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1

Large hadron collider (LHC) project quality assurance plan  

E-Print Network (OSTI)

PUB-5478-Rev.B Large Hadron Collider (LHC) Project Qualityobjectives of the Large Hadron Collider (LHC) Project in aparticipation in the Large Hadron Collider Project. The LHC/

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

2002-01-01T23:59:59.000Z

2

Fermilab Now - LHC Large Hadron Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Large Hadron Collider (LHC) Over the next few months, a 12,500-ton detector will be lowered almost 300 feet below ground near the French-Swiss border. Dubbed "CMS," this detector...

3

Updated electron-cloud simulation results for the Large Hadron Collider (LHC)  

E-Print Network (OSTI)

RESULTS FOR THE LARGE HADRON COLLIDER LHC ? M. A. Furman andscreen of the Large Hadron Collider (LHC). We pay particular

Furman, M.A.; Pivi, M.

2001-01-01T23:59:59.000Z

4

Broadband impedance calculations of the TAN vacuum chamber for the Large Hadron Collider (LHC)  

E-Print Network (OSTI)

CHAMBER FOR THE LARGE HADRON COLLIDER (LHC) ? D. Li , G.chamber for the Large Hadron Collider (LHC). The TAN is the

Li, D.; Lambertson, G.; Turner, W.

2001-01-01T23:59:59.000Z

5

Large hadron collider (LHC) project quality assurance plan  

Science Conference Proceedings (OSTI)

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

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

2002-09-30T23:59:59.000Z

6

Searches for extra dimensions in the CMS experiment at the Large Hadron Collider (LHC)  

Science Conference Proceedings (OSTI)

Predictions of multidimensonal theories are analyzed, and the possibility of detecting signals from extra spatial dimensions in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) is studied.

Shmatov, S. V., E-mail: shmatov@cern.ch [Joint Institute for Nuclear Research (Russian Federation); Collaboration: CMS Collaboration

2011-03-15T23:59:59.000Z

7

90Exploring the Large Hadron Collider The 27-kilometer diameter LHC ring, buried deep underground, uses thousands of  

E-Print Network (OSTI)

90Exploring the Large Hadron Collider The 27-kilometer diameter LHC ring, buried deep underground Joules)? During November, 2009 the Large Hadron Collider experiment at CERN began a slow, step, uses thousands of magnets to steer two beams of protons so that they collide at specific points along

8

Cryogenic Safety Aspect of the Low-? Magnet Systems at the Large Hadron Collider (LHC)  

E-Print Network (OSTI)

The low-? magnet systems are located in the LHC insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process and will allow proton collisions at a luminosity of up to 1034cm-2s-1. Large radiation dose deposited at the proximity of the beam collisions dictate stringent requirements for the design and operation of the systems. The hardware commissioning phase of the LHC was completed in the winter of 2010 and permitted to validate this system safe operation. This paper presents the analysis used to qualify and quantify the safe operation of the low-? magnet systems in the Large Hadron Collider (LHC) for the first years of operation.

Darve, C

2011-01-01T23:59:59.000Z

9

Production of exotic atoms at the CERN Large Hadron Collider (LHC)  

E-Print Network (OSTI)

We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider (LHC) at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.

Bertulani, C A

2010-01-01T23:59:59.000Z

10

Production of exotic atoms at the CERN Large Hadron Collider (LHC)  

E-Print Network (OSTI)

We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider (LHC) at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.

C. A. Bertulani; M. Ellermann

2010-03-17T23:59:59.000Z

11

A laser-based longitudinal density monitor for the large hadron collider  

E-Print Network (OSTI)

MONITOR FOR THE LARGE HADRON COLLIDER * J. -F. Beche, J.profile in the Large Hadron Collider (LHC). The technique

2004-01-01T23:59:59.000Z

12

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

SciTech Connect

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

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

2011-05-01T23:59:59.000Z

13

Hadron Colliders and Hadron Collider Physics Symposium  

E-Print Network (OSTI)

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

Denisov, Dmitri

2013-01-01T23:59:59.000Z

14

Minimum Bias Measurements with the ATLAS Detector at the CERN Large Hadron Collider  

E-Print Network (OSTI)

Experiment at the Large Hadron Collider. Masters thesis,1 ATLAS & LHC 1.1 Large Hadron Collider 1.2 Physics at theDetector at the CERN Large Hadron Collider by Michael A.

Leyton, Michael A.

2009-01-01T23:59:59.000Z

15

Brookhaven and the Large Hadron Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Brookhaven & the Large Hadron Collider Brookhaven & the Large Hadron Collider Home News Brookhaven & ATLAS ATLAS ATLAS Calorimeter ATLAS Muon Spectrometer Construction Computing Upgrades RHIC & LHC Education LHC tunnel ATLAS detector ATLAS detector RACF BNL built superconducting magnets Brookhaven & the LHC The world's most powerful particle accelerator, the Large Hadron Collider (LHC) in Switzerland, powers unprecedented explorations of the deepest mysteries of the universe. In addition to serving as the U.S. host laboratory for the ATLAS experiment at the LHC, Brookhaven National Lab plays multiple roles in this international collaboration, from construction and project management to data storage and distribution. ATLAS rendering Brookhaven and ATLAS Brookhaven physicists and engineers are participating in one of the most

16

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

Energy.gov (U.S. Department of Energy (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,...

17

Estimation of the Invisible Z Background to Hadronic Supersymmetry Searches Performed With Proton-Proton Collision Data at 7 and 8 TeV Observed With the CMS Detector During the First run of the CERN Large Hadron Collider  

E-Print Network (OSTI)

The Large Hadron Collider (LHC) accelerator system, showingEW electroweak. 8 LHC Large Hadron Collider. xii, 1721, 37,at the CERN Large Hadron Collider, JINST 3 (2008) S08003,

Sturdy, Jared

2013-01-01T23:59:59.000Z

18

Higgs boson production at hadron colliders: Signal and background processes  

SciTech Connect

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.

David Rainwater; Michael Spira; Dieter Zeppenfeld

2004-01-12T23:59:59.000Z

19

Results from hadron colliders  

SciTech Connect

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

Pondrom, L.G. (Wisconsin Univ., Madison, WI (USA))

1990-12-14T23:59:59.000Z

20

The Large Hadron Electron Collider Project  

E-Print Network (OSTI)

A Conceptual Design Report (CDR) for the Large Hadron Electron Collider, the LHeC, is being prepared, to which an introduction was given for the plenary panel discussion on the future of deep inelastic scattering held at DIS09. This is briefly summarised here. The CDR will comprise designs of the ep/eA collider, based on ring and linear electron accelerators, of the interaction region, designed for simultaneous $ep$ and $pp$ operation, of a new, modular detector, and it will present basics on the physics motivation for a high luminous Tera scale electron-nucleon collider as a complement to the LHC.

Max Klein

2009-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Director's colloquium March 18 large hadron collider  

NLE Websites -- All DOE Office Websites (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...

22

The Very Large Hadron Collider: The farthest energy frontier  

E-Print Network (OSTI)

THE VERY LARGE HADRON COLLIDER: THE FARTHEST ENERGY FRONTIERAbstract The Very Large Hadron Collider (or Eloisatron)

Barletta, William A.

2001-01-01T23:59:59.000Z

23

First Beam for Large Hadron Collider | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Beam for Large Hadron Collider Beam for Large Hadron Collider First Beam for Large Hadron Collider September 10, 2008 - 3:20pm Addthis WASHINGTON, DC - An international collaboration of scientists today sent the first beam of protons zooming at nearly the speed of light around the world's most powerful particle accelerator-the Large Hadron Collider (LHC)-located at the CERN laboratory near Geneva, Switzerland. The U.S. Department of Energy (DOE) and the National Science Foundation (NSF) invested a total $531 million in the construction of the accelerator and its detectors, which scientists believe could help unlock extraordinary discoveries about the nature of the physical universe. Celebrations across the U.S. and around the world mark the LHC's first circulating beam, an occasion more than 15 years in the making. An

24

String resonances at the Large Hadron Collider  

E-Print Network (OSTI)

The Large Hadron Collider promises to discover new physics beyond the Standard Model. An exciting possibility is the formation of string resonances at the TeV scale. In this article, we show how string resonances may be detected at the LHC in the $pp\\to\\gamma+jet$ channel. Our study is based on event shape variables, missing energy and momentum, maximum transverse momentum of photons and dijet invariant mass. These observables provide interesting signatures which enable us to discriminate string events from the Standard Model background.

Arunava Roy; Marco Cavaglia

2009-02-09T23:59:59.000Z

25

Probing two-photon decay widths of mesons at energies available at the CERN Large Hadron Collider (LHC)  

E-Print Network (OSTI)

Meson production cross sections in ultra-peripheral relativistic heavy ion collisions at LHC are revisited. The relevance of meson models and of exotic QCD states is discussed. This study includes states that have not been considered before in the literature.

C. A. Bertulani

2009-03-18T23:59:59.000Z

26

Taking the 'Large' out of Large Hadron Collider: Computational Breakthrough  

NLE Websites -- All DOE Office Websites (Extended Search)

Home » News & Publications » News » Science News » Taking the 'Large' out of Large Hadron Collider Taking the 'Large' out of Large Hadron Collider Computational breakthrough hastens modeling of 'tabletop accelerators' August 9, 2010 | Tags: Accelerator Science Contact: Margie Wylie | mwylie@lbl.gov | 510-486-7421 mori1 This 3D simulation shows how laser pulses create plasma wakes that propel electrons forward, much as a surfer is propelled forward by an ocean wave. Laser wakefield acceleration promises electron accelerators that are thousands of times more powerful than, yet a fraction the size of, conventional radio frequency devices. Particle accelerators like the Large Hadron Collider (LHC) at CERN are the big rock stars of high-energy physics-really big. The LHC cost nearly

27

Summary of the Very Large Hadron Collider Physics and Detector Workshop  

E-Print Network (OSTI)

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

G. Anderson; U. Baur; M. Berger; F. Borcherding; A. Brandt; D. Denisov; S. Eno; T. Han; S. Keller; D. Khazins; T. LeCompte; J. Lykken; F. Olness; F. Paige; R. Scalise; E. H. Simmons; G. Snow; C. Taylor; J. Womersley

1997-10-06T23:59:59.000Z

28

Distinguishing Spins in Decay Chains at the Large Hadron Collider.  

E-Print Network (OSTI)

ar X iv :h ep -p h/ 06 05 28 6v 4 2 9 A ug 2 00 8 Preprint typeset in JHEP style - PAPER VERSION CavendishHEP06/11(rev.) Distinguishing Spins in Decay Chains at the Large Hadron Collider? Christiana Athanasiou1, Christopher G. Lester2... particles at the LHC, Phys. Lett. B596 (2004) 205212, hep-ph/0405052. [2] T. Goto, K. Kawagoe, and M. M. Nojiri, Study of the slepton non-universality at the CERN Large Hadron Collider, Phys. Rev. D70 (2004) 075016, hep-ph/0406317. 21 [3] H. C. Cheng...

Athanasiou, Christiana; Lester, Christopher G; Smillie, Jennifer M; Webber, Bryan R

29

Distinguishing Spins in Decay Chains at the Large Hadron Collider  

E-Print Network (OSTI)

ar X iv :h ep -p h/ 06 05 28 6v 4 2 9 A ug 2 00 8 Preprint typeset in JHEP style - PAPER VERSION CavendishHEP06/11(rev.) Distinguishing Spins in Decay Chains at the Large Hadron Collider? Christiana Athanasiou1, Christopher G. Lester2... particles at the LHC, Phys. Lett. B596 (2004) 205212, hep-ph/0405052. [2] T. Goto, K. Kawagoe, and M. M. Nojiri, Study of the slepton non-universality at the CERN Large Hadron Collider, Phys. Rev. D70 (2004) 075016, hep-ph/0406317. 21 [3] H. C. Cheng...

Athanasiou, Christiana; Lester, Christopher G; Smillie, Jennifer M; Webber, Bryan R

30

Establishing the Mirage Mediation Model at the Large Hadron Collider  

E-Print Network (OSTI)

This thesis describes the research I did during my Master's study. I investigated the stau-neutralino coannihilation region of the Mirage Mediation Model at the Large Hadron Collider (LHC). By constructing five kinematic observables at the LHC, the masses of supersymmetric particles (sparticles) were determined. The Mirage Mediation Model parameters were determined from the sparticles' masses. This is the first time to establish the Mirage Mediation Model at the LHC. All these techniques can be applied to other coannihilation regions of the Mirage Mediation Model and other supersymmetry (SUSY) models.

Wang, Kechen

2011-08-01T23:59:59.000Z

31

Big Science and the Large Hadron Collider  

E-Print Network (OSTI)

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

Gian Francesco Giudice

2011-06-13T23:59:59.000Z

32

Hadronic Production of the Doubly Heavy Baryon $?_{bc}$ at LHC  

E-Print Network (OSTI)

We investigate the hadronic production of the doubly heavy baryon $\\Xi_{bc}$ at the large hadron collider (LHC), where contributions from the four $(bc)$-diquark states $(bc)_{\\bf\\bar{3},6}[^1S_0]$ and $(bc)_{\\bf\\bar{3},6}[^3S_1]$ have been taken into consideration. Numerical results show that under the condition of $p_T>4$ GeV and $|y|energy $\\sqrt{S}=7$ TeV and $\\sqrt{S}=14$ TeV respectively. For experimental usage, the total and the interested differential cross-sections are estimated under some typical $p_T$- and $y$- cuts for the LHC detectors CMS, ATLAS and LHCb. Main uncertainties are discussed and a comparative study on the hadronic production of $\\Xi_{cc}$, $\\Xi_{bc}$ and $\\Xi_{bb}$ at LHC are also presented.

Jia-Wei Zhang; Xing-Gang Wu; Tao Zhong; Yao Yu; Zhen-Yun Fang

2011-01-06T23:59:59.000Z

33

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

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.

Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Machado, M. V. T. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS (Brazil)

2011-07-15T23:59:59.000Z

34

Trilepton Higgs boson signal at hadron colliders  

SciTech Connect

Most Higgs boson searches pursued at hadron colliders require Yukawa interactions either in the production or the decay of a Higgs boson. We propose a trilepton Higgs boson search based only upon the gauge interactions of the Higgs boson. This strategy can be utilized successfully for the standard model (SM) Higgs boson as well as nonstandard Higgs bosons which break electroweak symmetry but have little to do with fermion mass generation. The trileptons come from Wh production followed by Wh{r_arrow}WWW{sup ({asterisk})}{r_arrow}3l decays. A SM Higgs trilepton signal would be difficult to detect at the Fermilab Tevatron collider: with 100fb{sup {minus}1} of data, only a 3{sigma} signal above background can be achieved after cuts if 140GeV{lt}m{sub h{sub sm}{sup 0}}{lt}175GeV. Some discrimination of signal over background can be gained by analyzing the opposite sign dilepton p{sub T} distributions. At the CERN LHC with 30(100)fb{sup {minus}1} a clear discovery above the 5{sigma} level is possible for a Higgs boson mass in the range 140{endash}185(125{endash}200)GeV. Prospects for a trilepton Higgs boson discovery are greatly improved for models with nonstandard Higgs boson sectors where a Higgs boson couples preferentially to vector bosons rather than to fermions. {copyright} {ital 1998} {ital The American Physical Society}

Baer, H. [Department of Physics, Florida State University, Tallahassee, Florida32306 (United States); Wells, J.D. [Stanford Linear Accelerator Center, Stanford University, Stanford, California94309 (United States)

1998-04-01T23:59:59.000Z

35

Discriminating Supersymmetry and Black Holes at the Large Hadron Collider  

E-Print Network (OSTI)

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

Arunava Roy; Marco Cavaglia

2008-01-21T23:59:59.000Z

36

Forward Jet Production at the Large Hadron Collider  

E-Print Network (OSTI)

At the Large Hadron Collider (LHC) it will become possible for the first time to investigate experimentally the forward region in hadron-hadron collisions via high-$p_T$ processes. In the LHC forward kinematics QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. We analyze the hadroproduction of forward jets in the framework of QCD high-energy factorization, which allows one to resum consistently both kinds of corrections to higher orders in QCD perturbation theory. We compute the short-distance matrix elements needed to evaluate the factorization formula at fully exclusive level. We discuss numerically dynamical features of multi-gluon emission at large angle encoded in the factorizing high-energy amplitudes.

M. Deak; F. Hautmann; H. Jung; K. Kutak

2009-08-04T23:59:59.000Z

37

Charged heavy vector boson production at the Large Hadron Collider  

E-Print Network (OSTI)

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

Dal Soo Oh; M. H. Reno

1998-12-02T23:59:59.000Z

38

Perturbative probes of QCD matter at the Large Hadron Collider  

E-Print Network (OSTI)

The main results on electroweak probes, jets, high-pT hadrons, heavy-flavour and quarkonia production from the first two years of heavy-ion operation at the Large Hadron Collider (LHC) are briefly reviewed. Data measured at center-of-mass energies sqrt(s_NN) = 2.76 TeV in lead-lead (Pb-Pb) collisions are compared to proton-proton (p-p) measurements in order to extract information on the properties of hot and dense strongly-interacting matter.

David d'Enterria

2012-07-18T23:59:59.000Z

39

Perturbative probes of QCD matter at the Large Hadron Collider  

E-Print Network (OSTI)

The main results on electroweak probes, jets, high-pT hadrons, heavy-flavour and quarkonia production from the first two years of heavy-ion operation at the Large Hadron Collider (LHC) are briefly reviewed. Data measured at center-of-mass energies sqrt(s_NN) = 2.76 TeV in lead-lead (Pb-Pb) collisions are compared to proton-proton (p-p) measurements in order to extract information on the properties of hot and dense strongly-interacting matter.

d'Enterria, David

2012-01-01T23:59:59.000Z

40

Signatures for right-handed neutrinos at the Large Hadron Collider  

E-Print Network (OSTI)

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

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

2008-03-19T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Predicting Large Hadron Collider Observations using Kazuo Kondo's Mass Quantum Cascade  

E-Print Network (OSTI)

The late Kazuo Kondo left a hitherto unknown a priori particle theory which provides predictions of massive particles which may be detected by the Large Hadron Collider (LHC). This article briefly introduces Kondo's work and documents the derivation and masses of his expected hyper-mesons, hyper-hadrons, heavy leptons and massive neutrinos. Several particles in these classes may have already been detected.

Grenville J. Croll

2008-04-27T23:59:59.000Z

42

Properties of Jets Measured with Charged Particles with the ATLAS Detector at the Large Hadron Collider  

E-Print Network (OSTI)

3 The Large Hadron Collider and ATLAS3.1 The Large Hadron Collider Complex . . . . . . . .of QCD at the Large Hadron Collider. These improvements will

Zenz, Seth Conrad

2011-01-01T23:59:59.000Z

43

Black Hole Cross Section at the Large Hadron Collider  

E-Print Network (OSTI)

Black hole production at the Large Hadron Collider (LHC) was first discussed in 1999. Since then, much work has been performed in predicting the black hole cross section. In light of the start up of the LHC, it is now timely to review the state of these calculations. We review the uncertainties in estimating the black hole cross section in higher dimensions. One would like to make this estimate as precise as possible since the predicted values, or lower limits, obtain for the fundamental Planck scale and number of extra dimensions from experiments will depend directly on the accuracy of the cross section. Based on the current knowledge of the cross section, we give a range of lower limits on the fundamental Planck scale that could be obtained at LHC energies.

Douglas M. Gingrich

2006-09-06T23:59:59.000Z

44

eta_c production at the Large Hadron Collider  

E-Print Network (OSTI)

We have studied the production of the 1S_0 charmonium state, eta_c, at the Large Hadron Collider (LHC) in the framework of Non-Relativistic Quantum Chromodynamics (NRQCD) using heavy-quark symmetry. We find that NRQCD predicts a large production cross-section for this resonance at the LHC even after taking account the small branching ratio of eta_c into two photons. We show that it will be possible to test NRQCD through its predictions for eta_c, with the statistics that will be achieved at the early stage of the LHC, running at a center of mass energy of 7 TeV with an integrated luminosity of 100 pb^{-1}

Sudhansu S. Biswal; K. Sridhar

2010-07-29T23:59:59.000Z

45

Higgs Physics at the Large Hadron Collider  

E-Print Network (OSTI)

A major goal of the future Large Hadron Collider will be the Higgs boson search. In this paper the discovery In this paper the discovery potential is described as a function of the Higgs mass showing that a Standard Model Higgs boson can be discovered after less than two years of running of the collider. The MSSM Higgs searches and the precision achievable on the measurement of the Higgs boson parameters are also discussed.

Davide Costanzo

2001-05-15T23:59:59.000Z

46

A review of Quantum Gravity at the Large Hadron Collider  

E-Print Network (OSTI)

The aim of this article is to review the recent developments in the phenomenology of quantum gravity at the Large Hadron Collider. We shall pay special attention to four-dimensional models which are able to lower the reduced Planck mass to the TeV region and compare them to models with a large extra-dimensional volume. We then turn our attention to reviewing the emission of gravitons (massless or massive) at the LHC and to the production of small quantum black holes.

Xavier Calmet

2010-05-11T23:59:59.000Z

47

Study of highly-excited string states at the Large Hadron Collider  

E-Print Network (OSTI)

In TeV-scale gravity scenarios with large extra dimensions, black holes may be produced at future colliders. Good arguments have been made for why general relativistic black holes may be just out of reach of the Large Hadron Collider (LHC). However, in weakly-coupled string theory, highly excited string states - string balls - could be produced at the LHC with high rates and decay thermally, not unlike general relativistic black holes. In this paper, we simulate and study string ball production and decay at the LHC. We specifically emphasize the experimentally-detectable similarities and differences between string balls and general relativistic black holes at a TeV scale.

Douglas M. Gingrich; Kevin Martell

2008-08-19T23:59:59.000Z

48

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  

Science Conference Proceedings (OSTI)

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.

Long Haiyan; Feng Shengqin; Zhou Daimei; Yan Yuliang; Ma Hailiang; Sa Benhao [Department of Physics, College of Science, China Three Gorges University, Yichang 443002 (China); Institute of Particle Physics, Huazhong Normal University, Wuhan 430082 (China); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); China Institute of Atomic Energy, P.O. Box 275 (18), Beijing 102413 (China); Institute of Particle Physics, Huazhong Normal University, Wuhan 430082 (China); CCAST (World Laboratory), P.O. Box 8730, Beijing 100080 (China)

2011-09-15T23:59:59.000Z

49

Department of Energy assessment of the Large Hadron Collider  

SciTech Connect

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

1996-06-01T23:59:59.000Z

50

Warped Views on the Large Hadron Collider  

E-Print Network (OSTI)

Models with warped extra dimensions, and their strongly coupled duals, offer a nice solution to the hierarchy problem and a very appealing realisation of flavour. Compatibility with the very stringent electroweak and flavour tests have made a generic picture emerge, with a composite Higgs, partial compositeness and custodial symmetry as the main ingredients. We review the main features of this picture and discuss how -and when- models with warped extra dimensions could be discovered at the Large Hadron Collider.

Jose Santiago

2011-03-21T23:59:59.000Z

51

The Protection System for the Superconducting Elements of the Large Hadron Collider at CERN  

E-Print Network (OSTI)

The protection system for the superconducting elements of the Large Hadron Collider (LHC) [1] at the European Laboratory for Particle Physics (CERN), and its associated equipment are presented: quench detectors, cold diodes, quench heaters and related power supplies, extraction resistors and associated current breakers. Features such as radiation resistance, redundancy and required reliability are discussed.

Dahlerup-Petersen, K; Gmez-Costa, J L; Hagedorn, Dietrich; Proudlock, Paul; Rodrguez-Mateos, F; Schmidt, R; Sonnemann, F

1999-01-01T23:59:59.000Z

52

Improving the discovery potential of charged Higgs bosons at the Tevatron and Large Hadron Collider  

E-Print Network (OSTI)

We outline several improvements to the experimental analyses carried out at Tevatron (Run 2) or simulated in view of the Large Hadron Collider (LHC) that could increase the scope of CDF/D0 and ATLAS/CMS in detecting charged Higgs bosons

S. Moretti

2002-05-10T23:59:59.000Z

53

Signals of neutralinos and charginos from gauge boson fusion at the CERN Large Hadron Collider  

E-Print Network (OSTI)

We point out that interesting signals of the non-strongly interacting sector of the supersymmetric standard model arise from the production of charginos and neutralinos via vector boson fusion (VBF) at the Large Hadron Collider (LHC). In particular, if R-parity is violated, the hadronically quiet signals of charginos and neutralinos through direct production get considerably suppressed. We show that in such cases, the VBF channel can be useful in identifying this sector through clean and background-free final states.

Anindya Datta; Partha Konar; Biswarup Mukhopadhyaya

2001-09-09T23:59:59.000Z

54

Optimization of muon timing and searches for heavy long-lived charged particles with the Compact Muon Solenoid detector at the Large Hadron Collider  

E-Print Network (OSTI)

Large Hadron Collider . . . . . . . . . . . . . . . . . . . . . . . .detector at the Large Hadron Collider A dissertationdetector at the Large Hadron Collider by Christopher Patrick

Farrell, Christopher Patrick

2013-01-01T23:59:59.000Z

55

Dijet asymmetry at the Large Hadron Collider  

E-Print Network (OSTI)

The MARTINI numerical simulation allows for direct comparison of theoretical model calculations and the latest results for dijet asymmetry from the ATLAS and CMS collaborations. In this paper, partons are simulated as undergoing radiative and collisional processes throughout the evolution of central lead-lead collisions at the Large Hadron Collider. Using hydrodynamical background evolution determined by a simulation which fits well with the data on charged particle multiplicities from ALICE and a value of $\\alpha_s\\approx 0.25-0.3$, the dijet asymmetry is found to be consistent with partonic energy loss in a hot, strongly-interacting medium.

Clint Young; Bjrn Schenke; Sangyong Jeon; Charles Gale

2011-03-29T23:59:59.000Z

56

Exploring anomalous top interactions via the final lepton in ttbar productions/decays at hadron colliders  

E-Print Network (OSTI)

We study momentum distributions of the final-state charged lepton in ppbar/pp --> ttbar --> l^+ X (l=e or mu) at hadron colliders, i.e., Tevatron and Large Hadron Collider (LHC) in order to explore possible new-physics effects in the top-quark sector. Assuming general model-independent ttbar g + ttbar gg and tbW interactions beyond the standard model, we first derive analytical formulas for the corresponding parton-parton processes. We then compute the lepton angular, energy and transverse-momentum distributions in ppbar/pp collisions to clarify how they are affected by those anomalous couplings.

Zenro HIOKI; Kazumasa OHKUMA

2011-04-07T23:59:59.000Z

57

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

Science Conference Proceedings (OSTI)

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

Berger, C. F. [Center for Theoretical Physics, MIT, Cambridge, Massachusetts 02139 (United States); Bern, Z.; Ita, H. [Department of Physics and Astronomy, UCLA, Los Angeles, California 90095-1547 (United States); Dixon, L. J. [Theory Division, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)] [SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94309 (United States); Cordero, F. Febres [Departamento de Fisica, Universidad Simon Bolivar, Caracas 1080A (Venezuela, Bolivarian Republic of); Forde, D. [Theory Division, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)] [NIKHEF Theory Group, Science Park 105, NL-1098 XG Amsterdam (Netherlands); Gleisberg, T. [SLAC National Accelerator Laboratory, Stanford University, Stanford, California 94309 (United States); Kosower, D. A. [Institut de Physique Theorique, CEA-Saclay, F-91191 Gif-sur-Yvette cedex (France); Maitre, D. [Department of Physics, University of Durham, Durham DH1 3LE (United Kingdom)

2011-03-04T23:59:59.000Z

58

Large Hadron Collider probe of supersymmetric neutrinoless double beta decay mechanism.  

E-Print Network (OSTI)

ar X iv :0 90 2. 46 97 v1 [ he p- ph ] 26 Fe b 2 00 9 CAVENDISH-HEP-2009-03, DAMTP-2009-15, DO-TH-09/01 Large Hadron Collider probe of supersymmetric neutrinoless double beta decay mechanism B. C. Allanach? DAMTP, University of Cambridge... how data from the Large Hadron Collider (LHC) can favor or disfavor the latter possibility. The experimental observations of neutrino oscillations has lead to the realization that at least two of the three known neutrinos have masses [5]. Thus...

Allanach, B C; Kom, C H; Pas, H

59

Hadronic production of the doubly heavy baryon {Xi}{sub bc} at the LHC  

Science Conference Proceedings (OSTI)

We investigate the hadronic production of the doubly heavy baryon {Xi}{sub bc} at the Large Hadron Collider (LHC), where contributions from the four (bc)-diquark states (bc){sub 3,6}[{sup 1}S{sub 0}] and (bc){sub 3,6}[{sup 3}S{sub 1}] have been taken into consideration. Numerical results show that under the condition of p{sub T}>4 GeV and |y|energy {radical}(S)=7 TeV and {radical}(S)=14 TeV, respectively. For experimental usage, the total and the interested differential cross sections are estimated under some typical p{sub T} and y cuts for the LHC detectors CMS, ATLAS, and LHCb. The main uncertainties are discussed and a comparative study on the hadronic production of {Xi}{sub cc}, {Xi}{sub bc}, and {Xi}{sub bb} at the LHC are also presented.

Zhang Jiawei; Wu Xinggang; Zhong Tao; Yu Yao; Fang Zhenyun [Department of Physics, Chongqing University, Chongqing 400044 (China)

2011-02-01T23:59:59.000Z

60

MULTI-CHANNEL SEARCH FOR SUPERGRAVITY AT THE LARGE HADRON COLLIDER  

E-Print Network (OSTI)

The potential of seeing supersymmetry (SUSY) at the CERN Large Hadron Collider (LHC) was studied by looking at 3 types of signals: dilepton events from slepton pair productions, trilepton events from chargino/neutralino productions and missing energy plus multi-jet events from gluino/squark productions. I described my results by mapping out reachable areas in the supergravity parameter space. Areas explorable at LEP II were also mapped out for comparison.

Chih-Hao Chen

1995-03-09T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Sensitivity to the Single Production of Vector-Like Quarks at an Upgraded Large Hadron Collider  

E-Print Network (OSTI)

In this note we consider the sensitivity of the Large Hadron Collider (LHC) to the single production of new heavy vector-like quarks. We consider a model with large mixing with the standard model top quark with electroweak production of single heavy top quarks. We consider center of mass energies of 14, 33, and 100 TeV with various pileup scenarios and present the expected sensitivity and exclusion limits.

Tim Andeen; Clare Bernard; Kevin Black; Taylor Childres; Lidia Dell'Asta; Natascia Vignaroli

2013-09-07T23:59:59.000Z

62

Cryogenic studies for the proposed CERN large hadron electron collider (LHEC)  

Science Conference Proceedings (OSTI)

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option

2012-01-01T23:59:59.000Z

63

Test of relativistic gravity for propulsion at the Large Hadron Collider  

E-Print Network (OSTI)

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

Franklin Felber

2009-10-06T23:59:59.000Z

64

Prospects for heavy flavor physics at hadron colliders  

SciTech Connect

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

Butler, J.N.

1997-09-01T23:59:59.000Z

65

Heavy flavor production and top quark search at hadron colliders  

SciTech Connect

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

Baer, H.A.

1991-01-01T23:59:59.000Z

66

Search for Effect of Influence from Future in Large Hadron Collider  

E-Print Network (OSTI)

We propose an experiment which consists of drawing a card and using it to decide restrictions on the running of Large Hadron Collider (LHC for short) at CERN, such as luminosity, and beam energy. There may potentially occur total shut down. The purpose of such an experiment is to search for influence from the future, that is, backward causation. Since LHC will produce particles of a mathematically new type of fundamental scalars, i.e., the Higgs particles, there is potentially a chance to find unseen effects, such as on influence going from future to past, which we suggest in the present paper.

Holger B. Nielsen; Masao Ninomiya

2007-07-13T23:59:59.000Z

67

An iterated search for influence from the future on the Large Hadron Collider  

E-Print Network (OSTI)

We analyse an iterated version of Nielsen and Ninomiya (N&N)'s proposed card game experiment to search for a specific type of backward causation on the running of the Large Hadron Collider (LHC) at CERN. We distinguish "endogenous" and "exogenous" potential causes of failure of LHC and we discover a curious "cross-talk" between their respective probabilities and occurrence timescales when N&N-style backward causation is in effect. Finally, we note a kind of "statistical cosmic censorship" preventing the influence from the future from showing up in a statistical analysis of the iterated runs.

Iain Stewart

2007-12-05T23:59:59.000Z

68

Z' Discovery Reach at Future Hadron Colliders: A Snowmass White Paper  

E-Print Network (OSTI)

Extra neutral gauge bosons are a feature of many models of physics beyond the standard model (BSM) and their discovery could possibly be the first evidence for new physics. In this Snowmass white paper we compare the discovery reach of the high energy hadron colliders considered by the Snowmass study for a broad range of BSM models. It is expected that the LHC should be able to see evidence for a Z' arising from a large variety of BSM models up to a mass of ~5 TeV when the LHC reaches its design energy and luminosity, and up to ~6 TeV with the high luminosity upgrade. Further into the future, the high energy LHC would substantially extend this reach to ~11 TeV, while the ~100 TeV VHE-LHC could see evidence for Z' 's up to ~30 TeV.

Stephen Godfrey; Travis Martin

2013-09-06T23:59:59.000Z

69

Anomaly driven signatures of new invisible physics at the Large Hadron Collider  

E-Print Network (OSTI)

Many extensions of the Standard Model (SM) predict new neutral vector bosons at energies accessible by the Large Hadron Collider (LHC). We study an extension of the SM with new chiral fermions subject to non-trivial anomaly cancellations. If the new fermions have SM charges, but are too heavy to be created at LHC, and the SM fermions are not charged under the extra gauge field, one would expect that this new sector remains completely invisible at LHC. We show, however, that a non-trivial anomaly cancellation between the new heavy fermions may give rise to observable effects in the gauge boson sector that can be seen at the LHC and distinguished from backgrounds.

Ignatios Antoniadis; Alexey Boyarsky; Sam Espahbodi; Oleg Ruchayskiy; James D. Wells

2009-01-06T23:59:59.000Z

70

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

NLE Websites -- All DOE Office Websites (Extended Search)

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,...

71

How to Find a Hidden World at the Large Hadron Collider  

E-Print Network (OSTI)

I discuss how the Large Hadron Collider era should broaden our view of particle physics research, and apply this thinking to the case of Hidden Worlds. I focus on one of the simplest representative cases of a Hidden World, and detail the rich implications it has for LHC physics, including universal suppression of Higgs boson production, trans-TeV heavy Higgs boson signatures, heavy-to-light Higgs boson decays, weakly coupled exotic gauge bosons, and Higgs boson decays to four fermions via light exotic gauge bosons. Some signatures may be accessible in the very early stages of collider operation, whereas others motivate a later high-lumonosity upgrade.

James D. Wells

2008-03-08T23:59:59.000Z

72

The LHC as a Proton-Nucleus Collider  

E-Print Network (OSTI)

Following its initial operation as a proton-proton (p-p) and heavy-ion (208Pb82+-208Pb82+) collider, the LHC is expected to operate as a p-Pb collider. Later it may collide protons with other lighter nuclei such as 40Ar18+ or 16O8+. We show how the existing proton and lead-ion injector chains may be efficiently operated in tandem to provide these hybrid collisions. The two-in-one magnet design of the LHC main rings imposes different revolution frequencies for the two beams in part of the magnetic cycle. We discuss and evaluate the consequences for beam dynamics and estimate the potential performance of the LHC as a proton-nucleus collider.

Carli, C

2006-01-01T23:59:59.000Z

73

Flat beams in a 50 TeV hadron collider  

SciTech Connect

The basic beam dynamics of a next generation 50 x 50 TeV hadron collider based on a high field magnet approach have been outlined over the past several years. Radiation damping not only produces small emittances, but also flat beams, just as in electron machines. Based on {open_quotes}Snowmass 96{close_quotes} parameters, we investigate the issues associated with flat beams in very high energy hadron colliders.

Peggs, S.; Harrison, M.; Pilat, F.; Syphers, M.

1997-08-01T23:59:59.000Z

74

The Standard Model and Supersymmetric Flavor Puzzles at the Large Hadron Collider  

E-Print Network (OSTI)

Can the Large Hadron Collider explain the masses and mixings of the known fermions? A promising possibility is that these masses and mixings are determined by flavor symmetries that also govern new particles that will appear at the LHC. We consider well-motivated examples in supersymmetry with both gravity- and gauge-mediation. Contrary to spreading belief, new physics need not be minimally flavor violating. We build non-minimally flavor violating models that successfully explain all known lepton masses and mixings, but span a wide range in their predictions for slepton flavor violation. In natural and favorable cases, these models have metastable sleptons and are characterized by fully reconstructible events. We outline many flavor measurements that are then possible and describe their prospects for resolving both the standard model and new physics flavor puzzles at the Large Hadron Collider.

Jonathan L. Feng; Christopher G. Lester; Yosef Nir; Yael Shadmi

2007-12-05T23:59:59.000Z

75

Hadronic Production of the Doubly Heavy Baryon $\\Xi_{bc}$ at LHC  

E-Print Network (OSTI)

We investigate the hadronic production of the doubly heavy baryon $\\Xi_{bc}$ at the large hadron collider (LHC), where the contributions from the four $(bc)$-diquark states $(bc)_{\\bf\\bar{3},6}[^1S_0]$ and $(bc)_{\\bf\\bar{3},6}[^3S_1]$ have been taken into consideration. Numerical results show that sizable $\\Xi_{bc}$ events about $ 1.1\\times 10^7$ and $2.0\\times10^9$ per year can be produced for the case of the center-of-mass energy $\\sqrt{S}=7$ TeV and $\\sqrt{S}=14$ TeV accordingly. For experimental usage, the total and the interested differential cross-sections are estimated under some typical $p_T$- and $y$- cuts for the LHC detectors CMS, ATLAS and LHCb, respectively.

Zhang, Jia-Wei; Zhong, Tao; Yu, Yao; Fang, Zhen-Yun

2011-01-01T23:59:59.000Z

76

Exploring small extra dimensions at the large hadron collider.  

E-Print Network (OSTI)

been shown that the ATLAS detector at the Large Hadron Collider can identify such narrow states up to a mass of 2080 GeV in the decay mode G ? e+e?, using a conservative model. This work extends the study of the e+e? channel over the full accessible... , the underlying parameters can be extracted. In one test model, the size of the extra dimension can be determined to a precision in length of 7 10?33 m. Keywords: Hadronic Colliders, Beyond Standard Model, Extra Large Dimensions. Contents 1. Introduction 1 2...

Allanach, B C; Odagiri, Kosuke; Palmer, M J; Parker, Michael A; Sabetfakhri, A; Webber, Bryan R

77

Detecting exotic heavy leptons at the large hadron collider.  

E-Print Network (OSTI)

ar X iv :h ep -p h/ 01 08 09 7v 1 1 0 A ug 2 00 1 Preprint typeset in JHEP style. - HYPER VERSION Cavendish-HEP-01/10 DAMTP-2001-71 CERN-TH/2001-205 Detecting Exotic Heavy Leptons at the Large Hadron Collider B.C. Allanach?, C.M. Harris, M... , CB3 0WA, UK. Abstract: New almost-degenerate charged and neutral heavy leptons are a feature of a number of theories of physics beyond the Standard Model. The prospects for detecting these at the Large Hadron Collider using a time-of-flight technique...

Allanach, B C; Harris, Chris M; Parker, Michael A; Richardson, P; Webber, Bryan R

78

Four-Lepton Resonance at the Large Hadron Collider  

E-Print Network (OSTI)

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

Vernon Barger; Hye-Sung Lee

2011-11-02T23:59:59.000Z

79

Strong WW scattering physics: A comparative study for the LHC, NLC and a Muon Collider  

SciTech Connect

We discuss the model independent parameterization for a strongly interacting electroweak sector. Phenomenological studies are made to probe such a sector for future colliders such as the LHC, e{sup +}e{sup -} Linear collider and a muon collider.

Han, Tao

1997-04-01T23:59:59.000Z

80

Interpretation of strange hadron production at LHC  

E-Print Network (OSTI)

We extend the SHM analysis of hadron production results showing here consistency with the increased experimental data set, stability of the fit with regard to inclusion of finite resonance widths and 2-star hyperon resonances. We present new results on strangeness yield as a function of centrality and present their interpretation in terms of QGP inspired model of strangeness abundance in the hadronizing fireball.

Michal Petr?; Jean Letessier; Vojt?ch Petr?ek; Johann Rafelski

2013-09-25T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Soft-gluon resummation for Higgs differential distributions at the Large Hadron Collider  

E-Print Network (OSTI)

We study the transverse-momentum (q_T) and rapidity (y) distributions of the Higgs boson in perturbative QCD, including the most advanced theoretical information presently available: fixed-order perturbation theory at Next-to-Leading Order (NLO) in the large-q_T region (q_T ~ M_H, being M_H the Higgs mass), and soft-gluon resummation at the Next-to-Next-to-Leading Logarithmic accuracy (NNLL) in the small-q_T region (q_T Large Hadron Collider (LHC).

Giuseppe Bozzi

2007-10-12T23:59:59.000Z

82

W production at large transverse momentum at the Large Hadron Collider  

E-Print Network (OSTI)

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

Richard J. Gonsalves; Nikolaos Kidonakis; Agustin Sabio Vera

2005-07-27T23:59:59.000Z

83

Origin of the Large Perturbative Corrections to Higgs Production at Hadron Colliders  

E-Print Network (OSTI)

The very large K-factor for Higgs-boson production at hadron colliders is shown to result from enhanced perturbative corrections of the form (C_A\\pi\\alpha_s)^n, which arise in the analytic continuation of the gluon form factor to time-like momentum transfer. These terms are resummed to all orders in perturbation theory using the renormalization group. After the resummation, the K-factor for the production of a light Higgs boson at the LHC is reduced to a value close to 1.3.

Valentin Ahrens; Thomas Becher; Matthias Neubert; Li Lin Yang

2008-08-21T23:59:59.000Z

84

Summary of the Very Large Hadron Collider Physics and Detector Subgroup  

E-Print Network (OSTI)

We summarize the activity of the Very Large Hadron Collider Physics and Detector subgroup during Snowmass 96.

D. Denisov; S. Keller

1997-01-28T23:59:59.000Z

85

Higgs and Supersymmetry searches at the Large Hadron Collider  

E-Print Network (OSTI)

We present here the results for Higgs and Supersymmetry prospective searches at the Large Hadron Collider. We show that for one year at high luminosity, Standard Model and MSSM Higgs should be observed within the theoretically expected mass range. MSUGRA and restricted phenomenological MSSM searches lead to discovery of up to 2.5 TeV squarks and gluinos.

F. Charles

2001-05-03T23:59:59.000Z

86

The Thermal Model at the Large Hadron Collider  

E-Print Network (OSTI)

A discussion is presented of results with identified particles at the Large Hadron Collider. Possible deviations from the standard statistical distributions are investigated by considering in detail results obtained using the Tsallis distribution. Matter-antimatter production is discussed within the framework of chemical equilibrium in \\pp and heavy ion collisions.

J. Cleymans

2012-03-26T23:59:59.000Z

87

Composite Weak Bosons at the Large Hadron Collider  

E-Print Network (OSTI)

In a composite model of the weak bosons the excited bosons, in particular the p-wave bosons, are studied. The state with the lowest mass is identified with the boson, which has been discovered recently at the "Large Hadron Collider" at CERN. Specific properties of the excited weak bosons are studied, in particular their decays into weak bosons and into photons.

Harald Fritzsch

2013-07-24T23:59:59.000Z

88

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

E-Print Network (OSTI)

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 Au 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 Pb beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

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

2010-09-08T23:59:59.000Z

89

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

SciTech Connect

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.

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

2012-04-30T23:59:59.000Z

90

Higgs pair production due to a radion resonance in Randall-Sundrum model: prospects at the Large Hadron Collider  

E-Print Network (OSTI)

We consider Higgs pair production at the Large Hadron Collider (LHC) in a Randall-Sundrum scenario containing a radion field. It is shown that the enhanced effective coupling of the radion to gluons, together with contributions from a low-lying radion pole, can provide larger event rates compared to most new physics possibilities considered so far. We present the results for both an intermediate mass Higgs and a heavy Higgs, with a detailed discussion of the background elimination procedure.

Prasanta Kumar Das; Biswarup Mukhopadhyaya

2003-03-16T23:59:59.000Z

91

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

Science Conference Proceedings (OSTI)

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

Peskin, Michael E.; /SLAC

2011-11-21T23:59:59.000Z

92

Dragging Heavy Quarks in Quark Gluon Plasma at the Large Hadron Collider  

E-Print Network (OSTI)

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

Santosh K Das; Jan-e Alam; Payal Mohanty

2010-03-29T23:59:59.000Z

93

Suggestions for benchmark scenarios for MSSM Higgs Boson searches at hadron colliders.  

SciTech Connect

The Higgs boson search has shifted from LEP2 to the Tevatron and will subsequently move to the LHC. Due to the different initial states, the Higgs production and decay channels relevant for Higgs boson searches were different at LEP2 to what they are at hadron colliders. They suggest new benchmark scenarios for the MSSM Higgs boson search at hadron colliders that exemplify the phenomenology of different parts of the MSSM parameter space. Besides the m{sub h}{sup max} scenario and the no-mixing scenario used in the LEP2 Higgs boson searches, they propose two new scenarios. In one the main production channel at the LHC, gg {yields} h, is suppressed. In the other, important Higgs decay channels at the Tevatron and at the LCH, h {yields} b{bar b} and h {yields} {tau}{sup +}{tau}{sup -}, are suppressed. All scenarios evade the LEP2 constraints for nearly the whole M{sub A}-tan {beta}-plane.

Carena, M.; Heinemeyer, S.; Wagner, C.E.M.; Weiglein, G.

2002-04-15T23:59:59.000Z

94

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

SciTech Connect

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

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

2009-08-01T23:59:59.000Z

95

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

DOE Data Explorer (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.

96

Test of Influence from Future in Large Hadron Collider; A Proposal  

E-Print Network (OSTI)

We have earlier proposed the idea of making card drawing experiment of which outcome potentially decides whether Large Hadron Collider (LHC for short) should be closed or not. The purpose is to test theoretical models which, like e.g. our own model that has an imaginary part of the action with much a similar form to that of the real part. The imaginary part has influence on the initial conditions not only in the past but even from the future. It was speculated that all accelerators producing large amounts of Higgs particles like the Superconducting Super Collider (SSC for short) would call for initial conditions to have been so arranged as to finally not allow these accelerators to come to work. If there were such effects we could perhaps provoke a very clear cut "miracle" by having the effect make the drawn card be the one closing LHC. Here we shall, however, discuss that a total closing is hardly needed and seek to calculate how one could perform checking experiment for the proposed type of influence from future to be made in the statistically least disturbing and least harmful way. We shall also discuss how to extract most information about our effect or model in the unlikely case that a card restricting the running of LHC or the Tevatron would be drawn at all, by estimating say the relative importance of high beam energy or of high luminosity for the purpose of our effect.

Holger B. Nielsen; Masao Ninomiya

2008-02-21T23:59:59.000Z

97

Non-universal gaugino and scalar masses, hadronically quiet trileptons and the Large Hadron Collider  

E-Print Network (OSTI)

We investigate the parameter space of the minimal supersymmetric Standard Model (MSSM) where the gluino and squark masses are much above 1 TeV but the remaining part of the sparticle spectrum is accessible to the Large Hadron Collider at CERN. After pointing out that such a scenario may constitute an important benchmark of gaugino/scalar non-universality, we find that hadronically quiet trileptons are rather useful signals for it. Regions of the parameter space, where the signal is likely to be appreciable, are identified through a detailed scan. The advantage of hadronically quiet trileptons over other types of signals is demonstrated.

Subhaditya Bhattacharya; AseshKrishna Datta; Biswarup Mukhopadhyaya

2008-09-11T23:59:59.000Z

98

International Journal of Modern Physics Letters A Vol. 20 (2005) Higgs Boson Searches at Hadron Colliders  

E-Print Network (OSTI)

The investigation of the dynamics responsible for electroweak symmetry breaking is one of the prime tasks of experiments at present and future colliders. Experiments at the Tevatron pp Collider and at the CERN Large Hadron Collider (LHC) must be able to discover a Standard Model Higgs boson over the full mass range as well as Higgs bosons in extended models. In this review, the discovery potential for the Standard Model Higgs boson and for Higgs bosons in the Minimal Supersymmetric extension is summarized. Emphasis is put on those studies which have been performed recently within the experimental collaborations using a realistic simulation of the detector performance. This includes a discussion of the search for Higgs bosons using the vector boson fusion mode at the LHC, a discussion on the measurement of Higgs boson parameters as well as a detailed review of the MSSM sector for different benchmark scenarios. The Tevatron part of the review also contains a discussion of first physics results from data taken in the ongoing Run II. 1

Volker Bscher; Karl Jakobs

2005-01-01T23:59:59.000Z

99

Higgs friends and counterfeits at hadron colliders  

SciTech Connect

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.

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

2011-04-01T23:59:59.000Z

100

Higgs friends and counterfeits at hadron colliders  

E-Print Network (OSTI)

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.

Patrick J. Fox; David Tucker-Smith; Neal Weiner

2011-04-28T23:59:59.000Z

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101

Learning to See at the Large Hadron Collider  

E-Print Network (OSTI)

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

Chris Quigg

2010-01-12T23:59:59.000Z

102

Learning to See at the Large Hadron Collider  

SciTech Connect

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

Quigg, Chris

2010-01-01T23:59:59.000Z

103

NNLO Benchmarks for Gauge and Higgs Boson Production at TeV Hadron Colliders  

E-Print Network (OSTI)

The inclusive production cross sections for $W^+, W^-$ and $Z^0$-bosons form important benchmarks for the physics at hadron colliders. We perform a detailed comparison of the predictions for these standard candles based on recent next-to-next-to-leading order (NNLO) parton parameterizations and new analyses including the combined HERA data, compare to all available experimental results, and discuss the predictions for present and upcoming RHIC, SPS, Tevatron and LHC energies. The rates for gauge boson production at the LHC can be rather confidently predicted with an accuracy of better than about 10% at NNLO. We also present detailed NNLO predictions for the Higgs boson production cross sections for Tevatron and LHC energies (1.96, 7, 8, 14 TeV), and propose a possible method to monitor the gluon distribution experimentally in the kinematic region close to the mass range expected for the Higgs boson. The production cross sections of the Higgs boson at the LHC are presently predicted with an accuracy of about 10--17%. The inclusion of the NNLO contributions is mandatory for achieving such accuracies since the total uncertainties are substantially larger at NLO.

S. Alekhin; J. Blmlein; P. Jimenez-Delgado; S. Moch; E. Reya

2010-11-29T23:59:59.000Z

104

A 233 km tunnel for lepton and hadron colliders  

SciTech Connect

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.

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

2012-12-21T23:59:59.000Z

105

Higgs Boson Production at Hadron Colliders in NNLO QCD  

SciTech Connect

We compute the total cross-section for direct Higgs boson production in hadron collisions at NNLO in perturbative QCD. A new technique which allows us to perform an algorithmic evaluation of inclusive phase-space integrals is introduced, based on the Cutkosky rules, integration by parts and the differential equation method for computing master integrals. Finally, we discuss the numerical impact of the {Omicron}({alpha}{sub s}{sup 2}) QCD corrections to the Higgs boson production cross-section at the LHC and the Tevatron.

Anastasiou, Charalampos

2002-08-08T23:59:59.000Z

106

Compressed supersymmetry after 1/fb at the Large Hadron Collider  

E-Print Network (OSTI)

We study the reach of the Large Hadron Collider with 1/fb of data at sqrt{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 higher effective mass.

Thomas J. LeCompte; Stephen P. Martin

2011-11-29T23:59:59.000Z

107

Possible Signals of Wino LSP at the Large Hadron Collider  

E-Print Network (OSTI)

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

M. Ibe; Takeo Moroi; T. T. Yanagida

2006-10-21T23:59:59.000Z

108

A Method to Determine the Flexural Rigidity of the Main Dipole for the Large Hadron Collider  

E-Print Network (OSTI)

The Large Hadron Collider (LHC) superconducting dipole cold mass is a cylindrical structure 15 m long, made of a shrinking cylinder which contains iron laminations and collared coils. This structure, weighing about 28 ton is horizontally bent by 5 mrad. Its shape should be preserved from the assembly phase to the operational condition at cryogenic temperature. Hence an accurate comprehension of the mechanical behaviour of the cold mass is required. In particular the flexural rigidity in horizontal and vertical directions represents one of the foremost properties to be aware of. To determine the flexural rigidity, deformations of the cold mass induced by the self weight have been measured and compared with the predictions of an analytical structural model. A particular care has been taken in reducing the experimental error by an appropriate fitting procedure.

La China, M; Ferracin, P; Garca-Prez, J; Todesco, Ezio; Scandale, Walter; 10.1109/TASC.2003.812655

2003-01-01T23:59:59.000Z

109

Performance Assessment of 239 Series Sub-cooling Heat Exchangers for the Large Hadron Collider  

E-Print Network (OSTI)

Helium sub-cooling heat exchangers of the counter-flow type are used to minimize the vapor fraction produced in the final expansion of the 1.9 K distributed cooling loops used for cooling the superconducting magnets of the Large Hadron Collider (LHC). These components are of compact design, featuring low-pressure drop and handling very low pressure vapor at low temperature. Following a qualification phase of prototypes, a contract has been placed in European industry for the supply of 239 heat exchanger units. Different levels of extracted heat load require three different variants of heat exchangers. This paper will describe the manufacturing phase with emphasis on the main difficulties encountered to keep the production quality after a brief recall of the prototype phase. Finally, the acceptance tests performed at room temperature and at the nominal cryogenic condition at the factory and at CEA-Grenoble will be presented.

Riddone, G; Roussel, P; Moracchioli, R; Tavian, L

2006-01-01T23:59:59.000Z

110

Geometrical position of the Large Hadron Collider main dipole inside the cryostat  

E-Print Network (OSTI)

The superconducting dipole of the Large Hadron Collider (LHC) is a cylindrical structure made of a shrinking cylinder containing iron laminations and collared coils. This 15 m long structure, weighing about 28 t, is horizontally bent by 5 mrad. Its geometrical shape should be preserved, from the assembly phase to the operational condition at cryogenic temperature. When inserted in its cryostat, the dipole cold mass is supported by three posts also providing the thermal insulation. Sliding interfaces should minimize the interference between the dipole and the cryostat during cooling down and warming up. Indeed, a possible non-linear response of the sliding interface can detrimentally affect the final dipole shape. This paper presents the results of dedicated tests investigating interferences and of specific simulations with a 3D finite element model (FEM) describing the mechanical behaviour of the dipole inside the cryostat. Comparison between measurements and FEM simulations is also discussed.

La China, M; Gubello, G; Hauviller, Claude; Scandale, Walter; Todesco, Ezio

2002-01-01T23:59:59.000Z

111

Meson production in two-photon interactions at energies available at CERN Large Hadron Collider  

E-Print Network (OSTI)

The meson production cross sections are estimated considering photon-photon interactions in hadron - hadron collisions at CERN LHC energies. We consider a large number of mesons with photon-photon partial decay width well constrained by the experiment and some mesons which are currently considered as hadronic molecule and glueball candidates. Our results demonstrate that the experimental analysis of these states is feasible at CERN - LHC.

V. P. Goncalves; D. T. da Silva; W. K. Sauter

2012-09-04T23:59:59.000Z

112

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

E-Print Network (OSTI)

We present the next-to-leading order (NLO) QCD results for W+4-jet production at hadron colliders. This is the first hadron-collider process with five final-state objects to be computed at NLO. It represents an important ...

Berger, Carola

113

Ultrafast tracking electronics for the ATLAS trigger at the CERN Large Hadron Collider  

E-Print Network (OSTI)

FTK Ultrafast tracking electronics for the ATLAS trigger at the CERN Large Hadron Collider Italy challenge at a hadron collider is determining what a new phenomenon is. Higgs, SUSY, KK excitations, Z of decay products multiple decay modes couplings to other particles · For each of these, large samples

114

Hadron production at LHC in dipole momentum space  

Science Conference Proceedings (OSTI)

The dipole color approach is the framework that considers the quark-antiquark pair scattering off the target. The rapidity evolution of color dipoles is given by the nonlinear Balitsky-Kovchegov (BK) equation, for which analytical solutions are not yet known. A good way to explore the asymptotic BK solutions is through the traveling wave method of QCD, that uses a correspondence between the BK evolution equation in momentum space and reaction-diffusion physics. Using the traveling wave based AGBS model for the dipole amplitude in momentum space, and within the k{sub t}-factorization formalism, we describe the LHC data on single inclusive hadron yield for p-p collisions.

Basso, E. A.; Gay Ducati, M. B. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970 - Porto Alegre, RS (Brazil); De Oliveira, E. G. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05314-970 Sao Paulo, SP (Brazil)

2013-03-25T23:59:59.000Z

115

The Local Helium Compound Transfer Lines for the Large Hadron Collider Cryogenic System  

E-Print Network (OSTI)

The cryogenic system for the Large Hadron Collider (LHC) under construction at CERN will include twelve new local helium transfer lines distributed among five LHC points in underground caverns. These lines, being manufactured and installed by industry, will connect the cold boxes of the 4.5-K refrigerators and the 1.8-K refrigeration units to the cryogenic interconnection boxes. The lines have a maximum of 30-m length and may possess either small or large re-distribution units to allow connection to the interface ports. Due to space restrictions the lines may have complex routings and require several elbowed sections. The lines consist of a vacuum jacket, a thermal shield and either three or four helium process pipes. Specific internal and external supporting and compensation systems were designed for each line to allow for thermal contraction of the process pipes (or vacuum jacket, in case of a break in the insulation vacuum) and to minimise the forces applied to the interface equipment. Whenever possible, f...

Parente, C; Munday, A; Wiggins, P

2006-01-01T23:59:59.000Z

116

A novel method for modeling the recoil in W boson events at hadron collider  

E-Print Network (OSTI)

We present a new method for modeling the hadronic recoil in W->lnu events produced at hadron colliders. The recoil is chosen from a library of recoils in Z->ll data events and overlaid on a simulated W->lnu 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-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.

V. M. Abazov

2009-07-21T23:59:59.000Z

117

Hadronic forward scattering: Predictions for the Large Hadron Collider and cosmic rays  

E-Print Network (OSTI)

The status of hadron-hadron interactions is reviewed, with emphasis on the forward and near-forward scattering regions. From analyticity, Finite Energy Sum Rules are introduced from which new analyticity constraints are derived that exploit the many very accurate low energy experimental cross sections, i.e., they constrain the values of the asymptotic cross sections and their derivatives at low energies just above the resonance regions, allowing us new insights into duality. A new robust fitting technique is introduced in order to `clean up' large data samples that are contaminated by outliers. Using our analyticity constraints, new methods of fitting high energy hadronic data are introduced which result in much more precise estimates of the fit parameters, allowing accurate extrapolations to much higher energies. It's shown that the $\\gamma p$, $\\pi^\\pm p$ and nucleon-nucleon cross sections {\\em all} go asymptotically as $\\ln^2s$, saturating the Froissart bound, while conclusively ruling out $\\ln s$ and $s^{\\alpha}$ ($\\alpha\\sim 0.08$) behavior. Implications of this saturation for predictions of $\\sigma_{pp}$ and $\\rho_{pp}$ at the LHC and for cosmic rays p-air cross sections are given.

Martin M. Block

2006-06-20T23:59:59.000Z

118

Linear Collider LHC Subpanel | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Subpanel on the Linear Collider and the Large Hadron Subpanel on the Linear Collider and the Large Hadron Collider High Energy Physics Advisory Panel (HEPAP) HEPAP Home Meetings Members .pdf file (20KB) Charges/Reports Charter .pdf file (44KB) HEP Committees of Visitors HEP Home Charges/Reports Subpanel on the Linear Collider and the Large Hadron Collider Print Text Size: A A A RSS Feeds FeedbackShare Page Joseph Lykken (FNAL) Co-Chair James Siegrist (LBNL) Co-Chair Jonathan Bagger (JHU) Barry Barish (Caltech) Neil Calder (SLAC) Jonathan Feng (UC Irvine) Fred Gilman (Carnegie Mellon) JoAnne Hewett (SLAC) John Huth (Harvard) Judy Jackson (Fermilab) Young-Kee Kim (Chicago) Rocky Kolb (Fermilab) Joe Lykken (Fermilab) Konstantin Matchev (Florida) Hitoshi Murayama (UC Berkeley) Jim Siegrist (UC Berkeley) Paris Sphicas (CERN/Athens)

119

Dark matter at colliders  

SciTech Connect

We show that colliders can impose strong constraints on dark matter. We take an effective field theory approach where dark matter couples to quarks and gluons through high dimensional operators. We discuss limits on interactions of dark matter and hadronic matter from the ATLAS experiment at the Large Hadron Collider (LHC). For spin-independent scattering, the LHC limits are stronger than those from direct detection experiments for light WIMPs. For spin-dependent scattering, the LHC sets better limits over much of parameter space.

Yu Haibo [Department of Physics, University of Michigan, Ann Arbor, MI, 48109 (United States)

2013-05-23T23:59:59.000Z

120

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

SciTech Connect

The production of a Higgs boson in association with a pair of t{bar t} or b{bar b} quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief introduction, we review the results obtained for both the Tevatron and the Large Hadron Collider.

DAWSON,S.JACKSON,C.B.ORR,L.H.REINA,L.WACKEROTH,D.

2003-07-17T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Phenomenology of the minimal $B-L$ Model: the Higgs sector at the Large Hadron Collider and future Linear Colliders  

E-Print Network (OSTI)

This Thesis is devoted to the study of the phenomenology of the Higgs sector of the minimal $B-L$ extension of the Standard Model at present and future colliders. Firstly, the motivations that call for the minimal $B-L$ extension are summarised. In addition, the model is analysed in its salient parts. Moreover, a detailed review of the phenomenological allowed Higgs sector parameter space is given. Finally, a complete survey of the distinctive Higgs boson signatures of the model at both the Large Hadron Collider and the future linear colliders is presented.

Giovanni Marco Pruna

2011-06-23T23:59:59.000Z

122

QCD and low-x physics at a Large Hadron electron Collider  

E-Print Network (OSTI)

The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC for electron-proton scattering, through the addition of a new electron accelerator. This contribution, which is derived from the draft CERN-ECFA-NuPECC Conceptual Design report (due for release in 2012), addresses the expected impact of the LHeC precision and extended kinematic range for low Bjorken-x and diffractive physics, and detailed simulation studies and prospects for high precision QCD and electroweak fits. Numerous observables which are sensitive to the expected low-x saturation of the parton densities are explored. These include the inclusive electron-proton scattering cross section and the related structure functions $F_2$ and $F_L$, as well as exclusive processes such as deeply-virtual Compton scattering and quasi-elastic heavy vector meson production and diffractive virtual photon dissociation. With a hundred times the luminosity that was achieved at HERA, salient expectations for the LHeC include the complete determination of all light and heavy quark parton distributions for the first time, the high precision extraction of the gluon density, the determination of the strong coupling constant to per-mil accuracy and the precision study of the running of the electroweak mixing angle.

Paul Laycock

2012-02-13T23:59:59.000Z

123

GPU Enhancement of the Trigger to Extend Physics Reach at the Large Hadron Collider  

E-Print Network (OSTI)

At the Large Hadron Collider (LHC), the trigger systems for the detectors must be able to process a very large amount of data in a very limited amount of time, so that the nominal collision rate of 40 MHz can be reduced to a data rate that can be stored and processed in a reasonable amount of time. This need for high performance places very stringent requirements on the complexity of the algorithms that can be used for identifying events of interest in the trigger system, which potentially limits the ability to trigger on signatures of various new physics models. In this paper, we present an alternative tracking algorithm, based on the Hough transform, which avoids many of the problems associated with the standard combinatorial track finding currently used. The Hough transform is also well-adapted for Graphics Processing Unit (GPU)-based computing, and such GPU-based systems could be easily integrated into the existing High-Level Trigger (HLT). This algorithm offers the ability to trigger on topological signatures of new physics currently not practical to reconstruct, such as events with jets or black holes significantly displaced from the primary vertex. This paper presents, for the first time, an implementation and preliminary performance results using NVIDIA Tesla C2075 and K20c GPUs.

P. Lujan; V. Halyo; A. Hunt; P. Jindal; P. LeGresley

2013-11-12T23:59:59.000Z

124

SIMULATION OF THE HIGGS BOSON PRODUCTION AT LHC, ILC AND PHOTON LINEAR COLLIDER ?  

E-Print Network (OSTI)

Prospects for precise determination of the Higgs boson couplings from a combined analysis of LHC, ILC and the Photon Linear Collider data are studied in detail for the CP-conserving Two Higgs Doublet Model (II). LHC, ILC and the Photon Collider measurements are complementary, being sensitive to different coupling combinations. For the mass of the heavy scalar Higgs boson between 200 and 350 GeV, where ZZ and W + W ? decaychannels dominate, only the combined analysis of the LHC, ILC and the Photon Collider data allows for unique determination of the basic Higgs boson couplings and for establishing evidence for the possible CP violation in 2HDM. Additional constraints on the model parameters can be obtained by combining available data for the production and decays of the heavy Higgs boson H with the corresponding measurements for the light Higgs boson h. PACS numbers: 11.15.Ex, 11.30.Er, 12.60.Fr, 14.80.Cp 1.

P. Nie?urawski; A. F. ?arnecki; M. Krawczyk

2006-01-01T23:59:59.000Z

125

Performance analysis of a file catalog for the LHC computing grid  

Science Conference Proceedings (OSTI)

The Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, needs to produce unprecedented volumes of data when it starts operation in 2007. To provide for its computational needs, the LHC computing grid (LCG) should be deployed ...

J.-P. Baud; J. Casey; S. Lemaitre; C. Nicholson

2005-07-01T23:59:59.000Z

126

Using Gordon to accelerate LHC science  

Science Conference Proceedings (OSTI)

The discovery of the Higgs boson by the Large Hadron Collider (LHC) has garnered international attention. In addition to this singular result, the LHC may also uncover other fundamental particles, including dark matter. Much of this research is being ... Keywords: CMS, Gordon, LHC, OSG, SDSC, WLCG, dataintensive, filesystems, higgs, high-throughput computing, physics, workflow, workflows

Rick Wagner; Mahidhar Tatineni; Eva Hocks; Kenneth Yoshimoto; Scott Sakai; Michael L. Norman; Brian Bockelman; Igor Sfiligoi; Matevz Tadel; James Letts; Frank Wrthwein; Lothar A. Bauerdick

2013-07-01T23:59:59.000Z

127

Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider  

E-Print Network (OSTI)

We calculate the thermal photon transverse momentum spectra and elliptic flow in $\\sqrt{s_{NN}} = 200$ GeV Au+Au collisions at RHIC and in $\\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC, using an ideal-hydrodynamical framework which is constrained by the measured hadron spectra at RHIC and LHC. The sensitivity of the results to the QCD-matter equation of state and to the photon emission rates is studied, and the photon $v_2$ is discussed in the light of the photonic $p_T$ spectrum measured by the PHENIX Collaboration. In particular, we make a prediction for the thermal photon $p_T$ spectra and elliptic flow for the current LHC Pb+Pb collisions.

Hannu Holopainen; Sami Rsnen; Kari J. Eskola

2011-04-28T23:59:59.000Z

128

QCD effects in Higgs boson production at hadron colliders  

E-Print Network (OSTI)

We present updated predictions for Higgs boson production at the Tevatron and the LHC and we review their corresponding uncertainties. We report on a study of the impact of QCD radiative corrections on the Higgs boson search at the Tevatron.

M. Grazzini

2010-01-21T23:59:59.000Z

129

Top Quark Production at the LHC  

E-Print Network (OSTI)

Top quark production in proton proton collisions at the Large Hadron Collider (LHC) is reviewed using data collected by the ATLAS and CMS detectors. Most recent results on searches for new physics related to top quark production mechanism are included.

Francesco Span; for the ATLAS; CMS collaborations

2011-12-16T23:59:59.000Z

130

LHC Dipole Acceptance | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnet Division designed, constructed and tested dipole magnets for the Large Hadron Collider (LHC) at CERN. Each of the BNL-built dipole magnets was tested at the Lab's...

131

Hadron production and QGP Hadronization in Pb--Pb collisions at $\\sqrt{s_{NN}}=2.76$ TeV  

E-Print Network (OSTI)

We show that all central rapidity hadron yields measured in Pb--Pb collisions at $\\sqrt{s_{NN}}=2.76$ TeV are well described by the chemical non-equilibrium statistical hadronization model (SHM), where the chemically equilibrated QGP source breaks up directly into hadrons. SHM parameters are obtained as a function of centrality of colliding ions, and we compare CERN Large Hadron Collider (LHC) with Brookhaven National Laboratory Relativistic Heavy Ion Collider (RHIC) results. We predict yields of unobserved hadrons and address anti-matter production. The physical properties of the quark--gluon plasma fireball particle source show universality of hadronization conditions at LHC and RHIC.

Michal Petran; Jean Letessier; Vojtech Petracek; Johann Rafelski

2013-03-08T23:59:59.000Z

132

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

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.

Miller, David Wilkins

2012-03-20T23:59:59.000Z

133

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

E-Print Network (OSTI)

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

Douglas M. Gingrich

2010-01-05T23:59:59.000Z

134

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

SciTech Connect

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

Gingrich, Douglas M. [Centre for Particle Physics, Department of Physics, University of Alberta, Edmonton, AB T6G 2G7 (Canada)

2010-03-01T23:59:59.000Z

135

SUSY-induced FCNC top-quark processes at the Large Hadron Collider  

E-Print Network (OSTI)

We systematically calculate various flavor-changing neutral-current top-quark processes induced by supersymmetry at the Large Hadron Collider, which include five decay modes and six production channels. To reveal the characteristics of these processes, we first compare the dependence of the rates for these channels on the relevant supersymmetric parameters, then we scan the whole parameter space to find their maximal rates, including all the direct and indirect current experimental constraints on the scharm-stop flavor mixings. We find that, under all these constraints, only a few channels, through cg->t at parton-level and t-> ch, may be observable at the Large Hadron Collider.

J. J. Cao; G. Eilam; M. Frank; K. Hikasa; G. L. Liu; I. Turan; J. M. Yang

2007-02-26T23:59:59.000Z

136

The Standard Model and Supersymmetric Flavor Puzzles at the Large Hadron Collider  

E-Print Network (OSTI)

ar X iv :0 71 2. 06 74 v1 [ he p- ph ] 5 D ec 20 07 UCI-TR-2007-49 The Standard Model and Supersymmetric Flavor Puzzles at the Large Hadron Collider Jonathan L. Feng,1 Christopher G. Lester,2 Yosef Nir,3 and Yael Shadmi4 1Department of Physics... Israel Institute of Technology, Haifa 32000, Israel (Dated: December 2007) Abstract Can the Large Hadron Collider explain the masses and mixings of the known fermions? A promising possibility is that these masses and mixings are determined by flavor symmetries...

Feng, Jonathan; Lester, Christopher G; Nir, Yosef; Shadmi, Yael

2008-01-01T23:59:59.000Z

137

Search for Gluino-Mediated Supersymmetry in Events With Bottom-Quark Jets and Missing Transverse Energy With the Compact Muon Solenoid Detector at the Large Hadron Collider With Proton-Proton Collisions at 8 TeV  

E-Print Network (OSTI)

Detector at the Large Hadron Collider With Proton-ProtonDetector at the Large Hadron Collider With Proton-Protonthe CMS detec- tor at the Large Hadron Collider in 2012. The

Nguyen, Harold

2013-01-01T23:59:59.000Z

138

A Measurement of the Underlying Event Distributions in Proton-Proton Collisions at sqrt(s) = 7 TeV in Events containing Charged Particle Jets using the ATLAS Detector at the Large Hadron Collider  

E-Print Network (OSTI)

3 The ATLAS Inner Detector at the Large Hadron Collider 3.1The Large Hadron Collider at CERN . . . . . . . . . . 3.2Experiment at the Large Hadron Collider, PhD thesis, 2010. [

Virzi, Joseph Salvatore

2012-01-01T23:59:59.000Z

139

Heavy Flavor at the Large Hadron Collider in a Strong Coupling Approach  

E-Print Network (OSTI)

Employing nonperturbative transport coefficients for heavy-flavor (HF) diffusion through quark-gluon plasma (QGP), hadronization and hadronic matter, we compute $D$- and $B$-meson observables in Pb+Pb ($\\sqrt{s}$=2.76\\,TeV) collisions at the LHC. Elastic heavy-quark scattering in the QGP is evaluated within a thermodynamic $T$-matrix approach, generating resonances close to the critical temperature which are utilized for recombination into $D$ and $B$ mesons, followed by hadronic diffusion using effective hadronic scattering amplitudes. The transport coefficients are implemented via Fokker-Planck Langevin dynamics within hydrodynamic simulations of the bulk medium in nuclear collisions. The hydro expansion is quantitatively constrained by transverse-momentum spectra and elliptic flow of light hadrons. Our approach thus incorporates the paradigm of a strongly coupled medium in both bulk and HF dynamics throughout the thermal evolution of the system.

Min He; Rainer J. Fries; Ralf Rapp

2014-01-16T23:59:59.000Z

140

TESLA*HERA as Lepton (Photon)-Hadron Collider  

E-Print Network (OSTI)

New facilities for particle and nuclear physics research, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

O. Yavas; A. K. Ciftci; S. Sultansoy

2000-04-11T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Ground Vibration Measurements at LHC Point 4  

Science Conference Proceedings (OSTI)

Ground vibration was measured at Large Hadron Collider (LHC) Point 4 during the winter shutdown in February 2012. This report contains the results, including power and coherence spectra. We plan to collect and analyze vibration data from representative collider halls to inform specifications for future linear colliders, such as ILC and CLIC. We are especially interested in vibration correlations between final focus lens locations.

Bertsche, Kirk; /SLAC; Gaddi, Andrea; /CERN

2012-09-17T23:59:59.000Z

142

Predictions for p+Pb at 5.02A TeV to test initial state nuclear shadowing at the Large Hadron Collider  

E-Print Network (OSTI)

Collinear factorized perturbative QCD model predictions are compared for $p+{\\rm Pb}$ at 5.02$A$ TeV to test nuclear shadowing of parton distribution at the Large Hadron Collider (LHC). The pseudorapidity distribution and the nuclear modification factor (NMF), $R_{p{\\rm Pb}}(y=0,p_T<20\\;{\\rm GeV}/{\\it c}) = dn_{p{\\rm Pb}} /(N_{\\rm coll}(b)dn_{pp})$, is computed within {\\small HIJING/\\=B v2.0 model}. These results are updated calculations of those presented in Ref. Phys. Rev C85, 024903 (2012).

Barnafoldi, G G; Gyulassy, M; Levai, P; Petrovici, M; Pop, V Topor

2012-01-01T23:59:59.000Z

143

Top quark and charged Higgs production at hadron colliders  

Science Conference Proceedings (OSTI)

I present a brief theoretical update on top quark pair production at the Tevatron and give values of the NNLO-NNNLL cross section for both mt = 175 and 178 GeV. I then present a calculation of the cross section for charged Higgs production in association with a top quark at the LHC, including NNLO soft-gluon corrections.

Kidonakis, Nikolaos [Kennesaw State University, Physics no. 1202, 1000 Chastain Rd, Kennesaw, GA 30144-5591 (United States)

2005-10-06T23:59:59.000Z

144

Single Production of Fourth Family b' Quark at the Large Hadron electron Collider  

E-Print Network (OSTI)

We examined the single production of fourth family b' quarks at the Large Hadron electron Collider (LHeC).We have analyzed the background and the signal processes for the mass range 300-800 GeV. We find the discovery region for an optimal parametrization of the Vqb' matrix elements.

O. Cakir; V. Cetinkaya

2009-12-10T23:59:59.000Z

145

Jet substructure as a new Higgs search channel at the Large Hadron Collider  

E-Print Network (OSTI)

We show that W H and Z H production where the Higgs boson decays to bbbar can be recovered as good search channels for the Standard Model Higgs at the Large Hadron Collider. This is done by requiring the Higgs to have high transverse momentum, and employing state-of-the-art jet reconstruction and decomposition techniques.

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

2008-10-02T23:59:59.000Z

146

Constraints on New Physics from Baryogenesis and Large Hadron Collider Data  

E-Print Network (OSTI)

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

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

2013-05-19T23:59:59.000Z

147

NCG gluon fusion for the Higgs production at large hadron colliders  

Science Conference Proceedings (OSTI)

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.

Chadou, I.; Mebarki, N.; Bekli, M. R. [Laboratoire de Physique Mathematique et Subatomique, University of Constantine (Algeria)

2012-06-27T23:59:59.000Z

148

Summary of the Very Large Hadron Collider Physics and Detector subgroup  

SciTech Connect

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

Denisov, D.; Keller, S.

1996-12-31T23:59:59.000Z

149

Pseudoscalar Higgs boson production at hadron colliders in NNLO QCD  

SciTech Connect

We compute the total cross-section for direct production of the pseudoscalar Higgs boson in hadron collisions at next-to-next-to-leading order (NNLO) in perturbative QCD. The {Omicron}({alpha}{sub s}{sup 2}) QCD corrections increase the NLO production cross-section by approximately 20-30%.

Anastasiou, Charalampos

2002-08-26T23:59:59.000Z

150

Exploring higher dimensional black holes at the large hadron collider.  

E-Print Network (OSTI)

formation in the grazing collision of high-energy particles, Phys. Rev. D67 (2003) 024009, [gr-qc/0209003]. [27] C. M. Harris, Physics Beyond the Standard Model: Exotic Leptons and Black Holes at Future Colliders. PhD thesis, University of Cambridge, 2003...

Harris, Chris M; Palmer, M J; Parker, Michael A; Richardson, P

151

Signals of doubly-charged Higgsinos at the CERN Large Hadron Collider  

SciTech Connect

Several supersymmetric models with extended gauge structures, motivated by either grand unification or by neutrino mass generation, predict light doubly-charged Higgsinos. In this work we study productions and decays of doubly-charged Higgsinos present in left-right supersymmetric models, and show that they invariably lead to novel collider signals not found in the minimal supersymmetric model or in any of its extensions motivated by the {mu} problem or even in extra dimensional theories. We investigate their distinctive signatures at the Large Hadron Collider in both pair- and single-production modes, and show that they are powerful tools in determining the underlying model via the measurements at the Large Hadron Collider experiments.

Demir, Durmus A. [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir (Turkey); Deutsches Elektronen--Synchrotron, DESY, D-22603 Hamburg (Germany); Frank, Mariana; Turan, Ismail [Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6 (Canada); Huitu, Katri; Rai, Santosh Kumar [Department of Physics, University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FIN-00014 Helsinki (Finland)

2008-08-01T23:59:59.000Z

152

Simulations of electron-cloud heat load for the cold arcs of the CERN Large Hadron Collider and its high-luminosity upgrade scenarios  

E-Print Network (OSTI)

The heat load generated by an electron cloud in the cold arcs of the Large Hadron Collider (LHC) is a concern for operation near and beyond nominal beam current. We report the results of simulation studies, with updated secondary- emission models, which examine the severity of the electron heat load over a range of possible operation parameters, both for the nominal LHC and for various luminosity-upgrade scenarios, such as the so-called full crab crossing and early separation schemes, the large Piwinski angle scheme, and a variant of the latter providing compatibility with the (upgraded) LHCb experiment. The variable parameters considered are the maximum secondary-emission yield, the number of particles per bunch, and the spacing between bunches. In addition, the dependence of the heat load on the longitudinal bunch profile is investigated.

Maury Cuna, H; Zimmermann, F

2012-01-01T23:59:59.000Z

153

Nuclear shadowing and prompt photons at relativistic hadron colliders  

E-Print Network (OSTI)

The production of prompt photons at high energies provides a direct probe of the dynamics of the strong interactions. In particular, one expect that it could be used to constrain the behavior of the nuclear gluon distribution in $pA$ and $AA$ collisions. In this letter we investigate the influence of nuclear effects in the production of prompt photons and estimate the transverse momentum dependence of the nuclear ratios $R_{pA} = {\\frac{d\\sigma (pA)}{dy d^2 p_T}} / A {\\frac{d\\sigma (pp)}{dy d^2 p_T}}$ and $R_{AA} = {\\frac{d\\sigma (AA)}{dy d^2 p_T}} / A^2 {\\frac{d\\sigma (pp)}{dy d^2 p_T}}$ at RHIC and LHC energies. We demonstrate that the study of these observables can be useful to determine the magnitude of the shadowing and antishadowing effects in the nuclear gluon distribution.

C. Brenner Mariotto; V. P. Goncalves

2008-07-10T23:59:59.000Z

154

Electroweak and flavor dynamics at hadron colliders - I  

SciTech Connect

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

Elchtent, E.; Lane, K. [Boston Univ., MA (United States)

1998-02-01T23:59:59.000Z

155

Effect of charged partons on black hole production at the Large Hadron Collider  

E-Print Network (OSTI)

The cross section for black hole production in hadron colliders is calculated using a factorization hypothesis in which the parton-level process is integrated over the parton density functions of the protons. The mass, spin, charge, colour, and finite size of the partons are usually ignored. We examine the effects of parton electric charge on black hole production using the trapped-surface approach of general relativity. Accounting for electric charge of the partons could reduce the black hole cross section by one to four orders of magnitude at the Large Hadron Collider. The cross section results are sensitive to the Standard Model brane thickness. Lower limits on the amount of energy trapped behind the event horizon in the collision of charged particles are also calculated.

Douglas M. Gingrich

2006-12-09T23:59:59.000Z

156

Missing energy in black hole production and decay at the Large Hadron Collider  

E-Print Network (OSTI)

Black holes could be produced at the Large Hadron Collider in TeV-scale gravity scenarios. We discuss missing energy mechanisms in black hole production and decay in large extra-dimensional models. In particular, we examine how graviton emission into the bulk could give the black hole enough recoil to leave the brane. Such a perturbation would cause an abrupt termination in Hawking emission and result in large missing-energy signatures.

Douglas M. Gingrich

2007-06-05T23:59:59.000Z

157

Comparison of Higgs Boson Mass and Width Determination of the LHC and a Linear Collider  

E-Print Network (OSTI)

Two important properties of a Higgs boson are its mass and width. They may distinguish the Standard Model (SM) Higgs boson from Higgs bosons of extended models. We show results from a direct mass and width reconstruction for a Higgs boson mass range from 120 to 340 GeV/c 2. The mass and width have been reconstructed from the H ? ZZ ? ? + ? + ? reaction in an LHC simulation of the CMS detector. The determined mass accuracy has been compared with that obtained from studies for a linear collider (LC). The mass precision from the latter studies is derived by scaling previous LC simulation results according to the expected event rates. For the Higgs boson width we compare a direct determination with indirect methods and find good complementarity. Talk at the Worldwide Workshop on Future e + e ? Collider, Chicago, November 2000, to be published in the proceedings. Comparison of Higgs Boson Mass and Width Determination of the LHC and a Linear Collider

V. Drollinger; A. Sopczak; Volker Drollinger; Andr Sopczak A

2001-01-01T23:59:59.000Z

158

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

SciTech Connect

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

Ferrera, Giancarlo [Dipartimento di Fisica e Astronomia, Universita di Firenze and INFN, Sezione di Firenze, I-50019 Sesto Fiorentino, Florence (Italy); Grazzini, Massimiliano [Institut fuer Theoretische Physik, Universitaet Zuerich, CH-8057 Zuerich (Switzerland); Tramontano, Francesco [Theory Group, Physics Department, CERN, CH-1211 Geneva 23 (Switzerland)

2011-10-07T23:59:59.000Z

159

Energy Extraction in the CERN Large Hadron Collider a Project Overview  

E-Print Network (OSTI)

In case of a resistive transition (quench), fast and reliable extraction of the magnetic energy, stored in the superconducting coils of the electromagnets of a particle collider, represents an important part of its magnet protection system. In general, the quench detectors, the quench heaters and the cold by-pass diodes across each magnet, together with the energy extraction facilities provide the required protection of the quenching superconductors against damage due to local energy dissipation. In CERN's LHC machine the energy stored in each of its eight superconducting dipole chains exceeds 1300 MJ. Following an opening of the extraction switches this energy will be absorbed in large extraction resistors located in the underground collider tunnel or adjacent galleries, during the exponential current decay. Also the sixteen, 13 kA quadrupole chains (QF, QD) and more than one hundred and fifty, 600 A circuits of the corrector magnets will be equipped with extraction systems. The extraction switch-gear is bas...

Dahlerup-Petersen, K; Kazmine, B; Medvedko, A S; Sytchev, V V; Vasilev, L B

2001-01-01T23:59:59.000Z

160

18 kA vapour cooled current leads to test superconducting magnet models for the proposed Large Hadron Collider at CERN using wire matrix heat exchangers  

E-Print Network (OSTI)

18 kA vapour cooled current leads to test superconducting magnet models for the proposed Large Hadron Collider at CERN using wire matrix heat exchangers

Hagedorn, Dietrich; Oberli, L R

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Production of exotic atoms at energies available at the CERN Large Hadron Collider  

E-Print Network (OSTI)

We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.

C. A. Bertulani; M. Ellermann

2010-05-21T23:59:59.000Z

162

Production of exotic atoms at energies available at the CERN Large Hadron Collider  

E-Print Network (OSTI)

We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.

Bertulani, C A

2010-01-01T23:59:59.000Z

163

Dijet asymmetry at the energies available at the CERN Large Hadron Collider  

SciTech Connect

The martini numerical simulation allows for direct comparison of theoretical model calculations and the latest results for dijet asymmetry from the ATLAS and CMS collaborations. In this paper, partons are simulated as undergoing radiative and collisional processes throughout the evolution of central lead-lead collisions at the Large Hadron Collider. Using hydrodynamical background evolution determined by a simulation which fits well with the data on charged particle multiplicities from ALICE and a value of {alpha}{sub s} {approx} 0.25-0.3, the dijet asymmetry is found to be consistent with partonic energy loss in a hot, strongly interacting medium.

Young, C.; Schenke, B.; Jean, S., Gale, C.

2011-08-15T23:59:59.000Z

164

Standard Model Higgs boson searches with the ATLAS detector at the Large Hadron Collider  

E-Print Network (OSTI)

The investigation of the mechanism responsible for electroweak symmetry breaking is one of the most important tasks of the scientific program of the Large Hadron Collider. The experimental results on the search of the Standard Model Higgs boson with 1 to 2 fb^-1 of proton proton collision data at sqrt s=7 TeV recorded by the ATLAS detector are presented and discussed. No significant excess of events is found with respect to the expectations from Standard Model processes, and the production of a Higgs boson is excluded at 95% Confidence Level for the mass regions 144-232, 256-282 and 296-466 GeV.

Aleandro Nisati; for the ATLAS Collaboration

2011-11-30T23:59:59.000Z

165

Observable T{sub 7] lepton flavor symmetry at the large hadron collider.  

SciTech Connect

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.

Cao, Q.-H.; Khalil, S.; Ma, E.; Okada, H. (High Energy Physics); (Univ. of Chicago); (British Univ. in Egypt); (Ain Shams Univ.); (Univ. of California at Riverside)

2011-03-29T23:59:59.000Z

166

Probing new physics in diphoton production with proton tagging at the Large Hadron Collider  

E-Print Network (OSTI)

The sensitivities to anomalous quartic photon couplings at the Large Hadron Collider are estimated using diphoton production via photon fusion. The tagging of the protons proves to be a very powerful tool to suppress the background and unprecedented sensitivities down to $6 \\cdot 10^{-15}$\\gev$^{-4}$ are obtained, providing a new window on extra dimensions and strongly-interacting composite states in the multi-TeV range. Generic contributions to quartic photon couplings from charged and neutral particles with arbitrary spin are also presented.

S. Fichet; G. von Gersdorff; O. Kepka; B. Lenzi; C. Royon; M. Saimpert

2013-12-18T23:59:59.000Z

167

Scrutinizing the ZW+W- vertex at the Large Hadron Collider at 7 TeV  

E-Print Network (OSTI)

We analyze the potential of the CERN Large Hadron Collider running at 7 TeV to search for deviations from the Standard Model predictions for the triple gauge boson coupling ZW+W- assuming an integrated luminosity of 1 fb^{-1}. We show that the study of W+W- and W^\\pm Z productions, followed by the leptonic decay of the weak gauge bosons can improve the present sensitivity on the anomalous couplings \\Delta g_1^Z, \\Delta \\kappa_Z, \\lambda_Z, g_4^Z, and \\tilde{\\lambda}_Z at the 2\\sigma level.

O. J. P. Eboli; J. Gonzalez-Fraile; M. C. Gonzalez-Garcia

2010-06-17T23:59:59.000Z

168

Measuring the Higgs boson mass in dileptonic W-boson decays at hadron colliders  

E-Print Network (OSTI)

ar X iv :0 90 2. 48 64 v2 [ he p- ph ] 22 Ju l 2 00 9 Cavendish-HEP-09/04 Measuring the Higgs boson mass in dileptonic W -boson decays at hadron colliders Alan J. Barr,1, ? Ben Gripaios,2, and Christopher G. Lester3, 1Denys Wilkinson... measurements of the Higgs boson mass using the decay h ? W+W?, followed by the leptonic decay of each W -boson, will be performed by fitting the shape of a distribution that is sensitive to the Higgs mass. We demonstrate that the variable most commonly used...

Barr, Alan; Gripaios, Ben; Lester, Christopher G

2009-01-01T23:59:59.000Z

169

W Production at Large Transverse Momentum at the CERN Large Hadron Collider  

SciTech Connect

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

Gonsalves, Richard J. [Department of Physics, University at Buffalo, State University of New York, Buffalo, New York 14260-1500 (United States); Kidonakis, Nikolaos [Kennesaw State University, Physics no. 1202, 1000 Chastain Road, Kennesaw, Georgia 30144-5591 (United States); Vera, Agustin Sabio [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)

2005-11-25T23:59:59.000Z

170

Hadron Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

in Particle Physics: Chuck Marofske 9 Electrical Accident 10 Banners Simulation of a Higgs boson decay. DOE Photo By Judy Jackson, Office of Public Affairs As they cleared security...

171

Optimization of the design of DC-DC converters for improving the electromagnetic compatibility with the Front-End electronic for the super Large Hadron Collider Trackers  

E-Print Network (OSTI)

The upgrade of the Large Hadron Collider (LHC) experiments at CERN sets new challenges for the powering of the detectors. One of the powering schemes under study is based on DC-DC buck converters mounted on the front-end modules. The hard environmental conditions impose strict restrictions to the converters in terms of low volume, radiation and magnetic field tolerance. Furthermore, the noise emission of the switching converters must not affect the performance of the powered systems. A study of the sources and paths of noise of a synchronous buck converter has been made for identifying the critical parameters to reduce their emissions. As proof of principle, a converter was designed following the PCB layout considerations proposed and then used for powering a silicon strip module prototype for the ATLAS upgrade, in order to evaluate their compatibility.

Fuentes Rojas, Cristian Alejandro; Blanchot, G

2011-01-01T23:59:59.000Z

172

DETERMINING THE RATIO OF THE H+ YIELDS TV TO H+ YIELDS TB DECAY RATES FOR LARGE TAN BETA AT THE LARGE HADRON COLLIDER.  

SciTech Connect

We present results on the determination of the observable ratio R = BR(H{sup +} {yields} {tau}{sup +}{nu}{sup -})/BR(H{sup +} {yields} t{bar b}) of charged Higgs boson decay rates as a discriminant quantity between Supersymmetric and non-Supersymmetric models. Simulation of measurements of this quantity through the analysis of the charged Higgs production process gb {yields} tbH{sup +} and relative backgrounds in the two above decay channels has been performed in the context of ATLAS. A {approx} 12-14% accuracy on R can be achieved for tan {beta} = 50, m{sub H{sup {+-}}} = 300-500 GeV and after an integrated luminosity of 300 fb{sup -1}. With this precision measurement, the Large Hadron Collider (LHC) can easily discriminate between models for the two above scenarios, so long as tan {beta} > 20.

ASSAMAGAN,K.A.GUASCH,J.MORETTI,S.PENARANDA,S.

2003-05-27T23:59:59.000Z

173

A study of tau identification with the CMS detector at the LHC  

E-Print Network (OSTI)

In this thesis I explore the identification of [tau] leptons from simulated reconstructed data that will be collected by the Compact Muon Solenoid (CMS) detector on the Large Hadron Collider (LHC) at CERN. The two components ...

Ilten, Philip James

2008-01-01T23:59:59.000Z

174

Studying the effects of minimal length in large extra dimensional models in the jet + missing energy channels at hadron colliders  

E-Print Network (OSTI)

Theories of quantum gravity suggest the existence of a minimal length scale. We study the consequences of a particular implementation of the idea of a minimal length scale in the model of large extra dimensions, the ADD model. To do this we have looked at real graviton production in association with a jet at hadron colliders. In the minimal length scenario, the bounds on the effective string scale are significantly less stringent than those derived in the conventional ADD model, both at the upgraded Tevatron and at the Large Hadron Collider.

Gautam Bhattacharyya; Kumar Rao; K. Sridhar

2005-12-04T23:59:59.000Z

175

Electroweak boson-tagged jet event asymmetries at the Large Hadron Collider  

E-Print Network (OSTI)

Tagged jet measurements provide a promising experimental channel to quantify the similarities and differences in the mechanisms of jet production in proton-proton and nucleus-nucleus collisions. We present the first calculation of the transverse momentum asymmetry of $Z^0/\\gamma^*$-tagged jet events and the momentum imbalance of $\\gamma$-tagged jet events in $\\sqrt{s}=2.76$ TeV reactions at the LHC. Our results combine the ${\\cal O}(G_F\\alpha_s^2)$, ${\\cal O}(G_F\\alpha_s^2)$ perturbative cross sections with the radiative and collisional processes that modify parton showers in the presence of dense QCD matter. We find that strong asymmetry momentum and imbalance, respectively, are generated in central Pb+Pb reactions that have little sensitivity to the fluctuations of the underlying soft hadronic background. We present theoretical model predictions for their shape and magnitude.

Ivan Vitev

2012-10-03T23:59:59.000Z

176

Is it possible to create a quantum electromagnetic "black hole" at the Large Hadron Collider?  

E-Print Network (OSTI)

As demonstrated by Chernodub, strong magnetic field forces vacuum to develop real condensates of electrically charged rho mesons, which form an anisotropic inhomogeneous superconducting state similar to Abrikosov vortex lattice. As far as electromagnetic field behaviour is concerned, this state of vacuum constitutes a hyperbolic metamaterial [1]. Here we demonstrate that spatial variations of magnetic field may lead to formation of electromagnetic "black holes" inside this metamaterial. Similar to real black holes, horizon area of the electromagnetic "black holes" is quantized in units of the effective "Planck scale" squared. The magnetic fields of the required strength and geometrical configuration may be created on Earth in heavy-ion collisions at the Large Hadron Collider. We evaluate electromagnetic field distribution around an electromagnetic "black hole" which may be created as a result of such collision.

Igor I. Smolyaninov

2012-04-04T23:59:59.000Z

177

Observation of diffraction with the CMS experiment at the Large Hadron Collider  

E-Print Network (OSTI)

A clear evidence of inclusive diffraction observed by the CMS detector at the Large Hadron Collider in minimum bias events at $\\sqrt{s}=$0.9 TeV, 2.36 TeV is presented. The observed diffractive signal is dominated by inclusive single-diffractive dissociation and can be identified by the presence of a Large Rapidity Gap that extends over the forward region of the CMS detector. A comparison of the data with Monte Carlo predictions provided by PYTHIA6 and PHOJET generators is given. In addition, first observation of the single-diffractive production of di-jets at $\\sqrt{s}=$7 TeV is presented.

Dmytro Volyanskyy

2011-02-03T23:59:59.000Z

178

Signals of an invisibly decaying Higgs in a scalar dark matter scenario: a study for the Large Hadron Collider  

E-Print Network (OSTI)

We consider the collider phenomenology of a singlet Majoron model with softly broken lepton number. Lepton number is spontaneously broken when the real part of a new singlet scalar develops vacuum expectation value. With the additional soft terms violating lepton numbers, the imaginary part of this singlet scalar becomes a massive pseudo-Majoron which can account for the dark matter. In presence of the coupling of the pseudo-Majoron with the Standard Model (SM) Higgs, the SM Higgs mostly decays into a pair of pseudo-Majorons, giving rise to missing transverse energy signals at a hadron collider. Since the Higgs visible decay branching fractions get reduced in presence of this invisible decay mode, the bounds on the SM Higgs mass from the LEP and Tevatron experiments get diluted and the invisible decay channel of the Higgs become important for the discovery of low mass Higgs at the Large Hadron Collider.

Kirtiman Ghosh; Biswarup Mukhopadhyaya; Utpal Sarkar

2011-05-29T23:59:59.000Z

179

Search for Heavy Resonances Decaying to Taus in 7 TeV Proton-Proton Collisions at the Large Hadron Collider  

E-Print Network (OSTI)

Over the last few decades, the Standard Model (SM) of particle physics has been used as a means of understanding the world around us. However, there is an increasing amount of data that suggests the SM of particle physics only describes nature up to energies of the electroweak scale. Extensions to the SM have been developed as a means of explaining experimental observation. If these extensions are indeed the correct mathematical descriptions of nature, the Large Hadron Collider (LHC), located at the European Center for Nuclear Research (CERN) near Geneva, Switzerland, is expected to produce new and exciting physics signatures that can shed light on the evolution of our universe since the early hypothesized Big Bang. Of particular interest are models that may lead to events with highly energetic tau lepton pairs. In this dissertation, focus is placed on a possible search for new heavy gauge bosons decaying to highly energetic tau pairs using a data sample corresponding to an integrated luminosity of 36 pb^-1 of proton-proton collisions at sqrt(s) = 7 TeV collected with the CMS detector at the CERN LHC. The number of observed events in the data is in good agreement with the predictions for SM background processes. In the context of the Sequential SM, a Z0 with mass less than 468 GeV/c^2 is excluded at 95 percent credibility level, exceeding the sensitivity by the Tevatron experiments at the Fermi National Accelerator Laboratory.

Gurrola, Alfredo

2011-08-01T23:59:59.000Z

180

Charged Higgs Production in Association With W^{\\pm} at Large Hadron Colliders  

E-Print Network (OSTI)

Many new physics models beyond the standard model, such as the littlest higgs models and the left right twin higgs models, predict the existence of the large charged higgs couplings H^-q\\bar b and H^+b\\bar q, where q=t or the new vector-like heavy quark T; On the other hand, some new physics models like the littlest higgs also predict the gauge-higgs couplings. Such couplings may have rich collider phenomenology. We focus our attention on these couplings induced by the littlest higgs models and the left right twin higgs models models and consider their contributions to the production cross section for W^\\pm H^\\mp production at the large hadron colliders. We find that the cross sections, in the littlest higgs models, on the parton level gg \\to W^\\pm H^\\mp and q\\bar q \\to W^\\pm H^\\mp (q=u,d,s,c,b) may reach tens of several dozen femtobarns in reasonable parameters space at the collision energy of 14 TeV and that the total cross section can even reach a few hundred femtobarns in certain favored space. While in the left right twin higgs models, the production rates are basically one order lower than these in littlest higgs. Therefore, due to the large cross sections of that in the littlest higgs, it may be possible to probe the charged higgs via this process in a large parameter space.

Guo-Li Liu; Fei Wang; Shuo Yang

2013-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Kaluza-Klein gluon searches using the three-b-jet decay channel at the Large Hadron Collider  

E-Print Network (OSTI)

We study observability of a Kaluza-Klein (KK) excitation of a gluon in a five-dimensional model with a warped geometry at the Large Hadron Collider. In this model, the Standard Model fields reside in the bulk and the third generation quarks couple to the KK gluon strongly. We focus on the processes including three b-quarks as a final state where the first KK gluon propagates as an intermediate state. We evaluate a significance of those processes by taking account of kinematical cuts and a detector efficiency at the Large Hadron Collider and find that the significance is lager than 5-sigma with the integrated luminosity of 10 (100) fb^{-1} for a certain range of parameters of the model.

Masato Arai; Gi-Chol Cho; Karel Smolek

2013-07-24T23:59:59.000Z

182

Suppression of high-p{sub T} hadrons in Pb+Pb collisions at energies available at the CERN Large Hadron Collider  

Science Conference Proceedings (OSTI)

The nuclear modification factor R{sub AA}(p{sub T}) for large transverse momentum pion spectra in Pb+Pb collisions at {radical}(s)=2.76 TeV is predicted within the next-to-leading order perturbative QCD parton model. The effect of jet quenching is incorporated through medium-modified fragmentation functions within the higher-twist approach. The jet transport parameter that controls medium modification is proportional to the initial parton density, and the coefficient is fixed by data on the suppression of large-p{sub T} hadron spectra obtained at the BNL Relativistic Heavy Ion Collider. Data on charged hadron multiplicity dN{sub ch}/d{eta}=1584{+-}80 in central Pb+Pb collisions from the ALICE experiment at the CERN Large Hadron Collider are used to constrain the initial parton density both for determining the jet transport parameter and the 3 + 1 dimensional (3 + 1D) ideal hydrodynamic evolution of the bulk matter that is employed for the calculation of R{sub PbPb}(p{sub T}) for neutral pions.

Chen Xiaofang; Wang Enke; Zhang Hanzhong [Institute of Particle Physics, Huazhong Normal University, Wuhan 430079 (China); Hirano, Tetsufumi [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Nuclear Science Division, MS 70R0319, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Wang Xinnian [Institute of Particle Physics, Huazhong Normal University, Wuhan 430079 (China); Nuclear Science Division, MS 70R0319, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2011-09-15T23:59:59.000Z

183

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

Science Conference Proceedings (OSTI)

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.

Djuvsland, Oystein; Nystrand, Joakim [Department of Physics and Technology, University of Bergen, Bergen (Norway)

2011-04-15T23:59:59.000Z

184

Trigger and Data Acquisition for hadron colliders at the Energy Frontier  

E-Print Network (OSTI)

The LHC trigger and data acquisition systems will need significant modifications to operate at the HL-LHC. Due to the increased occupancy of each crossing, Level-1 trigger systems would experience degraded performance of the LHC algorithms presently selecting up to 100 kHz of crossings from the LHC input rate of 40 MHz. The DAQ systems will experience larger event sizes due to greater occupancy and higher channel counts of new detectors. This paper summarizes findings and recommendations to upgrade the LHC experiments trigger and data acquisition systems for operation at the HL-HLC.

Smith, Wesley H

2013-01-01T23:59:59.000Z

185

Trigger and Data Acquisition for hadron colliders at the Energy Frontier  

E-Print Network (OSTI)

The LHC trigger and data acquisition systems will need significant modifications to operate at the HL-LHC. Due to the increased occupancy of each crossing, Level-1 trigger systems would experience degraded performance of the LHC algorithms presently selecting up to 100 kHz of crossings from the LHC input rate of 40 MHz. The DAQ systems will experience larger event sizes due to greater occupancy and higher channel counts of new detectors. This paper summarizes findings and recommendations to upgrade the LHC experiments trigger and data acquisition systems for operation at the HL-HLC.

Wesley H. Smith

2013-07-02T23:59:59.000Z

186

Discriminators of 2 Higgs Doublets at the LHC14, ILC and MuonCollider(125): A Snowmasss White Paper  

E-Print Network (OSTI)

The historic LHC discovery of the 125 GeV particle with properties that closely resemble the Standard Model (SM) Higgs boson verifies our understanding of electroweak symmetry breaking, but solidifies the need for a resolution to the hierarchy problem. Many extensions of the SM that address the hierarchy problem contain a non-minimal Higgs sector. Therefore, as a benchmark alternative to the SM Higgs mechanism, we study a general 2 Higgs doublet model (2HDM-G) framework for evaluating future sensitivity to Higgs couplings. We study how well it can be distinguished from the SM Higgs boson by future measurements at LHC14, ILC (250, 500,1000 GeV) and a Muon Collider (125 GeV). Additionally, our study bears on singlet Higgs extensions of two Higgs doublet models through predicted coupling relationships.

Vernon Barger; Lisa L. Everett; Heather E. Logan; Gabe Shaughnessy

2013-07-13T23:59:59.000Z

187

New Physics at the LHC: A Les Houches Report. Physics at Tev Colliders 2007 - New Physics Working Group  

SciTech Connect

We present a collection of signatures for physics beyond the standard model that need to be explored at the LHC. The signatures are organized according to the experimental objects that appear in the final state, and in particular the number of high p{sub T} leptons. Our report, which includes brief experimental and theoretical reviews as well as original results, summarizes the activities of the 'New Physics' working group for the 'Physics at TeV Colliders' workshop (Les Houches, France, 11-29 June, 2007).

Brooijmans, Gustaaf H.; /Columbia U.; Delgado, A.; /Notre Dame U.; Dobrescu, Bogdan A.; /Fermilab; Grojean, C.; /CERN /Saclay, SPhT; Narain, Meenakshi; /Brown U.; Alwall, Johan; /SLAC; Azuelos, Georges; /Montreal U. /TRIUMF; Black, K.; /Harvard U.; Boos, E.; /SINP, Moscow; Bose, Tulika; /Brown U.; Bunichev, V.; /SINP, Moscow; Chivukula, R.S.; /Michigan State U.; Contino, R.; /CERN; Djouadi, A.; /Louis Pasteur U., Strasbourg I /Orsay, LAL; Dudko, Lev V.; /Durham U.; Ferland, J.; /Montreal U.; Gershtein, Yuri S.; /Florida State U.; Gigg, M.; /Durham U.; Gonzalez de la Hoz, S.; /Valencia U., IFIC; Herquet, M.; /Louvain U.; Hirn, J.; /Yale U. /Brown U. /Boston U. /Annecy, LAPTH /INFN, Turin /Valencia U., IFIC /Yale U. /Arizona U. /Louis Pasteur U., Strasbourg I /Orsay, LAL /KEK, Tsukuba /Moscow State U. /Lisbon, LIFEP /CERN /Durham U. /Valencia U., IFIC /Sao Paulo, IFT /Fermilab /Zurich, ETH /Boston U. /DESY /CERN /Saclay, SPhT /Durham U. /Cambridge U. /Michigan State U. /Louis Pasteur U., Strasbourg I /Orsay, LAL /Annecy, LAPTH /Fermilab /CERN /Arizona U. /Northwestern U. /Argonne /Kyoto U. /Valencia U., IFIC /UC, Berkeley /LBL, Berkeley

2011-12-05T23:59:59.000Z

188

Hadron production in p+p, p+Pb, and Pb+Pb collisions with the HIJING 2.0 model at energies available at the CERN Large Hadron Collider  

E-Print Network (OSTI)

The HIJING (Heavy-ion Jet Interaction Generator) Monte Carlo model is updated with the latest parton distributions functions (PDF) and new set of the parameters in the two-component mini-jet model that controls total $p+p$ cross section and the central pseudorapity density. We study hadron spectra and multiplicity distributions using the HIJING 2.0 model and compare to recent experimental data from $p+p$ collisions at the LHC energies. We also give predictions of hadron production in $p+p$, $p+Pb$ and $Pb+Pb$ collisions at the full LHC energy.

Wei-Tian Deng; Xin-Nian Wang; Rong Xu

2010-08-11T23:59:59.000Z

189

A search for direct heffalon production using the ATLAS and CMS experiments at the Large Hadron Collider  

E-Print Network (OSTI)

The first search is reported for direct heffalon production, using 23.3/fb per experiment of delivered integrated luminosity of proton-proton collisions at rootS = 8TeV from the Large Hadron Collider. The data were recorded with the ATLAS and the CMS detectors. Each exotic composite is assumed to be stable on the detector lifetime (tau >> ns). A particularly striking signature is expected. No signal events are observed after event selection. The cross section for heffalon production is found to be less than 64ab at the 95% confidence level.

Alan J. Barr; Christopher G. Lester

2013-03-29T23:59:59.000Z

190

Preliminary considerations about the injectors of the HE-LHC  

E-Print Network (OSTI)

A hadron collider operating at an energy much larger than the LHC ("HE-LHC") would be a logical successor to the LHC itself, especially if its cost can be minimized by reusing a significant part of the CERN infrastructure like the existing tunnels and/or accelerators. The injector complex must however be extended to reach a beam energy of ~1.2 TeV and. in view of the time span of the HE-LHC project, the replacement of ageing accelerators can also be necessary. The main possible options are outlined together with their specificities.

Garoby, R

2011-01-01T23:59:59.000Z

191

Single and Double Photonuclear Excitations in Pb+Pb Collisions at sqrt(s_NN) = 2.76 TeV at the CERN Large Hadron Collider  

E-Print Network (OSTI)

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

Oystein Djuvsland; Joakim Nystrand

2010-11-22T23:59:59.000Z

192

NMSSM Higgs Detection: LHC, LC, $\\gam C$ Collider Complementarity and Higgs-to-Higgs Decays  

E-Print Network (OSTI)

We discuss the importance of being able to detect Higgs-to-Higgs-pair decays in the context of the Next-to-Minimal Supersymmetric Model (NMSSM) and demonstrate the excellent capabilities of a photon collider for this purpose.

John F. Gunion; Michal Szleper

2004-09-17T23:59:59.000Z

193

Constraints on the gluon PDF from top quark pair production at hadron colliders  

E-Print Network (OSTI)

Using the recently derived NNLO cross sections \\cite{Czakon:2013goa}, we provide NNLO+NNLL theoretical predictions for top quark pair production based on all the available NNLO PDF sets, and compare them with the most precise LHC and Tevatron data. In this comparison we study in detail the PDF uncertainty and the scale, $m_t$ and $\\alpha_s$ dependence of the theoretical predictions for each PDF set. Next, we observe that top quark pair production provides a powerful direct constraint on the gluon PDF at large $x$, and include Tevatron and LHC top pair data consistently into a global NNLO PDF fit. We then explore the phenomenological consequences of the reduced gluon PDF uncertainties, by showing how they can improve predictions for Beyond the Standard Model processes at the LHC. Finally, we update to full NNLO+NNLL the theoretical predictions for the ratio of top quark cross sections between different LHC center of mass energies, as well as the cross sections for hypothetical heavy fourth-generation quark production at the LHC.

Michal Czakon; Michelangelo L. Mangano; Alexander Mitov; Juan Rojo

2013-03-28T23:59:59.000Z

194

Level-3 Trigger for a Heavy Ion Experiment at LHC  

Science Conference Proceedings (OSTI)

At the upcoming Large Hadron Collider (LHC) at CERN one expects to measure 20,000 particles in a single Pb-Pb event resulting in a data rate of ?75MByte/event. The event rate is limited by the bandwidth of the storage system. Higher rates are possible ...

U. Frankenfeld; H. Helstrup; J. Lien; Volker Lindenstruth; Dieter Rhrich; M. Schulz; B. Skaali; Timm M. Steinbeck; K. Ullaland; Anders Strand Vestb; Arne Wiebalck

2001-08-01T23:59:59.000Z

195

B-Tagging at CDF and DO, Lessons for LHC  

E-Print Network (OSTI)

The identification of jets resulting from the fragmentation and hadronization of b quarks is an important part of high-pT collider physics. The methods used by the CDF and DO collaborations to perform this identification are described, including the calibration of the efficiencies and fake rates. Some thoughts on the application of these methods in the LHC environment are also presented.

T. Wright; for the CDF; D Collaborations

2007-07-11T23:59:59.000Z

196

Klystron switching power supplies for the Internation Linear Collider  

Science Conference Proceedings (OSTI)

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.

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

2009-12-01T23:59:59.000Z

197

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

Science Conference Proceedings (OSTI)

The measurement of the identified charged hadron p t spectra using the ITS energy loss signal in the pp data at 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

Emanuele Biolcati; The ALICE collaboration

2011-01-01T23:59:59.000Z

198

The Strongly Interacting Quark Gluon Plasma at RHIC and LHC  

E-Print Network (OSTI)

The study of heavy-ion collisions has currently unprecedented opportunities with two first class facilities, the Relativistic Heavy Ion Collider (RHIC) at BNL and the Large Hadron Collider (LHC) at CERN, and five large experiments ALICE, ATLAS, CMS, PHENIX and STAR producing a wealth of high quality data. Selected results recently obtained are presented on the study of flow, energy loss and direct photons.

Itzhak Tserruya

2012-12-30T23:59:59.000Z

199

Experimental and numerical studies on the proposed application of hollow electron beam collimation for the LHC at CERN  

E-Print Network (OSTI)

This thesis work was carried out in the framework of U.S. LHC Accelerator Research Program (USLARP), a collaboration between the European Organization for Nuclear Research (CERN) and the U.S. Department of Energy. The first half of the work was completed at Fermilab (USA), the location of the Tevatron, a proton-antiproton collider and the second largest particle collider in the world. The second half was completed at CERN (Switzerland), the location of the largest proton collider in the world (Large Hadron Collider (LHC)).\

Moens, Vince; Redaelli, Stefano; Rivkin, Leonid

200

Elliptic flow ($v_2$) in pp collisions at energies available at the CERN Large Hadron Collider: A hydrodynamical approach  

E-Print Network (OSTI)

At Large Hadron Collider energy, the expected large multiplicities suggests the presence of collective behavior even in pp collisions. A hydrodynamical approach has been applied to estimate the expected elliptic flow measured by the azimuthal asymmetry parameter $v_2$, in pp collisions at $\\surd$s = 14 TeV. $v_2$ of $\\pi^-$ is found to be strongly dependent on the parton density profile inside a proton [e.g., surface diffuseness parameter ($\\xi$)]. For $\\xi$ = 0.105, $v_2$ is found to be positive while at $\\xi$ = 0.25, $v_2$ is close to zero and approaches negative values at large $p_t$. The impact parameter dependence of $v_2$ has also been studied.

S. K. Prasad; Victor Roy; S. Chattopadhyay; A. K. Chaudhuri

2009-10-26T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Hadron Collider Production of Massive Color-Octet Vector Bosons at Next-to-Leading Order  

E-Print Network (OSTI)

This paper completes the study of the next-to-leading order (NLO) QCD corrections to massive color-octet vector boson production at the LHC and Tevatron. The massive color-octet vector bosons are generically referred to as colorons. Building on our previous calculation of quark-initiated coloron production at NLO, we use the pinch technique to investigate coloron production via gluon fusion. We demonstrate that this one-loop production amplitude is finite, and find that its numerical contribution to coloron production is typically four orders of magnitude smaller than the contribution from quark annihilation. Coloron production via gluon fusion is therefore only relevant if the colorons are (nearly) fermiophobic. We then present extensive plots and tables of our full results for NLO coloron production at the Tevatron and the LHC.

R. Sekhar Chivukula; Arsham Farzinnia; Jing Ren; Elizabeth H. Simmons

2013-03-05T23:59:59.000Z

202

Irradiation Tests and Expected Performance of Readout Electronics of the ATLAS Hadronic Endcap Calorimeter for the HL-LHC  

E-Print Network (OSTI)

The readout electronics of the ATLAS Hadronic Endcap Calorimeter (HEC) will have to withstand an about 3-5 times larger radiation environment at the future high-luminosity LHC (HLLHC) compared to their design values. The preamplifier and summing boards (PSBs), which are equipped with GaAs ASICs and comprise the heart of the readout electronics, were irradiated with neutrons and protons with fluences surpassing several times ten years of operation of the HL-LHC. Neutron tests were performed at the NPI in Rez, Czech Republic, where a 36 MeV proton beam was directed on a thick heavy water target to produce neutrons. The proton irradiation was done with 200 MeV protons at the PROSCAN area of the Proton Irradiation Facility at the PSI in Villigen, Switzerland. In-situ measurements of S-parameters in both tests allow the evaluation of frequency dependent performance parameters, like gain and input impedance, as a function of fluence. The linearity of the ASIC response was measured directly in the neutron tests with a triangular input pulse of varying amplitude. The results obtained allow an estimation of the expected performance degradation of the HEC. For a possible replacement of the PSB chips, alternative technologies were investigated and exposed to similar neutron radiation levels. In particular, IHP 250 nm Si CMOS technology has turned out to show good performance and match the specifications required. The performance measurements of the current PSB devices, the expected performance degradations under HL-LHC conditions, and results from alternative technologies will be presented.

Martin Nagel

2013-09-03T23:59:59.000Z

203

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

SciTech Connect

Presented is a measurement of the simultaneous production of a W{sup {+-}} boson in association with a second weak boson (W{sup {+-}} or Z{sup 0}) in p{bar p} collisions at {radical}s = 1.96 TeV. Events are consider with one electron or one muon, missing transverse energy, and at least two hadronic jets. The data were collected by the D0 detector in Run IIa of the Tevatron accelerator and correspond to 1.07 fb{sup -1} of integrated luminosity for each of the two channels (WW/WZ {yields} e{nu}q{bar q} and WW/WZ {yields} {mu}{nu}q{bar q}). The cross section for WW + WZ production is measured to be 20.2 {+-} 2.5(stat) {+-} 3.6(sys) {+-} 1.2(lum) pb with a Gaussian significance of 4.4 standard deviations above the background-only scenario. This measurement is consistent with the Standard Model prediction and represents the first direct evidence for WW and WZ production with semi-leptonic decays at a hadron collider.

Haley, Joseph Glenn Biddle; /Princeton U.

2009-03-01T23:59:59.000Z

204

Search for Large Extra Dimensions in the Diphoton Final State at the Large Hadron Collider  

E-Print Network (OSTI)

A search for large extra spatial dimensions via virtual-graviton exchange in the diphoton channel has been carried out with the CMS detector at the LHC. No excess of events above the standard model expectations is found using a data sample collected in proton-proton collisions at sqrt(s) = 7 TeV and corresponding to an integrated luminosity of 36 inverse picobarns. New lower limits on the effective Planck scale in the range of 1.6-2.3 TeV at the 95% confidence level are set, providing the most restrictive bounds to date on models with more than two large extra dimensions.

CMS Collaboration

2011-03-22T23:59:59.000Z

205

Pair Production of Heavy Quarkonium and $B_c(^*)$ Mesons at Hadron Colliders  

E-Print Network (OSTI)

We investigate the pair production of S-wave heavy quarkonium at the LHC in the color-singlet mechanism (CSM) and estimate the contribution from the gluon fragmentation process in the color-octet mechanism (COM) for comparison. With the matrix elements extracted previously in the leading order calculations, the numerical results show that the production rates are quite large for the pair production processes at the LHC. The $p_t$ distribution of double $J/\\psi$ production in the CSM is dominant over that in the COM when $p_t$ is smaller than about 8GeV. For the production of double $\\Upsilon$, the contribution of the COM is always larger than that in the CSM. The large differences in the theoretical predictions between the CSM and COM for the $p_t$ distributions in the large $p_t$ region are useful in clarifying the effects of COM on the quarkonium production. We also investigate the pair production of S-wave $B_c$ and $B_c^*$ mesons, and the measurement of these processes is useful to test the CSM and extract the LDMEs for the $B_c$ and $B_c^*$ mesons.

Rong Li; Yu-Jie Zhang; Kuang-Ta Chao

2009-03-12T23:59:59.000Z

206

Detecting H{yields}hh in the mirror model at the CERN Large Hadron Collider  

SciTech Connect

The Higgs sector may play an important role in detecting mirror particles, which can be the candidates of dark matter and appear as missing energy in the detectors at the LHC. In this paper we worked out the Higgs boson spectrum and the Higgs couplings for the symmetric vacuum, namely v{sub 1}=v{sub 2}=v, in the mirror model, and investigated the constraints from electroweak precision observables. Our study showed that electroweak precision observables have already constrained the Higgs boson sector severely. We then explored the Higgs boson phenomenology, and focused on the scenario that the heavier Higgs boson H can decay into a pair of lighter Higgs bosons h. We proposed to study the invisible decay of the Higgs boson via the pair production of them, in which one Higgs boson decays into bottom quarks and the other decays invisibly. Our detail simulation for signals and backgrounds showed that the observation of the signal can reach 5{sigma} significance for m{sub H}=260 GeV and m{sub h}=115 GeV with 10 fb{sup -1} integrated luminosity at the LHC. Moreover the possible method to further suppress dominant Zbb background was discussed. We also simulated the signals and backgrounds for H{yields}hh{yields}4b. Our results showed that it is very difficult to isolate the signals from huge QCD continuum backgrounds.

Li Wensheng; Yin Pengfei; Zhu Shouhua [Institute of Theoretical Physics, School of Physics, Peking University, Beijing 100871 (China)

2007-11-01T23:59:59.000Z

207

Emittance Preservation at the LHC  

E-Print Network (OSTI)

The Large Hadron Collider (LHC) at CERN is a high energy storage ring that provides proton and heavy ion collisions to study fundamental particle processes. The luminosity production is tightly linked to emittance preservation in the accelerator. During the 2012 LHC proton run about 30 % of the potential luminosity performance was lost through the different phases of the LHC cycle, mainly due to blow-up of the transverse emittance. At the LHC design stage the total allowed emittance increase through the cycle was set to 7 %. A breakdown of the growth through the various phases in the LHC cycle is given, as well as a comparison with the data from the LHC experiments for the transverse beam size. In 2012 a number of possible causes and solutions of emittance blow-up in the LHC have been studied. Among the sources are intra-beam scattering and 50 Hz noise. A possible remedy for some of the growth is higher transverse damper gain. The results of the investigations are summarized in this thesis. Measuring the emit...

Kuhn, Maria; Kain, Verena

208

Using neural networks to enhance the Higgs boson signal at hadron colliders  

SciTech Connect

Neural networks are used to help distinguish the ZZ {yields} {ell}{sup +}{ell}{sup {minus}}-jet-jet signal produced by the decay of a 400 GeV Higgs boson at a proton-proton collider energy of 15 TeV from the ``ordinary`` QCD Z + jets background. The ideal case where only one event at a time enters the detector (no pile-up) and the case of multiple interactions per beam crossing (pile-up) are examined. In both cases, when used in conjunction with the standard cuts, neural networks provide an additional signal to background enhancement.

Field, R.D.; Kanev, Y.; Tayebnejad, M. [Univ. of Florida, Gainesville, FL (United States); Griffin, P.A. [Rockefeller Univ., New York, NY (United States)

1995-12-31T23:59:59.000Z

209

Measurement of identified charged hadron spectra with the ALICE experiment at the LHC  

E-Print Network (OSTI)

The ALICE experiment features multiple particle identification systems. The measurement of the identified charged hadron $p_{t}$ spectra in proton-proton collisions at $\\sqrt{s}=900$ GeV will be discussed. In the central rapidity region ($|\\eta|energy loss signal in the ITS and TPC. In addition, the information from TOF is used to identify hadrons at higher momenta. Finally, the kink topology of the weak decay of charged kaons provides an alternative method to extract the transverse momentum spectra of charged kaons. This combination allows to track and identify charged hadrons in the transverse momentum ($p_{t}$) range from 100 MeV/c up to 2.5 GeV/$c$. Mesons containing strange quarks (\\kos, $\\phi$) and both singly and doubly strange baryons (\\lam, \\lambar, and \\xip + \\xim) are identified by their decay topology inside the TPC detector. Results obtained with the various identification tools above described and a comparison with theoretical models and previously published data will be presented.

L. Milano for the ALICE Collaboration

2013-08-16T23:59:59.000Z

210

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

Science Conference Proceedings (OSTI)

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.

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

2011-03-03T23:59:59.000Z

211

Nuclear Effects in Prompt Photon Production at the Large Hadron Collider  

E-Print Network (OSTI)

We present a detailed study of prompt photon production cross section in heavy-ion collisions in the central rapidity region at energy of $\\sqrt{s}=5.5$ TeV, appropriate to LHC experiment. We include the next-to-leading order radiative corrections, $O(\\alpha_{em}\\alpha_s^2)$, nuclear shadowing and the parton energy loss effects. We find that the nuclear effects can reduce the invariant cross section for prompt photon production by an order of magnitude at $p_t=3$ GeV. We discuss theoretical uncertainties due to parton energy loss and nuclear shadowing parameters. We show that the K-factor, which signifies the importance of next-to-leading order corrections, is large and has a strong $p_t$ dependence.

Jamal Jalilian-Marian; Kostas Orginos; Ina Sarcevic

2001-01-04T23:59:59.000Z

212

The Little Randall-Sundrum Model at the Large Hadron Collider  

E-Print Network (OSTI)

We present a predictive warped model of flavor that is cut off at an ultraviolet scale O(10^3) TeV. This "Little Randall-Sundrum (LRS)" model is a volume-truncation, by a factor $y \\approx 6$, of the RS scenario and is holographically dual to dynamics with number of colors larger by $y$. The LRS couplings between Kaluza-Klein states and the Standard Model fields, including the proton constituents, are explicitly calculable without ad hoc assumptions. Assuming separate gauge and flavor dynamics, a number of unwanted contributions to precision electroweak, $Z b\\bar b$ and flavor observables are suppressed in the LRS framework, compared with the corresponding RS case. An important consequence of the LRS truncation, independent of precise details, is a significant enhancement of the clean (golden) di-lepton LHC signals, by O(y^3), due to a larger "$\\rho$-photon" mixing and a smaller inter-composite coupling.

Hooman Davoudiasl; Gilad Perez; Amarjit Soni

2008-02-04T23:59:59.000Z

213

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Launches Website for U.S. Role at Large 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 particle accelerator that will begin operating in Europe, near Geneva, Switzerland, next year. Hundreds of physicists, engineers and students from the United States are joining with colleagues from around the globe in the largest and most complex scientific experiments ever built. The LHC experiments will address some of the most

214

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

SciTech Connect

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.

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.

2011-12-01T23:59:59.000Z

215

Present status and future prospects for a Higgs boson discovery at the Tevatron and LHC  

E-Print Network (OSTI)

Discovering the Higgs boson is one of the primary goals of both the Tevatron and the Large Hadron Collider (LHC). The present status of the Higgs search is reviewed and future prospects for discovery at the Tevatron and LHC are considered. This talk focuses primarily on the Higgs boson of the Standard Model and its minimal supersymmetric extension. Theoretical expectations for the Higgs boson and its phenomenological consequences are reviewed.

Howard E. Haber

2010-11-04T23:59:59.000Z

216

Using model checking to analyze the system behavior of the LHC production grid  

Science Conference Proceedings (OSTI)

DIRAC (Distributed Infrastructure with Remote Agent Control) is the grid solution designed to support production activities as well as user data analysis for the Large Hadron Collider ''beauty'' experiment. It consists of cooperating distributed services ... Keywords: Distributed system, Grid, LHC, Model checking, Process algebra, Workflow

Daniela Remenska, Tim A. C. Willemse, Kees Verstoep, Jeff Templon, Henri Bal

2013-10-01T23:59:59.000Z

217

LHC Magnet Program | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnet Program Magnet Program The Superconducting Magnet Division is building a number of dipole magnets for the Large Hadron Collider (LHC), which is now under construction at CERN in Geneva, Switzerland. Scheduled to begin operation in 2007, this machine will collide beams of protons with the unprecedented energy of 7 TeV per beam to explore the nature of matter at its most basic level (RHIC can collide beams of protons with energies of 0.25 TeV, but is mostly used to collide heavy ions with energies of 0.1 TeV per nucleon). The magnets are being built as part of the US program, recommended by the High Energy Physics Advisory Panel (HEPAP) and approved by Congress, to contribute to the construction and, later, use of that frontier machine by the US high energy physics community. Fermi National Accelerator Laboratory (FNAL) and

218

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

SciTech Connect

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.

Yeh, G.P.; /Fermilab

2010-01-01T23:59:59.000Z

219

Prospects on the search for invisible Higgs decays in the ZH channel at the LHC and HL-LHC: A Snowmass White Paper  

E-Print Network (OSTI)

We show prospects on a search for invisible decays of a Higgs boson at the Large Hadron Collider (LHC) and High Luminosity LHC (HL-LHC). This search is performed on a Higgs boson produced in association with a Z boson. We expect that the branching ratio of 17-22% (6-14%) could be excluded at 95% confidence level with 300 fb^{-1} (3000 fb^{-1}) of data at sqrt(s)=14 TeV. The range indicates different assumptions on the control of systematic uncertainties. Interpretations with Higgs-portal dark matter models are also considered.

Hideki Okawa; Josh Kunkle; Elliot Lipeles

2013-09-30T23:59:59.000Z

220

Heavy quark production at HERA and its relevance for the LHC  

E-Print Network (OSTI)

The import of HERA data on heavy quark production for LHC experiments is discussed. Knowlegde of all aspects of the beauty and charm production process, viz. the parton density functions of colliding hadrons, the hard scatter, and the fragmentation of the quarks into hadrons, can aid LHC experimentation. This short write-up concentrates on possible influences HERA data can have and on the current status (and history) of beauty production from both HERA and Tevatron experiments. In general, next-to-leading order QCD gives a reasonable description of beauty production although some regions of phase space such as low p_T show indications of differences.

M. Wing

2006-06-17T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Searches for Physics Beyond the Standard Model and Triggering on Proton-Proton Collisions at 14 TEV LHC  

SciTech Connect

This document describes the work achieved under the OJI award received May 2008 by Peter Wittich as Principal Investigator. The proposal covers experimental particle physics project searching for physics beyond the standard model at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research.

Wittich, Peter

2011-10-14T23:59:59.000Z

222

LHC Discovers New Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

The newest particle physics instruments for the energy frontier are CERN's Large hadron Collider and its detectors. Physicists look for new science by looking for the...

223

Searches for BSM and Higgs boson at LHC  

Science Conference Proceedings (OSTI)

This article reviews the recent results from the two energy frontier experiments, ATLAS and CMS at the large hadron collider (LHC), using the data collected during 2011 corresponding up to 4.9 fb{sup -1} integrated luminosity of {radical}(s) = 7TeV proton proton collisions. The recent results of searches for the Standard Model Higgs boson, and searches for beyond Standard Model physics based on supersymmetry and other new exotic models are presented.

Jinnouchi, O. [Tokyo Institute of Technology, Department of Physics, Graduate School of Science and Engineering (Japan); Collaboration: ATLAS Collaboration; CMS Collaboration

2012-07-27T23:59:59.000Z

224

LHC Physics Center | (none)  

NLE Websites -- All DOE Office Websites (Extended Search)

Physics Center Physics Center Fermilab Home Visit LPC Physics Programs LPC Guest and Visitors HATS@LPC, Workshops and CMSDAS Jet-Substructure HATS CMS Data Analysis School 2013 CMS Data Analysis School 2012 CMS Data Analysis School 2011 EJTERM (CMS Data Analysis School 2010) Confronting Theory with Experiment: November 2011 Standard Model Benchmarks at the Tevatron and LHC Standard Model Benchmarks at High-Energy Hadron Colliders GED workshop 20-22 Aug, 2012 Topic of the Week Upcoming Past Speakers Archive Program Info LPC Physics Forum LPC Snowmass Efforts The INFIERI Project Fellows LPC Fellows Program Newsletter - LPC Fellows LPC Fellows - 2014 LPC Fellows - 2013 LPC Fellows - 2012 LPC Fellows - 2011 Community Faces of the LPC LPC Fellows - Current LPC Coffee Hour Calendar LPC Conf. Room Calendar

225

Silicon strip prototypes for the Phase-II upgrade of the ATLAS tracker for the HL-LHC  

E-Print Network (OSTI)

This paper describes the integration structures for the silicon strips tracker of the ATLAS detector proposed for the Phase-II upgrade of the Large Hadron Collider (LHC), also referred to as High Luminosity LHC (HL-LHC). In this proposed detector Silicon strip sensors are arranged in highly modular structures, called `staves' and `petals'. This paper presents performance results from the latest prototype stave built at Berkeley. This new, double-sided prototype is composed of a specialized core structure, in which a shield-less bus tape is embedded in between carbon fiber lay-ups. A detailed description of the prototype and its electrical performance are discussed in detail.

Diez, Sergio

2013-01-01T23:59:59.000Z

226

Silicon strip prototypes for the Phase-II upgrade of the ATLAS tracker for the HL-LHC  

E-Print Network (OSTI)

This paper describes the integration structures for the silicon strips tracker of the ATLAS detector proposed for the Phase-II upgrade of the Large Hadron Collider (LHC), also referred to as High Luminosity LHC (HL-LHC). In this proposed detector Silicon strip sensors are arranged in highly modular structures, called `staves' and `petals'. This paper presents performance results from the latest prototype stave built at Berkeley. This new, double-sided prototype is composed of a specialized core structure, in which a shield-less bus tape is embedded in between carbon fiber lay-ups. A detailed description of the prototype and its electrical performance are discussed in detail.

Sergio Diez

2013-10-01T23:59:59.000Z

227

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

SciTech Connect

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.

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)

2010-07-01T23:59:59.000Z

228

Linear Collider Physics Resource Book Snowmass 2001  

Science Conference Proceedings (OSTI)

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 built in a few years, it would make sense to wait for the results of each accelerator before planning the next one. Thus, we would wait for the results from the Tevatron before planning the LHC experiments, and wait for the LHC before planning any later stage. In reality accelerators require a long time to construct, and they require such specialized resources and human talent that delay can cripple what would be promising opportunities. In any event, we believe that the case for the linear collider is so compelling and robust that we can justify this facility on the basis of our current knowledge, even before the Tevatron and LHC experiments are done. The physics prospects for the linear collider have been studied intensively for more than a decade, and arguments for the importance of its experimental program have been developed from many different points of view. This book provides an introduction and a guide to this literature. We hope that it will allow physicists new to the consideration of linear collider physics to start from their own personal perspectives and develop their own assessments of the opportunities afforded by a linear collider.

Ronan (Editor), M.T.

2001-06-01T23:59:59.000Z

229

Press Pass - Press Release - U.S. LHC first beam  

NLE Websites -- All DOE Office Websites (Extended Search)

8-15 8-15 Aug. 8, 2008 For immediate release Media Contacts: Brookhaven National Laboratory - Kendra Snyder, ksnyder@bnl.gov, 631-344-8191 Fermilab - Judy Jackson, 630-840-3351, jjackson@fnal.gov Lawrence Berkeley National Laboratory - Dan Krotz, dakrotz@lbl.gov, (510) 486-4019 and Paul Preuss, paul_preuss@lbl.gov, 510-486-6249 CERN - James Gillies, james.gillies@cern.ch, +41 22 767 4101 Photos and graphics of the Large Hadron Collider are available at: http://multimedia-gallery.web.cern.ch/multimedia-gallery/PhotoGallery_Main.aspx and http://www.uslhc.us/Images. U.S. scientists count down to LHC startup Batavia, IL, Berkeley, CA and Upton, NY - On September 10, scientists at the Large Hadron Collider will attempt for the first time to send a proton beam zooming around the 27-kilometer-long accelerator. The LHC, the world's most powerful particle accelerator, is located at CERN in Geneva, Switzerland. Journalists are invited to attend LHC first beam events at CERN and several locations within the United States. Information about the CERN event and accreditation procedures is available at . A list of LHC startup events in the U.S. and contact information for each is available at http://www.uslhc.us/first_beam.

230

Scalar and Pseudoscalar Higgs Boson Plus One Jet Production at the LHC and Tevatron  

E-Print Network (OSTI)

The production of the Standard Model (SM) Higgs boson (H) in association with a jet is compared with that of the lightest scalar Higgs boson (h^0) and the pseudoscalar Higgs boson (A^0) of the Minimal Supersymmetric Model (MSSM) at both the CERN Large Hadron Collider (LHC) and the Fermilab Tevatron. We include both top and bottom quark loops to lowest order in QCD and investigate the limits of zero quark mass and infinite quark mass.

B. Field; S. Dawson; J. Smith

2003-11-14T23:59:59.000Z

231

Dark matter and Higgs boson collider implications of fermions in an abelian-gauged hidden sector  

E-Print Network (OSTI)

We add fermions to an abelian-gauged hidden sector. We show that the lightest can be the dark matter with the right thermal relic abundance, and discovery is within reach of upcoming dark matter detectors. We also show that these fermions change Higgs boson phenomenology at the Large Hadron Collider (LHC), and in particular could induce a large invisible width to the lightest Higgs boson state. Such an invisibly decaying Higgs boson can be discovered with good significance in the vector boson fusion channel at the LHC.

Shrihari Gopalakrishna; Seung J. Lee; James D. Wells

2009-04-13T23:59:59.000Z

232

Tevatron-for-LHC Report: Top and Electroweak Physics  

E-Print Network (OSTI)

The top quark and electroweak bosons (W and Z) represent the most massive fundamental particles yet discovered, and as such refer directly to the Standard Model's greatest remaining mystery: the mechanism by which all particles gained mass. This report summarizes the work done within the top-ew group of the Tevatron-for-LHC workshop. It represents a collection of both Tevatron results, and LHC predictions. The hope is that by considering and comparing both machines, the LHC program can be improved and aided by knowledge from the Tevatron, and that particle physics as a whole can be enriched. The report includes measurements of the top quark mass, searches for single top quark production, and physics of the electroweak bosons at hadron colliders.

C. E. Gerber; P. Murat; T. M. P. Tait; D. Wackeroth; A. Arbuzov; D. Bardin; U. Baur; J. A. Benitez; S. Berge; S. Bondarenko; E. E. Boos; M. T. Bowen; R. Brock; V. E. Bunichev; J. Campbell; F. Canelli; Q. -H. Cao; C. M. Carloni Calame; F. Chevallier; P. Christova; C. Ciobanu; S. Dittmaier; L. V. Dudko; S. D. Ellis; A. I. Etienvre; F. Fiedler; A. Garcia-Bellido; A. Giammanco; D. Glenzinski; P. Golonka; C. Hays; S. Jadach; S. Jain; L. Kalinovskaya; M. Kramer; A. Lleres; J. Luck; A. Lucotte; A. Markina; G. Montagna; P. M. Nadolsky; O. Nicrosini; F. I. Olness; W. Placzek; R. Sadykov; V. I. Savrin; R. Schwienhorst; A. V. Sherstnev; S. Slabospitsky; B. Stelzer; M. J. Strassler; Z. Sullivan; F. Tramontano; A. Vicini; W. Wagner; Z. Was; G. Watts; M. Weber; S. Willenbrock; U. K. Yang; C-P. Yuan; J. Zhu

2007-05-22T23:59:59.000Z

233

Suppression of bottomonia states in finite size quark gluon plasma in PbPb collisions at Large Hadron Collider  

E-Print Network (OSTI)

The bottomonium states due to their varying binding energies dissolve at different temperatures and thus their nuclear modification factors and relative yields have potential to map the properties of Quark Gluon Plasma (QGP). We estimate the suppression of bottomonia states due to color screening in an expanding QGP of finite lifetime and size with the conditions relevant for PbPb collisions at LHC. The properties of $\\Upsilon$ states and recent results on their dissociation temperatures have been used as ingredient in the study. The nuclear modification factors and the ratios of yields of $\\Upsilon$ states are then obtained as a function of transverse momentum and centrality. We compare our theoretical calculations with the bottomonia yields measured with CMS in PbPb collisions at $\\sqrt{s_{\\rm NN}}$ = 2.76 TeV. The model calculations explain the data very well.

A. Abdulsalam; Prashant Shukla

2012-10-29T23:59:59.000Z

234

Dependability analysis of a safety critical system the LHC beam dumping system at CERN  

E-Print Network (OSTI)

This thesis presents the dependability study of the Beam Dumping System of the Large Hadron Collider (LHC), the high energy particle accelerator to be commissioned at CERN in summer 2007. There are two identical, independent LHC Beam Dumping Systems (LBDS), one per LHC beam, each consisting of a series of magnets that extract the particle beam from the LHC ring into the extraction line leading to the absorbing block. The consequences of a failure within the LBDS can be very severe. This risk is reduced by applying redundancy to the design of the most critical components and on-line surveillance that, in case of a detected failure, issues a safe operation abort, called false beam dump. The system has been studied applying Failure Modes Effects and Criticality Analysis (FMECA) and reliability prediction. The system failure processes have been represented with a state transition diagram, governed by a Markov regenerative stochastic process, and analysed for different operational scenarios for one year of operati...

Filippini, R

2006-01-01T23:59:59.000Z

235

The Integration Of The LHC Cryogenics Control System Data Into The CERN Layout Database  

E-Print Network (OSTI)

The Large Hadron Colliders Cryogenic Control System makes extensive use of several databases to manage data appertaining to over 34,000 cryogenic instrumentation channels. This data is essential for populating the software of the PLCs which are responsible for maintaining the LHC at the appropriate temperature. In order to reduce the number of data sources and the overall complexity of the system, the databases have been rationalised and the automatic tool, that extracts data for the control software, has been simplified. This paper describes the main improvements that have been made and considers the success of the project.

Fortescue-Beck, E; Gomes, P

2011-01-01T23:59:59.000Z

236

A Minimal Spontaneously Broken Hidden Sector and its Impact on Higgs Boson Physics at the Large Hadron Collider  

E-Print Network (OSTI)

Little experimental data bears on the question of whether there is a spontaneously broken hidden sector that has no Standard Model quantum numbers. Here we discuss the prospects of finding evidence for such a hidden sector through renormalizable interactions of the Standard Model Higgs boson with a Higgs boson of the hidden sector. We find that the lightest Higgs boson in this scenario has smaller rates in standard detection channels, and it can have a sizeable invisible final state branching fraction. Details of the hidden sector determine whether the overall width of the lightest state is smaller or larger than the Standard Model width. We compute observable rates, total widths and invisible decay branching fractions within the general framework. We also introduce the ``A-Higgs Model'', which corresponds to the limit of a hidden sector Higgs boson weakly mixing with the Standard Model Higgs boson. This model has only one free parameter in addition to the mass of the light Higgs state and it illustrates most of the generic phenomenology issues, thereby enabling it to be a good benchmark theory for collider searches. We end by presenting an analogous supersymmetry model with similar phenomenology, which involves hidden sector Higgs bosons interacting with MSSM Higgs bosons through D-terms.

Robert Schabinger; James D. Wells

2005-09-21T23:59:59.000Z

237

Diffraction, Saturation and pp Cross Sections at the LHC  

E-Print Network (OSTI)

Results from the large hadron collider (LHC) show that no available Monte Carlo simulation incorporates our pre-LHC knowledge of soft and hard diffraction in a way that could be reliably extrapolated to LHC energies. As a simulation is needed to establish triggers, perform underlying event corrections and calculate acceptances, the lack of a robust simulation affects all measurements at the LHC. Particularly affected are the measurements of processes with large diffractive rapidity gaps, which constitute about one quarter of the inelastic cross section. In this paper, a previously described phenomenological model based on a saturation effect observed in single diffraction dissociation in pre-LHC data, validated by its successful application to several diffractive processes, is used to predict the total and total-inelastic proton-proton cross sections at the LHC. The prediction for the total-inelastic cross section at a center of mass collision energy of 7 TeV is compared with recent results from ATLAS and CMS.

Konstantin Goulianos

2011-05-25T23:59:59.000Z

238

Higgs Boson Properties and BSM Higgs Boson Searches at LHC  

E-Print Network (OSTI)

At the end of 2008, the Large Hadron Collider (LHC) will come into operation and the two experiments ATLAS and CMS will start taking data from proton-proton collisions at a center-of-mass energy of \\sqrt{s}=14 TeV. In preparation for the data taking period, the discovery potential for Higgs bosons beyond the Standard Model has been updated by both experiments and is reviewed here. In addition, the prospects for measuring the properties of a Higgs boson like its mass and width, its CP eigenvalues and its couplings to fermions and gauge bosons are discussed.

Wolfgang F. Mader

2008-09-24T23:59:59.000Z

239

Theoretical Modeling and Experimental Investigation of the Thermal Performance of the LHC Prototype Lattice Cryostats  

E-Print Network (OSTI)

This thesis presents the thermal performance of the LHC (Large Hadron Collider) prototype cryostats both in steady-state and in transient conditions. LHC will be built in the 27 km LEP tunnel and will provide proton-proton collisions. It will make use of superconducting magnets operating in static bath of superfluid helium at 1.9 K. The thesis is mainly divided in three parts. The first part cont ains three chapters which present a brief overview of the LHC project. Part 1-Chapter 1 gives a short introduction to the LHC design layout and performance. Part 1-Chapter 2 refers to LHC cryogenic s ystem and describes the general architecture of the cryogenic plants, the temperature levels and the heat loads. The 50 m long LHC prototype half-cell contains one twin-bore quadrupole and four twin-a perture dipoles. In Part 1-Chapter 3 the design and construction of the prototype dipole and quadrupole cryostats are presented. The LHC prototype cryostats have integrated cryogenic lines, while the final LHC cryostats hav...

Riddone, G

1997-01-01T23:59:59.000Z

240

First Results of the LHC Longitudinal Density Monitor  

Science Conference Proceedings (OSTI)

The Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. It is designed to accelerate and collide protons or heavy ions up to the center-of-mass energies of 14 TeV. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, in particular to check the injection quality and to measure the proportion of charge outside the nominally filled bunches during the physics periods. In order to study this so-called ghost charge at levels very much smaller than the main bunches, a longitudinal profile measurement with a very high dynamic range is needed. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. A prototype was installed during the 2010 LHC run and was able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 105 to be achieved. First measurements with the LDM are presented here along with an analysis of its performance and an outlook for future upgrades.

Jeff, A.; /CERN /Liverpool U.; Boccardi, A.; /CERN; Bravin, E.; /CERN; Fisher, A.S.; /SLAC; Lefevre, T.; /CERN; Rabiller, A.; /CERN; Roncarolo, F.; /CERN; Welsch, C.P.; /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech.

2012-04-19T23:59:59.000Z

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241

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

SciTech Connect

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

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

2011-08-11T23:59:59.000Z

242

International linear collider reference design report  

Science Conference Proceedings (OSTI)

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.

Aarons, G.

2007-06-22T23:59:59.000Z

243

Coldmass for LHC Dipole Insertion Magnets  

E-Print Network (OSTI)

Wanderer, E. Willen, K.C. Wu Brookhaven National Laboratory,NY 11973, USA Abstract-Brookhaven National Laboratory (BNL)Hadron Collider, the Brookhaven National Laboratory has

Gupta, R.

2011-01-01T23:59:59.000Z

244

Physics of Hot Partonic Matter at LHC-ALICE  

SciTech Connect

The field of high energy nuclear physics has recently reached epoch making discoveries at the Relativistic Heavy Ton Collider at Brookhaven National Laboratory, highlighted with that of new state of nuclear matter with partonic degrees of freedom. The ALICE experiment at the Large Hadron Collider at CERN aims at comprehensive investigation and understanding of properties of the hot and dense partonic matter, as the only experiment dedicated to nucleus-nucleus collisions at the facility. Physics prospects at ALICE are reviewed including jet quenching as a probe of energy loss of quarks in the created medium, direct and thermal photons as vital probes of the thermal properties, and quarkonia as a beloved probe of color deconfinement, along with latest status of the detector systems including the high resolution electromagnetic calorimeter, PHOS, and a quick report from the first operation of LHC and ALICE in December, 2009.

Shigaki, K. [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan)

2010-06-01T23:59:59.000Z

245

Heavy quark production in the black hole evaporation at LHC  

SciTech Connect

The understanding of Quantum Chromodynamics (QCD) and Quantum Gravity are currently two of the main open questions in Physics. In order to understand these problems some authors proposed the existence of extra dimensions in the Nature. These extra dimensions would be compacted and not visible on the macroscopic world, but the effects would be manifest in ultrarelativistic colision process. In particular, black holes (BH) could be produced in proton-proton colisions in the Large Hadron Collider (LHC) and in future colliders. The BH is an object characterized by its mass and temperature wich also characterizes the evaporation process. All kind of particle should be produced in this process. Our goal in this contribution is to study the BH production in proton - proton collisions at LHC and its evaporation rate in heavy quarks. We present our estimate considering two scenarios (with and without trapped energy corrections) and compare our predictions with those obtained using perturbative QCD. Our results demonstrate that in both scenarios the charm and bottom production in the BH evaporation are smaller than the QCD prediction at LHC. In contrast, the top production is similar or larger than the QCD prediction, if the trapped energy corrections are disregarded.

Thiel, M.; Goncalves, V. P.; Sauter, W. K. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas (Brazil)

2013-03-25T23:59:59.000Z

246

Estimation of the Invisible Z Background to Hadronic Supersymmetry Searches Performed With Proton-Proton Collision Data at 7 and 8 TeV Observed With the CMS Detector During the First run of the CERN Large Hadron Collider  

E-Print Network (OSTI)

III Analysis of all-hadronic events in the context of ato collect all the events an analysis would like to analyzeselect classes of events for specific analysis. The HLT is

Sturdy, Jared

2013-01-01T23:59:59.000Z

247

Production of jets at forward rapidities in hadronic collisions  

E-Print Network (OSTI)

We discuss high-pT production processes at forward rapidities in hadron-hadron collisions, and describe recent results from using QCD high-energy factorization in forward jet production at the LHC.

F. Hautmann

2009-09-07T23:59:59.000Z

248

A Cryogenic Test Station for Subcooling Helium Heat Exchangers for LHC  

E-Print Network (OSTI)

The superconducting magnets of the Large Hadron Collider (LHC) will be cooled at 1.9 K by distributed cooling loops where counter-flow heat exchangers will be integrated. To qualify potential suppliers for the 250-units series production, prototypes of various technologies have been selected by CERN and a test station was set up at CEA-Grenoble. This test station, is constituted of a cryostat allowing an easy access to the heat exchanger to be tested as well as very low pressure pumping facilities.

Roussel, P; Tavian, L

2000-01-01T23:59:59.000Z

249

ALICE diffractive physics in p-p and Pb-Pb collisions at the LHC  

SciTech Connect

The ALICE experiment at the Large Hadron Collider LHC is presently being commissioned. ALICE consists of a central barrel, a muon spectrometer and neutron calorimeters at 0 deg. Additional detectors for event classification and trigger purposes are located on both sides of the central barrel. The geometry of the ALICE detector allows the implementation of a diffractive double gap trigger by requiring two or more tracks in the central barrel but no activity in the event classification detectors. Some selected diffractive physics channels are discussed which become accessible by a double gap trigger. The interest of such diffractive measurements in proton-proton as well as in lead-lead collisions is outlined.

Schicker, R. [Phys. Inst., Philosophenweg 12, 69120 Heidelberg (Germany)

2009-03-23T23:59:59.000Z

250

Physics validation studies for muon collider detector background simulations  

Science Conference Proceedings (OSTI)

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 interaction cross sections for boron. While corrections to the data files themselves are simple to implement and distribute, it is quite possible, however, that coding changes may be required in G4beamline or even in GEANT4 to fully correct nuclear interactions. Regardless, these studies are ongoing and future results will be reflected in updated releases of G4beamline.

Morris, Aaron Owen; /Northern Illinois U.

2011-07-01T23:59:59.000Z

251

General-purpose event generators for LHC physics  

SciTech Connect

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.

Buckley, Andy; /Edinburgh U.; Butterworth, Jonathan; /University Coll. London; Gieseke, Stefan; /Karlsruhe U., ITP; Grellscheid, David; /Durham U., IPPP; Hoche, Stefan; /SLAC; Hoeth, Hendrik; Krauss, Frank; /Durham U., IPPP; Lonnblad, Leif; /Lund U., Dept. Theor. Phys. /CERN; Nurse, Emily; /University Coll. London; Richardson, Peter; /Durham U., IPPP; Schumann, Steffen; /Heidelberg U.; Seymour, Michael H.; /Manchester U.; Sjostrand, Torbjorn; /Lund U., Dept. Theor. Phys.; Skands, Peter; /CERN; Webber, Bryan; /Cambridge U.

2011-03-03T23:59:59.000Z

252

Muon performance aspects and measurement of the inclusive ZZ production cross section through the four lepton final state with the ATLAS experiment at the LHC  

E-Print Network (OSTI)

The "Large Hadron Collider" (LHC) is currently the most powerful particle accelerator. It provides particle collisions at a center of mass energy in the Tera-electronvolt range, which had never been reached in a laboratory before. Thereby a new era in high energy particle physics has began. Now it is possible to test one of the most precise theories in physics, the Standard Model of particle physics, at these high energies. The purpose is particularly served by four large experiments installed at the LHC, namely "A Toroidal LHC ApparatuS" (ATLAS), the "Compact-Muon-Solenoid" (CMS), the "Large Hadron Collider beauty" (LHCb) and "A Large Ion Collider Experiment" (ALICE). Besides exploring the high energy behavior of the well-established portions of the Standard Model, one of the main objectives is to find the Higgs boson included in the model, but not discovered by any preceding effort. It is of tremendous importance since fermions and heavy electroweak gauge bosons acquire mass because of this boson. Although ...

Meyer, Jochen; Strhmer, Raimund

2013-07-08T23:59:59.000Z

253

Scalar neutrinos at the LHC  

Science Conference Proceedings (OSTI)

We study a softly broken supersymmetric model whose gauge symmetry is that of the standard model gauge group times an extra Abelian symmetry U(1){sup '}. We call this gauge-extended model the U(1){sup '} model, and we study a U(1){sup '} model with a secluded sector such that neutrinos acquire Dirac masses via higher-dimensional terms allowed by the U(1){sup '} invariance. In this model the {mu} term of the minimal supersymmetric model (MSSM) is dynamically induced by the vacuum expectation value of a singlet scalar. In addition, the model contains exotic particles necessary for anomaly cancellation, and extra singlet bosons for achieving correct Z{sup '}/Z mass hierarchy. The neutrinos are charged under U(1){sup '}, and thus, their production and decay channels differ from those in the MSSM in strength and topology. We implement the model into standard packages and perform a detailed analysis of sneutrino production and decay at the Large Hadron Collider, for various mass scenarios, concentrating on three types of signals: (1) 0l+MET, (2) 2l+MET, and (3) 4l+MET. We compare the results with those of the MSSM whenever possible, and analyze the standard model background for each signal. The sneutrino production and decays provide clear signatures enabling distinction of the U(1){sup '} model from the MSSM at the LHC.

Demir, Durmus A. [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir, Turkey, (Turkey); Frank, Mariana [Department of Physics, Concordia University, 7141 Sherbrooke St. West, Montreal, Quebec, Canada H4B 1R6, (Canada); Selbuz, Levent [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir, Turkey, (Turkey); Department of Engineering Physics, Ankara University, TR06100 Ankara (Turkey); Turan, Ismail [Ottawa-Carleton Institute of Physics, Carleton University, 1125 Colonel By Drive Ottawa, Ontario, K1S 5B6 (Canada)

2011-05-01T23:59:59.000Z

254

P{bar P} collider physics  

Science Conference Proceedings (OSTI)

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

Demarteau, M. [State Univ. of New York, Stony Brook, NY (United States)

1992-04-01T23:59:59.000Z

255

Very Fast Losses of the Circulating LHC Beam, their Mitigation and Machine Protection  

E-Print Network (OSTI)

The Large Hadron Collider (LHC) has a nominal energy of 362MJ stored in each of its two counter-rotating beams - over two orders of magnitude more than any previous accelerator and enough to melt 880kg of copper. Therefore, in case of abnormal conditions comprehensive machine protection systems extract the beams safely from the LHC within not more than three turns $\\approx$270$\\mu$s. The first years of LHC operation demonstrated a remarkable reliability of the major machine protection systems. However, they also showed that the LHC is vulnerable to losses of the circulating beams on very fast timescales, which are too fast to ensure an active protection. Very fast equipment failures, in particular of normal-conducting dipole magnets and the transverse damper can lead to such beam losses. Whereas these failures were already studied in the past, other unexpected beam loss mechanisms were observed after the LHC start-up: so-called (un)identified falling objects (UFOs), which are believed to be micrometer-sized m...

Baer, Tobias; Elsen, Eckhard

256

Probing QCD with the ALICE detector at the LHC  

Science Conference Proceedings (OSTI)

We will review the main results obtained so far within the ALICE experiment at the CERNs Large Hadron Collider.

A. Andronic; The ALICE Collaboration

2010-01-01T23:59:59.000Z

257

ElectroWeak theory after the first LHC phase  

E-Print Network (OSTI)

I summarize the status of the ElectroWeak Interactions after the first phase of the Large Hadron Collider and I give an outlook on its possible developments.

Riccardo Barbieri

2013-09-13T23:59:59.000Z

258

ElectroWeak theory after the first LHC phase  

E-Print Network (OSTI)

I summarize the status of the ElectroWeak Interactions after the first phase of the Large Hadron Collider and I give an outlook on its possible developments.

Barbieri, Riccardo

2013-01-01T23:59:59.000Z

259

High throughput lessons from the LHC experience.Johnston.TNC2013  

NLE Websites -- All DOE Office Websites (Extended Search)

high throughput in widely distributed data high throughput in widely distributed data management and analysis systems: Lessons from the LHC William E. Johnston ESnet, Lawrence Berkeley National Laboratory e-mail: wej@es.net Eli Dart ESnet, Lawrence Berkeley National Laboratory e-mail: dart@es.net Michael Ernst RHIC and ATLAS Computing Facility, Brookhaven National Laboratory e-mail: mernst@bnl.gov Brian Tierney ESnet, Lawrence Berkeley National Laboratory e-mail: bltierney@es.net Paper type Technical paper Abstract Today's large-scale science projects all involve world-wide collaborations that must routinely move 10s of petabytes per year between international sites in order to be successful. This is true for the two largest experiments at the Large Hadron Collider (LHC) at CERN - ATLAS and CMS - and for the climate science

260

The Control System for the Cryogenics in the LHC Tunnel [First Experience and Improvements  

E-Print Network (OSTI)

The Large Hadron Collider (LHC) was commissioned at CERN and started operation with beams in 2008. Several months of operation in nominal cryogenic conditions have triggered an optimisation of the process functional analysis. This lead to a few revisions of the control logic, which were realised on-the-fly. During the 2008-09 shut-down, and in order to enhance the safety, availability and operability of the LHC cryogenics, a major rebuild of the logic and several hardware modifications were implemented. The databases, containing instruments and controls in-formation, are being rationalized; the automatic tool, that extracts data for the control software, is being simplified. This paper describes the main improvements and sug-gests perspectives of further developments.

Gomes, P; Casas, J; Fluder, C; Fortescue, E; Le Roux, P; Penacoba, G; Pezzetti, M; Soubiran, M; Tovar, A; Zwalinski, L

2010-01-01T23:59:59.000Z

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261

Electroweak Precision Measurements and Collider Probes of the Standard Model with Large Extra Dimensions  

SciTech Connect

The elementary particles of the Standard Model may live in more than 3+1 dimensions. We study the consequences of large compactified dimensions on scattering and decay observables at high-energy colliders. Our analysis includes global fits to electroweak precision data, indirect tests at high-energy electron-positron colliders (LEP2 and NLC), and direct probes of the Kaluza-Klein resonances at hadron colliders (Tevatron and LHC). The present limits depend sensitively on the Higgs sector, both the mass of the Higgs boson and how many dimensions it feels. If the Higgs boson is trapped on a 3+1 dimensional wall with the fermions, large Higgs masses (up to 500 GeV) and relatively light Kaluza-Klein mass scales (less than 4 TeV) can provide a good fit to precision data. That is, a light Higgs boson is not necessary to fit the electroweak precision data, as it is in the Standard Model. If the Higgs boson propagates in higher dimensions, precision data prefer a light Higgs boson (less than 260 GeV), and a higher compactification scale (greater than 3.8 TeV). Future colliders can probe much larger scales. For example, a 1.5 TeV electron-positron linear collider can indirectly discover Kaluza-Klein excitations up to 31 TeV if 500 fb{sup {minus}1} integrated luminosity is obtained.

Rizzo, Thomas G.

1999-06-03T23:59:59.000Z

262

First Beam Measurements with the LHC Synchrotron Light Monitors  

SciTech Connect

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.

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

2012-07-13T23:59:59.000Z

263

Higgs-boson production at the Photon Collider at TESLA  

E-Print Network (OSTI)

In this thesis feasibility of the precise measurement of the Higgs-boson production cross section gamma+gamma->higgs->b+bbar at the Photon Collider at TESLA is studied in detail. The study is based on the realistic luminosity spectra simulation. The heavy quark background is estimated using the dedicated code based on NLO QCD calculations. Other background processes, which were neglected in the earlier analyses, are also studied. Also the contribution from the overlaying events, gamma+gamma->hadrons, is taken into account. The non-zero beam crossing angle and the finite size of colliding bunches are included in the event generation. The analysis is based on the full detector simulation with realistic b-tagging, and the criteria of event selection are optimized separately for each considered Higgs-boson mass. For the Standard-Model Higgs boson with mass of 120 to 160 GeV the partial width \\Gamma(h->gamma+gamma)BR(h->b+bbar) can be measured with a statistical accuracy of 2.1-7.7% after one year of the Photon Collider running. The systematic uncertainties of the measurement are estimated to be of the order of 2%. For MSSM Higgs bosons A and H, for M_A=200-350 GeV and tan(beta)=7, the statistical precision of the cross-section measurement is estimated to be 8--34%, for four considered MSSM parameters sets. As heavy neutral Higgs bosons in this scenario may not be discovered at LHC or at the first stage of the e+e- collider, an opportunity of being a discovery machine is also studied for the Photon Collider.

Piotr Niezurawski

2005-03-31T23:59:59.000Z

264

$WW?/Z$ production in the Randall-Sundrum model at LHC and CLIC  

E-Print Network (OSTI)

We study the $W^+W^-\\gamma(Z)$ productions at both the CERN Large Hadron Collider (LHC) and the Compact Linear Collider (CLIC) in the framework of the Randall-Sundrum (RS) model. The impacts of the virtual RS Kaluza-Klein (KK) graviton on these processes are studied and compared with the standard model (SM) background. We present the integrated and differential cross sections in both the RS model and the SM. The results show that the relative RS discrepancies at the CLIC differ from those at the LHC, particularly in the transverse momentum and rapidity distributions. We also find that the RS signature performance, as a result of the resonance character of the RS KK-graviton spectrum, is distinctively unlike that in the large extra dimensions model. We conclude that the CLIC with unprecedented precision and high center-of-mass energy has a potential advantage over the LHC in exploring the effects of the RS KK graviton on the $W^+W^-\\gamma(Z)$ production processes.

Li Xiao-Zhou; Ma Wen-Gan; Zhang Ren-You; Guo Lei

2013-03-10T23:59:59.000Z

265

Status of the Atlas Liquid Argon Calorimeter and its Performance after two years of LHC operation  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.4-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three years period prior to first collisions in 2009, using cosmic rays and single LHC beam...

AbouZeid, H; The ATLAS collaboration

2012-01-01T23:59:59.000Z

266

Status of the Atlas Liquid Argon Calorimeter and its Performance after three years of LHC operation  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.4-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three years period prior to first collisions in 2009, using cosmic rays and single LHC beam...

De La Torre, H; The ATLAS collaboration

2013-01-01T23:59:59.000Z

267

Heavy Ion Collisions at the LHC - Last Call for Predictions  

SciTech Connect

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 each prediction should be summarized on at most two pages, and that predictions should be presented, whenever possible, in figures which display measurable quantities. Full model descriptions were not accepted--the authors were encouraged to indicate the relevant references for the interested reader. Participants had the possibility to submit multiple contributions on different topics, but it was part of the subsequent editing process to ensure that predictions on neighboring topics were merged wherever possible. The contributions summarized here are organized in several sections,--though some of them contain material related with more than one section--roughly by going from low transverse momentum to high transverse momentum and from abundant to rare measurements. In the low transverse momentum regime, we start with predictions on multiplicity distributions, azimuthal asymmetries in particle production and hadronic flavor observables, followed by correlation and fluctuation measurements. The contributions on hard probes at the LHC start with predictions for single inclusive high transverse momentum spectra, and jets, followed by heavy quark and quarkonium measurements, leptonic probes and photons. A final section 'Others' encompasses those predictions which do not fall naturally within one of the above-mentioned categories, or discuss the more speculative phenomena that may be explored at the LHC.

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

2008-02-25T23:59:59.000Z

268

Mirage Models Confront the LHC: II. Flux-Stabilized Type IIB String Theory  

E-Print Network (OSTI)

We continue the study of a class of string-motivated effective supergravity theories in light of current data from the CERN Large Hadron Collider (LHC). In this installment we consider Type IIB string theory compactified on a Calabi-Yau orientifold in the presence of fluxes, in the manner originally formulated by Kachru, et al. We allow for a variety of potential uplift mechanisms and embeddings of the Standard Model field content into D3 and D7 brane configurations. We find that an uplift sector independent of the Kahler moduli, as is the case with anti-D3 branes, is inconsistent with data unless the matter and Higgs sectors are localized on D7 branes exclusively, or are confined to twisted sectors between D3 and D7 branes. We identify regions of parameter space for all possible D-brane configurations that remain consistent with PLANCK observations on the dark matter relic density and measurements of the CP-even Higgs mass at the LHC. Constraints arising from LHC searches at 8 TeV center-of-mass energies, and the LUX dark matter detection experiment, are discussed. The discovery prospects for the remaining parameter space at dark matter direct detection experiments are described, and signatures for detection of superpartners at the LHC, with center-of-mass energy of 14 TeV, are analyzed.

Bryan Kaufman; Brent D. Nelson

2013-12-23T23:59:59.000Z

269

Supersymmetric discovery potential and benchmarks for early runs at {radical}(s)=7 TeV at the LHC  

Science Conference Proceedings (OSTI)

We carry out an analysis of the potential of the Large Hadron Collider (LHC) to discover supersymmetry in runs at {radical}(s)=7 TeV with an accumulated luminosity of (0.1-2) fb{sup -1} of data. The analysis is done with both minimal supergravity and supergravity models with nonuniversal soft breaking. Benchmarks for early discovery with (0.1-2) fb{sup -1} of data are given. We provide an update of b-tagging efficiencies in PGS 4 appropriate for LHC analyses. A large number of signature channels are analyzed, and it is shown that each of the models exhibited are discoverable at the 5{sigma} level or more above the standard model background in several signature channels which would provide cross checks for a discovery of supersymmetry. It is shown that some of the benchmarks are discoverable with 0.1 fb{sup -1} of data again with detectable signals in several channels.

Altunkaynak, Baris; Holmes, Michael; Nath, Pran; Nelson, Brent D.; Peim, Gregory [Department of Physics, Northeastern University, Boston, Massachusetts 02115 (United States)

2010-12-01T23:59:59.000Z

270

Dilepton Spectroscopy of QCD Matter at Collider Energies  

E-Print Network (OSTI)

Low-mass dilepton spectra as measured in high-energy heavy-ion collisions are a unique tool to obtain spectroscopic information about the strongly interacting medium produced in these reactions. Specifically, in-medium modifications of the vector spectral function, which is well known in the vacuum, can be deduced from the thermal radiation off the expanding QCD fireball. This, in particular, allows to investigate the fate of the $\\rho$ resonance in the dense medium, and possibly infer from it signatures of the (partial) restoration of chiral symmetry, which is spontaneously broken in the QCD vacuum. After briefly reviewing calculations of thermal dilepton emission rates from hot QCD matter, utilizing effective hadronic theory, lattice QCD or resummed perturbative QCD, we focus on applications to dilepton spectra at heavy-ion collider experiments at RHIC and LHC. This includes invariant-mass spectra at full RHIC energy with transverse-momentum dependencies and azimuthal asymmetries, as well as a systematic investigation of the excitation function down to fixed-target energies, thus making contact to previous precision measurements at the SPS. Furthermore, predictions for the energy frontier at the LHC are presented in both dielectron and dimuon channels.

Ralf Rapp

2013-04-08T23:59:59.000Z

271

Status of the Atlas Liquid Argon Calorimeter and its Performance after two years of LHC operation  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry. The most forward part (pseudo-rapidity region 3.1-4.9) contains a electromagnetic section and two hadronic wheels. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over t...

AperioBella, L; The ATLAS collaboration

2012-01-01T23:59:59.000Z

272

Accessing the Distribution of Linearly Polarized Gluons in Unpolarized Hadrons  

SciTech Connect

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.

Boer, Daniel; /Groningen, KVI; Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; Mulders, Piet J.; /Vrije U., Amsterdam; Pisano, Cristian; /Cagliari U. /INFN, Cagliari

2011-08-19T23:59:59.000Z

273

Review of Higgs Physics at the LHC  

E-Print Network (OSTI)

Nobody knows exactly what kind of Higgs physics will be unveiled when the Large Hadron Collider is turned on. There could be one Standard Model Higgs boson or five Higgs bosons as is the case in two-Higgs-doublet models; there could be more exotic or even completely unexpected scenarios. In order to be prepared for the LHC era, a solid understanding of Standard Model or Standard-Model-like Higgs physics is necessary. The first goal is to discover the Higgs boson. Afterwards it has to be proven that the new particle is indeed a Higgs boson. The Higgs boson has to couple to mass and its spin has to be zero. Additional observables, such as decay width or CP eigenvalue, help to distinguish between different models. Due to an almost infinite variety of models, another important goal is to prepare for all possible situations. For example, Higgs bosons could be produced in decays of heavier particles, or could decay to invisible particles. In the following, a selection of mainly new studies by ATLAS and CMS is presented.

V. Drollinger

2004-05-04T23:59:59.000Z

274

Performance of the ATLAS Liquid Argon Calorimeter after three years of LHC operation and plans for a future upgrade  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.4-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three years period prior to first collisions in 2009, using cosmic rays and single LHC beam...

Nikiforou, N; The ATLAS collaboration

2013-01-01T23:59:59.000Z

275

OPEN MIDPLANE DIPOLE DESIGN FOR LHC IR UPGRADE.  

SciTech Connect

The proposed luminosity upgrade of the Large Hadron Collider (LHC), now under construction, will bring a large increase in the number of secondary particles from p-p collisions at the interaction point (IP). Energy deposition will be so large that the lifetime and quench performance of interaction region (IR) magnets may be significantly reduced if conventional designs are used. Moreover, the cryogenic capacity of the LHC will have to be significantly increased as the energy deposition load on the interaction region (IR) magnets by itself will exhaust the present capacity. We propose an alternate open midplane dipole design concept for the dipole-first optics that mitigates these issues. The proposed design takes advantage of the fact that most of the energy is deposited in the midplane region. The coil midplane region is kept free of superconductor, support structure and other material. Initial energy deposition calculations show that the increase in temperature remains within the quench tolerance of the superconducting coils. In addition, most of the energy is deposited in a relatively warm region where the heat removal is economical. We present the basic concept and preliminary design that includes several innovations.

GUPTA,R.; ANERELLA,M.; HARRISON,M.; SCHMALZLE,J.; MOKHOV,N.

2004-01-21T23:59:59.000Z

276

International Linear Collider-A Technical Progress Report  

Science Conference Proceedings (OSTI)

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.

Elsen, Eckhard; /DESY; Harrison, Mike; /Brookhaven; Hesla, Leah; /Fermilab; Ross, Marc; /Fermilab; Royole-Degieux, Perrine; /Paris, IN2P3; Takahashi, Rika; /KEK, Tsukuba; Walker, Nicholas; /DESY; Warmbein, Barbara; /DESY; Yamamoto, Akira; /KEK, Tsukuba; Yokoya, Kaoru; /KEK, Tsukuba; Zhang, Min; /Beijing, Inst. High Energy Phys.

2011-11-04T23:59:59.000Z

277

LHC Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

- from the International Committee for Future Accelerators' Beacons of Discovery The Higgs Boson: Is the End in Sight? - from the Physics Teacher Physicists built the LHC and its...

278

Comparison of LHC and ILC Capabilities for Higgs Boson Coupling Measurements  

Science Conference Proceedings (OSTI)

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.

Peskin, Michael E.; /SLAC

2012-07-11T23:59:59.000Z

279

CGC, Full 3D Hydro, and Hadronic Cascade  

E-Print Network (OSTI)

Abstract. We investigate how robust the discovery of perfect fluid is through comparison of hydrodynamic calculations with elliptic flow coefficient v2 at midrapidity in Au+Au collisions at ? sNN = 200 GeV. Employing the Glauber model for initial entropy density distributions, we reasonably reproduce centrality dependence of v2 by using ideal fluid description of the early QGP stage and a hadronic cascade in the late hadronic stage. On the other hand, initial conditions based on the Colour Glass Condensate model are found to generate larger elliptic flow due to larger initial eccentricity ?. We further predict v2/? at a fixed impact parameter as a function of collision energy ? sNN up to the LHC energy. One of the important new discoveries made at the Relativistic Heavy Ion Collider (RHIC) is the large elliptic flow v2 in non-central Au+Au collisions [1]. At the highest RHIC energy, the observed v2 values near midrapidity at low transverse momentum pT in central and semicentral collisions agree with predictions from ideal fluid dynamics [2]. The ideal fluid dynamical description, however, gradually breaks down as one moves away from midrapidity or studies in peripheral collisions. This requires more realistic

T Hirano; U Heinz; D Kharzeev; R Lacey; Y Nara

2007-01-01T23:59:59.000Z

280

The Beam Energy Tracking System of the LHC Beam Dumping System  

E-Print Network (OSTI)

The LHC Beam Dumping System (LBDS) of the Large Hadron Collider (LHC), presently under construction at CERN, will be installed around the straight section 6. It comprises per ring 15 horizontally deflecting extraction kickers, followed by 1 quadrupole, 15 vertically deflecting steel septum magnets, 10 dilution kickers and, in a separate cavern several hundred meters away, an external absorber assembly. A beam dump request can occur at any moment during the operation of the collider, from injection at 450 GeV up to top energy at 7 TeV. The Beam Energy Tracking System (BETS) monitors the deflection strength of each active element of the LBDS with respect to the beam energy in order to guarantee the correct extraction trajectory over the complete operational range and under all operational conditions. Its main functions are the acquisition of the beam energy, the generation of the kick strength reference signals for the extraction and dilution kickers, the continuous checking that the kicker high voltage generat...

Barlow, R A; Carlier, E; Grwer, G; Voumard, N; Gjelsvik, R

2005-01-01T23:59:59.000Z

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281

Charged hadrons and nuclear parton distributions in p(d)A collisions  

E-Print Network (OSTI)

Nuclear gluon modifications are the least constrained component of current global fits to nuclear parton distributions, due to the inadequate constraining power of presently available experimental data from nuclear deep inelastic scattering and nuclear Drell-Yan lepton-pair production. A recent advance is the use of observables from relativistic nucleus-nucleus collisions to supplement the data pool for global fits. It is thus of interest to investigate the sensitivity of various experimental observables to different strengths of nuclear gluon modifications from large to small Bjorken $x$. In this work we utilize three recent global fits with different gluon strengths to investigate the sensitivity of three observables: nuclear modification factor, pseudorapidity asymmetry, and charge ratio. We observe that both nuclear modification factor and pseudorapidity asymmetry are quite sensitive to the strength of gluon modifications in a wide pseudorapidity interval. The sensitivity is greatly enhanced at LHC (Large Hadron Collider) energies relative to that at RHIC (Relativistic Heavy Ion Collider). The charge ratio is mildly sensitive only at large Bjorken x. Thus measurement of these observables in proton-lead collisions at the LHC affords the potential to further constrain gluon modifications in global fits.

Adeola Adeluyi; Trang Nguyen; Bao-An Li

2010-04-27T23:59:59.000Z

282

UFOs in the LHC  

E-Print Network (OSTI)

One of the major known limitations for the performance of the Large Hadron Collider are so called UFOs (Unidentified Falling Objects). UFOs were first observed in July 2010 and caused numerous protection beam dumps since then. They are presumably micrometer sized dust particles that lead to fast beam losses with a duration of about 10 turns when they interact with the beam. In 2011, the diagnostics for such events are highly increased which allows estimations of the properties, dynamics and production mechanisms of the dust particles. The state of knowledge and mitigation strategies are presented.

Baer, T; Goddard, B; Holzer, E B; Jimenez, J M; Lechner, V; Mertens, V; Nebot Del Busto, E; Nordt, A; Uythoven, J; Velghe, B; Wenninger, J; Zimmermann, F

2011-01-01T23:59:59.000Z

283

Superconducting Magnet Technology for Future Hadron Colliders  

E-Print Network (OSTI)

accelerators organized at Brookhaven National Laboratory inquadrupole magnets (Brookhaven. 1965). the first of a longbeam transport dipoles (Brookhaven. 1973 and Argonne. 1976).

Scanlan, R.M.

2011-01-01T23:59:59.000Z

284

Evaluation of Beam Losses And Energy Deposition for a Possible Phase II Design for LHC Collimation  

Science Conference Proceedings (OSTI)

The Large Hadron Collider (LHC) beams are designed to have high stability and to be stored for many hours. The nominal beam intensity lifetime is expected to be of the order of 20h. The Phase II collimation system has to be able to handle particle losses in stable physics conditions at 7 TeV in order to avoid beam aborts and to allow correction of parameters and restoration to nominal conditions. Monte Carlo simulations are needed in order to evaluate the behavior of metallic high-Z collimators during operation scenarios using a realistic distribution of losses, which is a mix of the three limiting halo cases. Moreover, the consequences in the IR7 insertion of the worst (case) abnormal beam loss are evaluated. The case refers to a spontaneous trigger of the horizontal extraction kicker at top energy, when Phase II collimators are used. These studies are an important input for engineering design of the collimation Phase II system and for the evaluation of their effect on adjacent components. The goal is to build collimators that can survive the expected conditions during LHC stable physics runs, in order to avoid quenches of the SC magnets and to protect other LHC equipments.

Lari, L.; Assmann, R.W.; Bracco, C.; Brugger, M.; Cerutti, F.; Ferrari, A.; Mauri, M.; Redaelli, S.; Sarchiapone, L.; Vlachoudis, Vasilis; Weiler, Th.; /CERN; Doyle, J.E.; Keller, L.; Lundgren, S.A.; Markiewicz, Thomas W.; Smith, J.C.; /SLAC; Lari, L.; /LPHE, Lausanne

2011-11-01T23:59:59.000Z

285

First proton--proton collisions at the LHC as observed with the ALICE detector: measurement of the charged particle pseudorapidity density at sqrt(s) = 900 GeV  

E-Print Network (OSTI)

On 23rd November 2009, during the early commissioning of the CERN Large Hadron Collider (LHC), two counter-rotating proton bunches were circulated for the first time concurrently in the machine, at the LHC injection energy of 450 GeV per beam. Although the proton intensity was very low, with only one pilot bunch per beam, and no systematic attempt was made to optimize the collision optics, all LHC experiments reported a number of collision candidates. In the ALICE experiment, the collision region was centred very well in both the longitudinal and transverse directions and 284 events were recorded in coincidence with the two passing proton bunches. The events were immediately reconstructed and analyzed both online and offline. We have used these events to measure the pseudorapidity density of charged primary particles in the central region. In the range |eta| < 0.5, we obtain dNch/deta = 3.10 +- 0.13 (stat.) +- 0.22 (syst.) for all inelastic interactions, and dNch/deta = 3.51 +- 0.15 (stat.) +- 0.25 (syst.) for non-single diffractive interactions. These results are consistent with previous measurements in proton--antiproton interactions at the same centre-of-mass energy at the CERN SppS collider. They also illustrate the excellent functioning and rapid progress of the LHC accelerator, and of both the hardware and software of the ALICE experiment, in this early start-up phase.

The ALICE Collaboration; K. Aamodt; N. Abel; U. Abeysekara; A. Abrahantes Quintana; A. Acero; D. Adamova; M. M. Aggarwal; G. Aglieri Rinella; A. G. Agocs; S. Aguilar Salazar; Z. Ahammed; A. Ahmad; N. Ahmad; S. U. Ahn; R. Akimoto; A. Akindinov; D. Aleksandrov; B. Alessandro; R. Alfaro Molina; A. Alici; E. Almaraz Avina; J. Alme; T. Alt; V. Altini; S. Altinpinar; C. Andrei; A. Andronic; G. Anelli; V. Angelov; C. Anson; T. Anticic; F. Antinori; S. Antinori; K. Antipin; D. Antonczyk; P. Antonioli; A. Anzo; L. Aphecetche; H. Appelshauser; S. Arcelli; R. Arceo; A. Arend; N. Armesto; R. Arnaldi; T. Aronsson; I. C. Arsene; A. Asryan; A. Augustinus; R. Averbeck; T. C. Awes; J. Aysto; M. D. Azmi; S. Bablok; M. Bach; A. Badala; Y. W. Baek; S. Bagnasco; R. Bailhache; R. Bala; A. Baldisseri; A. Baldit; J. Ban; R. Barbera; G. G. Barnafoldi; L. Barnby; V. Barret; J. Bartke; F. Barile; M. Basile; V. Basmanov; N. Bastid; B. Bathen; G. Batigne; B. Batyunya; C. Baumann; I. G. Bearden; B. Becker; I. Belikov; R. Bellwied; E. Belmont-Moreno; A. Belogianni; L. Benhabib; S. Beole; I. Berceanu; A. Bercuci; E. Berdermann; Y. Berdnikov; L. Betev; A. Bhasin; A. K. Bhati; L. Bianchi; N. Bianchi; C. Bianchin; J. Bielcik; J. Bielcikova; A. Bilandzic; L. Bimbot; E. Biolcati; A. Blanc; F. Blanco; F. Blanco; D. Blau; C. Blume; M. Boccioli; N. Bock; A. Bogdanov; H. Boggild; M. Bogolyubsky; J. Bohm; L. Boldizsar; M. Bombara; C. Bombonati; M. Bondila; H. Borel; V. Borshchov; C. Bortolin; S. Bose; L. Bosisio; F. Bossu; M. Botje; S. Bottger; G. Bourdaud; B. Boyer; M. Braun; P. Braun-Munzinger; L. Bravina; M. Bregant; T. Breitner; G. Bruckner; R. Brun; E. Bruna; G. E. Bruno; D. Budnikov; H. Buesching; K. Bugaev; P. Buncic; O. Busch; Z. Buthelezi; D. Caffarri; X. Cai; H. Caines; E. Camacho; P. Camerini; M. Campbell; V. Canoa Roman; G. P. Capitani; G. Cara Romeo; F. Carena; W. Carena; F. Carminati; A. Casanova Diaz; M. Caselle; J. Castillo Castellanos; J. F. Castillo Hernandez; V. Catanescu; E. Cattaruzza; C. Cavicchioli; P. Cerello; V. Chambert; B. Chang; S. Chapeland; A. Charpy; J. L. Charvet; S. Chattopadhyay; S. Chattopadhyay; M. Cherney; C. Cheshkov; B. Cheynis; E. Chiavassa; V. Chibante Barroso; D. D. Chinellato; P. Chochula; K. Choi; M. Chojnacki; P. Christakoglou; C. H. Christensen; P. Christiansen; T. Chujo; F. Chuman; C. Cicalo; L. Cifarelli; F. Cindolo; J. Cleymans; O. Cobanoglu; J. -P. Coffin; S. Coli; A. Colla; G. Conesa Balbastre; Z. Conesa del Valle; E. S. Conner; P. Constantin; G. Contin; J. G. Contreras; Y. Corrales Morales; T. M. Cormier; P. Cortese; I. Cortes Maldonado; M. R. Cosentino; F. Costa; M. E. Cotallo; E. Crescio; P. Crochet; E. Cuautle; L. Cunqueiro; J. Cussonneau; A. Dainese; H. H. Dalsgaard; A. Danu; I. Das; S. Das; A. Dash; S. Dash; G. O. V. de Barros; A. De Caro; G. de Cataldo; J. de Cuveland; A. De Falco; M. de Gaspari; J. de Groot; D. De Gruttola; A. P. de Haas; N. De Marco; R. de Rooij; S. De Pasquale; G. de Vaux; H. Delagrange; G. Dellacasa; A. Deloff; V. Demanov; E. Denes; A. Deppman; G. D~RErasmo; D. Derkach; A. Devaux; D. Di Bari; C. Di Giglio; S. Di Liberto; A. Di Mauro; P. Di Nezza; M. Dialinas; L. Diaz; R. Diaz; T. Dietel; H. Ding; R. Divia; O. Djuvsland; G. do Amaral Valdiviesso; V. Dobretsov; A. Dobrin; T. Dobrowolski; B. Donigus; I. Dominguez; D. M. M. Don; O. Dordic; A. K. Dubey; J. Dubuisson; L. Ducroux; P. Dupieux; A. K. Dutta Majumdar; M. R. Dutta Majumdar; D. Elia; D. Emschermann; A. Enokizono; B. Espagnon; M. Estienne; D. Evans; S. Evrard; G. Eyyubova; C. W. Fabjan; D. Fabris; J. Faivre; D. Falchieri; A. Fantoni; M. Fasel; R. Fearick; A. Fedunov; D. Fehlker; V. Fekete; D. Felea; B. Fenton-Olsen; G. Feofilov; A. Fernandez Tellez; E. G. Ferreiro; A. Ferretti; R. Ferretti; M. A. S. Figueredo; S. Filchagin; R. Fini; F. M. Fionda; E. M. Fiore; M. Floris; Z. Fodor; S. Foertsch; P. Foka; S. Fokin; F. Formenti; E. Fragiacomo; M. Fragkiadakis; U. Frankenfeld; A. Frolov; U. Fuchs; F. Furano; C. Furget; M. Fusco Girard; J. J. Gaardhoje; S. Gadrat; M. Gagliardi; A. Gago; M. Gallio; P. Ganoti; M. S. Ganti; C. Garabatos; C. Garc; J. Gebelein; R. Gemme; M. Germain; A. Gheata; M. Gheata; B. Ghidini; P. Ghosh; G. Giraudo; P. Giubellino; E. Gladysz-Dziadus; R. Glasow; P. Glassel; A. Glenn; R. Gomez; H. Gonzalez Santos; L. H. Gonzalez-Trueba; P. Gonzalez-Zamora; S. Gorbunov; Y. Gorbunov; S. Gotovac; H. Gottschlag; V. Grabski; R. Grajcarek; A. Grelli; A. Grigoras; C. Grigoras; V. Grigoriev; A. Grigoryan; B. Grinyov; N. Grion; P. Gros; J. F. Grosse-Oetringhaus; J. -Y. Grossiord; R. Grosso; C. Guarnaccia; F. Guber; R. Guernane; B. Guerzoni; K. Gulbrandsen; H. Gulkanyan; T. Gunji; A. Gupta; R. Gupta; H. -A. Gustafsson; H. Gutbrod; O. Haaland; C. Hadjidakis; M. Haiduc; H. Hamagaki; G. Hamar; J. Hamblen; B. H. Han; J. W. Harris; M. Hartig; A. Harutyunyan

2009-11-28T23:59:59.000Z

286

Fake Dark Matter at Colliders  

E-Print Network (OSTI)

If the dark matter (DM) consists of a weakly interacting massive particle (WIMP), it can be produced and studied at future collider experiments like those at the LHC. The production of collider-stable WIMPs is characterized by hard scattering events with large missing transverse energy. Here we point out that the discovery of this well-characterized DM signal may turn out to be a red herring. We explore an alternative explanation -- fake dark matter -- where the only sources of missing transverse energy are standard model neutrinos. We present examples of such models, focusing on supersymmetric models with R-parity violation. We also briefly discuss means of differentiating fake dark matter from the production of new collider-stable particles.

Chang, Spencer

2009-01-01T23:59:59.000Z

287

Fake Dark Matter at Colliders  

E-Print Network (OSTI)

If the dark matter (DM) consists of a weakly interacting massive particle (WIMP), it can be produced and studied at future collider experiments like those at the LHC. The production of collider-stable WIMPs is characterized by hard scattering events with large missing transverse energy. Here we point out that the discovery of this well-characterized DM signal may turn out to be a red herring. We explore an alternative explanation -- fake dark matter -- where the only sources of missing transverse energy are standard model neutrinos. We present examples of such models, focusing on supersymmetric models with R-parity violation. We also briefly discuss means of differentiating fake dark matter from the production of new collider-stable particles.

Spencer Chang; Andre de Gouvea

2009-01-30T23:59:59.000Z

288

Validation and performance of the LHC cryogenic system through commissioning of the first sector  

Science Conference Proceedings (OSTI)

The cryogenic system [1] for the Large Hadron Collider accelerator is presently in its final phase of commissioning at nominal operating conditions. The refrigeration capacity for the LHC is produced using eight large cryogenic plants and eight 1.8 K refrigeration units installed on five cryogenic islands. Machine cryogenic equipment is installed in a 26.7-km circumference ring deep underground tunnel and are maintained at their nominal operating conditions via a distribution system consisting of transfer lines, cold interconnection boxes at each cryogenic island and a cryogenic distribution line. The functional analysis of the whole system during all operating conditions was established and validated during the first sector commissioning in order to maximize the system availability. Analysis, operating modes, main failure scenarios, results and performance of the cryogenic system are presented.

Serio, L.; Bouillot, A.; Casas-Cubillos, J.; /CERN; Chakravarty, A.; /Tata Inst.; Claudet, S.; /CERN; Gicquel, F.; /LBL, Berkeley; Gomes, P.; /CERN; Kumar, M.; Kush, P.K.; /Indore, Ctr. for Advanced Tech.; Millet, F.; Perin, A.; /CERN /Fermilab /Tata Inst. /CERN

2007-12-01T23:59:59.000Z

289

Using Worldfip for Synchronization and Time Stamping in the LHC Accelerator  

E-Print Network (OSTI)

Time is one of the key topics in the construction of particle accelerators for which very accurate synchronization and high resolution time stamping are required. Nowadays, accelerator control systems may profit of the same industrial components than automotive industries and oil refineries are using: PLCs and Fieldbuses. WorldFIP, one of the three fieldbuses that have been selected at CERN, is the only one that is intrinsically deterministic. Therefore, in addition to the general control and monitoring functions that any fieldbus may provide, its determinism brings in the unique capability of transmitting time related data for setting to the same value the clocks of the equipment. With the use of the GPS, any equipment located around the Large Hadron Collider (LHC) accelerator may thus be exactly in phase with the Universal Time. Thanks to its judicious design, WorldFIP supports also many other very interesting features like Web or video transmission. Current developments around this powerful fieldbus will a...

Brun, R; Sicard, Claude Henri

2003-01-01T23:59:59.000Z

290

Energy Efficiency of large Cryogenic Systems: the LHC Case and Beyond  

E-Print Network (OSTI)

Research infrastructures for high-energy and nuclear physics, nuclear fusion and production of high magnetic fields are increasingly based on applied superconductivity and associated cryogenics in their quest for scientific breakthroughs at affordable capital and operation costs, a condition for their acceptance and sustained funding by society. The thermodynamic penalty for operating at low temperature makes energy efficiency a key requirement for their large cryogenic systems, from conceptual design to procurement, construction and operation. Meeting this requirement takes a combined approach on several fronts in parallel: management of heat loads and sizing of cooling duties, distribution of cooling power matching the needs of the superconducting devices, efficient production of refrigeration, optimal control resting on precise instrumentation and diagnostics, as well as a targeted industrial procurement policy. The case of the Large Hadron Collider (LHC) at CERN is presented. Potential improvements for fu...

Claudet, S; Ferlin, G; Lebrun, P; Tavian, L; Wagner, U

2013-01-01T23:59:59.000Z

291

Helium Recovery in the LHC Cryogenic System following Magnet Resistive Transitions  

E-Print Network (OSTI)

A resistive transition (quench) of the Large Hadron Collider magnets provokes the expulsion of helium from the magnet cryostats to the helium recovery system. A high-volume, vacuum-insulated recovery line connected to several uninsulated medium-pressure gas storage tanks, forms the main constituents of the system. Besides a dedicated hardware configuration, helium recovery also implies specific procedures that should follow a quench, in order to conserve the discharged helium and possibly make use of its refrigeration capability. The amount of energy transferred after a quench from the magnets to the helium leaving the cold mass has been estimated on the basis of experimental data. Based on these data, the helium thermodynamic state in the recovery system is calculated using a lumped parameter approach. The LHC magnet quenches are classified ina parametric way from their cryogenic consequences and procedures that should follow the quench are proposed.

Chorowski, M; Serio, L; Tavian, L; Wagner, U; Van Weelderen, R

1998-01-01T23:59:59.000Z

292

The ATLAS Muon Trigger - Experience and Performance in the first 3 years of LHC pp runs  

E-Print Network (OSTI)

The ATLAS experiment at CERN's Large Hadron Collider (LHC) deploys three-levels processing scheme for the trigger system. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 trigger followed by an event filter for a staged trigger approach. It has access to the data of the precision muon detectors and other detector elements to refine the muon hypothesis. The ATLAS experiment has taken data with high efficiency continuously over entire running periods form 2010 to 2012, for which sophisticated triggers to guard the highest physics output while reducing effectively the event rate were mandatory. The ATLAS Muon trigger has successfully adapted to this changing environment. The selection strategy has been optimized for the various physics analysis involving mu...

Ventura, A; The ATLAS collaboration

2013-01-01T23:59:59.000Z

293

Carbon-Fibre-Reinforced Laminates for the Tuning Structure of the LHC RF Cavities  

E-Print Network (OSTI)

A carbon-fibre-reinforced tube is proposed for the tuning structure of the superconducting RF cavities of the Large Hadron Collider (LHC). It has a high axial stiffness and provides thermal insulation between the cold RF cavity and the tuning actuator at room temperature. The tube is subjected to a high number of mechanical load cycles, high temperature gradients, thermal cycling, and ionizing radiation. Laminate theory is applied to a simplified model of the tube for a failure analysis. Long duration fatigue tests under nominal mechanical and thermal loads were performed on two tubes. The tubes were examined before and after the fatigue tests by geometric measurements, microscopy, and ultrasonic inspection. No damage such as fibre breakage, delamination, or matrix micro cracking could be detected.

Pflanz, G; Tischhauser, Johann

1997-01-01T23:59:59.000Z

294

Signatures of doubly-charged Higgsinos at colliders  

SciTech Connect

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

Demir, D. A. [Department of Physics, Izmir Institute of Technology, IZTECH, TR35430 Izmir (Turkey); Deutsches Elektronen-Synchrotron, DESY, D-22603 Hamburg (Germany); Frank, M.; Turan, I. [Department of Physics, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec, H4B 1R6 (Canada); Huitu, K.; Rai, S. K. [Department of Physics, University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FIN-00014, Helsinki (Finland)

2008-11-23T23:59:59.000Z

295

The promise of the large collider  

E-Print Network (OSTI)

"In 2007, the most powerful particle accelerator ever built, CERN's new Large hadron Collider, will probe the secrets of matter in the energy states prevailing in the moments after the Big Bang. By colliding particles together when they are moving at close to the speed of ight, physicists hope to find out about matter in its earliest forms, using the energy produced by the collisions." (2 pages)

2007-01-01T23:59:59.000Z

296

Muon Collider Progress: Accelerators  

SciTech Connect

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.

Zisman, Michael S.

2011-09-10T23:59:59.000Z

297

Status of the Atlas Liquid Argon Calorimeter and its Performance after Three Years of LHC Operation  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions pro- duced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo- rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.5-4.9. The electromagnetic calorimeters use lead as passive material and are characterised by an accordion geometry that allows a fast and uniform az- imuthal response without any gap. Copper and tungsten were chosen as pas- sive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical elec- trodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at approximately 89 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three-year period prior to first collisions in 2009, using cosmic ra...

Lampl, W; The ATLAS collaboration

2013-01-01T23:59:59.000Z

298

Status of the Atlas Liquid Argon Calorimeter and its Performance after Three Years of LHC Operation  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo- rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.5-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at approximately 89 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three-year period prior to first collisions in 2009, using cosmic rays and s...

Lampl, W; The ATLAS collaboration

2013-01-01T23:59:59.000Z

299

Status of the ATLAS Liquid Argon Calorimeter; Performance after 2 years of LHC operation  

E-Print Network (OSTI)

The ATLAS experiment is designed to study the proton-proton collisions produced at the Large Hadron Collider(LHC) at CERN. Liquid argon sampling calorimeters are used for all electromagnetic calorimetry covering the pseudo-rapidity region up to 3.2, as well as for hadronic calorimetry in the range 1.4-4.9. The electromagnetic calorimeters use lead as passive material and are characterized by an accordion geometry that allows a fast and uniform azimuthal response without any gap. Copper and tungsten were chosen as passive material for the hadronic calorimetry; whereas a classic plate geometry was adopted at large polar angles, an innovative one based on cylindrical electrodes with thin argon gaps was designed for the coverage at low angles, where the particles flow is higher. All detectors are housed in three cryostats kept at about 87 K. After installation in 2004-2006, the calorimeters were extensively commissioned over the three years period prior to first collisions in 2009, using cosmic rays and single LH...

AbouZeid, H; The ATLAS collaboration

2012-01-01T23:59:59.000Z

300

Studies of Hadronization Mechanisms using Pion Electroproduction in Deep Inelas tic Scattering from Nuclei  

SciTech Connect

Atomic nuclei can be used as spatial analyzers of the hadronization process in semi-inclusive deep inelastic scattering. The study of this process using fully-identified final state hadrons began with the HERMES program in the late 1990s, and is now continuing at Jefferson Lab. In the measurement described here, electrons and positive pions were measured from a 5 GeV electron beam incident on targets of liquid deuterium, C, Fe, and Pb using CLAS in Hall B. The broadening of the transverse momentum of positive pions has been studied in detail as a function of multiple kinematic variables, and interpreted in terms of the transport of the struck quark through the nuclear systems. New insights are being obtained into the hadronization process from these studies; and experiments of this type can be relevant for the interpretation of jet quenching and proton-nucleus collisions at RHIC and LHC. These measurements will be extended in the next few years with the approved Jlab experiment E12-06-117, and later at a future Electron-Ion Collider.

Will Brooks, Hayk Hakobyan, Cristian Pea, Miguel Arratia, Constanza Valds

2012-04-01T23:59:59.000Z

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301

COLLOQUIUM: Fundamental Physics and the LHC: A Progress Report...  

NLE Websites -- All DOE Office Websites (Extended Search)

WC17APR2013NAHamed.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...

302

String Phenomenology at the LHC  

E-Print Network (OSTI)

We consider extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. Assuming that the fundamental string mass scale is in the TeV range and the theory is weakly coupled, we review possible signals of string physics at the Large Hadron Collider.

Luis A. Anchordoqui; Haim Goldberg; Dieter Lust; Stephan Stieberger; Tomasz R. Taylor

2009-09-11T23:59:59.000Z

303

CERN Courier Article  

NLE Websites -- All DOE Office Websites (Extended Search)

the hadron-hadron collider energy frontier will be provided by the CERN Large Hadron Collider (LHC), a proton-proton collider with a center-of-mass energy of 14 TeV due to...

304

Muon Collider Papers and Reports  

NLE Websites -- All DOE Office Websites (Extended Search)

of muon collider papers and reports. Muon Collider Feasibilty Study ... Snowmass Book BNL Muon Collider Project Publication Index Fermilab Muon Collider Notes Muon Collider...

305

A method for the separation and reconstructions of charged hadron and neutral hadron from their overlapped showers in electromagnetic calorimeter  

E-Print Network (OSTI)

The separation and reconstructions of charged hadron and neutral hadron from their overlapped showers in electromagnetic calorimeter is very important for the reconstructions of some particles with hadronic decays, for example the tau reconstruction in the searches for the Standard Model and supersymmetric Higgs bosons at the LHC. In this paper, a method combining the shower cluster in electromagnetic calorimeter and the parametric formula for hadron showers, was developed to separate the overlapped showers between charged hadron and neutral hadron. Taking the hadronic decay containing one charged pion and one neutral pion in the final status of tau for example, satisfied results of the separation of the overlapped showers, the reconstructions of the energy and positions of the hadrons were obtained. An improved result for the tau reconstruction with this decay model can be also achieved after the application of the proposed method.

Liang Song; Tao Jun-Quan; Shen Yu-Qiao; Fan Jia-Wei; Xiao Hong; Chen Guo-Ming

2013-05-09T23:59:59.000Z

306

Development of a Beam Condition Monitor System for the Experimental Areas of the LHC Using CVD Diamond  

E-Print Network (OSTI)

The CERN Large Hadron Collider (LHC) will store 2808 bunches per colliding beam, each bunch consisting of 10^11 protons at an energy of 7 TeV. If there is a failure in an element of the accelerator, the resulting beam losses could cause damages not only to the machine but also to the experiments. A Beam Condition Monitor (BCM) is foreseen to monitor fast increments of particle fluxes near the interaction point and, if necessary, to generate an abort signal to the LHC accelerator control to dump the beams. The system is being developed initially for the CMS experiment but is sufficiently general to find potential applications elsewhere. Due to its high radiation hardness, CVD diamond has been studied for use as the BCM sensor. Various samples of CVD diamond have been characterized extensively with a Sr-90 source and high intensity test beams in order to assess the capabilities of such sensors and to study whether this detector technology is suitable for a BCM system. The results from these investigations are p...

Fernndez-Hernando, L

2004-01-01T23:59:59.000Z

307

Flavor changing neutral decay effects in models with two Higgs boson doublets: Applications to LHC Physics  

E-Print Network (OSTI)

In this Thesis we have investigated some effects appearing in top quark and Higgs boson decays with flavor changing neutral currents (FCNC) in the framework of generic Two Higgs Doblet Models (2HDM) and the Minimal Supersymmetric Standard Model (MSSM). We have applied these two extensions to the SM to see whether they can produce new FCNC effects. Introductory chapters deal with the 2HDM and the MSSM. In the next chapters we have computed the following FCNC decays: (1) the branching ratios (B) of the top quark to Higgs bosons and charm quark in the 2HDM; (2) B and number of events at the Large Hadron Collider (LHC) of the Higgs bosons to top and charm quarks in the 2HDM; (3) B of the Higgs bosons to bottom and strange quarks in the MSSM; (4) cross section and number of events at the LHC of the Higgs bosons to FCNC final states involving the heavy quarks like the top and bottom quark in the MSSM (Higgs bosons = h^0, H^0, A^0). We also studied the experimental signatures that would allow discover of the nature of these Higgs bosons in the LHC. In this study we have applied the severe restrictions from observed low-energy FCNC processes like b -> s\\gamma. Our general conclusion is that the physics of the processes with flavor changing neutral currents can be very important in seeing the physics beyond the Standard Model and to disentangle the nature of the most adequate model. Experiments at the LHC can be crucial to unravel signs of FCNC physics beyond the SM.

Santi Bejar

2006-06-12T23:59:59.000Z

308

LHC signals for coset electroweak gauge bosons in warped/composite pseudo-Goldstone boson Higgs models  

SciTech Connect

The framework of a warped extra dimension with the standard model (SM) fields propagating in it is a very well-motivated extension of the SM since it can address both the Planck-weak and flavor hierarchy problems of the SM. Within this framework, solution to the little hierarchy problem motivates extending the SM electroweak (EW) 5D gauge symmetry in such a way that its breakdown to the SM delivers the SM Higgs boson. We study signals at the large hadron collider (LHC) for the extra EW (called coset) gauge bosons, a fundamental ingredient of this framework. The coset gauge bosons, due to their unique EW gauge quantum numbers [doublets of SU(2){sub L}], do not couple at leading order to two SM particles. We find that, using the associated production of the charged coset gauge bosons via their coupling to bottom quark and a (light) Kaluza-Klein excitation of the top quark, the LHC can have a 3{sigma} reach of {approx}2(2.6) TeV for the coset gauge boson masses with {approx}100(1000) fb{sup -1} luminosity. Since current theoretical framework(s) suggest an indirect lower limit on coset gauge boson masses of > or approx. 3 TeV, luminosity or energy upgrade of LHC is likely to be crucial in observing these states.

Agashe, Kaustubh; Azatov, Aleksandr; Zhu Lijun [Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States); Han Tao; Li Yingchuan [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Si Zongguo [Department of Physics, Shandong University, Jinan Shandong 250100 (China)

2010-05-01T23:59:59.000Z

309

Performance of the ATLAS Tau and Missing Energy triggers with 7 TeV proton proton collisions at the LHC  

E-Print Network (OSTI)

A study of the performance of the ATLAS tau and missing energy triggers with data collected in spring 2010 at {\\surd}s = 7 TeV proton-proton collisions at the Large Hadron Collider (LHC) is presented. A comparison was performed between data and Monte Carlo simulations for the tau and missing transverse energy triggers. As well as a comparison between missing transverse energy trigger quantities and their offline reconstructed counterparts. Tau trigger results compare well with predictions from Monte Carlo simulations. Slight deviations are observed for tau shower shape quantities. Possible sources contributing to the discrepancy such as the simulation of the underlying event are currently being studied. The missing transverse energy reconstructed by the Event Filter is well correlated with the offline result. In addition, there is good agreement between the results obtained with collision data and Monte Carlo simulations.

Hooft van Huysduynen, L

2010-01-01T23:59:59.000Z

310

Performance of the ATLAS Tau and Missing Energy triggers with 7 TeV proton proton collisions at the LHC  

E-Print Network (OSTI)

A study of the performance of the ATLAS tau and missing energy triggers with data collected in spring 2010 at {\\surd}s = 7 TeV proton-proton collisions at the Large Hadron Collider (LHC) is presented. A comparison was performed between data and Monte Carlo simulations for the tau and missing transverse energy triggers. As well as a comparison between missing transverse energy trigger quantities and their offline reconstructed counterparts. Tau trigger results compare well with predictions from Monte Carlo simulations. Slight deviations are observed for tau shower shape quantities. Possible sources contributing to the discrepancy such as the simulation of the underlying event are currently being studied. The missing transverse energy reconstructed by the Event Filter is well correlated with the offline result. In addition, there is good agreement between the results obtained with collision data and Monte Carlo simulations.

L. Hooft van Huysduynen

2010-10-05T23:59:59.000Z

311

Ion desorption stability in superconducting high energy physics proton colliders  

DOE Green Energy (OSTI)

In this article we extend our previous analysis of a cold beam tube vacuum in a superconducting proton collider to include ion desorption in addition to thermal desorption and synchrotron radiation induced photodesorption. The ion desorption terms introduce the possibility of vacuum instability. This is similar to the classical room temperature case but is 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 {ital s}(H{sub 2}) less than a monolayer and by thermal desorption for {ital s}(H{sub 2}) greater than a monolayer. For a few percent of a monolayer, characteristic of a beam screen, the photodesorption rate exceeds the ion desorption rate by more than two orders of magnitude. The photodesorption rate corresponds to a sojourn time of approximately 100 s. The article then turns to the evaluation of stability margins and the 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 coaxial 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. (Abstract Truncated)

Turner, W.C. [E. O. Lawrence Berkeley National Laboratory, University of California--Berkeley, Berkeley, California 94720 (United States)] [E. O. Lawrence Berkeley National Laboratory, University of California--Berkeley, Berkeley, California 94720 (United States)

1996-07-01T23:59:59.000Z

312

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

SciTech Connect

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.

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

2006-05-01T23:59:59.000Z

313

LHC Workshop 2011  

NLE Websites -- All DOE Office Websites (Extended Search)

Fourth Generation Particles Fourth Generation Particles Scientists have built a well-tested model of the building blocks of the universe. But experiments at the Large Hadron Collider could reveal additional types of subatomic particles that make up our world. Read More Everything we see Ð from coffee cups to computers to human beings Ð is made up of just three basic particles: two types of quarks that make up the nucleus of an atom and an electron that orbits that nucleus. But scientists have found the particles most familiar to us have heavier cousins, other elementary particles that share some of their properties but have different masses. Over the past century, physicists have discovered 12 elementary particles, which they organized into the Standard Model of particle physics. It serves as a kind of periodic table of elements for

314

Higgs Boson Production Rates in Hadronic Collisions  

E-Print Network (OSTI)

Higgs boson production rates at hadron colliders are reviewed with particular emphasis on progress in the calculation of higher order QCD effects. Emphasis is placed on the uncertainties in the predictions for Higgs boson production. A firm understanding of these uncertainties is crucial for extracting new physics signals.

S. Dawson

2001-11-19T23:59:59.000Z

315

GPU Enhancement of the Trigger to Extend Physics Reach at the LHC  

E-Print Network (OSTI)

Significant new challenges are continuously confronting the High Energy Physics (HEP) experiments, in particular the two detectors at the Large Hadron Collider (LHC) at CERN, where nominal conditions deliver proton-proton collisions to the detectors at a rate of 40 MHz. This rate must be significantly reduced to comply with both the performance limitations of the mass storage hardware and the capabilities of the computing resources to process the collected data in a timely fashion for physics analysis. At the same time, the physics signals of interest must be retained with high efficiency. The quest for rare new physics phenomena at the LHC leads us to evaluate a Graphics Processing Unit (GPU) enhancement of the existing High-Level Trigger (HLT), made possible by the current flexibility of the trigger system, which not only provides faster and more efficient event selection, but also includes the possibility of new complex triggers that were not previously feasible. A new tracking algorithm is evaluated on a NVIDIA Tesla K20c GPU, allowing for the first time the reconstruction of long-lived particles at the tracker system in the trigger. Preliminary time performance and efficiency will be presented.

V. Halyo; A. Hunt; P. Jindal; P. LeGresley; P. Lujan

2013-05-21T23:59:59.000Z

316

Performance of the ATLAS first-level Trigger with first LHC Data  

E-Print Network (OSTI)

ATLAS is one of the two general-purpose detectors at the Large Hadron Collider (LHC). Its trigger system must reduce the anticipated proton collision rate of up to 40 MHz to a recordable event rate of 100-200 Hz. This is realized through a multi-level trigger system. The first-level trigger is implemented with custom-built electronics and makes an initial selection which reduces the rate to less than 100 kHz. The subsequent trigger selection is done in software run on PC farms. The first-level trigger decision is made by the central-trigger processor using information from coarse grained calorimeter information, dedicated muon-trigger detectors, and a variety of additional trigger inputs from detectors in the forward regions. We present the performance of the first-level trigger during the commissioning of the ATLAS detector during early LHC running. We cover the trigger strategies used during the different machine commissioning phases from first circulating beams and splash events to collisions. It is descri...

Lundberg, J; The ATLAS collaboration

2010-01-01T23:59:59.000Z

317

The ALICE Photo Gallery: Images from A Large Ion Collider Experiment (ALICE) at CERN  

DOE Data Explorer (OSTI)

ALICE is the acronym for A Large Ion Collider Experiment, one of the largest experiments in the world devoted to research in the physics of matter at an infinitely small scale. Hosted at CERN, the European Laboratory for Nuclear Research, this project involves an international collaboration of more than 1000 physicists, engineers and technicians, including around 200 graduate students, from 105 physics institutes in 30 countries across the world. The ALICE Experiment is going in search of answers to fundamental questions, using the extraordinary tools provided by the Large Hadron Collider (LHC): 1) What happens to matter when it is heated to 100,000 times the temperature at the centre of the Sun? 2) Why do protons and neutrons weigh 100 times more than the quarks they are made of? 3) Can the quarks inside the protons and neutrons be freed? [copied from http://aliceinfo.cern.ch/Public/Welcome.html]

The Alice Photo Gallery highlights images taken by three professional photographers, Pavel Cugini, Peter Ginter, and Antonio Saba. Other pictures can be found in the Cern Document Server Database at http://cdsweb.cern.ch/.

Cugini, Pavel; Ginter, Peter; Saba, Antonio

318

Top Quark Physics at the LHC  

E-Print Network (OSTI)

An overview of the prospects of top quark physics at the LHC is presented. The ATLAS and the CMS detectors are about to produce a large amount of data with high top quark contents from the LHC proton-proton collisions. A wide variet y of physics analyses is planned in both experiments, and a number of useful insights have already been obtained regarding their detector performance and physics potential. This summary is based on the talk presented at the Hadron C ollider Physics Symposium 2008, Galena, Illinois, May 27-31, 2008.

Akira Shibata

2008-07-31T23:59:59.000Z

319

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

Science Conference Proceedings (OSTI)

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.

Harrison, M.

2011-04-30T23:59:59.000Z

320

Production of charged heavy quarkonium-like states at the LHC and the Tevatron  

E-Print Network (OSTI)

We study prompt hadroproduction of the charged bottomonium-like states $Z_b^\\pm (10610)$ and $Z_b^\\pm (10650)$, and the charged charmonium-like states $Z_c^\\pm (3900)$ and $Z_c^\\pm (4020)$, at the Tevatron and the LHC, provided that these states are $S$-wave hadronic molecules. Using two Monte Carlo event generators, Herwig and Pythia, to simulate the production of heavy meson pairs, we derive an order-of-magnitude estimate of the production rates for these four particles. Our estimates yield a cross section at the nb level for the $Z_b(10610)$ and $Z_b(10650)$. The results for the $Z_c(3900)$ and $Z_c(4020)$ are larger by a factor of 20-30. These cross sections are large enough to be observed, and measurements at hadron colliders in the future will supplement the study using electron-positron collisions, and therefore allow to explore the mysterious nature of these exotic states.

Feng-Kun Guo; Ulf-G. Meiner; Wei Wang

2013-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
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321

A Test Stand for the Muon Trigger Development for the CMS Experiment at the LHC  

E-Print Network (OSTI)

Compact Muon Solenoid (CMS) is one of the flagship experiments in particle physics operating at the Large Hadron Collider (LHC). CMS was built to search for signatures of Higgs bosons, supersymmetry, and other new phenomena. The coming upgrade of the collider will increase the rate of collisions and expand the physics reach of CMS, but will also push the detector systems beyond their current capabilities. One critically affected element is the CMS trigger, a system responsible for making a fast decision if a particular event is of interest and trigger the readout of the detector. As saving the data from every collision would require a technically unattainable bandwidth and is not possible, triggering inefficiencies propagate into reduction of physics reach for the entire experiment. One proposal to handle the future increase in collision rates aims to combine the capabilities of the existing Cathode Strip Chambers (CSC) with the newly proposed Gaseous Electron Multiplication (GEM) detectors to improve the efficiency and discriminating power of the electronics-based muon Level-1trigger. This project focuses on development of a test-stand to emulate operational conditions of such a system, taking into account geometries of the two detector elements. The results of this study will present a proof of principle that building a joint GEM-CSC trigger system is feasible and it can be used to improve trigger efficiency.

Lakdawala, Samir

2013-05-01T23:59:59.000Z

322

Black Holes at the LHC: Progress since 2002  

E-Print Network (OSTI)

We review the recent noticeable progresses in black hole physics focusing on the up-coming super-collider, the LHC. We discuss the classical formation of black holes by particle collision, the greybody factors for higher dimensional rotating black holes, the deep implications of black hole physics to the `energy-distance' relation, the security issues of the LHC associated with black hole formation and the newly developed Monte-Carlo generators for black hole events.

Seong Chan Park

2008-09-15T23:59:59.000Z

323

Muon Collider History  

NLE Websites -- All DOE Office Websites (Extended Search)

Colliders: A Brief History Below is a brief potted history of the muon collider concept. Click here for a one transparency summary. The muon collider concept is an idea dating back...

324

Testing Minimal Universal Extra Dimensions Using Higgs Boson Searches at the LHC  

E-Print Network (OSTI)

Large Hadron Collider (LHC) searches for the SM Higgs boson provide a powerful limit on models involving Universal Extra Dimensions (UED) where the Higgs production is enhanced. We have evaluated all one-loop diagrams for Higgs production from gluon fusion and decay to two photons within "minimal" UED (mUED), independently confirming previous results, and we have evaluated enhancement factors for Higgs boson production and decay over the mUED parameter space. Using these we have derived limits on the parameter space, combining data from both ATLAS and CMS collaborations for the most recent 7 TeV and 8 TeV LHC data. We have performed a rigorous statistical combination of several Higgs boson search channels which is important because mUED signatures from the Higgs boson are not universally enhanced. We have found that 1/R 1000 GeV) around m_h = 118 GeV are left. The latter is likely to be excluded as more data becomes available whereas the region around 125 GeV is where the recently discovered Higgs-like particle was observed and therefore where the exclusion limit is weaker. It is worth stressing that mUED predicts an enhancement for all channels for Higgs production by gluon fusion and decay while the vector boson fusion process WW/ZZ -> h -> AA is generically suppressed and WW/ZZ -> h -> WW*/ZZ* is standard. Therefore, as more 8 TeV LHC data becomes available, the information on individual Higgs boson production and decay processes provided by the CMS and ATLAS experiments can be effectively used to favour mUED or exclude it further.

Genevieve Belanger; Alexander Belyaev; Matthew Brown; Mitsuru Kakizaki; Alexander Pukhov

2012-07-03T23:59:59.000Z

325

Dark Matter Jets at the LHC  

SciTech Connect

We argue that dark matter particles which have strong interactions with the Standard Model particles are not excluded by current astrophysical constraints. These dark matter particles have unique signatures at colliders; instead of missing energy, the dark matter particles produce jets. We propose a new search strategy for such strongly interacting particles by looking for a signal of two trackless jets. We show that suitable cuts can plausibly allow us to find these signals at the LHC even in early data.

Bai, Yang; /SLAC; Rajaraman, Arvind; /UC, Irvine

2012-03-28T23:59:59.000Z

326

RHIC Newsroom  

NLE Websites -- All DOE Office Websites (Extended Search)

Division are in the final stages of assembling "replacement" magnets for the Large Hadron Collider (LHC) at CERN. Brookhaven built twenty magnets already installed at the LHC....

327

Muon Muon Collider: Feasibility Study  

SciTech Connect

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 reactions which are open to a muon collider and the physics of such reactions - what one learns and the necessary luminosity to see interesting events - are described in detail. Most of the physics accesible to an e{sup +} - e{sup -} collider could be studied in a muon collider. In addition the production of Higgs bosons in the s-channel will allow the measurement of Higgs masses and total widths to high precision; likewise, t{bar t} and W{sup +}W{sup -} threshold studies would yield m{sub t} and m{sub w} to great accuracy. These reactions are at low center of mass energy (if the MSSM is correct) and the luminosity and {Delta}p/p of the beams required for these measurements is detailed in the Physics Chapter. On the other hand, at 2 + 2 TeV, a luminosity of L {approx} 10{sup 35} cm{sup -2}s{sup -1} is desirable for studies such as, the scattering of longitudinal W bosons or the production of heavy scalar particles. Not explored in this work, but worth noting, are the opportunities for muon-proton and muon-heavy ion collisions as well as the enormous richness of such a facility for fixed target physics provided by the intense beams of neutrinos, muons, pions, kaons, antiprotons and spallation neutrons. To see all the interesting physics described herein requires a careful study of the operation of a detector in the very large background. Three sources of background have been identified. The first is from any halo accompanying the muon beams in the collider ring. Very carefully prepared beams will have to be injected and maintained. The second is due to the fact that on average 35% of the muon energy appears in its decay electron. The energy of the electron subsequently is converted into EM showers either from the synchrotron radiation they emit in the collider magnetic field or from direct collision with the surrounding material. The decays that occur as the beams traverse the low beta insert are of particular concern for detector backgrounds. A third source of background is e{sup +} - e{sup -} pair creation from {mu}{sup +} - {mu}{sup -} interaction. Studies of

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

2012-04-05T23:59:59.000Z

328

CERN  

NLE Websites -- All DOE Office Websites (Extended Search)

y nuevas partculas y fuerzas fundamentales. Para mayor informacin: LHC: Large Hadron Collider El gran colisionador de hadrones se ha planeado que habite en el mismo tnel...

329

Tau tau Fusion to SUSY Higgs Bosons at a Photon Collider: Measuring tan(beta)  

E-Print Network (OSTI)

Tau tau fusion to light h and heavy H,A Higgs bosons is investigated in the Minimal Supersymmetric Standard Model (MSSM) at a photon collider as a promising channel for measuring large values of tan(beta). For standard design parameters of a photon collider an error close to unity, uniform for tan(beta) above 10, may be expected, improving on complementary measurements at LHC and e+e- linear colliders.

S. Y. Choi; J. Kalinowski; J. S. Lee; M. M. Muehlleitner; M. Spira; P. M. Zerwas

2004-07-05T23:59:59.000Z

330

MARMOSET: The Path from LHC Data to the New Standard Model via On-Shell Effective Theories  

SciTech Connect

We describe a coherent strategy and set of tools for reconstructing the fundamental theory of the TeV scale from LHC data. We show that On-Shell Effective Theories (OSETs) effectively characterize hadron collider data in terms of masses, production cross sections, and decay modes of candidate new particles. An OSET description of the data strongly constrains the underlying new physics, and sharply motivates the construction of its Lagrangian. Simulating OSETs allows efficient analysis of new-physics signals, especially when they arise from complicated production and decay topologies. To this end, we present MARMOSET, a Monte Carlo tool for simulating the OSET version of essentially any new-physics model. MARMOSET enables rapid testing of theoretical hypotheses suggested by both data and model-building intuition, which together chart a path to the underlying theory. We illustrate this process by working through a number of data challenges, where the most important features of TeV-scale physics are reconstructed with as little as 5 fb{sup -1} of simulated LHC signals.

Arkani-Hamed, Nima; Schuster, Philip; Toro, Natalia; /Harvard U., Phys. Dept.; Thaler, Jesse; /UC, Berkeley /LBL, Berkeley; Wang, Lian-Tao; /Princeton U.; Knuteson, Bruce; /MIT, LNS; Mrenna, Stephen; /Fermilab

2007-03-01T23:59:59.000Z

331

Dark Matter May be Strongly Visible in UHE Cosmic Rays and Related New Physics May be Appearing at the LHC  

E-Print Network (OSTI)

A two flavor color sextet quark sector added to QCD yields the {\\it uniquely} unitary Critical Pomeron at high energy while also producing electroweak symmetry breaking. In this paper it is argued that a number of experimental phenomena in Cosmic Ray and hadron collider physics can be interpreted as evidence for the sextet sector, as follows. 1. The majority of UHE cosmic rays are Dark Matter sextet neutrons. 2. The cosmic ray spectrum knee is a production threshold for sextet states. 3. The enhancement of high multiplicities and small pT at the LHC is related to a sextet generated triple pomeron coupling. 4. Tevatron and LHC events containing a Z pair and a high multiplicity of small pT particles are associated with sextet electroweak symmetry breaking. 5. Top quark production is via the $\\eta_6$ sextet quark pseudoscalar resonance - interference with the background will produce an asymmetry. 6. Enhanced W pair production would produce an excess in the W + dijet cross-section. Combining the sextet sector and...

White, Alan R

2011-01-01T23:59:59.000Z

332

A two-Higgs-doublet model : from twisted theory to LHC phenomenology.  

E-Print Network (OSTI)

??At the dawn of the Large Hadron Collider era, the Brout-Englert-Higgs mechanism remains the most appealing theoretical explanation of the electroweak symmetry breaking, despite the (more)

Herquet, Michel

2008-01-01T23:59:59.000Z

333

Muon identification with the event filter of the ATLAS experiment at CERN LHC's  

Science Conference Proceedings (OSTI)

The Large Hadron Collider at CERN offers unprecedented challenges to the design and construction of detectors and trigger/data acquisition systems. For ATLAS, a three level trigger system has been developed to extract interesting physics signatures with ...

Gabriella Cataldi

2005-06-01T23:59:59.000Z

334

NLO QCD CORRECTIONS TO HADRONIC HIGGS PRODUCTION WITH HEAVY QUARKS.  

SciTech Connect

The production of a Higgs boson in association with a pair of t{bar t} or b{bar b} quarks plays a very important role at both the Tevatron and the Large Hadron Collider. The theoretical prediction of the corresponding cross sections has been improved by including the complete next-to-leading order QCD corrections. After a brief description of the most relevant technical aspects of the calculation, we review the results obtained for both the Tevatron and the Large Hadron Collider.

DAWSON,S.; JACKSON,C.; ORR,L.; REINA,L.; WACHEROTH,D.

2003-07-02T23:59:59.000Z

335

Brookhaven & the LHC | Newsroom  

NLE Websites -- All DOE Office Websites (Extended Search)

and in discovering the particle that proves the existence of the Higgs field, the Higgs boson. LHC magnets Backup Magnets Ready to Ship to LHC Monday, September 30, 2013...

336

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

Science Conference Proceedings (OSTI)

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.

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

2011-09-01T23:59:59.000Z

337

Searches for new gauge bosons at future colliders  

SciTech Connect

The search reaches for new gauge bosons at future hadron and lepton colliders are summarized for a variety of extended gauge models. Experiments at these energies will vastly improve over present limits and will easily discover a Z` and/or W` in the multi-TeV range.

Rizzo, T.G.

1996-09-01T23:59:59.000Z

338

Figures for CERN Courier  

NLE Websites -- All DOE Office Websites (Extended Search)

Collider (FMC), Next Muon Collider (NMC), Next Linear Collider (NLC), and Very Large Hadron Collider (VLHC). These are compared with the footprint of the LHC at CERN, and the...

339

Heavy Squarks at the LHC  

E-Print Network (OSTI)

The LHC, with its seven-fold increase in energy over the Tevatron, is capable of probing regions of SUSY parameter space exhibiting qualitatively new collider phenomenology. Here we investigate one such region in which first generation squarks are very heavy compared to the other superpartners. We find that the production of these squarks, which is dominantly associative, only becomes rate-limited at mSquark > 4(5) TeV for L~10(100) fb-1. However, discovery of this scenario is complicated because heavy squarks decay primarily into a jet and boosted gluino, yielding a dijet-like topology with missing energy (MET) pointing along the direction of the second hardest jet. The result is that many signal events are removed by standard jet/MET anti-alignment cuts designed to guard against jet mismeasurement errors. We suggest replacing these anti-alignment cuts with a measurement of jet substructure that can significantly extend the reach of this channel while still removing much of the background. We study a selection of benchmark points in detail, demonstrating that mSquark= 4(5) TeV first generation squarks can be discovered at the LHC with L~10(100)fb-1.

JiJi Fan; David Krohn; Pablo Mosteiro; Arun M. Thalapillil; Lian-Tao Wang

2011-02-01T23:59:59.000Z

340

Cryogenic Silicon Microstrip Detector Modules for LHC  

E-Print Network (OSTI)

CERN is presently constructing the LHC, which will produce collisions of 7 TeV protons in 4 interaction points at a design luminosity of 1034 cm-2 s-1. The radiation dose resulting from the operation at high luminosity will cause a serious deterioration of the silicon tracker performance. The state-of-art silicon microstrip detectors can tolerate a fluence of about 3 1014 cm-2 of hadrons or charged leptons. This is insufficient, however, for long-term operation in the central parts of the LHC trackers, in particular after the possible luminosity upgrade of the LHC. By operating the detectors at cryogenic temperatures the radiation hardness can be improved by a factor 10. This work proposes a cryogenic microstrip detector module concept which has the features required for the microstrip trackers of the upgraded LHC experiments at CERN. The module can hold an edgeless sensor, being a good candidate for improved luminosity and total cross-section measurements in the ATLAS, CMS and TOTEM experiments. The design o...

Perea-Solano, B

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Reach in All Hadronic Stop Decays: A Snowmass White Paper  

E-Print Network (OSTI)

We study the discovery prospects for stops which decay to a top and a light neutralino. We consider fully hadronic decays of the tops and present an estimate for the reach at various future collider runs. Our results are summarized in Table 1.

Stolarski, Daniel

2013-01-01T23:59:59.000Z

342

Reach in All Hadronic Stop Decays: A Snowmass White Paper  

E-Print Network (OSTI)

We study the discovery prospects for stops which decay to a top and a light neutralino. We consider fully hadronic decays of the tops and present an estimate for the reach at various future collider runs. Our results are summarized in Table 1.

Daniel Stolarski

2013-09-06T23:59:59.000Z

343

Post LHC8 SUSY benchmark points for ILC physics  

E-Print Network (OSTI)

We re-evaluate prospects for supersymmetry at the proposed International Linear e^+e^- Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with ~5 fb^{-1} of pp collisions at sqrt{s}=7 TeV and LHC8 with ~20 fb^{-1} at \\sqrt{s}=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m_h~125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, radiatively-driven natural SUSY (RNS), NUHM2 with low m_A, a focus point case from mSUGRA/CMSSM, non-universal gaugino mass (NUGM) model, stau-coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy (NMH), and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at \\sqrt{s}~0.25-1 TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post LHC8 era at both LHC and ILC.

Howard Baer; Jenny List

2013-07-02T23:59:59.000Z

344

Vector-boson pair production at the LHC to $\\mathcal{O}(\\alpha^3)$ accuracy  

E-Print Network (OSTI)

Building on earlier work on electroweak corrections to W-pair production, the first calculation of the full electroweak one-loop corrections to on-shell ZZ, W$^{\\pm}$Z and $\\gamma\\gamma$ production at hadron colliders is presented, explicitly taking into account the full vector-boson mass dependence. As a consequence, our results are valid in the whole energy range probed by LHC experiments. Until now, the electroweak corrections have only been known in dedicated high-energy approximations limited to a specific kinematic regime, in particular requiring high boson transverse momenta. Therefore, our results comprise an important and so far missing ingredient to improve on the theory predictions for these fundamental Standard-Model benchmark processes also at intermediate energies and small scattering angles, where actually the bulk of events is located. In case of Z-pair production we have also included the leptonic decays and the associated weak corrections in our analysis. For this particular channel, correct...

Bierweiler, Anastasiya; Khn, Johann H

2013-01-01T23:59:59.000Z

345

Vector-boson pair production at the LHC to $\\mathcal{O}(?^3)$ accuracy  

E-Print Network (OSTI)

Building on earlier work on electroweak corrections to W-pair production, the first calculation of the full electroweak one-loop corrections to on-shell ZZ, W$^{\\pm}$Z and $\\gamma\\gamma$ production at hadron colliders is presented, explicitly taking into account the full vector-boson mass dependence. As a consequence, our results are valid in the whole energy range probed by LHC experiments. Until now, the electroweak corrections have only been known in dedicated high-energy approximations limited to a specific kinematic regime, in particular requiring high boson transverse momenta. Therefore, our results comprise an important and so far missing ingredient to improve on the theory predictions for these fundamental Standard-Model benchmark processes also at intermediate energies and small scattering angles, where actually the bulk of events is located. In case of Z-pair production we have also included the leptonic decays and the associated weak corrections in our analysis. For this particular channel, corrections of about -4% are observed even close to the production threshold. For hard scattering processes with momentum transfers of several hundred GeV one finds large negative corrections which may amount to several tens of percent and lead to significant distortions of transverse-momentum and rapidity distributions.

Anastasiya Bierweiler; Tobias Kasprzik; Johann H. Khn

2013-05-23T23:59:59.000Z

346

There is no explosion risk associated with superfluid Helium in the LHC cooling system  

E-Print Network (OSTI)

We evaluate speculation about the possibility of a dangerous release of energy within the liquid Helium of the Large Hadron Collider (LHC) cryogenic system due to the occurrence of a "Bose-Nova". Bose-Novae are radial bursts of rapidly moving atoms which can occur when a Bose-Einstein Condensate (BEC) undergoes a collapse due the interatomic potential being deliberately made attractive using a magnetic field close to the Feshbach resonance. Liquid 4He has a monatomic structure with s-wave electrons, zero nuclear spin, no hyperfine splitting, and as a consequence no Feshbach resonance which would allow one to change its normally repulsive interactions to be attractive. Because of this, a Bose-Nova style collapse of 4He is impossible. Additional speculations concerning cold fusion during these events are easily dismissed using the usual arguments about the Coulomb barrier at low temperatures, and are not needed to explain the Bose-Einstein condensate Bose-Nova phenomenon. We conclude that that there is no physics whatsoever which suggests that Helium could undergo any kind of unforeseen catastrophic explosion.

Malcolm Fairbairn; Bob McElrath

2008-09-23T23:59:59.000Z

347

Testing nuclear parton distributions with pA collisions at the LHC  

E-Print Network (OSTI)

Global perturbative QCD analyses, based on large data sets from electron-proton and hadron collider experiments, provide tight constraints on the parton distribution function (PDF) in the proton. The extension of these analyses to nuclear parton distributions (nPDF) has attracted much interest in recent years. nPDFs are needed as benchmarks for the characterization of hot QCD matter in nucleus-nucleus collisions, and attract further interest since they may show novel signatures of non-linear density-dependent QCD evolution. However, it is not known from first principles whether the factorization of long-range phenomena into process-independent parton distribution, which underlies global PDF extractions for the proton, extends to nuclear effects. As a consequence, assessing the reliability of nPDFs for benchmark calculations goes beyond testing the numerical accuracy of their extraction and requires phenomenological tests of the factorization assumption. Here we argue that a proton-nucleus collision program at the LHC would provide a set of measurements allowing for unprecedented tests of the factorization assumption underlying global nPDF fits.

Paloma Quiroga-Arias; Jose Guilherme Milhano; Urs Achin Wiedemann

2010-02-12T23:59:59.000Z

348

Axis Measurements, Field Quality and Quench Performance of the First LHC Short Straight Sections  

E-Print Network (OSTI)

The series testing at 1.9 K of the 360 Short Straight Sections (SSS) for the Large Hadron Collider have started at CERN in September 2003. The SSS contain the lattice quadrupoles and correction magnets in a common cryostat. The lattice quadrupoles feature two collared coils with 56 mm bore assembled in a common yoke. The coils are wound in two-layers from 15.1mm wide NbTi cable, insulated with polyimide tape. The paper reviews the main test results performed in superfluid helium. The magnetic field and magnetic center position of the quadrupoles and associated correctors were measured with two independent systems, namely an automated scanner and a single stretched wire technique. The quench training, the field quality and the magnetic alignment measurements are presented and discussed in terms of the specifications and expected performances of these magnets in the LHC. We discuss in detail the field quality in terms of multipole errors measured at injection and nominal field and decomposed into geometric an...

Sanfilippo, S; Calvi, M; Chohan, V; Durante, M; Hagen, P; Pugnat, P; Smirnov, N; Schnizer, P; Sammut, N; Siemko, A; Simon, F; Stafiniak, A; Todesco, Ezio; Tortschanoff, Theodor; Walckiers, L; 10.1109/TASC.2005.849504

2005-01-01T23:59:59.000Z

349

Brookhaven and ATLAS | Brookhaven and the LHC  

NLE Websites -- All DOE Office Websites (Extended Search)

Brookhaven and ATLAS Brookhaven and ATLAS BNL scientists install cathode strip chambers BNL scientists install cathode strip chambers - designed and built at the Laboratory - and monitored drift tubes into the ATLAS small wheel. Image credit: CERN. Brookhaven physicists and engineers are participating in one of the most ambitious scientific projects in the world - constructing, operating, doing physics analysis of the data, and upgrading a machine the size of a seven-story building that will open up new frontiers in the human pursuit of knowledge about elementary particles and their interactions. The machine, dubbed ATLAS, is one of four facilities located at the LHC near Geneva, in Switzerland. The LHC consists of two circular vacuum pipes in which protons travel in opposite directions and collide at nearly the

350

Predicting ?-lepton polarization at the LHC  

E-Print Network (OSTI)

This is a master's thesis and it is written in Lithuanian language. The goal of this thesis is to predict the polarization of a \\tau-particle produced at the LHC and coming from a real W boson. This is achieved by calculating the projection of the expectation value of the polarization vector of the \\tau-particle. Calculations are done in the frame of the Standard Model. In this model only left-chiral currents couple to W bosons. The mass of the \\tau-particle is left non-zero, therefore one can see the influence of helicity mixing on polarization. The initial colliding particles at the LHC are protons and the most important channels for W production are quark fusion: $q\\bar{q} -> W^+ -> \\tau^+ \

Adomas Jelinskas

2013-10-07T23:59:59.000Z

351

Supersymmetry, Dark Matter and the LHC  

Science Conference Proceedings (OSTI)

The conceptually simplest scenario for dark matter (DM) is that it is a stable thermal relic from standard Big Bang cosmology, in many SUSY models the lightest neutralino. The relic density determination selects special regions in SUSY model parameter space with concomitant implications for collider physics, dark matter searches and low energy measurements. By studying various one-parameter extensions of the much-studied mSUGRA model (where we relax the untested universality assumptions) constructed to be in accord with the measured relic density, we show that these implications are in general model-dependent, so that LHC and DM measurements will provide clues to how sparticles acquire their masses. We point out some relatively robust implications for LHC and DM searches and conclude with an outlook for the future.

Tata, Xerxes [Department of Physics and Astronomy, University of Hawaii, Honolulu, HI 96825 (United States) and Physics Department, University of Wisconsin, Madison, WI 53705 (United States)

2010-02-10T23:59:59.000Z

352

New Perspectives for QCD Physics at the LHC  

SciTech Connect

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.

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

2011-02-07T23:59:59.000Z

353

Study of Higgs boson production and its b-bbar decay in gamma-gamma processes in proton-nucleus collisions at the LHC  

E-Print Network (OSTI)

We explore for the first time the possibilities to measure an intermediate-mass (mH = 115-140 GeV/c^2) Standard-Model Higgs boson in electromagnetic proton-lead (pPb) interactions at the CERN Large Hadron Collider (LHC) via its b-bbar decay. Using equivalent Weizsaecker-Williams photon fluxes and Higgs effective field theory for the coupling gamma-gamma --> H, we obtain a leading-order cross section of the order of 0.3 pb for exclusive Higgs production in elastic (pPb --> gamma-gamma --> p H Pb) and semielastic (pPb --> gamma-gamma --> Pb H X) processes at sqrt(s) = 8.8 TeV. After applying various kinematics cuts to remove the main backgrounds (gamma-gamma --> b-bbar and misidentified gamma-gamma-->q-qbar events), we find that a Higgs boson with mH = 120 GeV/c^2 could be observed in the b-bbar channel with a 3sigma-significance integrating 300 pb^-1 with an upgraded pA luminosity of 10^31 cm^-2s^-1. We also provide for the first time semielastic Higgs cross sections, along with elastic t-tbar cross sections, for electromagnetic pp, pA and AA collisions at the LHC.

David d'Enterria; Jean-Philippe Lansberg

2009-09-16T23:59:59.000Z

354

Study of Higgs boson production and its b-b(bar) decay in gamma-gamma processes in proton-nucleus collisions at the LHC  

SciTech Connect

We explore for the first time the possibilities to measure an intermediate-mass (m{sub H} = 115-140 GeV/c{sup 2}) Standard-Model Higgs boson in electromagnetic proton-lead (p Pb) interactions at the CERN Large Hadron Collider (LHC) via its b{bar b} decay. Using equivalent Weizsacker-Williams photon fluxes and Higgs effective field theory for the coupling {gamma}{gamma} {yields} H, we obtain a leading-order cross section of the order of 0.3 pb for exclusive Higgs production in elastic (p Pb {yields} {gamma}{gamma} p H Pb) and semielastic (p Pb {yields} {gamma}{gamma} X H Pb) processes at {radical}S{sub NN} = 8.8 TeV. After applying various kinematics cuts to remove the main backgrounds ({gamma}{gamma} {yields} b{bar b} and misidentified {gamma}{gamma} {yields} q{bar q} events), we find that a Higgs boson with m{sub H} = 120 GeV/c{sup 2} could be observed in the b{bar b} channel with a 3{sigma}-significance integrating 300 pb{sup -1} with an upgraded pA luminosity of 10{sup 31} cm{sup -2}s{sup -1}. We also provide for the first time semielastic Higgs cross sections, along with elastic t{bar t} cross sections, for electromagnetic pp, pA and AA collisions at the LHC.

d' Enterria, David; /ICC, Barcelona U. /ICREA, Barcelona; Lansberg, Jean-Philippe; /Ecole Polytechnique, CPHT /SLAC

2010-08-26T23:59:59.000Z

355

SANC system and its applications for LHC  

E-Print Network (OSTI)

The {\\tt SANC} computer system is aimed at support of analytic and numeric calculations for experiments at colliders. The system is reviewed briefly. Recent results on high-precision description of the Drell-Yan processes at the LHC are presented. Special attention is paid to the evaluation of higher order final-state QED corrections to the single $W$ and $Z$ boson production processes. A new Monte Carlo integrator {\\tt mcsanc} suited for description of a series of high-energy physics processes at the one-loop precision level is presented.

R. Sadykov; A. Arbuzov; D. Bardin; S. Bondarenko; P. Christova; L. Kalinovskaya; V. Kolesnikov; A. Sapronov; E. Uglov

2013-10-14T23:59:59.000Z

356

Discriminating between Z Prime -boson effects and effects of anomalous gauge couplings in the double production of W{sup {+-}} bosons at a linear collider  

Science Conference Proceedings (OSTI)

The potential of the International Linear electron-positron Collider (ILC) for seeking, in the annihilation production of W{sup {+-}}-boson pairs, signals induced by new neutral gauge bosons predicted by models belonging to various classes and featuring an extended gauge sector is studied. Limits that will be obtained at ILC for the parameters and masses of Z Prime bosons are compared with present-day and future data from the Large Hadron Collider (LHC). The possibility of discriminating between the effects of Z-Z Prime mixing and signals induced by anomalous gauge couplings (AGC) is demonstrated within theoretically motivated trilinear gauge models involving several free anomalous parameters. It is found that the sensitivity of ILC to the effects of Z-Z Prime mixing in the process e{sup +}e{sup -} {yields} W{sup +}W{sup -} and its ability to discriminate between these two new-physics scenarios, Z Prime and AGC, become substantially higher upon employing polarized initial (e{sup +}e{sup -}) and final (W{sup {+-}}) states.

Andreev, Vasili V., E-mail: quarks@gsu.by [Francisk Skorina Gomel State University (Belarus); Pankov, A. A., E-mail: pankov@ictp.it [Abdus Salam ICTP International Centre for Theoretical Physics (Italy)

2013-06-15T23:59:59.000Z

357

Updated measurements of hadronic B decays at CDF  

SciTech Connect

The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides a rich, and highly rewarding program that has currently reached full maturity. In the following I report some recent results on hadronic decays: the evidence for the charmless annihilation decay mode B{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}, and the first reconstruction in hadron collisions of the suppressed decays B{sup -} {yields} D({yields} K{sup +}{pi}{sup 0})K{sup -} and B{sup -} {yields} D({yields} K{sup +} {pi}{sup -}){pi}{sup -}.

Morello, Michael J.

2012-01-01T23:59:59.000Z

358

Fermilab | Muon Collider | Graphics  

NLE Websites -- All DOE Office Websites (Extended Search)

Graphics A chain of accelerators and other devices is necessary to produce and accelerate muons before scientists can make muons collide. Click image for larger version A muon...

359

The Particle Adventure | Glossary  

NLE Websites -- All DOE Office Websites (Extended Search)

LHC The Large Hadron Collider at the CERN laboratory in Geneva, Switzerland. LHC will collide protons into protons at a center-of-mass energy of about 14 TeV. When completed in the...

360

Next Linear Collider Home Page  

NLE Websites -- All DOE Office Websites (Extended Search)

Welcome to the Next Linear Collider NLC Home Page If you would like to learn about linear colliders in general and about this next-generation linear collider project's mission,...

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Papers on Muon Colliders  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnets for Muon Collider and Neutrino Storage Ring Magnets for Muon Collider and Neutrino Storage Ring (and Open Midplane Dipole for LARP): R. Gupta, et al., "High Field HTS Solenoid for a Muon Collider – Demonstrations, Challenges and Strategies, MT23, July 2013", presented at MT23, (talk) R. Weggel et al., "Open Midplane Dipoles for Muon Collider", 2011 Particle Accelerator Conference, New York (POSTER).. R. Gupta, M. Anerella, A. Ghosh, H. Kirk, R. Palmer, S. Plate, W. Sampson, Y. Shiroyanagi, P. Wanderer, B. Brandt, D. Cline, A. Garren, J. Kolonko, R. Scanlan, R. Weggel, "High field HTS R&D solenoid for muon collider", 2010 Applied Superconductivity Conference, Washington, DC, August 2010 >> Y. Shiroyanagi, W. Sampson, A. Ghosh, R. Gupta, "The Construction and

362

Exclusive Dijet production from CDF2LHC  

E-Print Network (OSTI)

Exclusive dijet production at the Tevatron can be used as a benchmark to establish predictions on exclusive diffractive Higgs production, a process with a much smaller cross section. Exclusive dijet production in Double Pomeron Exchange processes, including diffractive Higgs production with measurements at the Tevatron and predictions for the Large Hadron Collider are presented. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Upper limits on the exclusive dijet production cross section are presented and compared to current theoretical predictions.

Michele Gallinaro; for the CDF collaboration

2005-04-05T23:59:59.000Z

363

Calorimeter based detectors for high energy hadron colliders  

Science Conference Proceedings (OSTI)

This report discusses the following topics: the central calorimeter; and installation; commissioning; and calorimeter beam tests; the central drift chamber; cosmic ray and beam tests; chamber installation and commissioning; and software development; and SSC activities: the EMPACT project.

Marx, M.D.; Rijssenbeek, M. (State Univ. of New York, Stony Brook, NY (USA))

1990-01-01T23:59:59.000Z

364

Higgs Boson Production with Heavy Quarks at Hadron Colliders.  

E-Print Network (OSTI)

?? One of the remaining puzzles in particle physics is the origin of electroweak symmetry breaking. In the Standard Model (SM), a single doublet of (more)

Jackson, Christopher B.

2005-01-01T23:59:59.000Z

365

Phenomenological aspects of new physics at high energy hadron colliders  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.2.3 ISR effects without invisible particle emission . . . . . . . . . . . . 54 4.2.4 Mellin transform inversion . . . . . . . . . . . . . . . . . . . . . . . 65 4.2.5 ISR effects including invisible particle emission . . . . . . . . . . . . 68 4...

Papaefstathiou, Andreas

2011-07-12T23:59:59.000Z

366

Heavy-quark production at large rapidities at hadron colliders.  

E-Print Network (OSTI)

to those partonic subprocesses that feature a gluon exchange in the t-channel; this happens for gg ? QQg and qg ? QQq, and it is peculiar to the NLO computations of quark pair production, as opposed to Born-level predictions, in which only fermions... -energy limit is QQ+1 jet production. In this case the partonic subprocesses gg ? QQg and qg ? QQq, which feature a gluon exchange in the t-channel, are O(?3S) at the Born level. This can also be considered as a reformulation of the standard Mueller...

Andersen, Jeppe R; Del Duca, Vittoria; Frixione, Stefano; Maltoni, Fabio; Stirling, W James

367

New aspects of beam-beam interactions in hadron colliders  

Science Conference Proceedings (OSTI)

Beam-beam phenomena have until now limited the beam currents and luminosity achievable in the Tevatron. injected proton currents are about ten times larger than the anti-proton currents so beam-beam effects have largely acted on the anti-protons and at all stages of the operational cycle. The effects of the anti-protons on the protons have until now been relatively benign but that may change at higher anti-proton currents. After 36 bunches of protons are injected and placed on the proton helix, anti-protons are injected four bunches at a time. After all bunches are injected, acceleration to top energy takes bout 85 seconds. After reaching flat top, the optics around the interaction regions (IRs) is changed to lower {beta}* from 1.6 m to 0.35 m at B0 and D0. The beams are brought into collision by collapsing the separation bumps around the IPs. During a high energy physics store each bunch experiences two head-on collisions with bunches in the opposing beam and seventy long-range interactions. At all other stages of the operational cycle, each bunch experiences only long-range interactions--seventy two in all. Performance limitations from beam-beam effects until now have been primarily due to these long-range interactions. The anti-proton losses at 150 GeV have decreased during the last year mostly due to better control of the orbits, tunes and chromaticities. During this period proton intensities have increased about 50%, thus anti-proton losses at 150 GeV have not been very dependent on proton intensities. Anti-proton and proton losses on the ramp together with proton losses at 150 GeV are the dominant contributors to the Tevatron inefficiency.

Tanaji Sen

2003-06-02T23:59:59.000Z

368

Singlet scalars as Higgs imposters at the Large Hadron Collider  

SciTech Connect

An electroweak singlet scalar can couple to pairs of vector bosons through loop-induced dimension five operators. Compared to a Standard Model Higgs boson, the singlet decay widths in the diphotons and Z{gamma} channels are generically enhanced, while decays into massive final states like WW and ZZ are kinematically disfavored. The overall event rates into {gamma}{gamma} and Z{gamma} can exceed the Standard Model expectations by orders of magnitude. Such a singlet may appear as a resonant signal in the {gamma}{gamma} and Z{gamma} channels, even with a mass above the WW kinematic threshold.

Low, Ian; Lykken, Joseph; Shaughnessy, Gabe

2011-05-01T23:59:59.000Z

369

Z production via Vector Boson Fusion at LHC  

E-Print Network (OSTI)

The production of Z bosons via Vector Boson Fusion at the LHC collider at 10 TeV centre-of-mass energy has been studied. The aim is to investigate the possibility to isolate a known Standard Model process to be used as reference for the measurement of the detector performance for the search of the Higgs Boson produced via Vector Boson Fusion. The signal to background ratio has been estimated considering only the dominant sources of background.

Pietro Govoni; Chiara Mariotti

2010-01-25T23:59:59.000Z

370

When will we know a muon collider is feasible? Status and directions of muon accelerator R&D  

E-Print Network (OSTI)

Over the last decade there has been significant progress in developing the concepts and technologies needed to produce, capture, accelerate and collide high intensity beams of muons. At present, a high-luminosity multi-TeV muon collider presents a viable option for the next generation lepton-lepton collider, which is believed to be needed to fully explore high energy physics in the era following the LHC discoveries. This article briefly reviews the status of the accelerator R&D, addresses the question of the feasibility of a Muon Collider, what needs to be done to prove it and presents projected timeline of the project.

Vladimir Shiltsev

2010-03-16T23:59:59.000Z

371

LHC Workshop 2011  

NLE Websites -- All DOE Office Websites (Extended Search)

JavaScript is Turned Off or Not Supported in Your Browser. Some of the functionality of this page will not work. LHC New Physics Resources Extra Dimensions As far as we know, we...

372

muon Collider Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

Muon Collider Notes Muon Collider Notes MC-001 D. Neuffer, "Colliding Muon Beams at 90 GeV" Fermilab Note FN-319, July 1979. MC-002 D. Neuffer, "Principles and Applications of Muon Cooling" Proc. of the 12th International Conf. on High-Energy Accelerators, p. 481, 1983. MC-003 V.V. Parkhomchuk and A.N. Skrinsky, "Ionization Cooling: Physics and Applications" Proc. of the 12th International Conf. on High-Energy Accelerators, p. 485, 1983. MC-004 E.A. Perevedentsev and A.N. Skrinsky, "On the Proton Klystron" Proc. of the 12th International Conf. on High-Energy Accelerators, p. 508, 1983. MC-005 D. Neuffer, "Principles and Applications of Muon Cooling" Particle Accelerators, Vol. 14, p. 75, 1983. MC-006 D. Neuffer, "Multi-TeV Muon Colliders" Proc. of the Advanced

373

Linear collider: a preview  

Science Conference Proceedings (OSTI)

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

Wiedemann, H.

1981-11-01T23:59:59.000Z

374

The TESLA superconducting linear collider  

Science Conference Proceedings (OSTI)

This paper summarizes the present status of the studies for a superconducting Linear Collider (TESLA).

R. Brinkmann; the TESLA Collaboration

1997-01-01T23:59:59.000Z

375

Single Neutralino Production at the LHC  

E-Print Network (OSTI)

We consider that the direct production of a single neutralino in proton-proton collision at the CERN Large Hadron Collider focusing on the lightest neutralino is possibly a candidate for the dark matter and escapes detection. We present a comprehensive investigation of the dependence of total cross sections of the processes $pp(q\\bar q)\\rightarrow\\widetilde\\chi_{i}^{0}\\widetilde{\\text{g}}$, $pp(q \\text{g}) \\rightarrow\\widetilde\\chi_{i}^{0}\\widetilde{q}_{L,R}$, $pp(q\\bar{q}^{\\prime})\\rightarrow\\widetilde\\chi_{i}^{0}\\widetilde\\chi_{j}^{+}$ at tree-level and $pp(\\text{g}\\text{g})\\rightarrow\\widetilde\\chi_{i}^{0}\\widetilde{\\text{g}}$ at one-loop level, on the center-of-mass energy, on the $M_2$-$\\mu$ mass plane, on the squark mass and on the $\\tan\\beta$ for the Constrained Minimal Supersymmetric Standard Model and the three extremely different scenarios in the Minimal Supersymmetric Standard Model. In particular, the cross section of the process $p p \\to \\widetilde\\chi_{2}^{0}\\widetilde\\chi_{1}^{+}$ in the gaugino-like scenario can reach about 0.6 (1.7) pb at a center-of-mass energy of $\\sqrt{s}=$ 7 (14) TeV. We derive therefrom that our results might lead to new aspects corresponding to experimental explorations, and these dependencies might be used as bases of experimental research of the single neutralino production at hadron colliders.

A. I. Ahmadov; M. Demirci

2013-07-14T23:59:59.000Z

376

Inclusive Higgs Boson Searches in Four-Lepton Final States at the LHC  

E-Print Network (OSTI)

The inclusive search for the Standard Model Higgs boson in four-lepton final states with the ATLAS and CMS detectors at the LHC pp collider is presented. The discussion focusses on the H-> ZZ^(*)->4l+X decay mode for a Higgs boson in the mass range 120 ~Higgs boson properties is also given.

Evelyne Delmeire

2007-05-15T23:59:59.000Z

377

Single production of excited electrons at future e{sup +}e{sup -}, ep and pp colliders  

Science Conference Proceedings (OSTI)

We analyzed the potential of the LC with {radical}(s)=0.5 TeV, LCxLHC based ep collider with {radical}(s)=3.74 TeV and the LHC with {radical}(s)=14 TeV to search for excited electrons through transition magnetic type couplings with gauge bosons. The e*{yields}e{gamma} signal and corresponding backgrounds are studied in detail.

Cakir, O.; Yilmaz, A.; Sultansoy, S. [Ankara University, Faculty of Sciences, Department of Physics, 06100, Tandogan, Ankara (Turkey); Gazi University, Faculty of Arts and Sciences, Department of Physics, 06500, Teknikokullar, Ankara (Turkey); Azerbaijan Academy of Sciences, Institute of Physics, H. Cavid Ave. 33, Baku (Azerbaijan)

2004-10-01T23:59:59.000Z

378

Development of GEM-Based Digital Hadron Calorimetry Using the SLAC KPiX Chip  

Science Conference Proceedings (OSTI)

The development of Digital Hadron Calorimetry for the SiD detector Concept for the International Linear Collider is described. The jet energy requirements of the ILC physics program are discussed. The concept of GEM-based digital hadron calorimetry is presented, followed by a description of, and results from, prototype detectors. Plans are described for the construction of 1m{sup 2} GEM-DHCAL planes to be tested as part of a future calorimeter stack.

White, A.; /Texas U., Arlington /Washington U., Seattle /Unlisted /SLAC

2012-04-12T23:59:59.000Z

379

Photon collider at TESLA  

E-Print Network (OSTI)

High energy photon colliders (gamma-gamma, gamma-electron) based on backward Compton scattering of laser light is a very natural addition to e+e- linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the gamma-gamma luminosity luminosity in the high energy part of spectrum can reach (1/3)L_{e+e-}. Typical cross sections of interesting processes in gamma-gamma collisions are higher than those in e+e- collisions by about one order of magnitude, so the number of events in gamma-gamma collisions will be more than that in e+e- collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is ``an optical storage ring (optical trap)'' with diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based at TESLA, its possible parameters and existing problems.

Valery Telnov

2000-10-13T23:59:59.000Z

380

Physics Out Loud - Hadron  

NLE Websites -- All DOE Office Websites (Extended Search)

Gluons Previous Video (Gluons) Physics Out Loud Main Index Next Video (Hybrid Meson) Hybrid Meson Hadron David Lawrence, a physicist, uses a little Greek in his description of a...

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Page not found | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Quark Gluon Plasma, Solar-Power Generating Windows and CCS Field Studies Large Hadron Collider's (LHC) first record-setting run of high-energy proton collisions,...

382

Brace for Impact: Why Does Matter Dominate Our Universe? - NERSC...  

NLE Websites -- All DOE Office Websites (Extended Search)

(Courtesy of H. W. Linn, University of Washington) While the fireworks at CERN's Large Hadron Collider (LHC) transfix the world, theorists are quietly doing some computational...

383

Fermilab Today  

NLE Websites -- All DOE Office Websites (Extended Search)

CERN press release CERN experiments observe particle consistent with long-sought Higgs boson US LHC press release Search for Higgs boson at Large Hadron Collider reveals new...

384

Standard Model Higgs Boson Discovery Potential in the Decay Channel H - > ZZ(*) - > 4 mu with the CMS Detector.  

E-Print Network (OSTI)

??The Compact Muon Solenoid (CMS) is a general purpose detector at the Large Hadron Collider (LHC) currently under construction at CERN with start-up date in (more)

Drozdetski, Alexei Alexandrovic

2007-01-01T23:59:59.000Z

385

RHIC | Electron-Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Electron-Ion Collider A breakthrough particle accelerator could collide electrons with heavy ions or protons at nearly the speed of light to create rapid-fire, high-resolution...

386

HIGGS BOSON SEARCH AT PHOTON COLLIDER FOR MH = 140 ? 190 GEV.  

E-Print Network (OSTI)

A Higgs boson within the mass range MH = 140 ? 190 GeV can be discovered at a photon collider in the reaction ?? ? WW (with real or virtual W). Quite moderate resolution in the effective mass of the WW system is required. Preliminary remarks. A discovery of the Higgs boson is one of the main goals for the next generation of colliders. If the Higgs boson mass MH is larger than 2MZ, Higgs boson can be discovered at LHC, photon colliders [1] or e + e ? linear colliders [2] via the sizable decay mode H ? ZZ. For all types of collisions a background to this decay mode is rather small. If MH Higgs boson can be discovered at photon colliders or e + e ? linear colliders via the dominant decay mode H ? b b and at LHC via the decay mode H ? ??. The mass range MH = 140 ? 190 GeV is the most difficult one for the Higgs boson discovery. In this mass range the decay mode H ? W + W ? with real or virtual Ws (W ? ? qq, e?,...) is dominant, branching ratios of other decay modes decrease rapidly and their using for the Higgs boson discovery is very difficult. The use of the H ? W + W ? decay at e + e ?

unknown authors

1997-01-01T23:59:59.000Z

387

HIGGS BOSON SEARCH AT PHOTON COLLIDER FOR MH = 140 ? 190 GEV.  

E-Print Network (OSTI)

A Higgs boson within the mass range MH = 140 ? 190 GeV can be discovered at a photon collider in the reaction ?? ? WW (with real or virtual W) with the luminosity integral about 1 fb ?1. The reasonable resolution in the effective mass of the WW system is required. Preliminary remarks. A discovery of the Higgs boson is one of the main goals for the next generation of colliders. If the Higgs boson mass MH is larger than 2MZ, it can be discovered at LHC, photon colliders [1] or e + e ? linear colliders [2] via the sizable decay mode H ? ZZ. For all types of collisions a background to this decay mode is rather small. If MH Higgs boson can be discovered at e + e ? linear colliders or photon colliders via the dominant decay mode H ? b b and at LHC via the decay mode H ? ??. The mass range MH = 140 ? 190 GeV is the most difficult one for the Higgs boson discovery. In this mass range the decay mode H ? W + W ? with real or virtual Ws

unknown authors

1997-01-01T23:59:59.000Z

388

LHC Results - Highlights  

E-Print Network (OSTI)

The LHC has delivered already 10/fb of proton proton collisions at a centre- of-mass energy of 7-8 TeV. With this data set, ATLAS and CMS have discovered a new boson at a mass of about 125 GeV and have searched for new physics at the TeV scale.

Gigi Rolandi

2012-11-15T23:59:59.000Z

389

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

Science Conference Proceedings (OSTI)

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.

Bhat, C.M.; /Fermilab

2009-05-01T23:59:59.000Z

390

Fully hadronic ttbar cross section measurement with ATLAS detector  

E-Print Network (OSTI)

The top quark pair production cross section in the fully hadronic final state is characterized by a six jet topology, two of which could be identified as originating from a b-quark using ATLAS b-tagging algorithms. Compared to other decay channels, this final state presents an advantageous larger branching ratio; on the other hand it suffers from a very large QCD multi-jet background, generally difficult to estimate from Monte Carlo simulation and therefore evaluated using data-driven techniques. The analysis is performed using 36pb-1 of pp collisions produced at the LHC with a center-of-mass energy of 7 TeV. The observed upper limit is set at 261 pb at 95% confidence level, where the expected Standard Model cross-section for the ttbar process is 165+11-16 pb. In the future, when the LHC luminosity increases, it is essential, to efficiently trigger on these fully hadronic ttbar events, to use dedicated triggers. An overview of the analysis for ttbar production cross section measurement in the fully hadronic final state and the state-of-the-art of the b-jet trigger performance estimation are presented in this contribution.

Claudia Bertella

2011-11-16T23:59:59.000Z

391

Hard scattering phenomena from RHIC to LHC  

Science Conference Proceedings (OSTI)

In the Relativistic Heavy Ion Collider era the high-p{sub T} particle emerging from hard scattering became an important tool of exploration of excited nuclear medium formed in ultra-relativistic heavy ion collisions. Discovery of anomalous suppression of high-p{sub T} particle yield [1] together with an observation of disappearance of back-to-back hadron correlation in central Au+Au collisions in 2002 [2] were the key results interpreted as a manifestation of the deconfined QCD medium in heavy ion collisions. Analysis of the high-p{sub T} particle and jet production is already a standard experimental technique providing a test bench for pQCD description of the point-like constituent scattering in p+p collisions and sensitive probes of the excited nuclear medium in A+A collisions.

Rak, Jan [Jyvaeskylae University, FI-40014 Jyvaeskylae (Finland)

2011-05-23T23:59:59.000Z

392

Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider Relativistic Heavy Ion Collider managed for the U.S. Department of Energy by Brookhaven Science Associates, founded by Stony Brook University and Battelle. managed for the U.S. Department of Energy by Brookhaven Science Associates, a company founded by Stony Brook University and Battelle 07/07 Brookhaven National Laboratory Funded by the U.S. Department of Energy, Brookhaven National Laboratory is a multipurpose research institution located on a 5,300-acre site on Long Island, New York. Six Nobel Prize-winning discoveries have been made at Brookhaven Lab. The Laboratory operates large-scale scientific facilities and performs research in physics, chemistry, biology, medicine, applied science, and

393

Collider-Accelerator Department  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC Tunnel and Magnets RHIC Tunnel and Magnets RHIC Tunnel and Magnets AGS Tunnel and Magnets NSRL Beamline RF Kicker Snake 200-MeV LINAC AGS Cold Snake Magnet About the Collider-Accelerator Department The mission of the Collider-Accelerator Department is to develop, improve and operate the suite of particle / heavy ion accelerators used to carry out the program of accelerator-based experiments at BNL; to support the experimental program including design, construction and operation of the beam transports to the experiments plus support of detector and research needs of the experiments; to design and construct new accelerator facilities in support of the BNL and national missions. The C-A Department supports an international user community of over 1500 scientists. The department performs all these functions in an environmentally responsible and safe manner under a rigorous conduct of operations approach.

394

Aspects of Hadron Physics  

E-Print Network (OSTI)

Detailed investigations of the structure of hadrons are essential for understanding how matter is constructed from the quarks and gluons of Quantum chromodynamics (QCD), and amongst the questions posed to modern hadron physics, three stand out. What is the rigorous, quantitative mechanism responsible for confinement? What is the connection between confinement and dynamical chiral symmetry breaking? And are these phenomena together sufficient to explain the origin of more than 98% of the mass of the observable universe? Such questions may only be answered using the full machinery of nonperturbative relativistic quantum field theory. This contribution provides a perspective on progress toward answering these key questions. In so doing it will provide an overview of the contemporary application of Dyson-Schwinger equations in Hadron Physics. The presentation assumes that the reader is familiar with the concepts and notation of relativistic quantum mechanics, with the functional integral formulation of quantum field theory and with regularisation and renormalisation in its perturbative formulation.

C. D. Roberts; M. S. Bhagwat; S. V. Wright; A. Holl

2008-02-01T23:59:59.000Z

395

muon_collider  

NLE Websites -- All DOE Office Websites (Extended Search)

muon_collider muon_collider muon_collider FridayMeetings MCTFmeetings MondayMeetings prstab texput.log #prstab.tex# last.kumac prstab.ps arxiv.tar.gz prstab.tar.gz referee_response_II.pdf prstab.pdf prstab.aux prstab.dvi prstab.end prstab.log prstab.tex prstab.tex~ accel-010307-f03.eps accel-010307-f28.eps old conclusions.tex higgsfact.tex introduction.tex mice.tex neufact.tex physics.tex prstab.tex r_and_d.tex authors_merged.tex buncher.tex temp.prt last.kumacold ringfig.eps MICE-fig.ps chgr_norm.ps chgr_merit.ps temp.csh temp.prt~ xupdn-a-model-view-iron5.eps site1-Layout1.eps rla2.eps phaserot.eps mole-hill.eps intoap.eps emit.eps cavity.eps allcount.eps MICE-88MHz-cooling.eps changes hh_ha_susy_rtsscan.eps letter_plots.eps scott33.eps scott32b.eps scott32a.eps MICE-200MHz-long.eps MICE-resolution.eps dipole_fields.eps

396

High intensity hadron accelerators  

SciTech Connect

This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.

Teng, L.C.

1989-05-01T23:59:59.000Z

397

Hadronic Physics: an Outlook  

Science Conference Proceedings (OSTI)

A brief outlook, in two senses, is presented for hadronic physics. The likely near term future for experiment and lattice effort is sketched and I speculate on future directions in theory. I also look out at other fields, presenting a short review of QCD ideas in ''Beyond the Standard Model'' physics.

Swanson, Eric S. [Dept of Physics and Astronomy, University of Pittsburgh, Pittsburgh PA 15260 (United States)

2010-08-05T23:59:59.000Z

398

LHC Design & Construction | Brookhaven and the LHC  

NLE Websites -- All DOE Office Websites (Extended Search)

LHC Design & Construction LHC Design & Construction BNL-built superconducting magnet BNL engineers with the first of 20 BNL-built superconducting magnets for the LHC. Starting in 1996, Brookhaven scientists and engineers designed and constructed 20 of the total 1,200 superconducting magnets for the LHC. Now in place, these specialized dipole magnets, each weighing more than 25 tons, will guide the LHC's two counter-rotating beams of protons into collision. Tied to this effort, Brookhaven scientists also tested much of the associated superconducting wires and cables for the machine. In addition, Brookhaven scientists and engineers designed and built key parts of the ATLAS detector, including: pieces of the liquid argon calorimeter - a device that pinpoints electrons and photons emerging from

399

Back Covers [blanks  

Science Conference Proceedings (OSTI)

The Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, needs to produce unprecedented volumes of data when it starts operation in 2007. To provide for its computational needs, the LHC computing grid (LCG) should be deployed ...

2005-07-01T23:59:59.000Z

400

Front Inside Cover [blank  

Science Conference Proceedings (OSTI)

The Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, needs to produce unprecedented volumes of data when it starts operation in 2007. To provide for its computational needs, the LHC computing grid (LCG) should be deployed ...

2005-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Top Physics at the LHC  

E-Print Network (OSTI)

Top quark physics will be a prominent topic in Standard Model physics at the LHC. The enormous amount of top quarks expected to be produced will allow to perform a wide range of precision measurements. An overview of the planned top physics programme of the ATLAS and CMS experiments at the LHC is given.

Christian Weiser

2005-06-10T23:59:59.000Z

402

Jet Quenching at LHC  

E-Print Network (OSTI)

We review up-to-date results on high-pt particles and jets in heavy ion collisions by three major LHC experiments, ALICE, ATLAS, and CMS. Results of analyses of 2010 and 2011 Pb+Pb data at $\\sqrt{s_{NN}} = 2.76$ TeV are discussed. We concentrate mainly on results by fully reconstructed jets and discuss similarities and important differences in measurements among experiments. We point to the importance of understanding the results in a view of difference between quark-initiated and gluon-initiated jets

Martin Spousta

2013-05-28T23:59:59.000Z

403

Dictionary of LHC Signatures  

E-Print Network (OSTI)

We report on a plan to establish a "Dictionary of LHC Signatures", an initiative that started at the WHEPPX workshop in January 2008. This study aims towards the strategy on distinguishing of 3 classes of dark matter motivated scenarios such as R-parity conserved supersymmetry, Little Higgs models with T-parity conservation and Universal Extra Dimensions with KK-parity for generic cases of their realization in wide range of the model space. Discriminating signatures are tabulated and will need a further detailed analysis.

A. Belyaev; I. A. Christidi; A. De Roeck; R. M. Godbole; B. Mellado; A. Nyffeler; C. Petridou; D. P. Roy

2008-06-17T23:59:59.000Z

404

Photon collider at TESLA 1  

E-Print Network (OSTI)

High energy photon colliders (??, ?e) based on backward Compton scattering of laser light is a very natural addition to e + e ? linear colliders. In this report we consider this option for the TESLA project. Recent study has shown that the horizontal emittance in the TESLA damping ring can be further decreased by a factor of four. In this case the ?? luminosity in the high energy part of spectrum can reach about (1/3)L e e ?. Typical cross sections of interesting processes in ?? collisions are higher than those in e + e ? collisions by about one order of magnitude, so the number of events in ?? collisions will be more than that in e + e ? collisions. Photon colliders can, certainly, give additional information and they are the best for the study of many phenomena. The main question is now the technical feasibility. The key new element in photon colliders is a very powerful laser system. An external optical cavity is a promising approach for the TESLA project. A free electron laser is another option. However, a more straightforward solution is an optical storage ring (optical trap) with a diode pumped solid state laser injector which is today technically feasible. This paper briefly reviews the status of a photon collider based on the linear collider TESLA, its possible parameters and existing problems. PACS: 29.17.+w, 41.75.Ht, 41.75.Lx, 13.60.Fz Key words: photon collider; linear collider; photon photon; gamma gamma; photon electron; Compton scattering; backscattering 1

Valery Telnov

2001-01-01T23:59:59.000Z

405

Parton Distributions in Hadrons  

SciTech Connect

We use the statistical model of Zhang et al. to calculate parton distributions in hadrons. The model does reasonably well in predicting the distributions of partons in the proton, including the (d-bar - u-bar) excess in the proton sea. We extend the model to calculate quark and gluon distributions in the pion, kaon, and the pentaquark. The hadrons are described in terms of quark and gluon Fock states. Detailed balance between each pair of states is assumed, from which the coefficients of the Fock state expansion are determined. The parton distribution functions are found in the hadron rest frame from a Monte Carlo calculation. The results are evolved to appropriate QCD scales for comparison with experiment. Despite its simplicity, the model is in good agreement with the experimentally measured distributions of partons in the pion and kaon. This project has included significant participation by undergraduates at Seattle University, made possible by support from the Research in Undergraduate Institutions Program of the National Science Foundation.

Alberg, Mary [Department of Physics, Seattle University, Seattle, WA 98122 (United States); Department of Physics, University of Washington, Seattle, WA 98195 (United States); Henley, Ernest M. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Institute for Nuclear Theory, University of Washington, Seattle, WA 98195 (United States)

2006-07-11T23:59:59.000Z

406

Hadron Physics at the Charm and Bottom Thresholds and Other Novel QCD Physics Topics at the NICA Accelerator Facility  

Science Conference Proceedings (OSTI)

The NICA collider project at the Joint Institute for Nuclear Research in Dubna will have the capability of colliding protons, polarized deuterons, and nuclei at an effective nucleon-nucleon center-of mass energy in the range {radical}s{sub NN} = 4 to 11 GeV. I briefly survey a number of novel hadron physics processes which can be investigated at the NICA collider. The topics include the formation of exotic heavy quark resonances near the charm and bottom thresholds, intrinsic strangeness, charm, and bottom phenomena, hidden-color degrees of freedom in nuclei, color transparency, single-spin asymmetries, the RHIC baryon anomaly, and non-universal antishadowing.

Brodsky, Stanley J.; /SLAC

2012-06-20T23:59:59.000Z

407

Links to Muon Collider Related Web Pages  

NLE Websites -- All DOE Office Websites (Extended Search)

Muon Collider related web pages: Muon Collider Feasibility Study ... Fermilab Page MUCOOL Collaboration: Ionization Cooling R&D Snowmass 1996 Feasibility Study Book Brookhaven Muon...

408

Neutrino Physics at a Muon Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Physics at a Muon Collider The intense muon beams needed for high luminosity muon colliders produce intense beams of neutrinos. Dedicated muon storage rings with long straight...

409

Top Quark Anomalous Couplings at the International Linear Collider  

SciTech Connect

We present a study of the experimental determination of the forward-backward asymmetry in the process e{sup +}e{sup -} {yields} t{bar t} and in the subsequent t {yields} Wb decay, studied in the context of the International Linear Collider. 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. Measurement of the forward-backward asymmetry requires excellent b quark identification and determination of the quark charge. The study reported here is performed in the most challenging all-hadronic channel e{sup +}e{sup -} {yields} b{bar b}q{bar q}q{bar q}. It includes realistic details of the experimental environment, a full Monte Carlo simulation of the detector, based on the Silicon Detector concept, and realistic event reconstruction. The forward-backward asymmetries are determined to a precision of approximately 1% for each of two choices of beam polarization. We analyze the implications for the determination of the t{bar t}Z and Wt{bar b} couplings.

Devetak, Erik; Nomerotski, Andrei; /Oxford U.; Peskin, Michael; /SLAC

2011-08-15T23:59:59.000Z

410

Commissioning of CMS and early standard model measurements with jets, missing transverse energy and photons at the LHC  

E-Print Network (OSTI)

We report on the status and history of the CMS commissioning, together with selected results from cosmic-ray muon data. The second part focuses on strategies for optimizing the reconstruction of jets, missing transverse energy and photons for early standard model measurements at ATLAS and CMS with the first collision data from the Large Hadron Collider at CERN.

T. Christiansen

2008-05-13T23:59:59.000Z

411

LHC Higgs Boson searches  

E-Print Network (OSTI)

A summary of the Higgs boson searches by the ATLAS and CMS collabrations using 1 f b-1 of LHC data is presented, concentrating on the Standard Model Higgs boson. Both experiments have the sensitivity to exclude at 95% CL a Standard Model Higgs boson in most of the Higgs boson mass region between about 130 GeV and 400 GeV. The observed data allow the exclusion of a Higgs Boson of mass 155 GeV to 190 GeV and 295 GeV to 450 GeV (ATLAS) and 149 GeV to 206 GeV and 300 GeV to 440 GeV (CMS). The lower limits are not as constraining as might be expected due to an excess in both experiments of order 2-3{\\sigma} which could be related to a low mass Higgs boson or to a statistical fluctuation.

William Murray

2012-01-22T23:59:59.000Z

412

Fermilab | Muon Collider | How Does a Muon Collider Work?  

NLE Websites -- All DOE Office Websites (Extended Search)

A muon collider complex would comprise several machines and many different A muon collider complex would comprise several machines and many different components. Scientists across the world are developing and testing them. View full graphic How Does a Muon Collider Work? A muon collider complex would comprise several machines and many different components. Scientists across the world are developing and testing them. Proton accelerator To create lots of muons, scientists use a high-intensity proton accelerator that steers protons into a target. The collisions create short-lived particles called pions. Within 50 meters the pions decay into muons and neutral particles called neutrinos. The muons have an energy of about 200 MeV. Capture cavities Magnets guide the muons into and through a set of radiofrequency cavities. The electric field inside the cavities increases the energy of slow muons

413

Assessing Risk in Costing High-energy Accelerators: from Existing Projects to the Future Linear Collider  

E-Print Network (OSTI)

High-energy accelerators are large projects funded by public money, developed over the years and constructed via major industrial contracts both in advanced technology and in more conventional domains such as civil engineering and infrastructure, for which they often constitute one-of markets. Assessing their cost, as well as the risk and uncertainty associated with this assessment is therefore an essential part of project preparation and a justified requirement by the funding agencies. Stemming from the experience with large circular colliders at CERN, LEP and LHC, as well as with the Main Injector, the Tevatron Collider Experiments and Accelerator Upgrades, and the NOvA Experiment at Fermilab, we discuss sources of cost variance and derive cost risk assessment methods applicable to the future linear collider, through its two technical approaches for ILC and CLIC. We also address disparities in cost risk assessment imposed by regional differences in regulations, procedures and practices.

Lebrun, Philippe

2010-01-01T23:59:59.000Z

414

Hadron Spectroscopy in COMPASS  

E-Print Network (OSTI)

The COmmon Muon and Proton Apparatus for Structure and Spectroscopy (COMPASS) is a multi-purpose fixed-target experiment at the CERN Super Proton Synchrotron (SPS) aimed at studying the structure and spectrum of hadrons. In the naive Constituent Quark Model (CQM) mesons are bound states of quarks and antiquarks. QCD, however, predict the existence of hadrons beyond the CQM with exotic properties interpreted as excited glue (hybrids) or even pure gluonic bound states (glueballs). One main goal of COMPASS is to search for these states. Particularly interesting are so called spin-exotic mesons which have J^{PC} quantum numbers forbidden for ordinary q\\bar{q} states. Its large acceptance, high resolution, and high-rate capability make the COMPASS experiment an excellent device to study the spectrum of light-quark mesons in diffractive and central production reactions up to masses of about 2.5 GeV. COMPASS is able to measure final states with charged as well as neutral particles, so that resonances can be studied in different reactions and decay channels. During 2008 and 2009 COMPASS acquired large data samples using negative and positive secondary hadron beams on lH_2, Ni, and Pb targets. The presented overview of the first results from this data set focuses in particular on the search for spin-exotic mesons in diffractively produced \\pi^-\\pi^+\\pi^-, \\eta\\pi, \\eta'\\pi, and \\pi^-\\pi^+\\pi^-\\pi^+\\pi^- final states and the analysis of central-production of \\pi^+\\pi^- pairs in order to study glueball candidates in the scalar sector.

Boris Grube; for the COMPASS Collaboration

2013-01-31T23:59:59.000Z

415

Hadron Production in Heavy Ion Collisions  

E-Print Network (OSTI)

2A GeV 3 Hadron Production from AGS to RHIC 3.1 SystematicsHadron Production in Heavy Ion Collisions Hans Georg RitterAC02- 05CH11231. Hadron Production in Heavy Ion Collisions

Ritter, Hans Georg

2009-01-01T23:59:59.000Z

416

Tsallis Fits to p_T Spectra and Multiple Hard Scattering in pp Collisions at LHC  

Science Conference Proceedings (OSTI)

Phenomenological Tsallis fits to the CMS, ATLAS, and ALICE transverse momentum spectra of hadrons for pp collisions at LHC were recently found to extend over a large range of the fitting transverse momentum. We investigate whether the few degrees of freedom in the Tsallis parametrization may arising from the relativistic parton-parton hard-scattering and related hard processes. The effects of multiple hard-scattering and parton showering on the power law are discussed. We find that although the transverse spectra of both hadrons and jets exhibit power-law behaviour of 1/pT^n at high pT, the power indices n for hadrons are categorically greater than those for jets, for which n~4.

Wong, Cheuk-Yin [ORNL; Wilk, Grzegorz [National Centre for Nuclear Research, Warsaw, Poland

2013-01-01T23:59:59.000Z

417

Photons and Dileptons at LHC  

E-Print Network (OSTI)

We discuss real and virtual photon sources in heavy ion collisions and present results for dilepton yields in Pb+Pb collisions at the LHC at intermediate and large transverse momentum p_T.

Rainer J. Fries; S. Turbide; C. Gale; D. K. Srivastava

2007-07-02T23:59:59.000Z

418

Big Science and the LHC  

E-Print Network (OSTI)

Starting from the example of the LHC, I discuss the role of large projects in science and their impact on society. This article is based on a talk given at the Scuola Normale Superiore of Pisa.

Giudice, Gian Francesco

2012-01-01T23:59:59.000Z

419

Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data  

E-Print Network (OSTI)

We present the achievements of the last years of the experimental and theoretical groups working on hadronic cross section measurements at the low energy e+e- colliders in Beijing, Frascati, Ithaca, Novosibirsk, Stanford and Tsukuba and on tau decays. We sketch the prospects in these fields for the years to come. We emphasise the status and the precision of the Monte Carlo generators used to analyse the hadronic cross section measurements obtained as well with energy scans as with radiative return, to determine luminosities and tau decays. The radiative corrections fully or approximately implemented in the various codes and the contribution of the vacuum polarisation are discussed.

Actis, S; Arbuzov, A; Balossini, G; Beltrame, P; Bignamini, C; Bonciani, R; Carloni Calame, C M; Cherepanov, V; Czakon, M; Czyz, H; Denig, A; Eidelman, S; Fedotovich, G V; Ferroglia, A; Gluza, J; Grzeli nska, A; Gunia, M; Hafner, A; Ignatov, F; Jadach, S; Jegerlehner, F; Kalinowski, A; Kluge, W; Korchin, A; Kuhn, J H; Kuraev, E A; Lukin, P; Mastrolia, P; Montagna, G; Muller, S E; Nguyen, F; Nicrosini, O; Nomura, D; Pakhlova, G; Pancheri, G; Passera, M; Penin, A; Piccinini, F; Placzek, W; Przedzinski, T; Remiddi, E; Riemann, T; Rodrigo, G; Roig, P; Shekhovtsova, O; Shen, C P; Sibidanov, A L; Teubner, T; Trentadue, L; Venanzoni, G; van der Bij, J J; Wang, P; Ward, B F L; Was, Z; Worek, M; Yuan, C Z

2010-01-01T23:59:59.000Z

420

Quantum Gravity at the LHC  

E-Print Network (OSTI)

It has recently been shown that if there is a large hidden sector in Nature, the scale of quantum gravity could be much lower than traditionally expected. We study the production of massless gravitons at the LHC and compare our results to those obtained in extra dimensional models. The signature in both cases is missing energy plus jets. In case of non observation, the LHC could be used to put the tightest limit to date on the value of the Planck mass.

Xavier Calmet; Priscila de Aquino

2009-06-02T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

First Linear Collider ISG Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Collider Internation Study Group Workshop Full meeting proceedings Participant Photos Banquet Dinner Photos Note that you will need to have Adobe Reader 3.0 or GhostView installed...

422

Oscillation Energies of Colliding Raindrops  

Science Conference Proceedings (OSTI)

When raindrops collide, some of the kinetic energy involved in the collision will be available to initiate or sustain oscillations in the surviving drops. This paper presents results of a simple model of drop collisions that generates an estimate ...

David B. Johnson; Kenneth V. Beard

1984-04-01T23:59:59.000Z

423

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. RHIC...

424

Relativistic Heavy Ion Collider, RHIC  

NLE Websites -- All DOE Office Websites (Extended Search)

The Relativistic Heavy Ion Collider website has moved to www.bnl.govrhicdefault.asp Sponsored by the U.S. Department of Energy Office of Science, Office of Nuclear Physics. Last...

425

Muon muon collider: Feasibility study  

Science Conference Proceedings (OSTI)

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

NONE

1996-06-18T23:59:59.000Z

426

Distributed analysis at LHC$b$  

E-Print Network (OSTI)

The distributed analysis experience to date at LHC$b$ has been positive: job success rates are high and wait times for high-priority jobs are low. LHC$b$ users access the grid using the GANGA job-management package, while the LHC$b$ virtual organization manages its resources using the DIRAC package. This clear division of labor has benefitten LHC$b$ and its users greatly; it is a major reason why distributed analysis at LHC$b$ has been so successful. They newly formed LHC$b$ distributed analysis support team has also proved to be a success.

Williams, M; Paterson, S

2010-01-01T23:59:59.000Z

427

Higgs boson coupling sensitivity at the LHC using H->tau tau decays  

E-Print Network (OSTI)

We investigate the potential for measuring the relative couplings of a low-mass Higgs boson at the Large Hadron Collider using WH, ZH, and ttbarH production, where the Higgs boson decays to tau-lepton pairs. With 100/fb of sqrt(s) = 14 TeV pp collision data we find that these modes can improve sensitivity to coupling-ratio measurements of a Higgs boson with a mass of about 125 GeV/c^2.

Boddy, Christopher; Hays, Christopher

2012-01-01T23:59:59.000Z

428

Isolating Wt production at the LHC  

E-Print Network (OSTI)

We address the issue of single top production in association with a W boson at the Large Hadron Collider, in particular how to obtain an accurate description in the face of the top pair production background given that the two processes interfere with each other. We stress the advantages of an MC@NLO description, and find that for cuts used to isolate the signal, it makes sense to consider Wt as a well-defined production process in that the interference with top pair production is small, and the cross-section of the former is above the scale variation uncertainty associated with the latter. We also consider the case where both Wt and top pair production are backgrounds to a third process (Higgs boson production followed by decay to a W boson pair), and find in this context that interference issues can also be neglected. We discuss the generalization of our results to other situations, aided by a comparison between the MC@NLO approach and a calculation of the WWbb final state matched to a parton shower.

Chris D. White; Stefano Frixione; Eric Laenen; Fabio Maltoni

2009-08-05T23:59:59.000Z

429

LHC Engineering Documentation | Superconducting Magnet Division  

NLE Websites -- All DOE Office Websites (Extended Search)

RHIC - LHC D1 Post Structural Analysis (pdf) Memo - Pressure Test of the LHC D1 Dipole Heat Exchanger Bellows (pdf) D1 Phase Separator Stress Analysis (pdf) D1 Phase Separator...

430

Challenging the standard model at the Tevatron collider  

SciTech Connect

Even at a time where the world's eyes are focused on the Large Hadron Collider at CERN, which has reached the energy frontier in 2010, many important results are still being obtained from data analyses performed at the Tevatron collider at Fermilab. This contribution discusses recent highlights in the areas of B hadron, electroweak, top quark, and Higgs boson physics. The standard model (SM) of particle physics forms the cornerstone of our understanding of elementary particles and their interactions, and many of its aspects have been investigated in great detail. Yet it is generally suspected to be incomplete (e.g. by not allowing for the incorporation of gravity in a field theoretical setting) and un-natural (e.g. the mass of the Higgs boson is not well protected against radiative corrections). In addition, it does not explain the dark matter and dark energy content of the Universe. It is therefore of eminent importance to test the limits of validity of the SM. In the decade since its upgrade to a centre-of-mass energy {radical}s = 1.96 TeV, the Tevatron p{bar p} collider has delivered an integrated luminosity of about 10 fb{sup -1}, up to 9 fb{sup -1} of which are available for analysis by its CDF and D0 collaborations. These large datasets allow for stringent tests of the SM in two areas: direct searches for particles or final states that are not very heavy but that suffer from small production cross sections (e.g. the Higgs boson), and searches for indirect manifestations of beyond-the-standard-model (BSM) effects through virtual effects. The latter searches can often be carried out by precise measurements of otherwise known processes. This contribution describes such tests of the SM carried out by the CDF and D0 collaborations. In particular, recent highlights in the areas of B hadron physics, electroweak physics, top quark physics, and Higgs boson physics are discussed. Recent results of tests of QCD and of direct searches for new phenomena are described in another contribution.

Filthaut, Frank; /Nijmegen U.

2011-03-01T23:59:59.000Z

431

Challenging the standard model at the Tevatron collider  

SciTech Connect

Even at a time where the world's eyes are focused on the Large Hadron Collider at CERN, which has reached the energy frontier in 2010, many important results are still being obtained from data analyses performed at the Tevatron collider at Fermilab. This contribution discusses recent highlights in the areas of B hadron, electroweak, top quark, and Higgs boson physics. The standard model (SM) of particle physics forms the cornerstone of our understanding of elementary particles and their interactions, and many of its aspects have been investigated in great detail. Yet it is generally suspected to be incomplete (e.g. by not allowing for the incorporation of gravity in a field theoretical setting) and un-natural (e.g. the mass of the Higgs boson is not well protected against radiative corrections). In addition, it does not explain the dark matter and dark energy content of the Universe. It is therefore of eminent importance to test the limits of validity of the SM. In the decade since its upgrade to a centre-of-mass energy {radical}s = 1.96 TeV, the Tevatron p{bar p} collider has delivered an integrated luminosity of about 10 fb{sup -1}, up to 9 fb{sup -1} of which are available for analysis by its CDF and D0 collaborations. These large datasets allow for stringent tests of the SM in two areas: direct searches for particles or final states that are not very heavy but that suffer from small production cross sections (e.g. the Higgs boson), and searches for indirect manifestations of beyond-the-standard-model (BSM) effects through virtual effects. The latter searches can often be carried out by precise measurements of otherwise known processes. This contribution describes such tests of the SM carried out by the CDF and D0 collaborations. In particular, recent highlights in the areas of B hadron physics, electroweak physics, top quark physics, and Higgs boson physics are discussed. Recent results of tests of QCD and of direct searches for new phenomena are described in another contribution.

Filthaut, Frank; /Nijmegen U.

2011-03-01T23:59:59.000Z

432

The Future of Hadrons: The Nexus of Subatomic Physics  

SciTech Connect

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.

Quigg, Chris; /Fermilab

2011-09-01T23:59:59.000Z

433

Jet physics at HERA, Tevatron and LHC  

E-Print Network (OSTI)

In this short report, we discuss the Jet Physics results and perspectives at HERA, Tevatron and LHC.

C. Royon

2008-11-10T23:59:59.000Z

434

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites (Extended Search)

Relativistic Heavy Ion Collider Relativistic Heavy Ion Collider Photo of LINAC The Relativistic Heavy Ion Collider (RHIC) is a world-class particle accelerator at Brookhaven National Laboratory where physicists are exploring the most fundamental forces and properties of matter and the early universe. RHIC accelerates beams of particles (e.g., the nuclei of heavy atoms such as gold) to nearly the speed of light, and smashes them together to recreate a state of matter thought to have existed immediately after the Big Bang some 13.8 billion years ago. STAR and PHENIX, two large detectors located around the 2.4-mile-circumference accelerator, take "snapshots" of these collisions to reveal a glimpse of the basic constituents of visible matter, quarks and gluons. Understanding matter at

435

RHIC | Relativistic Heavy Ion Collider  

NLE Websites -- All DOE Office Websites

Brookhaven National Laboratory Brookhaven National Laboratory search U.S. Department of Energy logo Home RHIC Science News Images Videos For Scientists Björn Schenke 490th Brookhaven Lecture, 12/18 Join Björn Schenke of Brookhaven Lab's Physics Department for the 490th Brookhaven Lecture, titled 'The Shape and Flow of Heavy Ion Collisions,' on Wednesday, Dec. 18, at 4 p.m. in Berkner Hall. droplets Tiny Drops of Hot Quark Soup-How Small Can They Be? New analyses indicate that collisions of small particles with large gold nuclei at the Relativistic Heavy Ion Collider may be serving up miniscule servings of hot quark-gluon plasma. RHIC Physics RHIC is the first machine in the world capable of colliding ions as heavy as gold. The Spin Puzzle RHIC is the world's only machine capable of colliding beams of polarized

436

Linear Collider Collaboration Tech Notes  

NLE Websites -- All DOE Office Websites (Extended Search)

6, 27/05/99 6, 27/05/99 Tolerances of Random RF Jitters in X-Band Main Linacs May 27, 1999 Kiyoshi KUBO KEK Tsukuba, Japan Abstract: Tracking simulations have been performed for the main linacs of an X-band linear collider. We discuss the choice of phase of the accelerating field relative to the bunches. The tolerances of the phase and the amplitude errors are studied. Tolerances of Random RF Jitters in X-Band Main Linacs K. Kubo, KEK Abstract Tracking simulations have been performed for main linacs of X-band linear collider. We discuss about choice of the phase of the accelerating field relative to the bunches. The tolerances of the phase and the amplitude errors are studied. 1 INTRODUCTION In order to preserve the low emittance through the main linacs of future linear colliders, various effects

437

Polish contribution to the worldwide LHC computing  

Science Conference Proceedings (OSTI)

The computing requirements of LHC experiments, as well as their computing models, are briefly presented. The origin of grid technology and its development in high energy community is outlined, including the Polish participation. The LHC Computing Grid ... Keywords: LHC, Tier-2, WLCG, distributed computing, gLite, grid, high energy physics, middleware

Artur Binczewski; Micha$#322; Bluj; Antoni Cyz; Micha$#322; Dwu?nik; Maciej Filocha; ?ukasz Flis; Ryszard Gokieli; Jaros$#322;aw Iwaszkiewicz; Marek Kowalski; Patryk Laso$#324;; Rafa$#322; Lichwa$#322;a; Micha$#322; ?opuszy$#324;ski; Marek Magry$#347;; Piotr Malecki; Norbert Meyer; Krzysztof Nawrocki; Andrzej Olszewski; Andrzej Ozi?b$#322;o; Adam Pade; Henryk Pa$#322;ka; Marcin Pospieszny; Marcin Radecki; Rados$#322;aw Rowicki; Dorota Stojda; Marcin Stolarek; Tomasz Szepieniec; Tadeusz Szymocha; Micha$#322; Tura$#322;a; Karol Wawrzyniak; Wojciech Wi$#347;licki; Mariusz Witek; Pawe$#322; Wolniewicz

2012-01-01T23:59:59.000Z

438

LHC Symposium 2003: Summary Talk  

SciTech Connect

This summary talk reviews the LHC 2003 Symposium, focusing on expectations as we prepare to leap over the current energy frontier into new territory. We may learn from what happened in the two most recent examples of leaping into new energy territory. Quite different scenarios appeared in those two cases. In addition, they review the status of the machine and experiments as reported at the Symposium. Finally, I suggest an attitude which may be most appropriate as they look forward to the opportunities anticipated for the first data from the LHC.

Jeffrey A. Appel

2003-08-12T23:59:59.000Z

439

Hadron physics with KLOE-2  

E-Print Network (OSTI)

In the upcoming month the KLOE-2 data taking campaign will start at the upgraded DAFNE phi-factory of INFN Laboratori Nazionali di Frascati. The main goal is to collect an integrated luminosity of about 20 fb^(-1) in 3-4 years in order to refine and extend the KLOE program on both kaon physics and hadron spectroscopy. Here the expected improvements on the results of hadron spectroscopy are presented and briefly discussed.

Czerwinski, Eryk; Babusci, D; Badoni, D; Bencivenni, G; Bini, C; Bloise, C; Bocci, V; Bossi, F; Branchini, P; Budano, A; Bulychjev, S A; Campana, P; Capon, G; Ceradini, F; Ciambrone, P; Czerwinski, E; Dane, E; De Lucia, E; De Robertis, G; De Santis, A; De Zorzi, G; Di Domenico, A; Di Donato, C; Di Micco, B; Domenici, D; Erriquez, O; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Hoistad, B; Iarocci, E; Jacewicz, M; Johansson, T; Kulikov, V V; Kupsc, A; Lee-Franzini, J; Loddo, F; Martemianov, M A; Martini, M; Matsyuk, M A; Messi, R; Miscetti, S; Moricciani, D; Morello, G; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Ranieri, A; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Sciubba, A; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Versaci, R; Wislicki, W; Wolke, M; Zdebik, J

2010-01-01T23:59:59.000Z

440

Hadron nucleus interactions  

SciTech Connect

The elastic and inelastic scattering of intermediate energy (less than or equal to 1 GeV) protons by nuclei is considered first. The discussion focuses on the determination of the proton-nucleus optical potential in terms of the elementary nucleon-nucleon scattering amplitudes and the properties of the target and residual nucleus. The result is a series of terms for the optical potential. Then the interaction of pions with nuclei for energies in the neighborhood of the ..delta..-resonance is discussed. In this energy domain an incident pion will with high probability be absorbed by a nucleon to produce the ..delta..-resonance and thus form a ..delta..-particle hole state in the nucleus. Next, the subject of hypernuclei is taken up. The ..lambda.. hypernuclei and a recently observed ..sigma.. hypernuclei comprise situations in which the core nucleus can be probed by a baryon of roughly the same mass as a nucleon, with similar albeit not identical interactions with nucleons. But the ..lambda.. (or ..sigma..) does not need to satisfy the Pauli exclusion principle with respect to the nucleons, and therefore can be in orbits forbidden to it if it were a nucleon. As the energy of the projectile increases, it becomes correspondingly more important to take relativistic effects into account. The importance of these effects is strikingly revealed by experiments involving the collision of ultrarelativistic hadrons, protons, pions, kaons (up to Fermilab energies) with nuclei. This phenomenon forms part of the final topic, which includes as well as the collision of relativistic heavy ion projectiles with nuclei. A nuclear Weiszaecker-Williams method developed for dealing with peripheral collisions is described. 32 figures, 10 tables. (RWR)

Feshbach, H.

1980-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Investigation of Electroweak Production of the Top Quark at the LHC  

E-Print Network (OSTI)

This thesis presents a study of the prospects of measuring electroweak production of the top quark at the LHC. The study of the top quark is a highly topical subject as we expect significant numbers of top quarks at the LHC which will enable us to conduct precision measurements of the properties of the top. The t-channel "single top" is a relatively rare mode of top production but with it we can probe the spin structure of the Wtb vertex in the weak interaction at an unprecedented energy scale through the measurement of the top polarisation. Analysis strategies and computing tools were developed and tested extensively. The study was performed using the signal and background events modelled with Monte Carlo generators, many of which have been newly developed for the LHC analyses. Full and fast simulation of the ATLAS detector was performed to obtain realistic estimates of the sensitivity of the measurements. A new fully fledged analysis framework, "EventView" was developed for the ATLAS collaboration to process these data at the first level of analysis. Parameterised vertex tagging was developed to estimate the level of background for this analysis and a maximum likelihood fit was used for the precise extraction of the top polarisation. In the high energy hadronic environment at the LHC, the estimation of possible systematic errors, both experimental and theoretical, needs to be carefully considered. Important elements of the systematic errors were investigated and the main contributions were evaluated.

Akira Shibata

2008-04-23T23:59:59.000Z

442

Performance of the ATLAS tau trigger with 7 TeV collision data at the LHC  

E-Print Network (OSTI)

Tau leptons are a fundamental ingredient in the discovery of new physics at the LHC. The reconstruction of hadronic tau decays at the trigger level, although a very challenging task in proton-proton collision environments, allows us to double the sample of tau decays collected, and provides additional discovery power to final states which include tau leptons. In this contribution we show the understanding of the tau trigger system using data collected with the ATLAS detector at the LHC in proton-proton collisions at a center-of-mass energy of 7 TeV. We present the most relevant quantities used in the different stages of the trigger selection, and the trigger efficiencies as a function of ET using tau-like QCD events passing the offline reconstruction and identification selection.

Robinson, M; The ATLAS collaboration

2010-01-01T23:59:59.000Z

443

Exotic Higgs Decay h to 2a at the International Linear Collider: a Snowmass White Paper  

E-Print Network (OSTI)

A Higgs factory like the International Linear Collider (ILC) can play a significant role in searching for exotic decays of Higgs bosons. As an illustration, we investigate the ILC sensitivity for the decay topology $h\\to a_1 a_1 \\to \\tau\\bar \\tau\\tau \\bar \\tau$ in the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM). Here $h$ can be either Standard-Model-like or non-standard, and $a_{1}$ is the lightest CP-odd Higgs boson. We also compare results to expectations for this channel at the LHC.

Tao Liu; C. T. Potter

2013-08-30T23:59:59.000Z

444

The Control System for the Cryogenics in the LHC Tunnel  

E-Print Network (OSTI)

The Large Hadron Collider makes extensive use of superconductors, in magnets for bending and focusing the particles, and in RF cavities for accelerating them, which are operated at 1.9 K and 4.5 K. The process automation for the cryogenic distribution around the accelerator circumference is based on 16 Programmable Logic Controllers, each running 250 control loops, 500 alarms and interlocks, and a phase sequencer. Spread along 27 km and under ionizing radiation, 15 000 cryogenic sensors and actuators are accessed through industrial field networks. We describe the main hardware and software components of the control system, their deployment and commissioning, together with the project organization, challenges faced, and solutions found.

Gomes, P; Antoniotti, F; Avramidou, R; Balle, Ch; Blanco-Viuela, E; Carminati, Ch; Casas-Cubillos, J; Ciechanowski, M; Dragoneas, A; Dubert, P; Fampris, X; Fluder, C; Fortescue, E; Gaj, W; Gousiou, E; Jeanmonod, N; Jod?owski, P; Karagiannis, F; Klisch, M; Lpez, A; Macuda, P; Malinowski, P; Molina, E; Paiva, S; Patsouli, A; Penacoba, G; Sosin, M; Soubiran, M; Suraci, A; Tovar, A; Vauthier, N; Wolak, T; Zwalinski, L

2008-01-01T23:59:59.000Z

445

Nuclear physics with a medium-energy Electron-Ion Collider  

E-Print Network (OSTI)

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy sqrt(s) ~ 20-70 GeV and a luminosity ~ 10^{34} cm^{-2} s^{-1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.

A. Accardi; V. Guzey; A. Prokudin; C. Weiss

2011-10-05T23:59:59.000Z

446

Nuclear physics with a medium-energy Electron-Ion Collider  

Science Conference Proceedings (OSTI)

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy {radical}s {approx} 20-70 GeV and a luminosity {approx}10{sup 34} cm{sup -2} s{sup -1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.

A. Accardi, V. Guzey, A. Prokudin, C. Weiss

2012-06-01T23:59:59.000Z

447

The COMPASS Hadron Spectroscopy Programme  

E-Print Network (OSTI)

COMPASS is a fixed-target experiment at the CERN SPS for the investigation of the structure and the dynamics of hadrons. The experimental setup features a large acceptance and high momentum resolution spectrometer including particle identification and calorimetry and is therefore ideal to access a broad range of different final states. Following the promising observation of a spin-exotic resonance during an earlier pilot run, COMPASS focused on light-quark hadron spectroscopy during the years 2008 and 2009. A data set, world leading in terms of statistics and resolution, has been collected with a 190GeV/c hadron beam impinging on either liquid hydrogen or nuclear targets. Spin-exotic meson and glueball candidates formed in both diffractive dissociation and central production are presently studied. Since the beam composition includes protons, the excited baryon spectrum is also accessible. Furthermore, Primakoff reactions have the potential to determine radiative widths of the resonances and to probe chiral pe...

Austregesilo, A

2012-01-01T23:59:59.000Z

448

No-Scale F-SU(5) in the Light of LHC, Planck and XENON  

E-Print Network (OSTI)

We take stock of the No-Scale F-SU(5) model's experimental status and prospects in the light of results from LHC, Planck, and XENON100. Given that no conclusive evidence for light Supersymmetry (SUSY) has emerged from the 7, 8 TeV collider searches, the present work is focused on exploring and clarifying the precise nature of the high-mass cutoff enforced on this model at the point where the stau and neutralino mass degeneracy becomes so tight that cold dark matter relic density observations cannot be satisfied. This hard upper boundary on the model's mass scale constitutes a top-down theoretical mandate for a comparatively light (and testable) SUSY spectrum which does not excessively stress natural resolution of the gauge hierarchy problem. The overlap between the resulting model boundaries and the expected sensitivities of the future 14 TeV LHC and XENON 1-Ton direct detection SUSY / dark matter experiments is described.

Li, Tianjun; Nanopoulos, Dimitri V; Walker, Joel W

2013-01-01T23:59:59.000Z

449

Influence of the ATS Optics on Intra-Beam Scattering for HL-LHC  

E-Print Network (OSTI)

In the future High Luminosity (HL-)LHC the influence of intra-beam scattering (IBS) will be stronger than in the present LHC, because of higher bunch intensity, small emittance and new optics. The new ATS-optics scheme [1] modifies the lattice in the arcs around the main interaction points (IP) to provide ?? values as small as 0.15m at the IP but these modifications affect the IBS growth rates. In this paper proton IBS emittance growth rates are calculated with MADX [2] and the Collider Time Evolution (CTE) program [3] for two ATS-optics versions, different settings of the crossing angles and required corrections and various beam conditions at injection (450 GeV) and collision (7 TeV) energy. CTE simulations of the expected luminosity, intensity, emittance and bunch length evolution during fills are also presented.

Schaumann, M; Jowett, J M

2013-01-01T23:59:59.000Z

450

No-Scale F-SU(5) in the Light of LHC, Planck and XENON  

E-Print Network (OSTI)

We take stock of the No-Scale F-SU(5) model's experimental status and prospects in the light of results from LHC, Planck, and XENON100. Given that no conclusive evidence for light Supersymmetry (SUSY) has emerged from the 7, 8 TeV collider searches, the present work is focused on exploring and clarifying the precise nature of the high-mass cutoff enforced on this model at the point where the stau and neutralino mass degeneracy becomes so tight that cold dark matter relic density observations cannot be satisfied. This hard upper boundary on the model's mass scale constitutes a top-down theoretical mandate for a comparatively light (and testable) SUSY spectrum which does not excessively stress natural resolution of the gauge hierarchy problem. The overlap between the resulting model boundaries and the expected sensitivities of the future 14 TeV LHC and XENON 1-Ton direct detection SUSY / dark matter experiments is described.

Tianjun Li; James A. Maxin; Dimitri V. Nanopoulos; Joel W. Walker

2013-05-08T23:59:59.000Z

451

Possible links between the liquid-gas and deconfinement-hadronization phase transitions  

E-Print Network (OSTI)

It is commonly accepted that strongly interacting matter has several phase transitions in different domains of temperature and baryon density. In this contribution I discuss two most popular phase transitions which in principle can be accessed in nuclear collisions. One of them, the liquid-gas phase transition, is well established theoretically and studied experimentally in nuclear multifragmentation reactions at intermediate energies. The other one, the deconfinement-hadronization phase transition, is at the focus of present and future experimental studies with relativistic heavy-ion beams at SPS, RHIC and LHC. Pssible links between these two phase transitions are identified from the viewpoint of their manifestation in violent nuclear collisions.

I. N. Mishustin

2006-09-19T23:59:59.000Z

452

Tracking fast small color dipoles through strong gluon fields at the LHC  

E-Print Network (OSTI)

We argue that the process gamma +A \\to J/psi + gap + X at large momentum transfer provides a quick and effective way to test onset of a novel perturbative QCD regime of strong absorption for the interaction of small dipoles at the collider energies. We find that already the first heavy ion run at the LHC will allow to study this reaction with sufficient statistics via ultraperipheral collisions hence probing the interaction of q\\bar q dipoles of sizes ~ 0.2 fm with nuclear media down to x ~ 10^{-5}.

L. Frankfurt; M. Strikman; M. Zhalov

2008-11-03T23:59:59.000Z

453

Elliptic Flow from a Hybrid CGC, Full 3D Hydro and Hadronic Cascade Model  

E-Print Network (OSTI)

We investigate the robustness of the discovery of the perfect fluid through comparison of hydrodynamic calculations with the elliptic flow coefficient v_2 at midrapidity in Au+Au collisions at sqrt{s_{NN}}=200 GeV. Employing the Glauber model for initial entropy density distributions, the centrality dependence of v_2 is reasonably reproduced by using an ideal fluid description of the early QGP stage followed by a hadronic cascade in the late hadronic stage. On the other hand, initial conditions based on the Colour Glass Condensate model are found to generate larger elliptic flow due to larger initial eccentricity epsilon. We further predict v_2/epsilon at a fixed impact parameter as a function of collision energy sqrt{s_{NN}} up to the LHC energy.

Tetsufumi Hirano; Ulrich W. Heinz; Dmitri Kharzeev; Roy Lacey; Yasushi Nara

2007-01-25T23:59:59.000Z

454

Heavy ion physics at the LHC  

E-Print Network (OSTI)

Heavy Ion Physics at the LHC ? R. VogtLaboratory, Berkeley, CA USA Physics Department, Universityfor addressing unique physics issues in a completely new

Vogt, R.

2004-01-01T23:59:59.000Z

455

Quark confinement and hadronic interactions  

SciTech Connect

A study of quark models for many-hadron systems is presented. The starting point in the construction of these nonrelativistic models is a proper formal definition of the concept of color singlet and nonsinglet clusters in a multiquark system which respects the exchange symmetry of the quarks. This definition provides a natural way to impose saturation of the confining forces.

Lenz, F.; Londergan, J.T.; Moniz, E.J.; Rosenfelder, R.; Stingl, M.; Yazaki, K.

1986-08-01T23:59:59.000Z

456

The Vertex Tracker at the e+e- Linear Collider Conceptual Design, Detector R&D and Physics Performances for the Next Generation of Silicon Vertex Detectors  

E-Print Network (OSTI)

The e+e- linear collider physics programme sets highly demanding requirements on the accurate determination of charged particle trajectories close to their production point. A new generation of Vertex Trackers, based on different technologies of high resolution silicon sensors, is being developed to provide the needed performances. These developments are based on the experience with the LEP/SLC vertex detectors and on the results of the R&D programs for the LHC trackers and also define a further program of R&D specific to the linear collider applications. In this paper the present status of the conceptual tracker design, silicon detector R&D and physics studies is discussed.

Marco Battaglia; Massimo Caccia

1999-11-26T23:59:59.000Z

457

Inclusive distributions in p-p collisions at LHC energies compared with an adjusted DPMJET-III model with chain fusion  

E-Print Network (OSTI)

A DPMJET-III model (DPMJET-III-2011) with chain fusion adjusted to include energy.dependent parameters is used to calculate inclusive distributions in p-p collisions at LHC energies. Presented are charged hadrons rapidity distributions, transverse momentum distributions, multiplicity distributions as well as multiplicities at mid-rapidity as function of the collision energy. For hadrons with strangeness we present cms-rapidity distributions and transverse momentum distributions. With the considered merely energy-dependent adjustments the obtained agreement with the transversal \\Lambda and \\Xi distribution is not satisfactory.

F. Bopp; J. Ranft

2011-10-28T23:59:59.000Z

458

The Multi-Purpose Detector for NICA heavy-Ion Collider at JINR  

Science Conference Proceedings (OSTI)

The Multi-Purpose Detector (MPD) is designed to study heavy-ion collisions at the Nuclotron-based heavy Ion Collider fAcility (NICA) at JINR, Dubna. Its main components located inside a superconducting solenoid are a tracking system composed of a silicon microstrip vertex detector followed by a large volume time-projection chamber, a time-of-flight system for particle identification and a barrel electromagnetic calorimeter. A zero degree hadron calorimeter is designed specifically to measure the energy of spectators. In this paper, all parts of the apparatus are described and their tracking and particle identification parameters are discussed in some detail.

Rogachevsky, O. V., E-mail: rogachevsky@jinr.ru [JINR, Veksler and Baldin Laboratory on High Energy Physics (Russian Federation)

2012-05-15T23:59:59.000Z

459

Probing Higgs Boson Interactions At Future Colliders.  

E-Print Network (OSTI)

??We present in this thesis a detailed analysis of Higgs boson interactions at future colliders. In particular we examine, in a model independent way, the (more)

Biswal, Sudhansu Sekhar

2009-01-01T23:59:59.000Z

460

Links to Muon Collider Related Web Pages  

NLE Websites -- All DOE Office Websites (Extended Search)

useful nu-factory related web pages: Nu-FactoryMuon Collider Studies at Fermilab Neutrino Factory Design Study MUCOOL Collaboration: Ionization Cooling R&D Brookhaven Muon...

Note: This page contains sample records for the topic "hadron collider lhc" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Siting the International Linear Collider at Hanford  

SciTech Connect

Review of the proposed International Linear Collider, applications in high energy physics, and evaluation of the Hanford Site as a possible location for siting the facilityl.

Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.

2012-03-15T23:59:59.000Z

462

Siting the International Linear Collider at Hanford  

SciTech Connect

Review of the proposed International Linear Collider, applications in high energy physics, and evaluation of the Hanford Site as a possible location for siting the facility.

Kouzes, Richard T.; Asner, David M.; Brodzinski, Ronald L.; Fast, James E.; Miley, Harry S.

2012-05-01T23:59:59.000Z

463

Subcritical Fission Reactor Based on Linear Collider  

E-Print Network (OSTI)

The beams of Linear Collider after main collision can be utilized to build an accelerator--driven sub--critical reactor.

I. F. Ginzburg

2005-07-29T23:59:59.000Z

464

Flavor Physics and CP Violation at LHC  

E-Print Network (OSTI)

Flavor Physics at LHC will contribute significantly to the search for New Physics via precise and complementary measurements of CKM angles and the study of loop decays. Here we present the expected experimental sensitivity and physics performance of the LHC experiments that will to B-physics.

Andreas Schopper

2006-05-29T23:59:59.000Z

465

MSSM Forecast for the LHC  

E-Print Network (OSTI)

We perform a forecast of the MSSM with universal soft terms (CMSSM) for the LHC, based on an improved Bayesian analysis. We do not incorporate ad hoc measures of the fine-tuning to penalize unnatural possibilities: such penalization arises from the Bayesian analysis itself when the experimental value of $M_Z$ is considered. This allows to scan the whole parameter space, allowing arbitrarily large soft terms. Still the low-energy region is statistically favoured (even before including dark matter or g-2 constraints). Contrary to other studies, the results are almost unaffected by changing the upper limits taken for the soft terms. The results are also remarkable stable when using flat or logarithmic priors, a fact that arises from the larger statistical weight of the low-energy region in both cases. Then we incorporate all the important experimental constrains to the analysis, obtaining a map of the probability density of the MSSM parameter space, i.e. the forecast of the MSSM. Since not all the experimental information is equally robust, we perform separate analyses depending on the group of observables used. When only the most robust ones are used, the favoured region of the parameter space contains a significant portion outside the LHC reach. This effect gets reinforced if the Higgs mass is not close to its present experimental limit and persits when dark matter constraints are included. Only when the g-2 constraint (based on $e^+e^-$ data) is considered, the preferred region (for $\\mu>0$) is well inside the LHC scope. We also perform a Bayesian comparison of the positive- and negative-$\\mu$ possibilities.

Maria Eugenia Cabrera; Alberto Casas; Roberto Ruiz de Austri

2009-11-24T23:59:59.000Z

466

The Next Linear Collider Program  

NLE Websites -- All DOE Office Websites (Extended Search)

To use the left side navigation on this page, you will need to turn on To use the left side navigation on this page, you will need to turn on Javascript. You do not need JavaScript to use the text-based navigation bar at the bottom of the page. The Next Linear Collider at SLAC Navbar MISSION: Scientists expect research at this facility to answer fundamental questions about the behavior of matter and the origins of the Universe. NLC 8-Pack on the Drawing Board What's New In the Next Linear Collider: • NLC Newsletter October, 2001 • NLC Snowmass report 2001 • NLC All Hands Talk, August 2001 Upcoming Events: • Fall 2001 Working Sessions, Oct. 22-23, 2001 • Pulse Compression Workshop, Oct. 22-24, 2001 • Machine Advisory Committee Mtg., Oct. 24-26, 2001 • ISG-7 at KEK, Nov. 12-15, 2001 • LC' 02 at SLAC, Feb. 4-8, 2002 NLC Website Search: Entire SLAC Web | Help |

467

Stochastic cooling in muon colliders  

SciTech Connect

Analysis of muon production techniques for high energy colliders indicates the need for rapid and effective beam cooling in order that one achieve luminosities > 10{sup 30} cm{sup {minus}2}s{sup {minus}1} as required for high energy physics experiments. This paper considers stochastic cooling to increase the phase space density of the muons in the collider. Even at muon energies greater than 100 GeV, the number of muons per bunch must be limited to {approximately}10{sup 3} for the cooling rate to be less than the muon lifetime. With such a small number of muons per bunch, the final beam emittance implied by the luminosity requirement is well below the thermodynamic limit for beam electronics at practical temperatures. Rapid bunch stacking after the cooling process can raise the number of muons per bunch to a level consistent with both the luminosity goals and with practical temperatures for the stochastic cooling electronics. A major advantage of our stochastic cooling/stacking scheme over scenarios that employ only ionization cooling is that the power on the production target can be reduced below 1 MW.

Barletta, W.A.; Sessler, A.M.

1993-09-01T23:59:59.000Z

468

Hadron Physics with CLAS12  

DOE Green Energy (OSTI)

Hadron spectroscopy has been an essential part of the physics program with the CLAS detector in experimental Hall B at Jefferson Lab. Production of baryon and meson resonances with high energy (polarized) electron and photon beams was studied on a veriety of targets, ranging from hydrogen to lead. Physics topics of interest include: investigation of the spectrum of baryon and meson resonances, transition form-factors, meson-nucleon couplings (mesons in nuclei), and search for exotic and missing states. With the 12 GeV upgrade of the CEBAF machine, hadron spectroscopy in Hall B will be extended to a new domain of higher mass resonances and the range of higher transferred momentum using up to 11 GeV electron beams and the upgraded CLAS12 detector. In this paper a brief description of the CLAS12 detector and the physics program adopted for 12 GeV with emphasis to baryon and meson spectroscopy is presented.

Stepan Stepanyan

2010-08-01T23:59:59.000Z

469

Comments on "Wall-plug (AC) power consumption of a very high energy e+/e- storage ring collider" by Marc Ross  

E-Print Network (OSTI)

The paper arXiv:1308.0735 questions some of the technical assumptions made by the TLEP Steering Group when estimating in arXiv:1305.6498 the power requirement for the very high energy e+e- storage ring collider TLEP. We show that our assumptions are based solidly on CERN experience with LEP and the LHC, as well accelerators elsewhere, and confirm our earlier baseli