hadron Collisions

    SciTech Connect (OSTI)

    Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.

    2006-11-01

    We present the first observation of exclusive e{sup +}e{sup -} production in hadron-hadron collisions, using p{bar p} collision data at {radical}s = 1.96 TeV taken by the Run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb{sup -1}. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy E{sub T} > 5 GeV and pseudorapidity |{eta}| < 2. With these criteria, 16 events are observed compared to a background expectation of 1.9 {+-} 0.3 events. These events are consistent in cross section and properties with the QED process p{bar p} {yields} p + e{sup +}e{sup -} + {bar p} through two-photon exchange. The measured cross section is 1.6{sub -0.3}{sup +0.5}(stat) {+-} 0.3(syst) pb. This agrees with the theoretical prediction of 1.71 {+-} 0.01 pb.

  17. LHC - a "Why" Facility

    ScienceCinema (OSTI)

    Gordon Kane

    2010-01-08

    The Standard Models of particle physics and cosmology describe the world we see, and how it works, very well. But we want to understand (not just accommodate) much more ? how does the Higgs mechanism work, what is the dark matter, why is the universe matter and not antimatter, why is parity violated, why are the particles (quarks and leptons) what they are, and why are the forces that act on them to make our world what they are, and more. Today is an exciting time to be doing particle physics ? on the experimental side we have data coming from LHC and dark matter experiments that will provide clues to these questions, and on the theoretical side we have a framework (string theory) that addresses all these ?why? questions. LHC data will not qualitatively improve our description ? rather, it may provide the data that will allow us to learn about the dark matter, the Higgs physics, the matter asymmetry, etc, to test underlying theories such as string theory, and begin to answer the ?why? questions. Supersymmetry is the best motivated discovery, and it would also open a window to the underlying theory near the Planck scale.

  18. Forward Physics at the LHC: within and beyond the Standard Model

    SciTech Connect (OSTI)

    D'Enterria, David

    2008-08-29

    We review the detection capabilities in the forward direction of the various LHC experiments together with the associated physics programme. A selection of measurements accessible with near-beam instrumentation in various sectors (and extensions) of the Standard Model (SM) is outlined, including QCD (diffractive and elastic scattering, low-x parton dynamics, hadronic Monte Carlos for cosmic-rays), electroweak processes in {gamma}{gamma} interactions, and Higgs physics (vector-boson-fusion and central exclusive production)

  19. EIS-0138: Superconducting Super Collider

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy developed this EIS to analyze the potential environmental impacts of constructing the Superconducting Super Collider, a large proton accelerator, at each of seven alternative locations.

  20. Momentum space dipole amplitude for DIS and inclusive hadron production

    SciTech Connect (OSTI)

    Basso, E. A.; Gay Ducati, M. B.; De Oliveira, E. G.

    2013-03-25

    We show how the AGBS model, originally developed for deep inelastic scattering applied to HERA data on the proton structure function, can also describe the RHIC data on single inclusive hadron yield for d+Au and p+p collisions through a new simultaneous fit. The single inclusive hadron production is modeled through the color glass condensate, which uses the quark(and gluon) condensate amplitudes in momentum space. The AGBS model is also a momentum space model based on the asymptotic solutions of the BK equation, although a different definition of the Fourier transform is used. This description entirely in transverse momentum of both processes arises for the first time. The small difference between the simultaneous fit and the one for HERA data alone suggests that the AGBS model describes very well both kind of processes and thus emerges as a good tool to investigate the inclusive hadron production data. We use this model for predictions at LHC energies, which agree quite well with available experimental data.

  1. PDF4LHC recommendations for LHC Run II

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Butterworth, Jon; Carrazza, Stefano; Cooper-Sarkar, Amanda; Roeck, Albert De; Feltesse, Joel; Forte, Stefano; Gao, Jun; Glazov, Sasha; Huston, Joey; Kassabov, Zahari; et al

    2016-01-06

    We provide an updated recommendation for the usage of sets of parton distribution functions (PDFs) and the assessment of PDF and PDF+αs uncertainties suitable for applications at the LHC Run II. We review developments since the previous PDF4LHC recommendation, and discuss and compare the new generation of PDFs, which include substantial information from experimental data from the Run I of the LHC. We then propose a new prescription for the combination of a suitable subset of the available PDF sets, which is presented in terms of a single combined PDF set. Lastly, we finally discuss tools which allow for themore » delivery of this combined set in terms of optimized sets of Hessian eigenvectors or Monte Carlo replicas, and their usage, and provide some examples of their application to LHC phenomenology.« less

  2. Looking for intrinsic charm in the forward region at BNL RHIC and CERN LHC

    SciTech Connect (OSTI)

    Goncalves, V.; Ullrich, T.; Navarra, F.S.

    2010-04-21

    The complete understanding of the basic constituents of hadrons and the hadronic dynamics at high energies are two of the main challenges for the theory of strong interactions. In particular, the existence of intrinsic heavy quark components in the hadron wave function must be confirmed (or disproved). In this paper we propose a new mechanism for the production of D-mesons at forward rapidities based on the Color Glass Condensate (CGC) formalism and demonstrate that the resulting transverse momentum spectra are strongly dependent on the behavior of the charm distribution at large Bjorken x. Our results show clearly that the hypothesis of intrinsic charm can be tested in pp and p(d)A collisions at RHIC and LHC.

  3. Symmetry restored in dibosons at the LHC?

    SciTech Connect (OSTI)

    Brehmer, Johann; Hewett, JoAnne; Kopp, Joachim; Rizzo, Thomas; Tattersall, Jamie

    2015-10-28

    A number of LHC resonance search channels display an excess in the invariant mass region of 1.8–2.0 TeV. Among them is a 3.4σ excess in the fully hadronic decay of a pair of Standard Model electroweak gauge bosons, in addition to potential signals in the HW and dijet final states. We perform a model-independent cross-section fit to the results of all ATLAS and CMS searches sensitive to these final states. We then interpret these results in the context of the Left-Right Symmetric Model, based on the extended gauge group SU(2)L × SU(2)R × U(1)', and show that a heavy right-handed gauge boson WR can naturally explain the current measurements with just a single coupling gR ~ 0.4. Thus, we discuss a possible connection to dark matter.

  4. Inclusive Production of {rho}{+-}(770) Meson in Hadronic Decays of Z0 Boson

    SciTech Connect (OSTI)

    Beddall, A.; Beddall, A.; Binguel, A.

    2007-04-23

    The inclusive production of the charged vector meson {rho}{+-}(770) in hadronic Z decays is measured with the ALEPH detector at the LEP collider. Decays of {rho}{+-} {yields} {pi}0 + {pi}{+-} are reconstructed for x > 0.05 where x = E{rho}/Ebeam. The results are compared with Monte Carlo model predictions and OPAL measurements. Bose-Einstein effects are found to be important in extracting {rho}{+-}(770) from two pion invariant mass spectra.

  5. The Future of Hadrons: The Nexus of Subatomic Physics

    SciTech Connect (OSTI)

    Quigg, Chris

    2011-09-01

    The author offers brief observations on matters discussed at the XIV International Conference on Hadron Spectroscopy and explore prospects for hadron physics. Quantum chromodynamics (QCD) has been validated as a new law of nature. It is internally consistent up to very high energies, and so could be a complete theory of the strong interactions. Whether QCD is the final answer for the strong interactions is a subject for continuing experimental tests, which are being extended in experimentation at the Large Hadron Collider. Beyond the comparison of perturbative calculations with experiment, it remains critically important to test the confinement hypothesis by searching for free quarks, or for signatures of unconfined color. Sensitive negative searches for quarks continue to be interesting, and the definitive observation of free quarks would be revolutionary. Breakdowns of factorization would compromise the utility of perturbative QCD. Other discoveries that would require small or large revisions to QCD include the observation of new kinds of colored matter beyond quarks and gluons, the discovery that quarks are composite, or evidence that SU(3){sub c} gauge symmetry is the vestige of a larger, spontaneously broken, color symmetry. While probing our underlying theory for weakness or new openings, we have plenty to do to apply QCD to myriad experimental settings, to learn its implications for matter under unusual conditions, and to become more adept at calculating its consequences. New experimental tools provide the means for progress on a very broad front.

  6. HADRONIC FLUCTUATIONS IN THE QGP.

    SciTech Connect (OSTI)

    EJIRI, S.; KARSCH, F.; REDLICH, K.

    2005-08-04

    We analyze fluctuations of quark number and electric charge, in 2-flavour QCD at finite temperature and vanishing net baryon number density. In the hadronic phase we find that an enhancement of charge fluctuations arises from contributions of doubly charged hadrons to the thermodynamics. The rapid suppression of fluctuations seen in the high temperature phase suggests that in the QGP quark number and electric charge are predominantly carried by quasi-particles with the quantum numbers of quarks.

  7. Left-Right Symmetry: From the LHC to Neutrinoless Double Beta Decay

    SciTech Connect (OSTI)

    Tello, Vladimir [SISSA, Trieste (Italy); Nemevsek, Miha [ICTP, Trieste (Italy); Jozef Stefan Institute, Ljubljana (Slovenia); Nesti, Fabrizio [Universita di Ferrara, Ferrara (Italy); Senjanovic, Goran [ICTP, Trieste (Italy); Vissani, Francesco [LNGS, INFN, Assergi (Italy)

    2011-04-15

    The Large Hadron Collider has the potential to probe the scale of left-right symmetry restoration and the associated lepton number violation. Moreover, it offers the hope of measuring the right-handed leptonic mixing matrix. We show how this, together with constraints from lepton flavor violating processes, can be used to make predictions for neutrinoless double beta decay. We illustrate this connection in the case of the type-II seesaw.

  8. Muon Collider Task Force Report

    SciTech Connect (OSTI)

    Ankenbrandt, C.; Alexahin, Y.; Balbekov, V.; Barzi, E.; Bhat, C.; Broemmelsiek, D.; Bross, A.; Burov, A.; Drozhdin, A.; Finley, D.; Geer, S.; /Fermilab /Argonne /Brookhaven /Jefferson Lab /LBL, Berkeley /MUONS Inc., Batavia /UCLA /UC, Riverside /Mississippi U.

    2007-12-01

    Muon Colliders offer a possible long term path to lepton-lepton collisions at center-of-mass energies {radical}s {ge} 1 TeV. In October 2006 the Muon Collider Task Force (MCTF) proposed a program of advanced accelerator R&D aimed at developing the Muon Collider concept. The proposed R&D program was motivated by progress on Muon Collider design in general, and in particular, by new ideas that have emerged on muon cooling channel design. The scope of the proposed MCTF R&D program includes muon collider design studies, helical cooling channel design and simulation, high temperature superconducting solenoid studies, an experimental program using beams to test cooling channel RF cavities and a 6D cooling demonstration channel. The first year of MCTF activities are summarized in this report together with a brief description of the anticipated FY08 R&D activities. In its first year the MCTF has made progress on (1) Muon Collider ring studies, (2) 6D cooling channel design and simulation studies with an emphasis on the HCC scheme, (3) beam preparations for the first HPRF cavity beam test, (4) preparations for an HCC four-coil test, (5) further development of the MANX experiment ideas and studies of the muon beam possibilities at Fermilab, (6) studies of how to integrate RF into an HCC in preparation for a component development program, and (7) HTS conductor and magnet studies to prepare for an evaluation of the prospects for of an HTS high-field solenoid build for a muon cooling channel.

  9. Optimization of dynamic aperture for hadron lattices in eRHIC

    SciTech Connect (OSTI)

    Jing, Yichao; Litvinenko, Vladimir; Trbojevic, Dejan

    2015-05-03

    The potential upgrade of the Relativistic Heavy Ion Collider (RHIC) to an electron ion collider (eRHIC) involves numerous extensive changes to the existing collider complex. The expected very high luminosity is planned to be achieved at eRHIC with the help of squeezing the beta function of the hadron ring at the IP to a few cm, causing a large rise of the natural chromaticities and thus bringing with it challenges for the beam long term stability (Dynamic aperture). We present our effort to expand the DA by carefully tuning the nonlinear magnets thus controlling the size of the footprints in tune space and all lower order resonance driving terms. We show a reasonably large DA through particle tracking over millions of turns of beam revolution.

  10. Hadron particle theory

    SciTech Connect (OSTI)

    Alonso, J.R.

    1995-05-01

    Radiation therapy with ``hadrons`` (protons, neutrons, pions, ions) has accrued a 55-year track record, with by now over 30,000 patients having received treatments with one of these particles. Very good, and in some cases spectacular results are leading to growth in the field in specific well-defined directions. The most noted contributor to success has been the ability to better define and control the radiation field produced with these particles, to increase the dose delivered to the treatment volume while achieving a high degree of sparing of normal tissue. An additional benefit is the highly-ionizing, character of certain beams, leading to creater cell-killing potential for tumor lines that have historically been very resistant to radiation treatments. Until recently these treatments have been delivered in laboratories and research centers whose primary, or original mission was physics research. With maturity in the field has come both the desire to provide beam facilities more accessible to the clinical setting, of a hospital, as well as achieving, highly-efficient, reliable and economical accelerator and beam-delivery systems that can make maximum advantage of the physical characteristics of these particle beams. Considerable work in technology development is now leading, to the implementation of many of these ideas, and a new generation of clinically-oriented facilities is beginning to appear. We will discuss both the physical, clinical and technological considerations that are driving these designs, as well as highlighting, specific examples of new facilities that are either now treating, patients or that will be doing so in the near future.