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1

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

2

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,...

3

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

4

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

5

Exotic Leptons: Higgs, Flavor and Collider Phenomenology  

E-Print Network (OSTI)

We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h -> gamma gamma decay rate for new lepton masses in the 300 GeV - 1 TeV range. We analyze vaccum stability implications for different hypercharges. Effects in h -> Z gamma are typically much smaller than in h -> gamma gamma, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at the LHC, and find that signatures with multiple light leptons or taus are already probing interesting regions of parameter space.

Wolfgang Altmannshofer; Martin Bauer; Marcela Carena

2013-08-08T23:59:59.000Z

6

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

7

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

8

Exotic Leptons: Higgs, Flavor and Collider Phenomenology  

E-Print Network (OSTI)

We study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h -> gamma gamma decay rate for new lepton masses in the 300 GeV - 1 TeV range. We analyze vaccum stability implications for different hypercharges. Effects in h -> Z gamma are typically much smaller than in h -> gamma gamma, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at...

Altmannshofer, Wolfgang; Carena, Marcela

2013-01-01T23:59:59.000Z

9

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 |

10

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

11

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

12

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

13

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

14

Linear Collider Collaboration Tech Notes  

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

NLC Home Page NLC Technical SLAC The LCC Tech Note series was started in July 1998 to document the JLC/NLC collaborative design effort. The notes are numbered sequentially and may also be given a SLAC, FNAL, LBNL, LLNL and/or KEK publication number. The LCC notes will be distributed through the Web in electronic form as PDF files -- the authors are responsible for keeping the original documents. Other document series are the NLC Notes that were started for the SLAC ZDR, the KEK ATF Notes, and at some future time there should be a series of Technical (NLD) Notes to document work on detector studies for the next-generation linear collider. LCC-0001 "Memorandum of Understanding between KEK and SLAC," 2/98. LCC-0002 "Transparencies and Summaries from the 1st ISG meeting: January 1998," G. Loew, ed., 2/98.

15

Calorimetry for Lepton Collider Experiments - CALICE results and activities  

E-Print Network (OSTI)

The CALICE collaboration conducts calorimeter R&D for highly granular calorimeters, mainly for their application in detectors for a future lepton collider at the TeV scale. The activities ranges from generic R&D with small devices up to extensive beam tests with prototypes comprising up to several 100000 calorimeter cells. CALICE has validated the performance of particle flow algorithms with test beam data and delivers the proof of principle that highly granular calorimeters can be built, operated and understood. The successes achieved in the past years allows the step from prototypes to calorimeter systems for particle physics detectors to be addressed.

The CALICE Collaboration

2012-12-20T23:59:59.000Z

16

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...

17

Photon Linear Collider Gamma-Gamma Summary  

SciTech Connect

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

Gronberg, J

2012-02-27T23:59:59.000Z

18

Linear Collider Collaboration Tech Notes LCC-0100  

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

100 100 August 2002 Systematic Ground Motion and Macroalignment for Linear Colliders Rainer Pitthan Stanford Linear Accelerator Center Stanford University Stanford, CA 94309, USA Abstract: Future colliders with their µm-range operational tolerances still need to be classically aligned to the 50 - 100 µm range, and kept there, over the km range. This requirement will not be a show-stopper, but not be trivial either. 50 µm movements over a betatron wavelength is a the range where systematic long term motions can prevent efficient operation. Systematic Ground Motion and Macro-Alignment for Linear Colliders Complete talk at: http://www-project.slac.stanford.edu/lc/wkshp/snowmass2001/t6/info/pitthan july

19

Linear Collider Collaboration Tech Notes  

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

Notes Notes LCC - 0018, 15/06/99 Rev B, June 2002 Correct Account of RF Deflections in Linac Acceleration June 15, 1999 G.V. Stupakov Stanford Linear Accelerator Center Stanford, California Abstract: During acceleration in the linac structure, the beam not only increases its longitudinal momentum, but also experiences a transverse kick from the accelerating mode which is linear in accelerating gradient. This effect is neglected in such computer codes as LIAR and TRANSPORT. We derived the Hamiltonian equations that describe the effect of RF deflection into the acceleration process and included it into the computational engine of LIAR. By comparing orbits for the NLC main linac, we found that the difference between the two algorithms is about 10\%. The effect will be more pronounced at smaller

20

Linear Collider Collaboration Tech Notes  

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

1 1 May 2001 Lattice Description for NLC Damping Rings at 120 Hz Andrzej Wolski Lawrence Berkeley National Laboratory Abstract: We present a lattice design for the NLC Main Damping Rings at 120 Hz repe tition rate. A total wiggler length of a little over 46 m is needed to achieve the damping time required for extracted, normalized, vertical emittance below 0.02 mm mrad. The dynamic aperture (using a linear model for the wiggler) is in excess of 15 times the injected beam size. The principal lattice parameters and characteristics are presented in this note; we also outline results of studies of alignment and field quality tolerances. CBP Tech Note-227 LCC-0061 Lattice Description for NLC Main Damping Rings at 120 Hz Andrzej Wolski Lawrence Berkeley National Laboratory

Note: This page contains sample records for the topic "linear colliders lepton" 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

Linear Collider Collaboration Tech Notes  

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

0 0 April 2001 Rev.1 July 2003 Guide to LIBXSIF, a Library for Parsing the Extended Standard Input Format of Accelerated Beamlines Peter G. Tenenbaum Stanford Linear Accelerator Center Stanford University Stanford, CA Abstract: We describe LIBXSIF, a standalone library for parsing the Extended Standard Input Format of accelerator beamlines. Included in the description are: documentation of user commands; full description of permitted accelerator elements and their attributes; the construction of beamline lists; the mechanics of adding LIBXSIF to an existing program; and "under the hood" details for users who wish to modify the library or are merely morbidly curious. Guide to LIBXSIF, a Library for Parsing the Extended Standard Input Format of

22

Linear Collider Collaboration Tech Notes  

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

5 08//00 5 08//00 Study of Beam Energy Spectrum Measurement in the NLC Extraction Line August 2000 Yuri Nosochkov and Tor Raubenheimer Stanford Linear Accelerator Center Stanford, CA Abstract: The NLC extraction line optics includes a secondary focal point with a very small _- function and 2 cm dispersion which can be used for measurement of outgoing beam energy spread. In this study, we performed tracking simulations to transport the NLC disrupted beam from the Interaction Point (IP) to the extraction line secondary focus (the IP image), `measure' the transverse beam pro_le at the IP image and reconstruct the beam energy spectrum. The resultant distribution was compared with the original energy spectrum at the IP. Study of Beam Energy Spectrum Measurement

23

Linear Collider Collaboration Tech Notes  

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

2 03/12/99 2 03/12/99 PEP-II RF Cavity Revisited December 3, 1999 R. Rimmer, G. Koehler, D. Li, N. Hartmann, N. Folwell, J. Hodgson, B. McCandless Lawrence Berkeley National Laboratory Stanford Linear Accelerator Center Berkeley, CA, USA Stanford, CA, USA Abstract: This report describes the results of numerical simulations of the PEP-II RF cavity performed after the completion of the construction phase of the project and comparisons are made to previous calculations and measured results. These analyses were performed to evaluate new calculation techniques for the HOM distribution and RF surface heating that were not available at the time of the original design. These include the use of a high frequency electromagnetic element in ANSYS and the new Omega 3P code to study wall

24

Linear Collider Collaboration Tech Notes  

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

4, 10/03/00 4, 10/03/00 Luminosity for NLC Design Variations March 10, 1999 K.A. Thompson and T.O. Raubenheimer Stanford Linear Accelerator Center Stanford, CA, USA Abstract: In this note we give Guineapig simulation results for the luminosity and luminosity spectrum of three baseline NLC designs at 0.5~TeV and 1.0~TeV and compare the simulation results with analytic approximations. We examine the effects of varying several design parameters away from the NLC-B-500 and NLC-B-1000 designs, in order to study possible trade-offs of parameters that could ease tolerances, increase luminosity, or help to optimize machine operation for specific physics processes. Luminosity for NLC Design Variations K.A. Thompson and T.O.Raubenheimer INTRODUCTION In this note we give Guineapig [l] simulation results for the luminosity and

25

Linear Collider Collaboration Tech Notes  

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

Notes Notes LCC - 0038 29/04/00 CBP Tech Note - 234 Transverse Field Profile of the NLC Damping Rings Electromagnet Wiggler 29 April 2000 17 J. Corlett and S. Marks Lawrence Berkeley National Laboratory M. C. Ross Stanford Linear Accelerator Center Stanford, CA Abstract: The primary effort for damping ring wiggler studies has been to develop a credible radiation hard electromagnet wiggler conceptual design that meets NLC main electron and positron damping ring physics requirements [1]. Based upon an early assessment of requirements, a hybrid magnet similar to existing designs satisfies basic requirements. However, radiation damage is potentially a serious problem for the Nd-Fe-B permanent magnet material, and cost remains an issue for samarium cobalt magnets. Superconducting magnet designs have not been

26

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

27

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

28

Linear Collider Collaboration Tech Notes LCC-0104  

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

4 4 October 2002 Beamstrahlung Photon Load on the TESLA Extraction Septum Blade Andrei Seryi Stanford Linear Accelerator Center Stanford, CA 94309, USA Abstract: This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design. Beamstrahlung Photon Load on the TESLA Extraction Septum Blade ANDREI SERYI STANFORD LINEAR

29

Nonlinear Energy Collimation System for Linear Colliders  

E-Print Network (OSTI)

The post-linac energy collimation system of multi-TeV linear colliders is designed to fulfil an important function of protection of the Beam Delivery System (BDS) against miss-steered beams likely generated by failure modes in the main linac. For the case of the Compact Linear Collider (CLIC), the energy collimators are required to withstand the impact of a full bunch train in case of failure. This is a very challenging task, assuming the nominal CLIC beam parameters at 1.5 TeV beam energy. The increase of the transverse spot size at the collimators using nonlinear magnets is a potential solution to guarantee the survival of the collimators. In this paper we present an alternative nonlinear optics based on a skew sextupole pair for energy collimation. Performance simulation results are also presented.

Resta-Lopez, Javier

2011-01-01T23:59:59.000Z

30

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

31

Linear Collider Collaboration Tech Notes LCC-0108  

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

8 8 TESLA 2002-10 CBP Tech Note-268 November 2002 Comparison of Emittance Tuning Simulations in the NLC and TESLA Damping Rings Andrej Wolski Lawrence Berkeley National Laboratory University of California Berkeley, CA Winfried Decking Deutsches Elektron Synchrotron (DESY) Hamburg, Germany Abstract: Vertical emittance is a critical issue for future linear collider damping rings. Both NLC and TESLA specify vertical emittance of the order of a few picometers, below values currently achieved in any storage ring. Simulations show that algorithms based on correcting the closed orbit and the vertical dispersion can be effective in reducing the vertical emittance to the required levels, in the presence of a limited subset of

32

Frequency scaling of linear super-colliders  

SciTech Connect

The development of electron-positron linear colliders in the TeV energy range will be facilitated by the development of high-power rf sources at frequencies above 2856 MHz. Present S-band technology, represented by the SLC, would require a length in excess of 50 km per linac to accelerate particles to energies above 1 TeV. By raising the rf driving frequency, the rf breakdown limit is increased, thereby allowing the length of the accelerators to be reduced. Currently available rf power sources set the realizable gradient limit in an rf linac at frequencies above S-band. This paper presents a model for the frequency scaling of linear colliders, with luminosity scaled in proportion to the square of the center-of-mass energy. Since wakefield effects are the dominant deleterious effect, a separate single-bunch simulation model is described which calculates the evolution of the beam bunch with specified wakefields, including the effects of using programmed phase positioning and Landau damping. The results presented here have been obtained for a SLAC structure, scaled in proportion to wavelength.

Mondelli, A.; Chernin, D.; Drobot, A.; Reiser, M.; Granatstein, V.

1986-06-01T23:59:59.000Z

33

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

34

Linear Collider Collaboration Tech Notes LCC-0109  

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

9 9 TESLA 2002-11 CBP Tech Note-269 November 2002 Alignment Stability Models for Damping Rings Andrej Wolski Lawrence Berkeley National Laboratory University of California Berkeley, CA Winfried Decking Deutsches Elektron Synchrotron (DESY) Hamburg, Germany Abstract: Linear collider damping rings are highly sensitive to magnet alignment. Emittance tuning simulations for current designs of damping rings for TESLA and NLC have given encouraging results, but depend on invasive measurements of dispersion. The frequency with which such measurements must be made is therefore an operational issue, and depends on the time stability of the alignment. In this note, we consider three effects that lead to misalignment and the need to retune the damping ring: (1)

35

Considerations for a Dielectric-based Two-beam-accelerator Linear...  

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

WEPE033 Proceedings of IPAC'10, Kyoto, Japan 3428 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A03 Linear Colliders high coupling coefficient...

36

Governance of the International Linear Collider Project  

SciTech Connect

Governance models for the International Linear Collider Project are examined in the light of experience from similar international projects around the world. Recommendations for one path which could be followed to realize the ILC successfully are outlined. The International Linear Collider (ILC) is a unique endeavour in particle physics; fully international from the outset, it has no 'host laboratory' to provide infrastructure and support. The realization of this project therefore presents unique challenges, in scientific, technical and political arenas. This document outlines the main questions that need to be answered if the ILC is to become a reality. It describes the methodology used to harness the wisdom displayed and lessons learned from current and previous large international projects. From this basis, it suggests both general principles and outlines a specific model to realize the ILC. It recognizes that there is no unique model for such a laboratory and that there are often several solutions to a particular problem. Nevertheless it proposes concrete solutions that the authors believe are currently the best choices in order to stimulate discussion and catalyze proposals as to how to bring the ILC project to fruition. The ILC Laboratory would be set up by international treaty and be governed by a strong Council to whom a Director General and an associated Directorate would report. Council would empower the Director General to give strong management to the project. It would take its decisions in a timely manner, giving appropriate weight to the financial contributions of the member states. The ILC Laboratory would be set up for a fixed term, capable of extension by agreement of all the partners. The construction of the machine would be based on a Work Breakdown Structure and value engineering and would have a common cash fund sufficiently large to allow the management flexibility to optimize the project's construction. Appropriate contingency, clearly apportioned at both a national and global level, is essential if the project is to be realised. Finally, models for running costs and decommissioning at the conclusion of the ILC project are proposed. This document represents an interim report of the bodies and individuals studying these questions inside the structure set up and supervised by the International Committee for Future Accelerators (ICFA). It represents a request for comment to the international community in all relevant disciplines, scientific, technical and most importantly, political. Many areas require further study and some, in particular the site selection process, have not yet progressed sufficiently to be addressed in detail in this document. Discussion raised by this document will be vital in framing the final proposals due to be published in 2012 in the Technical Design Report being prepared by the Global Design Effort of the ILC.

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

2012-05-31T23:59:59.000Z

37

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

38

Design considerations for a laser-plasma linear collider  

SciTech Connect

Design considerations for a next-generation electron-positron linear collider based on laser-plasma-accelerators are discussed. Several of the advantages and challenges of laser-plasma based accelerator technology are addressed. An example of the parameters for a 1 TeV laser-plasma based collider is presented.

Schroeder, C. B.; Esarey, E.; Geddes, C. G. R.; Toth, Cs.; Leemans, W. P.

2008-08-01T23:59:59.000Z

39

Study of Higgs Boson Pair Production at Linear Collider  

E-Print Network (OSTI)

We study the potential of the TESLA linear collider operated at a center-of-mass energy of 500 to 1000 GeV for the measurement of the neutral Higgs boson properties within the framework of the MSSM. The process of associated Higgs boson production with subsequent decays of Higgs bosons into b-quark and tau-lepton pairs is considered. An integrated luminosity of 500 fb^{-1} is assumed at each energy. The Higgs boson masses and production cross sections are measured by reconstructing the bbbb and bb\\tau\\tau final states. The precision of these measurements is evaluated in dependence of the Higgs boson masses. Under the assumed experimental conditions a statistical accuracy ranging from 0.1 to 1.0 GeV is achievable on the Higgs boson mass. The topological cross section \\sigma(e+e- -> HA -> bbbb) can be determined with the relative precision of 1.5 - 6.6 % and cross sections \\sigma(e+e- -> HA -> bb \\tau\\tau) and \\sigma(e+e- -> HA -> \\tau\\tau bb) with precision of 4 - 30 %. Constraints on the Higgs boson widths can be set exploiting bb\\tau\\tau channel. The 5\\sigma discovery limit corresponds to the Higgs mass of around 385 GeV for the degenerate Higgs boson masses in the HA -> bbbb channel at \\sqrts = 800 GeV with integrated luminosity of 500 fb^{-1}. The potential of the Higgs mass determination for the benchmark point SPS 1a for the process e+e- -> HA -> bbbb at \\sqrt{s} = 1 TeV and luminosity 1000 fb^{-1} is investigated.

K. Desch; T. Klimkovich; T. Kuhl; A. Raspereza

2004-06-21T23:59:59.000Z

40

The polarized electron beam for the SLAC Linear Collider  

E-Print Network (OSTI)

The SLAC Linear Collider has been colliding a polarized electron beam with an unpolarized positron beam at the Z^0 resonance for the SLD experiment since 1992. An electron beam polarization of close to 80% has been achieved for the experiment at luminosities up to 8x10^29 cm^-2 s^-1. This is the world's first and only linear collider, and is a successful prototype for the next generation of high energy electron linear colliders. This paper discusses polarized beam operation for the SLC, and includes aspects of the polarized source, spin transport and polarimetry. Presented at the 12th International Symposium on High Energy Spin Physics held at Amsterdam, The Netherlands September 10-14, 1996.

M. Woods

1996-11-09T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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41

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Linear Collider Final Focus Magnet Construction Linear Collider Final Focus Magnet Construction The final focus magnets for the International Linear Collider require very small quadrupoles be placed within the detector background field for both the entrance and exit beams. The use of superconducting magnets for this function provide solutions to several problems confronting the machine designers. One constraint is the operation within the 3 tesla detector field. The direct wind magnets are capable of operation without the use of magnetic materials in their construction, making them ideal for compact focussing solutions within detectors. The second constraint is the small physical size dictated by the crossing angle of the beams and proximity to the IR within the detector solenoid. The Direct Wind design does not require a collar to withstand Lorentz

42

BEAM-BASED NON-LINEAR OPTICS CORRECTIONS IN COLLIDERS.  

Science Conference Proceedings (OSTI)

A method has been developed to measure and correct operationally the non-linear effects of the final focusing magnets in colliders, that gives access to the effects of multi-pole errors by applying closed orbit bumps, and analyzing the resulting tune and orbit shifts. This technique has been tested and used during 4 years of RHIC (the Relativistic Heavy Ion Collider at BNL) operations. I will discuss here the theoretical basis of the method, the experimental set-up, the correction results, the present understanding of the machine model, the potential and limitations of the method itself as compared with other non-linear correction techniques.

PILAT, R.; LUO, Y.; MALITSKY, N.; PTITSYN, V.

2005-05-16T23:59:59.000Z

43

Physics and technology of the Next Linear Collider  

E-Print Network (OSTI)

We present the current expectations for the design and physics program of an e+e- linear collider of center of mass energy 500 GeV -- 1 TeV. We review the experiments that would be carried out at this facility and demonstrate its key role in exploring physics beyond the Standard Model over the full range of theoretical possibilities. We then show the feasibility of constructing this machine, by reviewing the current status of linear collider technology and by presenting a precis of our `zeroth- order' design.

Kuhlman, S; Aiello, R; Akemoto, M; Alley, R; Assmann, R W; Baer, Howard W; Baltay, C; Bane, Karl Leopold Freitag; Barakat, B; Barker, A; Barklow, Timothy L; Barletta, W A; Bauer, D A; Bertolini, L R; Bharadwaj, V K; Bogart, J R; Bowden, G B; Bower, G; Brau, J E; Breidenbach, M; Brown, K L; Burke, D L; Burrows, P N; Byrd, J M; Cai, Y; Caryotakis, G; Cassel, R L; Chattopadhyay, S; Chen, P; Clark, S L; Cleaver, G B; Clem, D; Clendenin, J E; Corlett, J N; Corvin, C; Couture, G; Cuypers, F; Danielson, M; Deadrick, F J; Decker, Franz Josef; Donaldson, A R; Dragt, A J; Dubois, R; Early, R A; Ecklund, S D; Eichner, J; Einhorn, Martin B; Emma, P; Eppley, K R; Eriksson, L; Fahey, S; Farkas, Z D; Fawley, W M; Feng, J L; Fero, M J; Fisher, A S; Foundoulis, C; Fowkes, W R; Frey, R E; Frisch, J; Fuller, R W; Furman, M A; Genova, L F; Gintner, M; Giordano, G; Gluckstern, R L; Godfrey, S; Gold, S; Goluboff, M; Gross, G; Gunion, J F; Haber, Howard E; Han, T; Hanna, S; Hartman, S; Heifets, S A; Helm, R H; Hendrickson, L; Henestroza, E; Hertzbach, S S; Heusch, C A; Hewett, J L; Higashi, K; Higo, T; Hoag, H A; Hodgson, J; Hollebeek, R J; Holt, J A; Houck, T L; Humphrey, J W; Humphrey, R; Irwin, J; Jackson, A; Jacobsen, R A; Jaros, J A; Jobe, R Keith; Jones, R M; Kalyniak, P A; Kane, G L; Keller, L P; Kim, K J; Klem, D E; Ko, K; Koontz, R F; Kraft, E; Krejcik, P; Kroll, N M; Kubo, K; Kulikov, A; Lavine, T L; Li, H; Li, Z; Lidia, S M; Linebarger, W A; Loew, G A; Loewen, R J; Maeshima, K; Manly, S L; Marciano, W J; Markiewicz, T W; Maruyama, T; Mattison, T S; McDonald, K F; McKee, B; Messner, R; Meyerhofer, D D; Miller, R H; Minkowski, Peter; Minty, Michiko G; Moshammer, W; Munro, M H; Munroe, R; Murayama, H; Nantista, C D; Nauenberg, U; Nelson, E M; Nelson, H; Nelson, W R; Ng, C K; Nosochkov, Yu M; Ohgaki, T; Oide, K; Paige, Frank E; Palmer, D; Palmer, R B; Paterson, J M; Pearson, C; Perry, M; Peskin, Michael E; Phillips, R M; Phinney, N; Pope, R S; Raja, R; Raubenheimer, T O; Reginato, L; Rifkin, J; Riles, K; Rimmer, R A; Rinolfi, Louis; Rizzo, T; Robin, D; Rokni, S H; Ronan, Michael T; Rosenzweig, J; Ross, M C; Rowson, P C; Ruland, R E; Ruth, Ronald D; Saab, A; Sawyer, L; Schumm, B; Schwarz, H; Scott, B; Sessler, Andrew M; Sheppard, J C; Shoaee, H; Smith, S; Spence, W L; Spencer, C M; Spencer, J E; Sprehn, D; Strom, D; Stupakov, G; Takahashi, T; Tanaka, K; Tang, H; Tantawi, S G; Tata, Xerxes; Telnov, V I; Tenenbaum, P G; Thomas, S; Thompson, K A; Tian, F; Turner, J; Usher, T; Van Bibber, K; Van Kooten, R; Vanecek, D L; Vlieks, A E; Wagner, D L; Walz, D R; Wang, J W; Ward, B F L; Weidemann, A W; Westenskow, G A; White, T; Whittum, D H; Wilson, P B; Wilson, Z; Woodley, M; Woods, M; Wudka, J; Wurtele, J S; Xie, M; Yan, Y T; Yeremian, A D; Yokoya, K; Yu, S S; Zholents, A A; Zimmermann, Frank

1996-01-01T23:59:59.000Z

44

Linear Collider Collaboration Tech Notes LCC-0110  

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

0 0 December 2002 Post-Target Beamline Design for Proposed FFTB Experiment with Polarized Positrons Y. K. Batygin and J. C. Sheppard Stanford Linear Accelerator Center Stanford University Menlo Park, CA 04025 Abstract: The beamline after positron production target for the proposed experiment E-166 is discussed. The beamline includes bending magnets and solenoid to deliver polarized positron beam from the target to polarimeter. Results of simulation indicate that transmission efficiency of 1...3 % with beam polarization of 60...80 % can be obtained if beam energy resolution is required while the transmission of 40...77 % and polarization of 40% can be obtained without beam energy resolution. 13 December 2002

45

Linear Collider Collaboration Tech Notes LCC-0099  

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

099 099 August 2002 Space Charge Dynamics of Bright Electron Beams Alexander W. Chao, Rainer Pitthan, Toshiki Tajima, Dian Yeremian Stanford Linear Accelerator Center Stanford University Abstract: The longitudinal dynamics and its coupling with the transverse dynamics of bunched beams with strong space charge are analyzed. We introduce a self-consistent Vlasov description for the longitudinal phase space similar to the familiar description for the transverse phase space using a Kapchinskij-Vladimirskij (K-V) distribution [1]. A longitudinal beam envelope equation is derived. An exact solution is then obtained when coupling to the transverse dynamics is ignored. This longitudinal envelope equation is coupled to the transverse envelope

46

Linear Collider Collaboration Tech Notes LCC-70  

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

70 70 August 2001 Design Studies of Positron Collection for the NLC Yuri K. Batygin, Ninod K. Bharadwaj, David C. Schultz ,John C. Sheppard Stanford Linear Accelerator Center Stanford, CA Abstract: The positron source for the NLC project utilizes a 6.2 GeV electron beam interacting in a high-Z positron production target. The electromagnetic shower in the target results in large energy deposition which can cause damage to the target. Optimization of the collection system is required to insure long-term operation of the target with needed high positron yield into the 6-dimensional acceptance of the subsequent pre-damping ring. Positron tracking through the accelerating system indicates a dilution of the initial positron phase space density. Results of simulations indicate that a

47

Linear Collider Collaboration Tech Notes LCC-0101  

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

1 1 August 2002 Collimator Wakefield Calculations for ILC-TRC Report Peter Tenenbaum Stanford Linear Accelerator Center Stanford University Stanford, CA 94309, USA Abstract: We summarize the formalism of collimator wakefields and their effect on beams that are near the center of the collimator gap, and apply the formalism to the TESLA, NLC, and CLIC collimation systems. Collimator Wakefield Calculations for ILC-TRC Report P. Tenenbaum LCC-Note-0101 20-Aug-2002 Abstract We summarize the formalism of collimator wakefields and their effect on beams which are near the center of the collimator gap, and apply the formalism to the TESLA, NLC, and CLIC collimation systems. 1 Introduction One of the beam dynamics effects which must be evaluated for the

48

Linear Collider Collaboration Tech Notes LCC-0063  

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

3 3 May 2001 Varying alpha/lambda in NLC Structures - BNS Damping and Emittance Growth G. Stupakov and Z. Li Stanford Linear Accelerator Center Stanford, CA Abstract: In this note we consider the effect of varying this iris opening in the NLC structures on the beam dynamics and the rf efficiency in the linac. Varying a/λ in NLC structures - BNS damping and emittance growth G. Stupakov and Z. Li SLAC, Stanford University, Stanford, CA 94309 In this note we consider the effect of the varying the iris opening a in the NLC structures on the beam dynamics and the RF efficiency in the linac. The most important consequence of the variation of the iris openings is the change of the longitudinal and transverse wakefields. Wake as a function of parameter a for the NLC structures has been previously calculated by K. Bane. Here we will use his

49

Physics considerations for laser-plasma linear colliders  

SciTech Connect

Physics considerations for a next-generation linear collider based on laser-plasma accelerators are discussed. The ultra-high accelerating gradient of a laser-plasma accelerator and short laser coupling distance between accelerator stages allows for a compact linac. Two regimes of laser-plasma acceleration are discussed. The highly nonlinear regime has the advantages of higher accelerating fields and uniform focusing forces, whereas the quasi-linear regime has the advantage of symmetric accelerating properties for electrons and positrons. Scaling of various accelerator and collider parameters with respect to plasma density and laser wavelength are derived. Reduction of beamstrahlung effects implies the use of ultra-short bunches of moderate charge. The total linac length scales inversely with the square root of the plasma density, whereas the total power scales proportional to the square root of the density. A 1 TeV center-of-mass collider based on stages using a plasma density of 10{sup 17} cm{sup -3} requires tens of J of laser energy per stage (using 1 {micro}m wavelength lasers) with tens of kHz repetition rate. Coulomb scattering and synchrotron radiation are examined and found not to significantly degrade beam quality. A photon collider based on laser-plasma accelerated beams is also considered. The requirements for the scattering laser energy are comparable to those of a single laser-plasma accelerator stage.

Schroeder, Carl; Esarey, Eric; Geddes, Cameron; Benedetti, Carlo; Leemans, Wim

2010-06-11T23:59:59.000Z

50

Higgs Boson Search at e + e ? and Photon Linear Colliders ?  

E-Print Network (OSTI)

The various search modes for the Higgs bosons of the Standard Model (SM) and its Minimal Supersymmetric Extension (MSSM) at the International Linear Collider (ILC) will be summarized briefly. In particular, as a unique discovery mode the production of heavy neutral MSSM Higgs bosons for medium values of tan? in photon collisions will be presented. Furthermore, ? + ? ? fusion into MSSM Higgs bosons in the photon mode will be shown to give access to the mixing parameter tan ? with a precision of better than 10 % for large values of this parameter. PACS numbers: 12.15.-y, 12.60.-i 1.

M. M. Mhlleitner

2005-01-01T23:59:59.000Z

51

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

52

Reliability and Maintainability Issues for the Next Linear Collider  

Science Conference Proceedings (OSTI)

Large accelerators for high energy physics research traditionally have been designed using informal best design, engineering, and management practices to achieve acceptable levels of operational availability. However, the Next Linear Collider(NLC) project presents a particular challenge for operational availability due to the unprecedented size and complexity of the accelerator systems required to achieve the physics goals of high center-of-mass energy and high luminosity. Formal reliability and maintainability analysis, design, and implementation will be required to achieve acceptable operational availability for the high energy physics research program. This paper introduces some of the basic concepts of reliability analysis and applies them to the 2.6-cm microwave power system of the two 10-km-long, 250-GeV linacs that are currently proposed for the NLC design.

Wilson, Zane J.; Gold, Saul L.; Koontz, Ron F.; Lavine, Ted L.; /SLAC

2011-08-26T23:59:59.000Z

53

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

54

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

55

DAPNIA/SEA-00-15 TESLA Linear Collider : Status Report  

E-Print Network (OSTI)

DAPNIA/SEA-00-15 TESLA Linear Collider : Status Report O. Napoly for the TESLA Collaboration CEA) October 24-28, 2000, FNAL, Batavia, IL, USA #12;#12;TESLA Linear Collider : Status Report O. Napoly for the TESLA Collaboration CEA/Saclay, DAPNIA/SEA 91191 Gif-sur-Yvette, FRANCE Abstract. We review the current

56

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Six Layer Quadrupole Six Layer Quadrupole The incoming beam final quad for the linear collider 20 mr option requires a gradient of 140 T/m within a solenoid of 3 Tesla. To meet this goal, a design using 6 around 1 cable bonded to a one inch diameter tube was used. The magnet design required 6 layers of this cable. Two layers were bonded at a time, with S-glass compression wrap every two layers. Final cold testing results were very good, with only two training quenches before reaching short sample. Initial test results at a glance: Background Field Tesla Temp Kelvin Gradient T/m 3 4.3 158 4 4.22 139 5 4.22 134 6 3 137 This data scales to 232 Tesla/meter at 1.9 Kelvin in a 3 Tesla background field. Present field requirements for the 20 mr IR represents 60% of the magnet capability, a comfortable margin. Indeed, even at 4.3 Kelvin in a 3

57

Adjustable permanent quadrupoles for the next linear collider  

Science Conference Proceedings (OSTI)

The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 138 Tesla, with a maximum gradient of 141 Tesla per meter, an adjustment range of +0 to {minus}20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micron during the 20% adjustment. In an effort to reduce costs and increase reliability, several designs using hybrid permanent magnets have been developed. Four different prototypes have been built. All magnets have iron poles and use Samarium Cobalt to provide the magnetic fields. Two use rotating permanent magnetic material to vary the gradient, one uses a sliding shunt to vary the gradient and the fourth uses counter rotating magnets. Preliminary data on gradient strength, temperature stability, and magnetic center position stability are presented. These data are compared to an equivalent electromagnetic prototype.

James T. Volk et al.

2001-06-22T23:59:59.000Z

58

Prospects for Precision Higgs Physics at Linear Colliders  

E-Print Network (OSTI)

A linear e+e- collider provides excellent possibilities for precision measurements of the properties of the Higgs boson. At energies close to the Z-Higgs threshold, the Higgs boson can be studied in recoil against a Z boson, to obtain not only a precision mass measurement but also direct measurements of the branching ratios for most decay modes, including possible decay to invisible species. At higher energies, the Higgs boson coupling to top quarks and the Higgs boson self-coupling can also be measured. At energies approaching 1 TeV and above, the rising cross section for Higgs production in WW fusion allows the measurement of very small branching ratios, including the branching ratio to muon pairs. These experiments make it possible to determine the complete profile of the Higgs boson in a model-independent way. The prospects for these measurements are summarized, based on the results of detailed simulation studies performed within the frameworks of the CLIC conceptual design report and the ILC technical design report.

Frank Simon

2012-11-30T23:59:59.000Z

59

RESEARCH AND DEVELOPMENT FOR AN X-BAND LINEAR COLLIDER* C. Adolphsen  

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

AND DEVELOPMENT FOR AN AND DEVELOPMENT FOR AN X-BAND LINEAR COLLIDER* C. Adolphsen Stanford Linear Accelerator Center, Stanford University, Stanford CA 94309 USA Abstract At SLAC and KEK research is advancing toward a design for an electron-positron linear collider based on X-Band (11.4 GHz) rf accelerator technology. The nominal acceleration gradient in its main linacs will be about four times that in the Stanford Linear Collider (SLC). The design targets a 1.0 TeV center-of-mass energy but envisions initial operation at 0.5 TeV and allows for expansion to 1.5 TeV. A 10 34 cm -2 s -1 luminosity level will be achieved by colliding multiple bunches per pulse with bunch emittances about two orders of magnitude smaller than those in the SLC. The key components needed to realize such a collider are

60

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)

Note: This page contains sample records for the topic "linear colliders lepton" 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

Study of a TeV Level Linear Collider Using Short rf Pulse (20ns...  

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

efficiency and the cost to sustain such a gradient should be considered as well in the optimization process of an overall design. We propose a high energy linear collider based...

62

Pair Production of Tau Sneutrinos at Linear Colliders  

E-Print Network (OSTI)

The pair production of tau sneutrinos in $e^{+}e^{-}$ collisions and their subsequent decays are studied in a framework of the supersymmetric extension of the standard model. We present an analysis for the parameter space (BR vs. mass) which could be explored at the future high energy $e^{+}e^{-}$ colliders.

Ari, V

2010-01-01T23:59:59.000Z

63

Collider Detector at Fermilab (CDF): Data from W, Z bosons and Drell Yan lepton pairs research of the CDF Electroweak Group  

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 at Fermilab is organized into six working groups, each with a specific focus. The Electroweak group studies production and properties of W, Z bosons and Drell Yan lepton pairs. Their public web page makes data and numerous figures available from both CDF Runs I and II.

64

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

65

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

66

Electron-Cloud Effects in Transport Lines of a Normal Conducting Linear Collider  

SciTech Connect

In the transport lines of a normal conducting linear collider, the long positron bunch train can generate an electron cloud which can then amplify intra-train offsets. This is a transient effect which is similar to the electron-cloud driven coupled bunch instabilities in a positron storage ring. In this paper, we study this phenomenon analytically. Some criteria on the critical cloud density with respect to given collider parameters are discussed.

Wu, Juhao; Raubenheimer, T.O.; Pivi, M.T.F.; Seryi, A.; /SLAC

2005-06-15T23:59:59.000Z

67

R&D for a CCD Vertex Detector for the High Energy Linear e+e- Collider  

E-Print Network (OSTI)

I summarise the status of the LCFI Collaboration R&D programme for a CCD-based vertex detector for the linear collider.

P. N. Burrows

2001-12-21T23:59:59.000Z

68

Baseline Configuration of the Cryogenic System for the International Linear Collider  

SciTech Connect

The paper discusses the main constraints and boundary conditions and describes the baseline configuration of the International Linear Collider (ILC) cryogenic system. The cryogenic layout, architecture and the cooling principle are presented. The paper addresses a plan for study and development required to demonstrate and improve the performance, to reduce cost and to attain the desired reliability.

Casas-Cubillos, J.; Claudet, S.; Parma, V.; Riddone, G.; Serio, L.; Tavian, L.; Vullierme, B.; van Weelderen, R.; /CERN; Chorowski, M.; /Wroclaw Tech. U.; Ganni, R.; Rode, C.; /Jefferson Lab; Klebaner, A.; Peterson, T.; Theilacker, J.; /Fermilab; Rousset, B.; /Grenoble, CEN; Weisend, J.; /SLAC

2007-06-18T23:59:59.000Z

69

Higgs Coupling Measurements at a 1 TeV Linear Collider  

SciTech Connect

Methods for extracting Higgs boson signals at a 1 TeV center-of-mass energy e{sup +}e{sup -} linear collider are described. In addition, estimates are given for the accuracy with which branching fractions can be measured for Higgs boson decays to b{bar b} WW, gg, and {gamma}{gamma}.

Barklow, T

2003-12-18T23:59:59.000Z

70

Long ion chamber systems for the SLC (Stanford Linear Collider)  

Science Conference Proceedings (OSTI)

A Panofsky Long Ion Chamber (PLIC) is essentially a gas-filled coaxial cable, and has been used to protect the Stanford Linear Accelerator from damage caused by its electron beam, and as a sensitive diagnostic tool. This old technology has been updated and has found renewed use in the SLC. PLIC systems have been installed as beam steering aids in most parts of the SLC and are a part of the system that protects the SLC from damage by errant beams in several places. 5 refs., 3 figs., 1 tab.

Rolfe, J.; Gearhart, R.; Jacobsen, R.; Jenkins, T.; McComick, D.; Nelson, R.; Reagan, D.; Ross, M.

1989-03-01T23:59:59.000Z

71

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

72

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

73

A modified post damping ring bunch compressor beamline for the TESLA linear collider  

SciTech Connect

We propose a modified bunch compressor beamline, downstream of the damping ring, for the TESLA linear collider. This modified beamline uses a third harmonic radio-frequency section based on the 3.9 GHz superconducting cavity under development at Fermilab. In our design the beam deceleration is about {approx}50 MeV instead of {approx}450 MeV in the original design proposed.

Philippe R.-G. Piot; Winfried Decking

2004-03-23T23:59:59.000Z

74

Final Report for the UNIVERSITY-BASED DETECTOR RESEARCH AND DEVELOPMENT FOR THE INTERNATIONAL LINEAR COLLIDER  

Science Conference Proceedings (OSTI)

The U.S Linear Collider Detector R&D program, supported by the DOE and NSF umbrella grants to the University of Oregon, made significant advances on many critical aspects of the ILC detector program. Progress advanced on vertex detector sensor development, silicon and TPC tracking, calorimetry on candidate technologies, and muon detection, as well as on beamline measurements of luminosity, energy, and polarization.

Brau, James E [Univ. of Oregon] [Univ. of Oregon

2013-04-22T23:59:59.000Z

75

Luminosity limitations at the multi-TeV linear collider energy frontier  

E-Print Network (OSTI)

To achieve the desired high luminosity in e+ e- linear colliders with centre-of-mass energies above the TeV scale, careful optimisation of the beam parameters is necessary. Constraints arising from the RF structure design, the beam-beam interaction, the damping ring and the beam delivery system have to be taken into account and compromises between different requirements have to be found. The nature of these different constraints is discussed and the resulting limits for the luminosity are detailed.

Schulte, Daniel

2002-01-01T23:59:59.000Z

76

Effective Yukawa couplings and flavor-changing Higgs boson decays at linear colliders  

Science Conference Proceedings (OSTI)

We analyze the advantages of a linear-collider program for testing a recent theoretical proposal where the Higgs boson Yukawa couplings are radiatively generated, keeping unchanged the standard-model mechanism for electroweak-gauge-symmetry breaking. Fermion masses arise at a large energy scale through an unknown mechanism, and the standard model at the electroweak scale is regarded as an effective field theory. In this scenario, Higgs boson decays into photons and electroweak gauge-boson pairs are considerably enhanced for a light Higgs boson, which makes a signal observation at the LHC straightforward. On the other hand, the clean environment of a linear collider is required to directly probe the radiative fermionic sector of the Higgs boson couplings. Also, we show that the flavor-changing Higgs boson decays are dramatically enhanced with respect to the standard model. In particular, we find a measurable branching ratio in the range (10{sup -4}-10{sup -3}) for the decay H{yields}bs for a Higgs boson lighter than 140 GeV, depending on the high-energy scale where Yukawa couplings vanish. We present a detailed analysis of the Higgs boson production cross sections at linear colliders for interesting decay signatures, as well as branching-ratio correlations for different flavor-conserving/nonconserving fermionic decays.

Gabrielli, E. [CERN, PH-TH, CH-1211 Geneva 23 (Switzerland); Mele, B. [INFN, Sezione di Roma, c/o Dipartimento di Fisica, Universita di Roma 'La Sapienza', Piazzale A. Moro 2, I-00185 Rome (Italy)

2011-04-01T23:59:59.000Z

77

Zeroth-order design report for the next linear collider. Volume 2  

Science Conference Proceedings (OSTI)

This Zeroth-Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The ``design`` presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume II covers the following: collimation systems; IP switch and big bend; final focus; the interaction region; multiple bunch issues; control systems; instrumentation; machine protection systems; NLC reliability considerations; NLC conventional facilities. Also included are four appendices on the following topics: An RF power source upgrade to the NLC; a second interaction region for gamma-gamma, gamma-electron; ground motion: theory and measurement; and beam-based feedback: theory and implementation.

Raubenheimer, T.O. [ed.

1996-05-01T23:59:59.000Z

78

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

79

Zeroth-order design report for the next linear collider. Volume 1  

Science Conference Proceedings (OSTI)

This Zeroth Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The design presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume one covers the following: the introduction; electron source; positron source; NLC damping rings; bunch compressors and prelinac; low-frequency linacs and compressors; main linacs; design and dynamics; and RF systems for main linacs.

Raubenheimer, T.O. [ed.

1996-05-01T23:59:59.000Z

80

Linear collider signals of an invisible Higgs boson in theories of large extra dimensions  

SciTech Connect

We discuss the possibility of detecting a Higgs boson in electron-positron collider experiments if large extra dimensions are realized in nature. In such a case, the Higgs boson can decay invisibly by oscillating into a graviscalar Kaluza-Klein tower. We show that the search for such a Higgs boson at an e{sup +}e{sup -} linear collider entails more complications than are usually thought of in relation to an invisibly decaying Higgs boson. The main sources of such complications are due to the simultaneous presence of a continuum graviton production and the broadening of the Higgs peak. We discuss possible ways of overcoming such difficulties and conclude that the detection of such a Higgs boson might still be a problem beyond the mass range of 250-300 GeV.

Datta, Anindya [INFN, Sezione di Roma, Universita La Sapienza, P. le A. Moro 2, Rome I-00185 (Italy); Huitu, Katri [Helsinki Institute of Physics, P.O. Box 64, FIN-00014 University of Helsinki (Finland); High Energy Physics Division, Department of Physical Sciences, P.O. Box 64, FIN-00014 University of Helsinki (Finland); Laamanen, Jari [Helsinki Institute of Physics, P.O. Box 64, FIN-00014 University of Helsinki (Finland); Mukhopadhyaya, Biswarup [Harish Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad - 211 019 (India)

2004-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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81

The Linear Collider Physics Case: International Response to the Technology Independent Questions Posed by the International Technology Recommendation Panel  

E-Print Network (OSTI)

The International Technology Recommendation Panel distributed a list of questions to each major laboratory. Question 30, part b and d, were technology independent and related to the physics goals of the Linear Collider. An international panel, with representation from Asia, Europe, and the Americas, was formed by the World Wide Study during LCWS04 to formulate a response. This is given below and constitutes the response of the world-wide Linear Collider community.

Klaus Desch; JoAnne Hewett; Akiya Miyamoto; Yasuhiro Okada; Mark Oreglia; Georg Weiglein; Satoru Yamashita

2004-11-11T23:59:59.000Z

82

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

83

Higgs Boson Search at e+e- and Photon Linear Colliders  

E-Print Network (OSTI)

The various search modes for the Higgs bosons of the Standard Model (SM) and its Minimal Supersymmetric Extension (MSSM) at the International Linear Collider (ILC) will be summarized briefly. In particular, as a unique discovery mode the production of heavy neutral MSSM Higgs bosons for medium values of $\\tan\\beta$ in photon collisions will be presented. Furthermore, $\\tau^+\\tau^-$ fusion into MSSM Higgs bosons in the photon mode will be shown to give access to the mixing parameter $\\tan\\beta$ with a precision of better than 10% for large values of this parameter.

M. M. Muhlleitner

2005-12-19T23:59:59.000Z

84

Phenomenology of a leptonic goldstino and invisible Higgs boson decays  

E-Print Network (OSTI)

Non-linearly realized supersymmetry, combined with the Standard Model field content and SU(3)XSU(2)XU(1) gauge invariance, permits local dimension-six operators involving a goldstino, a lepton doublet and a Higgs doublet. These interactions preserve total lepton number if the left-handed goldstino transforms as an antilepton. We discuss the resulting phenomenology, in the simple limit where the new couplings involve only one lepton family, thus conserving also lepton flavour. Both the Z boson and the Higgs boson can decay into a neutrino and a goldstino: the present limits from the invisible Z width and from other observables leave room for the striking possibility of a Higgs boson decaying dominantly, or at least with a sizable branching ratio, via such an invisible mode. We finally comment on the perspectives at hadron and lepton colliders, and on possible extensions of our analysis.

Ignatios Antoniadis; Marc Tuckmantel; Fabio Zwirner

2004-10-12T23:59:59.000Z

85

DCal: A custom integrated circuit for calorimetry at the International Linear Collider  

SciTech Connect

A research and development collaboration has been started with the goal of producing a prototype hadron calorimeter section for the purpose of proving the Particle Flow Algorithm concept for the International Linear Collider. Given the unique requirements of a Particle Flow Algorithm calorimeter, custom readout electronics must be developed to service these detectors. This paper introduces the DCal or Digital Calorimetry Chip, a custom integrated circuit developed in a 0.25um CMOS process specifically for this International Linear Collider project. The DCal is capable of handling 64 channels, producing a 1-bit Digital-to-Analog conversion of the input (i.e. hit/no hit). It maintains a 24-bit timestamp and is capable of operating either in an externally triggered mode or in a self-triggered mode. Moreover, it is capable of operating either with or without a pipeline delay. Finally, in order to permit the testing of different calorimeter technologies, its analog front end is capable of servicing Particle Flow Algorithm calorimeters made from either Resistive Plate Chambers or Gaseous Electron Multipliers.

Hoff, James R.; Mekkaoui, Abderrazek; Yarema, Ray; /Fermilab; Drake, Gary; Repond, Jose; /Argonne

2005-10-01T23:59:59.000Z

86

Linear Collider Collaboration Tech Notes LCC-0073 SLAC-PUB-9004  

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

3 3 SLAC-PUB-9004 September 2001 Microwave Quadrupoles for Beam Break-up Supression In the NLC Main Linac K.L.F. Bane and G. Stupakov Stanford Linear Accelerator Center Stanford, CA Abstract: This is a preliminary study of the effect of using microwave quads (MQs) instead of rf phase shifting to induce BNS damping in the main linac of the NLC collider. We consider MQs running at X-band, and find that the total length of MQs needed for the NLC is 6% of the total length of the accelerating structures. We show through simulations that, by using MQs instead of phase shifting for BNS damping, the quad alignment tolerances can be relaxed but at the expense of shifting the tight tolerances to the MQs; this can be advantageous if the MQs can be better aligned

87

Results from a Prototype Chicane-Based Energy Spectrometer for a Linear Collider  

E-Print Network (OSTI)

The International Linear Collider and other proposed high energy e+ e- machines aim to measure with unprecedented precision Standard Model quantities and new, not yet discovered phenomena. One of the main requirements for achieving this goal is a measurement of the incident beam energy with an uncertainty close to 1e-4. This article presents the analysis of data from a prototype energy spectrometer commissioned in 2006--2007 in SLAC's End Station A beamline. The prototype was a 4-magnet chicane equipped with beam position monitors measuring small changes of the beam orbit through the chicane at different beam energies. A single bunch energy resolution close to 5e-4 was measured, which is satisfactory for most scenarios. We also report on the operational experience with the chicane-based spectrometer and suggest ways of improving its performance.

A. Lyapin; H. J. Schreiber; M. Viti; C. Adolphsen; R. Arnold; S. Boogert; G. Boorman; M. V. Chistiakova; F. Gournaris; V. Duginov; C. Hast; M. D. Hildreth; C. Hlaing; F. Jackson; O. Khainovsky; Yu. G. Kolomensky; S. Kostromin; K. Kumar; B. Maiheu; D. McCormick; D. J. Miller; N. Morozov; T. Orimoto; E. Petigura; M. Sadre-Bazzaz; M. Slater; Z. Szalata; M. Thomson; D. Ward; M. Wendt; M. Wing; M. Woods

2010-11-01T23:59:59.000Z

88

Adjustable Permanent Quadrupoles Using Rotating Magnet Material Rods for the Next Linear Collider  

Science Conference Proceedings (OSTI)

The proposed Next Linear Collider (NLC) will require over 1400 adjustable quadrupoles between the main linacs' accelerator structures. These 12.7 mm bore quadrupoles will have a range of integrated strength from 0.6 to 132 Tesla, with a maximum gradient of 135 Tesla per meter, an adjustment range of +0-20% and effective lengths from 324 mm to 972 mm. The magnetic center must remain stable to within 1 micrometer during the 20% adjustment. In an effort to reduce estimated costs and increase reliability, several designs using hybrid permanent magnets have been developed. All magnets have iron poles and use either Samarium Cobalt or Neodymium Iron to provide the magnetic fields. Two prototypes use rotating rods containing permanent magnetic material to vary the gradient. Gradient changes of 20% and center shifts of less than 20 microns have been measured. These data are compared to an equivalent electromagnet prototype.

James T Volk et al.

2001-09-24T23:59:59.000Z

89

Measurement of the Higgs Boson Mass with a Linear e+e- Collider  

E-Print Network (OSTI)

The potential of a linear e+e- collider operated at a centre-of-mass energy of 350 GeV is studied for the measurement of the Higgs boson mass. An integrated luminosity of 500 fb-1 is assumed. For Higgs boson masses of 120, 150 and 180 GeV the uncertainty on the Higgs boson mass measurement is estimated to be 40, 65 and 70 MeV, respectively. The effects of beam related systematics, namely a bias in the beam energy measurement, the beam energy spread and the luminosity spectrum due to beamstrahlung, on the precision of the Higgs boson mass measurement are investigated. In order to keep the systematic uncertainty on the Higgs boson mass well below the level of the statistical error, the beam energy measurement must be controlled with a relative precision better than 10-4.

P. Garcia-Abia; W. Lohmann; A. Raspereza

2005-05-30T23:59:59.000Z

90

Can we distinguish an MSSM higgs from a SM higgs at a linear collider?  

SciTech Connect

The authors study the prospects for distinguishing the CP-even Higgs boson of the minimal supersymmetric extension of the Standard Model (MSSM) from the Standard Model (SM) Higgs boson by measuring its branching ratios at an e{sup +}e{sup {minus}} linear collider. The regions of the M{sub A} - tan {beta} plane in which an MSSM Higgs boson can be distinguished from the SM Higgs boson depend strongly upon the supersymmetric parameters that enter the radiative corrections to the Higgs mass matrix and the Higgs couplings to fermions. In some regions of parameter space it is possible to extract the supersymmetric correction to the relation between the b quark mass and its Yukawa coupling from Higgs branching ratio measurements.

Logan, H.E.

2001-01-04T23:59:59.000Z

91

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

92

Using Spin Correlations to Distinguish Zh from ZA at the International Linear Collider  

Science Conference Proceedings (OSTI)

We investigate how to exploit the spin information imparted to the Z boson in associated Higgs production at a future linear collider as an aid in distinguishing between CP-even and CP-odd Higgs bosons. We apply a generalized spin-basis analysis which allows us to study the possibilities offered by non-traditional choices of spin projection axis. In particular, we find that the Z bosons produced in association with a CP-even Higgs via polarized collisions are in a single transverse spin-state (> 90% purity) when we use the Zh-transverse basis, provided that the Z bosons are not ultra-relativistic (speed < 0.9c). This same basis applied to the associated production of a CP-odd Higgs yields Z's that are an approximately equal mixture of longitudinal and transverse polarizations. We present a decay angular distribution which could be used to distinguish between the CP-even and CP-odd cases. Finally, we make a few brief remarks about how this distribution would be affected if the Higgs boson turns out to not be a CP-eigenstate.

Mahlon, Gregory; /Penn State U., Mont Alto; Parke, Stephen J.; /Fermilab

2006-06-01T23:59:59.000Z

93

Study of Higgs self couplings of a supersymmetric $E_6$ model at the International Linear Collider  

E-Print Network (OSTI)

We study the Higgs self couplings of a supersymmetric $E_6$ model that has two Higgs doublets and two Higgs singlets. The lightest scalar Higgs boson in the model may be heavier than 112 GeV, at the one-loop level, where the negative results for the Higgs search at the LEP2 experiments are taken into account. The contributions from the top and scalar top quark loops are included in the radiative corrections to the one-loop mass of the lightest scalar Higgs boson, in the effective potential approximation. The effect of the Higgs self couplings may be observed in the production of the lightest scalar Higgs bosons in $e^+e^-$ collisions at the International Linear Collider (ILC) via double Higgs-strahlung process. For the center of mass energy of 500 GeV with the integrated luminosity of 500 fb$^{-1}$ and the efficiency of 20 %, we expect that at least 5 events of the lightest scalar Higgs boson may be produced at the ILC via double Higgs-strahlung process.

S. W. Ham; Kideok Han; Jungil Lee; S. K. Oh

2009-11-30T23:59:59.000Z

94

An Automated Magnet Positioning System For Use in the Next Linear Collider  

SciTech Connect

The Next Linear Collider (NLC) is conceived as the world?¢????s most powerful electron-positron particle accelerator. Throughout the NLC, the beam itself will be used to measure errors in the positions of the lattice elements. This beam-based alignment strategy is an essential element of the NLC?¢????s design and precision adjustment systems have been identified as a critical enabling technology. Square One proposes a new type of precision manipulator that could be adapted for applications throughout the accelerator. As envisioned, this ?¢????Tri-Sphere?¢??? Adjustment System will possess up to six, non-redundant degrees of freedom, be capable of sub-micron resolutions and have ultimate load capacities in excess of 10,000 kg. The system will accommodate thermal expansions and contractions of the objects being supported and can be either motorized or manually actuated. Phase I development tasks will include detailed manipulator design, solution of the associated kinematic equations of motion and evaluation of actuators, gear reducers and transmission systems. The Phase I effort will culminate in the fabrication and full evaluation of a system prototype. A successfully developed Tri-Sphere manipulator could also be used to actively position critical fusion optics, adjust communication dishes or perform parts handling tasks in harsh manufacturing environments.

Viola, Robert J.

2006-02-21T23:59:59.000Z

95

Testing Higgs models via the H{sup {+-}}W{sup {-+}}Z vertex by a recoil method at the International Linear Collider  

SciTech Connect

In general, charged Higgs bosons H{sup {+-}} appear in nonminimal Higgs models. The H{sup {+-}}W{sup {-+}}Z vertex is known to be related to the violation of the global symmetry (custodial symmetry) in the Higgs sector. Its magnitude strongly depends on the structure of the exotic Higgs models which contain higher isospin SU(2){sub L} representations such as triplet Higgs bosons. We study the possibility of measuring the H{sup {+-}}W{sup {-+}}Z vertex via single charged Higgs boson production associated with the W{sup {+-}} boson at the International Linear Collider (ILC) by using the recoil method. The feasibility of the signal e{sup +}e{sup -}{yields}H{sup {+-}}W{sup {-+}}{yields}l{nu}jj is analyzed assuming the polarized electron and positron beams and the expected detector performance for the resolution of the two-jet system at the ILC. The background events can be reduced to a considerable extent by imposing the kinematic cuts even if we take into account the initial state radiation. For a relatively light charged Higgs boson whose mass m{sub H}{sup {+-}} is in the region of 120-130 GeV lepton specific. The exoticness of the extended Higgs sector can be explored by using combined information for this vertex and the rho parameter.

Kanemura, Shinya; Yagyu, Kei; Yanase, Kazuya [Department of Physics, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)

2011-04-01T23:59:59.000Z

96

International Linear Collider Reference Design Report Volume 2: Physics at the ILC  

SciTech Connect

The triumph of 20th century particle physics was the development of the Standard Model and the confirmation of many of its aspects. Experiments determined the particle constituents of ordinary matter, and identified four forces that hold matter together and transform it from one form to another. Particle interactions were found to obey precise laws of relativity and quantum theory. Remarkable features of quantum physics were observed, including the real effects of 'virtual' particles on the visible world. Building on this success, particle physicists are now able to address questions that are even more fundamental, and explore some of the deepest mysteries in science. The scope of these questions is illustrated by this summary from the report Quantum Universe: (1) Are there undiscovered principles of nature; (2) How can we solve the mystery of dark energy; (3) Are there extra dimensions of space; (4) Do all the forces become one; (5) Why are there so many particles; (6) What is dark matter? How can we make it in the laboratory; (7) What are neutrinos telling us; (8) How did the universe begin; and (9) What happened to the antimatter? A worldwide program of particle physics investigations, using multiple approaches, is already underway to explore this compelling scientific landscape. As emphasized in many scientific studies, the International Linear Collider is expected to play a central role in what is likely to be an era of revolutionary advances. Discoveries from the ILC could have breakthrough impact on many of these fundamental questions. Many of the scientific opportunities for the ILC involve the Higgs particle and related new phenomena at Terascale energies. The Standard Model boldly hypothesizes a new form of Terascale energy, called the Higgs field, that permeates the entire universe. Elementary particles acquire mass by interacting with this field. The Higgs field also breaks a fundamental electroweak force into two forces, the electromagnetic and weak forces, which are observed by experiments in very different forms. So far, there is no direct experimental evidence for a Higgs field or the Higgs particle that should accompany it. Furthermore, quantum effects of the type already observed in experiments should destabilize the Higgs boson of the Standard Model, preventing its operation at Terascale energies. The proposed antidotes for this quantum instability mostly involve dramatic phenomena at the Terascale: new forces, a new principle of nature called supersymmetry, or even extra dimensions of space. Thus for particle physicists the Higgs boson is at the center of a much broader program of discovery, taking off from a long list of questions. Is there really a Higgs boson? If not, what are the mechanisms that give mass to particles and break the electroweak force? If there is a Higgs boson, does it differ from the hypothetical Higgs of the Standard Model? Is there more than one Higgs particle? What are the new phenomena that stabilize the Higgs boson at the Terascale? What properties of Higgs boson inform us about these new phenomena? Another major opportunity for the ILC is to shed light on the dark side of the universe. Astrophysical data shows that dark matter dominates over visible matter, and that almost all of this dark matter cannot be composed of known particles. This data, combined with the concordance model of Big Bang cosmology, suggests that dark matter is comprised of new particles that interact weakly with ordinary matter and have Terascale masses. It is truely remarkable that astrophysics and cosmology, completely independently of the particle physics considerations reviewed above, point to new phenomena at the Terascale. If Terascale dark matter exists, experiments at the ILC should be able to produce such particles in the laboratory and study their properties. Another list of questions will then beckon. Do these new particles really have the correct properties to be the dark matter? Do they account for all of the dark matter, or only part of it? What do their properties tell us about the evolut

Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; /SLAC /Tokyo U. /Victoria U. /Beijing, Inst. High Energy Phys. /Tel Aviv U. /Birmingham U. /Annecy, LAPP /Minsk, High Energy Phys. Ctr. /DESY /Royal Holloway, U. of London /CERN /Pusan Natl. U. /KEK, Tsukuba /Orsay, LAL /Notre Dame U. /Frascati /Cornell U., Phys. Dept. /Oxford U. /Hefei, CUST /Bangalore, Indian Inst. Sci. /Fermilab

2011-11-14T23:59:59.000Z

97

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

98

Unique Identification of Lee-Wick Gauge Bosons at Linear Colliders  

E-Print Network (OSTI)

Grinstein, O'Connell and Wise have recently presented an extension of the Standard Model (SM), based on the ideas of Lee and Wick (LW), which demonstrates an interesting way to remove the quadratically divergent contributions to the Higgs mass induced by radiative corrections. This model predicts the existence of negative-norm copies of the usual SM fields at the TeV scale with ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. In earlier work, it was demonstrated that the LW states in the gauge boson sector of these models, though easy to observe, cannot be uniquely identified as such at the LHC. In this paper, we address the issue of whether or not this problem can be resolved at an $e^+e^-$ collider with a suitable center of mass energy range. We find that measurements of the cross section and the left-right polarization asymmetry associated with Bhabha scattering can lead to a unique identification of the neutral electroweak gauge bosons of the Lee-Wick type.

Thomas G. Rizzo

2007-12-11T23:59:59.000Z

99

Microsoft Word - WFnote-238_Summary of short pulse collider.doc  

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

electron-positron linear collider from the International Linear Collider (ILC) and Compact Linear Collider (CLIC) teams have been well established. Both proposed machines work...

100

Linear Collider Collaboration Tech Notes LCC-0113 CBP Tech Note-276  

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

3 3 CBP Tech Note-276 February 2003 The NLC Main Damping Ring Lattice Mark Woodley 1 and Andrzej Wolski 2 1 Stanford Linear Accelerator Center Stanford University Menlo Park, CA 04025 2 Lawrence Berkeley National Laboratory University of California Berkeley, CA Abstract: Studies of the NLC Main Damping Ring lattice since April 2001 have indicated that there are a number of collective effects that potentially limit operational performance. One possible way to reduce the impact of these effects is to raise the momentum compaction of the lattice, which requires a significant redesign. In this note, we present a lattice that has a momentum compaction four times larger than the previous design. We discuss the linear and nonlinear dynamical properties of the lattice, and

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101

Linear Collider Collaboration Tech Notes LCC-0062 CBP-tech Note228  

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

2 2 CBP-tech Note228 May 2001 Symplectic Integrators for Nonlinear Wiggler Fields Andrzej Wolski Lawrence Berkeley National Laboratory Abstract: To achieve fast damping, the NLC Main Damping Ring uses a wiggler with high field strength, 2.15 T, and over 45 m in length. An ideal wiggler with infinitely wide pole pieces may be treated as a linear eleme nt, and has no impact on the dynamic aperture. However, the integrated nonlinear components from a real wiggler with integrated field over 100 T 2 m can be significant, and the choice of methods for studying the effects in such cases is limited at present. We present two possibilities for symplectic tracking through a wiggler taking full account of the nonlinear components of the field, compare the results with

102

The characteristic initial value problem for colliding plane waves: The linear case  

E-Print Network (OSTI)

The physical situation of the collision and subsequent interaction of plane gravitational waves in a Minkowski background gives rise to a well-posed characteristic initial value problem in which initial data are specified on the two null characteristics that define the wavefronts. In this paper, we analyse how the Abel transform method can be used in practice to solve this problem for the linear case in which the polarization of the two gravitational waves is constant and aligned. We show how the method works for some known solutions, where problems arise in other cases, and how the problem can always be solved in terms of an infinite series if the spectral functions for the initial data can be evaluated explicitly.

J. B. Griffiths; M. Santano-Roco

2002-06-25T23:59:59.000Z

103

Development of an X-band magnicon amplifier for the Next Linear Collider  

SciTech Connect

The magnicon is a scanning-beam microwave amplifier that is being developed as a high power, highly efficient microwave source for use in powering the next generation of high gradient electron linear accelerators. In this paper, we first discuss the results from a cold cathode magnicon experiment at 11.12 GHz, driven by a single-shot Marx generator. We then present the design of a new thermionic magnicon experiment to produce more than 50 MW at 11.4 GHz, using a 210 A, 500 kV beam from an ultrahigh convergence thermionic electron gun driven by a rep-rated modulator. This new design has a predicted efficiency in excess of 60{percent}. {copyright} {ital 1997 American Institute of Physics.}

Gold, S.H.; Fliflet, A.W. [Beam Physics Branch, Plasma Physics Division, Naval Research Laboratory, Washington, District of Columbia 20375-5346 (United States); Kinkead, A.K. [Sachs/Freeman Associates, Inc., Landover, Maryland 20785 (United States); Hafizi, B. [Icarus Research, Inc., P.O. Box 30780, Bethesda, Maryland 20824-0780 (United States); Nezhevenko, O.A.; Yakovlev, V.P. [Budker Institute of Nuclear Physics, Novosibirsk, (Russia) 630090; Hirshfield, J.L. [Omega-P, Inc., 202008 Yale Station, New Haven, Connecticut 06520 (United States); True, R. [Litton Systems, Inc., Electron Devices Division, San Carlos, California 94070 (United States)

1997-03-01T23:59:59.000Z

104

Search for the Standard Model Higgs boson produced in association with a W Boson in the isolated-track charged-lepton channel using the Collider Detector at Fermilab  

SciTech Connect

The Higgs boson is the only elementary particle predicted by the Standard Model (SM) that has not yet been observed experimentally. If it exists, it explains the spontaneous electroweak symmetry breaking and the origin of mass for gauge bosons and fermions. We test the validity of the SM by performing a search for the associated production of a Higgs boson and a W boson in the channel where the Higgs boson decays to a bottom-antibottom quark pair and the W boson decays to a charged lepton and a neutrino (the WH channel). We study a dataset of proton-antiproton collisions at a centre-of-mass energy {radical}s = 1.96 TeV provided by the Tevatron accelerator, corresponding to an integrated luminosity of 5.7 fb{sup -1}, and recorded using the Collider Detector at Fermilab (CDF).We select events consistent with the signature of exactly one charged lepton (electron or muon), missing transverse energy due to the undetected neutrino (MET) and two collimated streams of particles (jets), at least one of which is required to be identified as originating from a bottom quark. We improve the discrimination of Higgs signal from backgrounds through the use of an artificial neural network. Using a Bayesian statistical inference approach, we set for each hypothetical Higgs boson mass in the range 100-150 GeV/c{sup 2} with 5 GeV/c{sup 2} increments a 95% credibility level (CL) upper limit on the ratio between the Higgs production cross section times branching fraction and the SM prediction. Our main original contributions are the addition of a novel charged lepton reconstruction algorithm with looser requirements (ISOTRK) with respect the electron or muon tight criteria (TIGHT), as well as the introduction of a novel trigger-combination method that allows to maximize the event yield while avoiding trigger correlations and that is used for the ISOTRK category. The ISOTRK candidate is a high-transverse-momentum good-quality track isolated from other activity in the tracking system and not required to match a calorimeter cluster, as for a tight electron candidate, or an energy deposit in the muon detector, as for a tight muon candidate. The ISOTRK category recovers real charged leptons that otherwise would be lost in the non-instrumented regions of the detector. This allows the reconstruction of more W boson candidates, which in turn increases the number of reconstructed WH signal candidate events, and therefore improves the sensitivity of the WH search. For the TIGHT charged lepton categories, we employ charged-lepton-dedicated triggers to improve the rate of WH signal acceptance during data taking. Since there is no ISOTRK-dedicated trigger at CDF, for the ISOTRK charged lepton category we employ three MET-plus-jets-based triggers. For each trigger we first identify the jet selection where the trigger efficiency is flat with respect to jet information (transverse energy and direction of motion in the transverse plane for the two jets in the event) and then we parametrize the trigger efficiency as a function of trigger MET. On an event-by-event basis, for each trigger we compute a trigger efficiency as a function of trigger parametrization, trigger MET, jet information, trigger prescale and information about whether the trigger is defined or not. For the ISOTRK category we combine the three triggers using a novel method, which allows the combination of any number of triggers in order to maximize the event yield while avoiding trigger correlations. On an event-by-event basis, only the trigger with the largest efficiency is used. By avoiding a logical 'OR' between triggers, the loss in the yield of events accepted by the trigger combination is compensated by a smaller and easier-to-compute corresponding systematic uncertainty. The addition of the ISOTRK charged lepton category to the TIGHT category produces an increase of 33% in the WH signal yield and a decrease of 15.5% to 19.0% in the median expected 95% CL cross-section upper limits across the entire studied Higgs mass interval. The improvement in analysis sensitivity is smaller than the i

Buzatu, Adrian; /McGill U.

2011-08-01T23:59:59.000Z

105

High Power Testing Results of the X-band Mixed-mode RF Windows for Linear Colliders  

SciTech Connect

In this paper, we summarize the high power testing results of the X-band mixed-mode RF windows at KEK and SLAC for linear colliders. The main feature of these windows is that the combination of modes on the surface of the ceramic significantly decreases the electric and magnetic fields in the junction between the ceramic and the metal. So far two types of high power windows (with the diameter of 53 mm and 64 mm) have been fabricated. A high power model of the smaller type window was fabricated and tested in a resonant ring at KEK. A maximum circulating power of 81 MW with 300 ns duration or 66 MW with 700 ns duration was achieved. Light emission was observed for a power level of over 10 MW. Later, both windows were shipped to SLAC for even higher power testing using combined power from two klystrons. The first window (53 mm diameter) achieved a transmitted power of 80 MW with 1.5 microsec duration at 30 Hz repetition. It was not destroyed during the testing. The testing of the second window was carried out next to the small type and achieved 62 MW with 1.5 microsec duration with 10 Hz repetition. The final results of both windows are presented in this report.

Loewen, Roderick J

2000-10-26T23:59:59.000Z

106

Lepton stability  

Science Conference Proceedings (OSTI)

The problem of flavor-changing currents in the lepton sector is reviewed. The emphasis is on the experimental situation, with a brief discussion of the theoretical problems which are addressed by the measurements.

Cooper, M.C.

1981-01-01T23:59:59.000Z

107

SLAC National Accelerator Laboratory - Lepton-Photon Conference...  

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

was still the biggest news at this year's Lepton-Photon: the discovery of a Higgs boson at CERN's Large Hadron Collider. Progress has been made in the past year: The new...

108

Research and Development of Future Muon Collider  

SciTech Connect

Muon collider is a considerable candidate of the next generation high-energy lepton collider machine. A novel accelerator technology must be developed to overcome several intrinsic issues of muon acceleration. Recent research and development of critical beam elements for a muon accelerator, especially muon beam phase space ionization cooling channel, are reviewed in this paper.

Yonehara, K.; /Fermilab

2012-05-01T23:59:59.000Z

109

Limits on tau lepton flavor violating decays in three charged leptons  

SciTech Connect

A search for the neutrinoless, lepton-flavor violating decay of the {tau} lepton into three charged leptons has been performed using an integrated luminosity of 468 fb{sup -1} collected with the BABAR detector at the PEP-II collider. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1.8-3.3) x 10{sup -8} at 90% confidence level.

Cervelli, Alberto

2010-04-29T23:59:59.000Z

110

A New Chicane Experiment In PEP-II to Test Mitigations of the Electron Cloud Effect for Linear Colliders  

Science Conference Proceedings (OSTI)

Beam instability caused by the electron cloud has been observed in positron and proton storage rings, and it is expected to be a limiting factor in the performance of future colliders [1-3]. The effect is expected to be particularly severe in magnetic field regions. To test possible mitigation methods in magnetic fields, we have installed a new 4-dipole chicane experiment in the PEP-II Low Energy Ring (LER) at SLAC with both bare and TiN-coated aluminum chambers. In particular, we have observed a large variation of the electron flux at the chamber wall as a function of the chicane dipole field. We infer this is a new high order resonance effect where the energy gained by the electrons in the positron beam depends on the phase of the electron cyclotron motion with respect to the bunch crossing, leading to a modulation of the secondary electron production. Presumably the cloud density is modulated as well and this resonance effect could be used to reduce its magnitude in future colliders. We present the experimental results obtained during January 2008 until the April final shut-down of the PEP-II machine.

Pivi, M.T.F.; Ng, J.S.T.; Arnett, D.; Cooper, F.; Kharakh, D.; King, F.K.; Kirby, R.E.; Kuekan, B.; Lipari, J.J.; Munro, M.; Olszewski, J.; Raubenheimer, T.O.; Seeman, J.; Smith, B.; Spencer, C.M.; Wang, L.; Wittmer, W.; Celata, C.M.; Furman, M.A.; /SLAC /LBL, Berkeley

2008-07-03T23:59:59.000Z

111

Glossary Term - Lepton  

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

Joule Previous Term (Joule) Glossary Main Index Next Term (Liquid Nitrogen) Liquid Nitrogen Lepton Leptons are particles with little mass that interact through the electromagnetic...

112

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

113

One-loop Higgs boson production at the Linear Collider within the general two-Higgs-doublet model: e+e- versus gamma-gamma  

E-Print Network (OSTI)

We present an updated overview on the phenomenology of one-loop Higgs boson production at Linear Colliders within the general Two-Higgs-Doublet Model (2HDM). First we report on the Higgs boson pair production, and associated Higgs-Z boson production, at O(alpha^3_{ew}) from e+e- collisions. These channels furnish cross-sections in the range of 10-100 fb for Ecm=0.5 TeV and exhibit potentially large radiative corrections (of order 50%), whose origin can be traced back to the genuine enhancement capabilities of the triple Higgs boson self-interactions. Next we consider the loop-induced production of a single Higgs boson from direct gamma-gamma scattering. We single out sizable departures from the corresponding rates in the Standard Model, which are again correlated to trademark dynamical features of the 2HDM -- namely the balance of the non-standard Higgs/gauge, Higgs/fermion and Higgs self-interactions leading to sizable (destructive) interference effects. This pattern of quantum effects is unmatched in the MSSM, and could hence provide distinctive footprints of non-supersymmetric Higgs boson physics. Both calculations are revisited within a common, brought-to-date framework and include, in particular, the most stringent bounds from unitarity and flavor physics.

Joan Sola; David Lopez-Val

2011-07-07T23:59:59.000Z

114

U.S. Working Groups on Physics and Experiments at a Future Linear Collider; Proceedings of the Workshop, Estes Park, Colorado, June 21-23, 1995  

SciTech Connect

On June 21-23, 1995 a group of 75 high energy physicists from Canada, Europe, Japan and the United States at the historical Stanley Hotel in Estes Park, Colorado which is the entrance to the beautiful Rocky Mountains National Park. The group was a good mix of experimentalists and theorists. The purpose of the meeting was to begin to discuss what needs to be accomplished during the next year in order to determine the detector parameters required to unravel the data and uncover the possible new particles produced in e{sup +}e{sup -} collisions with a center of mass energy between 0.5 and 1.5 TeV. Besides a good number of plenary talks we had about eight breakout groups that began to discuss what work needed to be done. In particular we discussed the development of event generators and the software needed to analyze their output. The weather cooperated; the rain stopped, the sun was present all the time and the scenery was beautiful. In spite of this a great deal of work was accomplished. We defined what results we needed to get within the next few months. We plan to have two additional workshops; one in the fall this year and one in the spring next year. We agreed that an e{sup +}e{sup -} linear collider with longitudinally polarized electrons was an ideal machine with which to uncover many of the interesting signals.

Burke, D

1995-07-26T23:59:59.000Z

115

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

116

The Next Linear Collider Program  

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

NLC Navbar Links NLC Navbar Links NLC Home Page NLC News Letter http://www-project.slac.stanford.edu/lc/local/Newsletter/backnumber.htm Standing Meetings http://www-project.slac.stanford.edu/lc/local/notes/Meetings-Schedule.html Notes & Report http://www-project.slac.stanford.edu/lc/home-page_new/meetings-and-notes.html Seminars http://www-project.slac.stanford.edu/lc/local/NLCSeminars/nlc_seminars_index.htm Workshops http://www-project.slac.stanford.edu/lc/wkshp/Wrkshops.htm Image Collections http://www.slac.stanford.edu/cgi-wrap/search-mtg?ABC&L=grp/ad/images/ Legacy Links http://www-project.slac.stanford.edu/lc/home-page_new/nlc-home-us.html NLC-Technical Safety Policy http://www-project.slac.stanford.edu/lc/local/Admin/Safety_Policy.html Video Collaboration Meetings

117

Linear Collider Collaboration Tech Notes  

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

of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion...

118

The Next Linear Collider Program  

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

8champs1 8champs2 Nancy Yu Power Point Presentation 10212003 Additional: FullBrasslayers.ppt PRN30c-231.875Select3Summary || Text Only | SLAC | Meeting Schedule |...

119

Short RF Pulse Linear Collider  

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

the efficiency and the cost to sustain the high gradient should also be considered in the optimization process of the overall design. In this article, we explore the parametric...

120

Linear Collider Collaboration Tech Notes  

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

section. The new bends are 34 times stronger than in the ZDR type design and generate an order of magnitude larger dispersion. Magnet parameters at 8 GeV for the new optics are...

Note: This page contains sample records for the topic "linear colliders lepton" 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

Linear Collider Collaboration Tech Notes  

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

be shunted to achieve a 1 s statistical resolution, given certain features of the lattice and assumptions about the shunting pattern and amount of data to be acquired. We give...

122

The Next Linear Collider Program  

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

SLAC SLAC Phonebook Entire SLAC Web FNAL Telephone Directory Fermilab Search LLNL Phone Book LLNL Web Servers LBNL Directory Services Web Search: A-Z Index KEK E-mail Database...

123

Linear Collider Collaboration Tech Notes  

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

care to save as much as possible from the fully loaded condition in the upgrade. Inverse learning curve @ 90% avg. powerkW 39 100 freqMHz 2856 952 data: 150k for the last one...

124

Linear Collider Collaboration Tech Notes  

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

j ( E j E j ,) is the electron's relative energy deviation normalized to the nominal energy. The transfer matrix of just the second compressor stage, from end of wiggler to...

125

Linear Collider Collaboration Tech Notes  

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

Wolski Lawrence Berkeley National Laboratory Berkeley, California Abstract: Adding a field gradient to the main dipoles for the NLC Main Damping Ring lattice has leads to...

126

Linear Collider Collaboration Tech Notes  

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

1 03/12/99 1 03/12/99 NLC Damping Ring Wiggler Studies 1999 December 3, 1999 J. Corlett, N. Hartmann, K. Kennedy, G. Koehler, S. Marks, J. Rasson, T. Saleh Lawrence Berkeley National Laboratory Berkeley, CA, USA Abstract: The primary objective of FY99 was to develop credible conceptual wiggler requirements. Three magnet technologies were considered: electromagnet, hybrid permanent magnet and superconducting. Based upon an early assessment of requirements, a hybrid magnet similar to existing designs, with appropriate modification of gap and period, satisfies basic requirements. However, radiation damage is potentially a serious problem for the ND-FE-B permanent magnet material, and cost remains an issue for samarium cobalt magnets. Therefore the primary effort was put into developing a radiation-hard electromagnet wiggler conceptual

127

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

128

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

129

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...

130

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

131

Searches for new quarks and leptons in Z boson decays  

SciTech Connect

Searches for the decay of Z bosons into pairs of new quarks and leptons in a data sample including 455 hadronic Z decays are presented. The Z bosons were produced in electon-positron annihilations at the SLAC Linear Collider operating in the center-of-mass energy range from 89.2 to 93.0 GeV. The Standard Model provides no prediction for fermion masses and does not exclude new generations of fermions. The existence and masses of these new particles may provide valuable information to help understand the pattern of fermion masses, and physics beyond the Standard Model. Specific searches for top quarks and sequential fourth generation charge--1/3(b{prime}) quarks are made considering a variety of possible standard and non-standard decay modes. In addition, searches for sequential fourth generation massive neutrinos {nu}{sub 4} and their charged lepton partners L{sup {minus}} are pursued. The {nu}{sub 4} may be stable or decay through mixing to the lighter generations. The data sample is examined for new particle topologies of events with high-momentum isolated tracks, high-energy isolated photons, spherical event shapes, and detached vertices. No evidence is observed for the production of new quarks and leptons. 95% confidence lower mass limits of 40.7 GeV/c{sup 2} for the top quark and 42.0 GeV/c{sup 2} for the b{prime}-quark mass are obtained regardless of the branching fractions to the considered decay modes. A significant range of mixing matrix elements of {nu}{sub 4} to other generation neutrinos for a {nu}{sub 4} mass from 1 GeV/c{sup 2} to 43 GeV/c{sup 2} is excluded at 95% confidence level. Measurements of the upper limit of the invisible width of the Z exclude additional values of the {nu}{sub 4} mass and mixing matrix elements, and also permit the exclusion of a region in the L{sup {minus}} mass versus {nu}{sub 4} mass plane.

Van Kooten, R.J.

1990-06-01T23:59:59.000Z

132

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

133

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

134

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

135

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...

136

LASER-PLASMA-ACCELERATOR-BASED GAMMA GAMMA COLLIDERS  

E-Print Network (OSTI)

LASER-PLASMA-ACCELERATOR-BASED ?? COLLIDERS ? C. B.linear col- lider based on laser-plasma-accelerators arediscussed, and a laser-plasma-accelerator-based gamma-

Schroeder, C. B.

2010-01-01T23:59:59.000Z

137

Martin Perl and the Tau Lepton  

Office of Scientific and Technical Information (OSTI)

Martin Perl and the Tau Lepton Martin Perl and the Tau Lepton Resources with Additional Information 'Martin L. Perl, a professor at the Stanford Linear Accelerator Center (SLAC), [was] awarded the 1995 Nobel Prize in physics ... for his 1975 discovery of a new elementary particle known as the tau lepton. ... The tau lepton is a superheavy cousin of the electron, the carrier of electrical current in household appliances. The two particles are identical in all respects except that the tau is more than 3,500 times heavier than the electron and survives less than a trillionth of a second, whereas the electron is stable. Martin Perl Courtesy AIP Emilio Segrè Visual Archives, W.F. Meggers Gallery of Nobel Laureates In the mid-1970s, working at the Stanford Positron-Electron Asymmetric Ring (SPEAR) in collaboration with 30 other physicists from SLAC and Lawrence Berkeley National Laboratory, Perl began to find events recorded by the detector that could not be explained by any of the known subatomic particles. After more than a year of analysis, Perl was able to convince the rest of his research team that they were in fact observing a new and different type of elementary particle, which he named the 'tau'.

138

Lepton flavour violating Higgs and tau to mu gamma  

E-Print Network (OSTI)

We update phenomenological constraints on a Two Higgs Doublet Model with lepton flavour non-conserving Yukawa couplings. We review that $\\tan \\beta$ is ambiguous in such "Type III" models, and define it from the $\\tau$ Yukawa coupling. The neutral scalars $\\phi$ could be searched for at hadron colliders in $ \\phi \\to \\tau \\bar{\\mu}$, and are constrained by the rare decay $\\tau \\to \\mu \\gamma$. The Feynman diagrams for the collider process, with Higgs production via gluon fusion, are similar to the two-loop "Barr-Zee" diagrams which contribute to $\\tau \\to \\mu \\gamma$. Some "tuning" is required to obtain a collider cross-section of order the Standard Model expectation for $\\sigma (gg \\to h_{SM} \\to \\tau^+ \\tau^-)$, while agreeing with the current bound from $\\tau \\to \\mu \\gamma$.

Sacha Davidson; Gerald Grenier

2010-01-04T23:59:59.000Z

139

Quark Lepton Similarity  

E-Print Network (OSTI)

We propose the lepton mixing matrix at high energy scale to be connected to quark mixing matrix by the similar transformation. The similarity between CKM and PMNS significantly narrows down the ranges in physical parameters. The condition requires $\\sin\\theta_{13}$ not to be larger than 0.15, masses to be of quasi-degenerate normal ordering, and $\\tan\\beta$ to be large.

Seungsu Hwang; Kim Siyeon

2010-08-20T23:59:59.000Z

140

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

Note: This page contains sample records for the topic "linear colliders lepton" 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

Measurement of the $?$-lepton lifetime at Belle  

E-Print Network (OSTI)

The lifetime of the $\\tau$-lepton is measured using the process $e^+e^-\\rightarrow\\tau^+\\tau^-$, where both $\\tau$-leptons decay to $3\\pi\

Belle Collaboration; K. Belous; M. Shapkin; A. Sokolov; I. Adachi; H. Aihara; D. M. Asner; V. Aulchenko; A. M. Bakich; A. Bala; B. Bhuyan; A. Bobrov; A. Bondar; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; D. ?ervenkov; V. Chekelian; A. Chen; B. G. Cheon; K. Chilikin; R. Chistov; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; J. Dalseno; Z. Doleal; D. Dutta; S. Eidelman; D. Epifanov; H. Farhat; J. E. Fast; T. Ferber; V. Gaur; S. Ganguly; A. Garmash; R. Gillard; Y. M. Goh; B. Golob; J. Haba; T. Hara; K. Hayasaka; H. Hayashii; Y. Hoshi; W. -S. Hou; T. Iijima; K. Inami; A. Ishikawa; R. Itoh; T. Iwashita; I. Jaegle; T. Julius; E. Kato; H. Kichimi; C. Kiesling; D. Y. Kim; H. J. Kim; J. B. Kim; M. J. Kim; Y. J. Kim; K. Kinoshita; B. R. Ko; P. Kody; S. Korpar; P. Krian; P. Krokovny; T. Kuhr; A. Kuzmin; Y. -J. Kwon; J. S. Lange; S. -H. Lee; J. Libby; D. Liventsev; P. Lukin; D. Matvienko; H. Miyata; R. Mizuk; G. B. Mohanty; T. Mori; R. Mussa; Y. Nagasaka; E. Nakano; M. Nakao; M. Nayak; E. Nedelkovska; C. Ng; N. K. Nisar; S. Nishida; O. Nitoh; S. Ogawa; S. Okuno; S. L. Olsen; W. Ostrowicz; G. Pakhlova; C. W. Park; H. Park; H. K. Park; T. K. Pedlar; R. Pestotnik; M. Petri?; L. E. Piilonen; M. Ritter; M. Rhrken; A. Rostomyan; S. Ryu; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; D. Santel; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; D. Semmler; K. Senyo; O. Seon; V. Shebalin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; S. Stani?; M. Stari?; M. Steder; T. Sumiyoshi; U. Tamponi; G. Tatishvili; Y. Teramoto; K. Trabelsi; T. Tsuboyama; M. Uchida; S. Uehara; T. Uglov; Y. Unno; S. Uno; Y. Usov; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; K. E. Varvell; A. Vinokurova; V. Vorobyev; M. N. Wagner; C. H. Wang; P. Wang; M. Watanabe; Y. Watanabe; K. M. Williams; E. Won; J. Yamaoka; Y. Yamashita; S. Yashchenko; Y. Yook; C. Z. Yuan; Z. P. Zhang; V. Zhilich; A. Zupanc

2013-10-31T23:59:59.000Z

142

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

143

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

144

TESLA*HERA Based gamma-p and gamma-A Colliders  

E-Print Network (OSTI)

Main parameters and physics search potential of gamma-p and gamma-A colliders, which will be available due to constructing the TESLA linear electron-positron collider tangentially to the HERA proton ring, are discussed.

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

2000-07-05T23:59:59.000Z

145

A Search for Neutrinoless Tau Decays to Three Leptons  

SciTech Connect

Using approximately 350 million {tau}{sup +}{tau}{sup -} pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction {Beta}({tau} {yields} {ell}{ell}{ell}) in the range (4-8) x 10{sup -8}.

Kolb, Jeffrey A.; /Oregon U. /SLAC

2008-09-24T23:59:59.000Z

146

Summary of Lepton Photon 2011  

SciTech Connect

In this lecture, I summarize developments presented at the Lepton Photon 2011 conference and give my perspective on the current situation in high-energy physics. I am grateful to the organizers of Lepton Photon 2011 for providing us a very pleasant and simulating week in Mumbai. This year's Lepton Photon conference has covered the full range of subjects that fall within the scope of high-energy physics, including connections to cosmology, nuclear physics, and atomic physics. The experiments that were discussed detect particles ranging in energy from radio frequencies to EeV.

Peskin, Michael E.; /SLAC

2012-03-14T23:59:59.000Z

147

International linear collider reference design report  

E-Print Network (OSTI)

Klystron A pk Pulse transformer average power output @ 5 Hzclosed loop. A LV transformer provides power in the shaftmodulators, pulse transformers); dc magnet power supplies;

Aarons, G.

2008-01-01T23:59:59.000Z

148

International linear collider reference design report  

E-Print Network (OSTI)

requires ?230 MW of electrical power. A summary of theuse a large amount of electrical power. In addition, thereand size of shafts, electrical power and process cooling

Aarons, G.

2008-01-01T23:59:59.000Z

149

International linear collider reference design report  

E-Print Network (OSTI)

c current, voltage and stability requirements, and the needand requirements are summarized in Table 3.3-1. Modulators High Voltagerequirements of the main linac are supplied by two high-voltage

Aarons, G.

2008-01-01T23:59:59.000Z

150

Proceedings of the International Linear Collider Workshop  

E-Print Network (OSTI)

condensation and evaporative inlet air cooling for the CTGs, the electrical switchyard and auxiliary equipment

151

International linear collider reference design report  

E-Print Network (OSTI)

for the Baseline cost estimate, may eventually prove bene?Reference Design and associated cost estimate began. The GDEand reviewing the cost estimate. A Design and Cost Board (

Aarons, G.

2008-01-01T23:59:59.000Z

152

Linear Collider Collaboration Tech Notes LCC-0120  

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

0 July 2003 Tunnel Wall Heat Transfer Gordon G. Bowden Stanford University Stanford, CA Abstract: Transient heat conduction from a warm accelerator tunnel to the earth 's surface...

153

International linear collider reference design report  

E-Print Network (OSTI)

c) Radiation Safety System, SLAC, April, 2006. (d) FermilabPolarized Electron Sources, SLAC-Pub 12249 (2006). DR [10]ILC Positron Source, PAC05, SLAC-PUB-11767 (2005). [24] A.

Aarons, G.

2008-01-01T23:59:59.000Z

154

International linear collider reference design report  

E-Print Network (OSTI)

refrigeration below 4.2 Kelvin. All of these e?ciencies are in accordance with recent industrial conceptual design

Aarons, G.

2008-01-01T23:59:59.000Z

155

International Linear Collider Reference Design Report  

E-Print Network (OSTI)

the piezoelectric system, value of avoided inspection costs for the roadway or railway, if any. #12;Released CONSULTANT REPORT Assessment of Piezoelectric Materials for Roadway Energy Harvesting Cost of Energy Commission seeks to better understand the current status of piezoelectric-based energy-harvesting technology

156

International linear collider reference design report  

E-Print Network (OSTI)

highly ac- tivated. A remote-handling system is used topower, but still requires remote handling. The positrons arethe undulator, target, remote handling and the OMD, costing

Aarons, G.

2008-01-01T23:59:59.000Z

157

Linear Collider Collaboration Tech Notes LCC-0076  

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

6 CBPTech Note - 238 November 2001 Transport Lines for the NLC Damping Rings Andrzej Wolski November 2001 Lawrence Berkeley National Laboratory Berkeley, California Abstract: The...

158

Linear Collider Collaboration Tech Notes LCC-0066  

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

chicane) severely affects the tuning flexibility, and makes it difficult to limit the beta functions to the low values needed to improve the acceptance. Adjustment of the...

159

Limits on tau lepton-flavor violating decays into three charged leptons  

E-Print Network (OSTI)

A search for the neutrinoless, lepton-flavor violating decay of the ? [tau] lepton into three charged leptons has been performed using an integrated luminosity of 468??fb-1 [fb superscript -1] collected with the BABAR ...

Cowan, Ray Franklin

160

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...

Note: This page contains sample records for the topic "linear colliders lepton" 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

Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector  

SciTech Connect

We present the search for the lepton flavour violating decay {tau} {yields} lK{sup 0}{sub s} with the BaBar experiment data. This process and many other lepton flavour violating {tau} decays, like {tau} {yields} {mu}{gamma} and {tau} {yields} lll, are one of the most promising channel to search for evidence of new physics. According to the Standard Model and the neutrino mixing parameters, branching fractions are estimated well below 10{sup -14}, but many models of new physics allow for branching fractions values close to the present experimental sensitivity. This analysis is based on a data sample of 469fb{sup -1} collected by BABAR detector at the PEP-II storage ring from 1999 to 2007, equivalent to 431 millions of {tau} pairs. the BABAR experiment, initially designed for studying CP violation in B mesons, has demonstrated to be one of the most suitable environments for studying {tau} decays. The tracking system, the calorimeter and the particle identification of BABAR, together with the knowledge of the {tau} initial energy, allow an extremely powerful rejection of background events that, for this analysis, is better than 10{sup -9}. Being {tau} {yields} lK{sup 0}{sub s} a decay mode without neutrinos, the signal {tau} decay can be fully reconstructed. Kinematical constraints are used in a fit that provides a decay tree reconstruction with a high resolution. For this analysis MC simulated events play a decisive role for estimating the signal efficiency and study the residual background. High statistics MC sample are produced simulating detector conditions for different periods of data collection, in order to reduce any discrepancies with the data. When discrepancies can not be removed, we perform studies to compute a correction factor or an estimation of systematic errors that need to be included in the final measurement. A significant improvement of the current result can be reached only with a higher statistics and, therefore, with a new collider providing a luminosity from 10 to 100 times more than PEP-II. A new detector, with improved performance and able to collect data in a high background environment, is also requested to fully exploit the capability of such amount of data. In fact, only keeping the efficiency and the background as similar as possible to present ones, we will be able to scale almost linearly the estimated upper limit according to the luminosity. The strong potential of improvement for the search of lepton flavour violation {tau} decays makes the building of such a machine highly desirable.

Cenci, Riccardo; /SLAC

2009-03-20T23:59:59.000Z

162

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

163

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

164

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

165

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

166

Lepton Number Violating Signals of the Top Partners in the Left-Right Twin Higgs Model  

E-Print Network (OSTI)

We study the collider signatures of the left-right twin Higgs model in the case that the right-handed neutrino mass is less than the mass of the right-handed gauge boson. In this scenario, new leptonic decay chains open up, allowing the particles which cancel the one-loop quadratic divergences of the Higgs, the right-handed gauge bosons and top-partners, to be discovered. Half of these events contain same-sign leptons without missing energy, which have no genuine standard model background and for which the backgrounds are purely instrumental. These signals may be used to complement other collider searches, and in certain regions of parameter space, may be the only way to observe the particles responsible for natural electroweak symmetry breaking in the left-right twin Higgs model.

Hock-Seng Goh; Christopher A. Krenke

2009-11-30T23:59:59.000Z

167

Microsoft Word - WFnote-239_short pulse collider.doc  

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

efficiency and the cost to sustain such a gradient should be considered as well in the optimization process of an overall design. We propose a high energy linear collider based...

168

Status of Heavy-lepton Searches  

DOE R&D Accomplishments (OSTI)

Searches for heavy leptons using e{sup +}e{sup -} annihilation, lepton-hadron collisions, photon-hadron collisions, hadron-hadron collisions, and studies of macroscopic matter are reviewed. The present experimental status and future possibilities are summarized.

Perl, M. L.

1981-06-00T23:59:59.000Z

169

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

170

e+ e- collider in the VLHC tunnel. Proceedings, Workshop, Chicago, USA, March 9-11, 2001  

SciTech Connect

This document is a collection of the contributions made to the March IIT workshop on an e{sup +}e{sup -} collider in the VLHC tunnel. This machine, which is based on a relatively conservative extrapolation of LEP technology, has a baseline luminosity of 10{sup 33}/cm{sup 2}/s at a CM energy of 370 GeV. The overall parameters and general description of such a machine is described in T. Sen and J. Norem, ''A Very Large Lepton Collider in the VLHC Tunnel'', to be published. A preprint of this paper is included as Appendix 2 of this report. The intention of the workshop was to define the parameters of such a collider and make them available to the community for use in further physics studies. It is clear that the machine cannot compete with a full scale linear collider. Its main interest would be if a VLHC were built and if a linear collider did not already exist. In this case, it could provide a limited and perhaps crucial view of low mass Higgs states. Although the study is incomplete, it does define rather well the parameters of the machine, as well as the challenges that the design faces. The study benefited greatly from the participation of the machine experts that were willing to spend time looking at the design. In this document, the workshop contributions are organized into sections which cover the physics motivation for the machine; the injector; beam dynamics issues in the collider; and accelerator systems. The physics section describes luminosity benchmarks for study of a light Higgs boson, and machine performance issues related to lineshape measurements at the t{bar t} threshold. The contribution on the injector presents a design for a 45 GeV injector. The injection energy is motivated by two considerations: the collider has potential stability problems at injection, which are mitigated by a relatively high injection energy; and, at this energy, the injector can also serve as a Z{sup 0} factory. One of the principal conclusions of the IIT workshop was that this was the most natural way to provide a high-luminosity Z{sup 0} factory with polarized beams. The beam dynamics contributions cover a range of topics, including experience from LEP, design options for the lattice and IR's that aim at increasing the luminosity to close to 10{sup 34}/cm{sup 2}/s, and considerations on beam stability, rf system distribution, beam separation, and radiative spin polarization of the beams. The magnet, vacuum system, and rf system required for the machine are discussed in the accelerator systems contributions. Finally, in the conclusions section, the leading R&D issues for the machine, as identified at the workshop, are summarized. In an Appendix, some thoughts on beam-beam considerations for a VLLC are provided.

Dugan, D., (ed.); /Cornell U., LEPP; Tollestrup, A., (ed.); /Fermilab

2001-07-01T23:59:59.000Z

171

Phenomenology of heavy vector-like leptons  

E-Print Network (OSTI)

We study the impact that a heavy generation of vector-like leptons can have on the value of the electric dipole moment of the electron, and the rates for the flavor violating processes mu --> e gamma and mu --> 3e. The smallness of the charged lepton masses suggests that at least some of the Yukawa coupling constants of the vector-like leptons to the ordinary leptons or amongst themselves are small, but even with such small couplings experiments trying to detect these quantities are sensitive to extra generation lepton masses up to about 100 TeV.

Koji Ishiwata; Mark B. Wise

2013-07-03T23:59:59.000Z

172

Lepton flavor violating Higgs bosons and {tau}{yields}{mu}{gamma}  

SciTech Connect

We update phenomenological constraints on a two Higgs doublet model with lepton flavor nonconserving Yukawa couplings. We review that tan{beta} is ambiguous in such 'type III' models, and define it from the {tau} Yukawa coupling. The neutral scalars {phi} could be searched for at hadron colliders in {phi}{yields}{tau}{mu} and are constrained by the rare decay {tau}{yields}{mu}{gamma}. The Feynman diagrams for the collider process, with Higgs production via gluon fusion, are similar to the two-loop ''Barr-Zee'' diagrams, which contribute to {tau}{yields}{mu}{gamma}. Some ''tuning'' is required to obtain a collider cross section of order the standard model expectation for {sigma}(gg{yields}h{sub SM{yields}{tau}}{sup +{tau}-}), while agreeing with the current bound from {tau}{yields}{mu}{gamma}.

Davidson, Sacha; Grenier, Gerald [IPNL, Universite de Lyon, Universite Lyon 1, CNRS/IN2P3, 4 rue E. Fermi 69622 Villeurbanne cedex (France)

2010-05-01T23:59:59.000Z

173

REVIEW OF HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* Martin L. Per1  

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

HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* HEAVY LEPTON PRODUCTION IN e+e- ANNIHILATION* Martin L. Per1 Stanford Linear Accelerator Center Stanford University, Stanford, California 94305 ABSTRACT * The existing data on e f p r , eixT, p xi:, and related events produced in e'e- annihilation are reviewed. All data are consistent with the exist- ence of a new charged lepton, T *, of m a s s 1.9 * . 1 GeV/c2. (Invited talk presented at the 1977 International Symposium on Lepton and Photon Interactions at High Energies, Hambrug, Cfirmany, August 25-31 , 1977.) *Work supported by the Department of Energy. NOTICE-- rpon.wred by the United States Government. Netther the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, Subcontractors, or thou employees. makes

174

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

175

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

176

Lepton Photon Symposium 2005: Summary and Outlook  

E-Print Network (OSTI)

Lepton Photon 2005 told the saga of the Standard Model which is still exhilarating because it leaves all questions of consequence unanswered.

Francis Halzen

2005-10-20T23:59:59.000Z

177

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...

178

Flavour models for TM1 lepton mixing  

E-Print Network (OSTI)

We present a framework for lepton flavour models such that the first column of the lepton mixing matrix is (2,-1,-1)/sqrt(6). We show that the flavour symmetry group adequate for this purpose is S4. Our models are based on a vacuum alignment that can be obtained in a supersymmetric framework.

Varzielas, Ivo de Medeiros

2012-01-01T23:59:59.000Z

179

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

180

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.

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181

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

182

Search for the standard model Higgs boson in tau lepton pair final states  

Science Conference Proceedings (OSTI)

We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb{sup -1} collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.

Abazov, V.M.

2012-03-01T23:59:59.000Z

183

Search for the Higgs boson in lepton, tau and jets final states  

E-Print Network (OSTI)

We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with two or more jets using 9.7 fb^{-1} of Run II Fermilab Tevatron Collider data collected with the D0 detector. The analysis is sensitive to Higgs boson production via gluon fusion, associated vector boson production, and vector boson fusion, followed by the Higgs boson decay to tau lepton pairs or to W boson pairs. The ratios of 95% C.L. upper limits on the cross section times branching ratio to those predicted by the standard model are obtained for orthogonal subsamples that are enriched in either H -> tau tau decays or H -> WW decays, and for the combination of these subsample limits. The observed and expected limit ratios for the combined subsamples at a Higgs boson mass of 125 GeV are 11.3 and 9.0 respectively.

D0 Collaboration

2012-11-29T23:59:59.000Z

184

Lepton Universality Test in Upsilon(1S) Decays at BaBar  

SciTech Connect

Using a sample of 122 million {Upsilon}(3S) decays collected with the BABAR detector at the PEP-II asymmetric energy collider at the SLAC National Accelerator Laboratory, we measure the ratio R{sub {tau}{mu}} = BR({Upsilon}(1S) {yields} {tau}{sup +}{tau}{sup -})/BR({Upsilon}(1S) {yields} {mu}{sup +}{mu}{sup -}); the measurement is intended as a test of lepton universality and as a possible search for a light pseudoscalar Higgs boson in Next to Minimal Supersymmetric Standard Model (NMSSM) scenarios. Such a boson could appear in a deviation of the ratio R{sub {tau}{mu}} from the Standard Model expectation, that is 1, except for small lepton mass corrections. The analysis exploits the decays {Upsilon}(3S) {yields} {Upsilon}(1S){pi}{sup +}{pi}{sup -}, {Upsilon}(1S) {yields} l{sup +}l{sup -}, where l = {mu},{tau}.

Guido, Elisa; /Genoa U. /INFN, Genoa

2012-04-10T23:59:59.000Z

185

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

186

Trigger Algorithm Design for a SUSY Lepton Trigger based on Forward Proton Tagging  

Science Conference Proceedings (OSTI)

At the Large Hadron Collider (LHC) pair production of SUSY leptons in gamma-gamma interactions will often include intact off-energy protons. Including detectors in the beampipe to measure these protons can give additional information to separate these events from background. We report on expected event rates and background rejection for a slepton trigger design in the Compact Muon Solenoid (CMS) experiment incorporating forward proton information. We conclude that a trigger that can observe an interesting number of events is feasible with the appropriate detector hardware.

Gronberg, J; Hollar, J

2010-03-29T23:59:59.000Z

187

B to tau Leptonic and Semileptonic Decays  

Science Conference Proceedings (OSTI)

Decays of B mesons to states involving {tau} leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B {yields} {tau}{nu} and B {yields} D{sup (*)}{tau}{nu} is discussed, together with limits on new physics effects from current results. Leptonic and semileptonic decays of B mesons into states involving {tau} leptons remain experimentally challenging, but can prove a useful tool for constraining Standard Model parameters, and also offer to constrain the effects of any new physics that may exist including the presence of a charged Higgs boson.

Barrett, M.; /Brunel U.

2011-11-17T23:59:59.000Z

188

Measuring the fermionic couplings of the Higgs boson at future colliders as a probe of a non-minimal flavor structure  

E-Print Network (OSTI)

We study the fermionic couplings of the neutral Higgs bosons in the THDM, assuming a four-texture structure for the Yukawa matrices. We then derive the low-energy constraints on the model, focusing in b-quark and lepton physics, and apply them to study Higgs boson detection at future colliders.

J. L. Diaz-Cruz; R. Noriega-Papaqui; A. Rosado

2004-10-28T23:59:59.000Z

189

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

190

Lepton Flavor Violating Decays - Review & Outlook  

E-Print Network (OSTI)

Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric theories or other models beyond the Standard Model. In contrast to physics of quark flavors that is dominated by the Cabibbo-Kobayashi-Maskawa matrix, LFV in charged leptons is a definitive signal of new physics. Currently active researches are rare tau decay searches at the B factories. The MEG experiment will soon start a sensitive search for the LFV muon decay, mu to e gamma. Prospects for searches at the LHC, a possibility of a fixed target LFV experiment with high energy muons, and a sensitivity of leptonic kaon decays to LFV are also briefly discussed.

Toshinori Mori

2006-05-30T23:59:59.000Z

191

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...

192

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...

193

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...

194

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

195

Measurements of the Top Quark at the Tevatron Collider  

SciTech Connect

The authors present recent preliminary measurements of the top-antitop pair production cross section and determinations of the top quark pole mass, performed using the data collected by the CDF and D0 Collaborations at the Tevatron Collider. In the lepton plus jets final state, with semileptonic B decay, the pair production cross section has now been measured at CDF using {approx} 760 pb{sup -1} of proton-antiproton collisions at a center-of-mass energy of {radical}s = 1.96 TeV. A measurement of the production cross section has also been made with {approx} 1 fb{sup -1} of data in the all-jets final state by the CDF Collaboration. The mass of the top quark has now been measured using {approx} 1 fb{sup -1} of collision data using all decay channels of the top quark pair, yielding the most precise measurements of the top mass to date.

Cerrito, Lucio; /Queen Mary, U. of London

2007-01-01T23:59:59.000Z

196

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

197

Triangular mass matrices for quarks and leptons  

E-Print Network (OSTI)

We assume that all quark and lepton $3 \\times 3$ mass matrices which appear in the standard model lagrangian (after spontaneous symmetry breaking) with neutrinos treated as Dirac patricles have the triangular form. Such matrices have not only less non-zero elements (three of them are equal to zero) but also lead to very asymmetrical decomposition into one diagonal and two unitary matrices for quarks and leptons. We also assume that unitary matrices which transform flavor into definite mass states for right handed components (weakly non-interacting) in the same weak isodoublet are equal. Using all available experimental data on quark and lepton masses and mixing angles, treating in the universal way quarks and leptons, we determine the triangular mass matrices for up and down type quarks, neutrinos and charged leptons and as a consequence mixing matrices for left-handed and right handed components. As the result of the fit we get predictions for the neutrino masses including smallest neutrino mass. The calculations without CP violation and with inclusion of this effect in quark sector are also presented.

S. Tatur; J. Bartelski

2006-05-24T23:59:59.000Z

198

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...

199

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...

200

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

Note: This page contains sample records for the topic "linear colliders lepton" 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

The Particle Adventure | What is the world made of? | Lepton...  

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

quiz Which lepton decays are possible? Why or why not? (A tau lepton decays into an electron, an electron antineutrino, and a tau neutrino.) Answer Yes Charge, tau number,...

202

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

203

Lepton-Flavor Violation and Physics beyond the Standard Model  

E-Print Network (OSTI)

This talk discusses recent studies of (charged) lepton-flavor violation in physics beyond the standard model.

Junji Hisano

2012-12-20T23:59:59.000Z

204

Flavor Violating Lepton Family U(1)$_\\lambda$  

E-Print Network (OSTI)

The Standard Model is extended minimally with a new flavor-violating family symmetry ${\\rm U(1)}_\\lambda$, which acts only on leptons including the right-handed neutrinos. The model is anomaly free with family-dependent ${\\rm U(1)}_\\lambda$ charges, and consistent with the observed neutrino mixing angles. It predicts charged lepton flavor-violating processes mediated by a new gauge boson. Under certain conditions, the smallness of $\\theta_{13}$ of neutrino mixing can be justified in terms of the muon-to-tau mass ratio, at the same time explaining the electron-to-tau large mass hierarchy.

La, HoSeong

2013-01-01T23:59:59.000Z

205

Report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012)  

E-Print Network (OSTI)

This paper is a summary report of the ICFA Beam Dynamics Workshop 'Accelerators for a Higgs Factory: Linear vs. Circular' (HF2012). It discusses four types of accelerators as possible candidates for a Higgs factory: linear e+e- colliders, circular e+e- colliders, muon collider and photon colliders. The comparison includes: physics reach, performance (energy and luminosity), upgrade potential, technology maturity and readiness, and technical challenges requiring further R&D.

Alain Blondel; Alex Chao; Weiren Chou; Jie Gao; Daniel Schulte; Kaoru Yokoya

2013-02-14T23:59:59.000Z

206

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

207

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

208

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

SciTech Connect

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

Canepa, Anadi; /Purdue U.

2006-08-01T23:59:59.000Z

209

Subcritical Fission Reactor Based on Linear  

E-Print Network (OSTI)

The beams of Linear Collider after main collision can be utilized to build an acceleratordriven subcritical reactor. ? The project of Linear Collider (LC) contains one essential element that is not present in other colliders. Here each electron (or positron or photon) bunch will be used only once, and physical collision leave two very dense and strongly collimated beams of high energy electrons or/and photons with precisely known time structure. We consider, for definiteness, electron beam parameters of the TESLA project [1] particle energy Ee = 250 GeV, number of electrons per second Ne = 2.7 10 14 /s, mean beam power Pb ? 11 MWt, transverse size and angular spread negligible. (1) In the Photon Collider mode the used beams contain photons, electrons and

I. F. Ginzburg

2005-01-01T23:59:59.000Z

210

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

211

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

212

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

213

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

214

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

215

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Single Strand Superconductor Windings Single Strand Superconductor Windings Initial direct wind quad coils were constructed using 13 mil diameter single strand wire. This wire provides the smallest coil patterns possible, with quad coils wound easily onto .75 inch (19mm) diameter support tubes. The 13mil diameter superconductor gives the smallest coils possible, the penalty being higher inductance and smaller transfer function, but allowing lower operational currents. long model magnet Figure 1 shows the first one foot long model magnet constructed using the 11 axis ultrasonic wiring machine with 13 mil superconducting wire, the same wire previously used for the 472 RHIC Corrector packages. Existing stock materials were used in the construction, and the coil pattern was not optimized for harmonics, but to put as many coil turns onto the tube as

216

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Superconducting Cable Winding Tests Superconducting Cable Winding Tests To increase the transfer function, a 6 around 1 cable was next used. This cable is more efficient because it allows the packing of more conductor within the volume surrounding the support tube. This also lowers the inductance of the coil, making quench protection easier, but requires a higher operating current. Traded off is the minimum radius of curvature that can be tolerated by the bonding process as well as the insulation integrity. For this test, the first layer was designed for a length of 8 inches, and the second layer is 6 inches long. The lengths were chosen to allow inspection of the different features which were designed in. The pole spacers on the first layer for this test were chosen to be solid copper wire, instead of the standard G-10 spacer. The copper allows for a

217

Comments on Linear Collider Beam-Based Alignment  

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

of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion...

218

Multi-Stage Bunch Compressors for the International Linear Collider  

E-Print Network (OSTI)

150 m RMS. The multi-stage compressors are somewhat longerthan the single-stage compressor and require additional RFof the NLC Bunch Compressor, (1999). [4] C. Adolphsen,

Tenenbaum, Peter G.; Raubenheimer, Tor O.; Wolski, Andrzej

2005-01-01T23:59:59.000Z

219

Linear Collider Collaboration Tech Notes LCC-0119 KEK-PREPRINT...  

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

red and blue are the signal sent on the 2 BPM antennas of the circuit and in yellow and green are the responses sent to the strips of the kicker. is reached (no more signal on...

220

International Linear Collider Accelerator Physics R&D  

Science Conference Proceedings (OSTI)

ILC work at Illinois has concentrated primarily on technical issues relating to the design of the accelerator. Because many of the problems to be resolved require a working knowledge of classical mechanics and electrodynamics, most of our research projects lend themselves well to the participation of undergraduate research assistants. The undergraduates in the group are scientists, not technicians, and find solutions to problems that, for example, have stumped PhD-level staff elsewhere. The ILC Reference Design Report calls for 6.7 km circumference damping rings (which prepare the beams for focusing) using conventional stripline kickers driven by fast HV pulsers. Our primary goal was to determine the suitability of the 16 MeV electron beam in the A region at Fermilab for precision kicker studies.We found that the low beam energy and lack of redundancy in the beam position monitor system complicated the analysis of our data. In spite of these issues we concluded that the precision we could obtain was adequate to measure the performance and stability of a production module of an ILC kicker, namely 0.5%. We concluded that the kicker was stable to an accuracy of ~2.0% and that we could measure this precision to an accuracy of ~0.5%. As a result, a low energy beam like that at A could be used as a rapid-turnaround facility for testing ILC production kicker modules. The ILC timing precision for arrival of bunches at the collision point is required to be 0.1 picosecond or better. We studied the bunch-to-bunch timing accuracy of a phase detector installed in A in order to determine its suitability as an ILC bunch timing device. A phase detector is an RF structure excited by the passage of a bunch. Its signal is fed through a 1240 MHz high-Q resonant circuit and then down-mixed with the A 1300 MHz accelerator RF. We used a kind of autocorrelation technique to compare the phase detector signal with a reference signal obtained from the phase detectors response to an event at the beginning of the run. We determined that the device installed in our beam, which was instrumented with an 8-bit 500 MHz ADC, could measure the beam timing to an accuracy of 0.4 picoseconds. Simulations of the device showed that an increase in ADC clock rate to 2 GHz would improve measurement precision by the required factor of four. As a result, we felt that a device of this sort, assuming matters concerning dynamic range and long-term stability can be addressed successfully, would work at the ILC. Cost effective operation of the ILC will demand highly reliable, fault tolerant and adaptive solutions for both hardware and software. The large numbers of subsystems and large multipliers associated with the modules in those subsystems will cause even a strong level of unit reliability to become an unacceptable level of system availability. An evaluation effort is underway to evaluate standards associated with high availability, and to guide ILC development with standard practices and well-supported commercial solutions. One area of evaluation involves the Advanced Telecom Computing Architecture (ATCA) hardware and software. We worked with an ATCA crate, processor monitors, and a small amount of ATCA circuit boards in order to develop a backplane spy board that would let us watch the ATCA backplane communications and pursue development of an inexpensive processor monitor that could be used as a physics-driven component of the crate-level controls system. We made good progress, and felt that we had determined a productive direction to extend this work. We felt that we had learned enough to begin designing a workable processor monitor chip if there were to be sufficient interest in ATCA shown by the ILC community. Fault recognition is a challenging issue in the crafting a high reliability controls system. With tens of thousands of independent processors running hundreds of thousands of critical processes, how can the system identify that a problem has arisen and determine the appropriate steps to take to correct, or compensate, for the

George D. Gollin; Michael Davidsaver; Michael J. Haney; Michael Kasten; Jason Chang; Perry Chodash; Will Dluger; Alex Lang; Yehan Liu

2008-09-03T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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

Vibration Model Validation for Linear Collider Detector Platforms  

SciTech Connect

The ILC and CLIC reference designs incorporate reinforced-concrete platforms underneath the detectors so that the two detectors can each be moved onto and off of the beamline in a Push-Pull configuration. These platforms could potentially amplify ground vibrations, which would reduce luminosity. In this paper we compare vibration models to experimental data on reinforced concrete structures, estimate the impact on luminosity, and summarize implications for the design of a reinforced concrete platform for the ILC or CLIC detectors.

Bertsche, Kirk; Amann, J.W.; Markiewicz, T.W.; Oriunno, M.; Weidemann, A.; White, G.; /SLAC

2012-05-16T23:59:59.000Z

222

Linear Collider Collaboration Tech Notes LCC-0064 CBP Tech Note...  

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

the ratio of vertical emittance growth to horizontal emittance growth is given by 2 : lattice x bends x x x y y where x is the dispersion invariant. In...

223

Pulse Capacitors for Next Generation Linear Colliders. Final Report  

DOE Green Energy (OSTI)

During this Phase I SBIR research program, Nanomaterials Research Corporation (NRC) successfully demonstrated high-voltage multilayer capacitors produced from sub-100 nm ceramic powders. The devices produced by NRC exhibited properties that make them particularly useful for pulse power applications. These properties include (1) high capacitance (2) low loss (3) high breakdown voltage (4) high insulation resistance and (5) rapid discharge characteristics. Furthermore, the properties of the nanostructured capacitors were consistently found to exceed those of components that represent the state of the art within the industry. Encouraged by these results, NRC is planning to submit a Phase II proposal with the objective of securing seed capital to continue this development effort.

Hooker, M.W.

2000-03-03T23:59:59.000Z

224

Linear Collider Collaboration Tech Notes LCC-0114 CBP Tech Note...  

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

the dynamic aperture is much larger (see Fig. 13). At this location, the horizontal beta function has a value of 2 m, the vertical beta function is 1.5 m, and the horizontal...

225

Linear Collider Final Focus Magnet Construction | Superconducting Magnet  

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

Two Layer Quadrupole Shielding Coil Two Layer Quadrupole Shielding Coil Near the interaction region if the ILC, the exit beam by design, is very close to the final focus quads, and is sensitive to the external field of the quads. To eliminate this effect and prevent disruption of the exiting beams, a two layer shielding quadrupole has been designed and wound. For simplicity as well as efficiency, the transfer function of this coilset has been designed to allow series connection of the focus quad with this outer shield coilset. The completed magnet will be finished with G-10 fillers, voltage taps and heaters will be added, blue epoxy filling for all interstitial spaces, and then the magnet will be wrapped with glass cloth and fiberglass roving, then cured. Once cured, this magnet will be capable of full power operation

226

Ground motion data for International Collider models  

SciTech Connect

The proposed location for the International Linear Collider (ILC) in the Americas region is Fermilab in Batavia Illinois. If built at this location the tunnels would be located in the Galena Platteville shale at a depth of 100 or more meters below the surface. Studies using hydro static water levels and seismometers have been conducted in the MINOS hall and the LaFrange Mine in North Aurora Illinois to determine the level of ground motion. Both these locations are in the Galena Platteville shale and indicate the typical ground motion to be expected for the ILC. The data contains both natural and cultural noise. Coefficients for the ALT law are determined. Seismic measurements at the surface and 100 meters below the surface are presented.

Volk, J.T.; LeBrun, P.; Shiltsev, V.; Singatulin, S.; /Fermilab

2007-11-01T23:59:59.000Z

227

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

228

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

229

Citation: K. Nakamura et al. (Particle Data Group), JPG 37, 075021 (2010) (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITS Note that LEP results

230

Citation: J. Beringer et al. (Particle Data Group), PR D86, 010001 (2012) (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITS Note that LEP results

231

Test of lepton universality and search for lepton flavor violation in Upsilon(1S,2S,3S) decays at CLEO  

E-Print Network (OSTI)

We present the analysis technique and preliminary results of two ongoing analyses at CLEO which put lepton universality and lepton flavor conservation to the test in Upsilon decays.

Istvan Danko; for the CLEO Collaboration

2006-01-18T23:59:59.000Z

232

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

233

Lepton Universality, |V(Us)| and Search for Second Class Current in Tau Decays  

SciTech Connect

Several hundred million {tau} decays have been studied with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of |V{sub us}| using {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {pi}{sup -}{nu}{sub {tau}}, K{sup -} {nu}{sub {tau}} and K{sub S}{sup 0}{pi}{sup -} {nu}{sub {tau}} decays, and a search for Second Class Current in {tau}{sup -} {yields} {pi}{sup -} {omega}{nu}{sub {tau}} decays are presented, where the charge conjugate decay modes are also implied.

Banerjee, Swagato; /Victoria U.

2011-11-10T23:59:59.000Z

234

Search for Lepton Flavour Violating Decays tau- to l- Ks with the BaBar experiment  

SciTech Connect

A search for the lepton flavor violating decays {tau}{sup -} {yields} l{sup -} K{sub S}{sup 0} (l = e or {mu}) has been performed using a data sample corresponding to an integrated luminosity of 469 fb{sup -1}, collected with the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} asymmetric energy collider. No statistically significant signal has been observed in either channel and the estimated upper limits on branching fractions are {Beta}({tau}{sup -} {yields} e{sup -} K{sub S}{sup 0}) < 3.3 x 10{sup -8} and {Beta}({tau}{sup -} {yields} {mu}{sup -}K{sub S}{sup 0}) < 4.0 x 10{sup -8} at 90% confidence level.

Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Cahn, R.N.; Jacobsen, R.G.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Karlsruhe U., EKP /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2009-01-06T23:59:59.000Z

235

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

236

Lepton production at the LHC from singly- and doubly-charged bilepton  

Science Conference Proceedings (OSTI)

Some extensions of the standard model predict the existence of particles having two units of leptonic charge, known as bileptons. One of such models is based on the SU(3){sub c} Multiplication-Sign SU(3){sub L} Multiplication-Sign U(1){sub X} symmetry group (3-3-1). Our search uses the minimal version of this model, having exotic charges for the quarks and gauge bosons. It predicts the existence of bileptons as vector particles having one unit of electric charge (V{sup {+-}}) or two units of electric charge (Y{sup {+-}{+-}}). Our aim is to establish the signatures for the production of four fermions in pp collisions at the LHC for 7 TeV center of mass energy. We present the total cross section and we show the leptons invariant mass and transverse momentum distributions. We conclude that LHC collider can show a clear signature for a process induced by bileptons as a signal of new physics.

Sa Borges, J. [Instituto de Fisica, UERJ, Rio de Janeiro, RJ (Brazil); Coutinho, Y. A. [Instituto de Fisica, UFRJ, Rio de Janeiro, RJ (Brazil); Barreto, E. R. [C C N H, UFABC, Santo Andre, SP (Brazil)

2013-03-25T23:59:59.000Z

237

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

238

Citation: K. Nakamura et al. (Particle Data Group), JPG 37, 075021 (2010) (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

239

Citation: J. Beringer et al. (Particle Data Group), PR D86, 010001 (2012) (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

240

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

Note: This page contains sample records for the topic "linear colliders lepton" 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.


241

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

242

Numerical and Experimental Studies of Dispersive, Active, and...  

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

breakdown. Proceedings of IPAC'10, Kyoto, Japan THPD070 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A14 Advanced Concepts 4443 Figure 2. Kerr medium;...

243

Experiment on a Tunable Dielectric-Loaded Accelerating Structure  

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

Proceedings of IPAC'10, Kyoto, Japan THPD068 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A14 Advanced Concepts 4437 is connected to the...

244

Observation of Wakefields in a Beam-Driven Photonic Band Gap...  

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

Proceedings of IPAC'10, Kyoto, Japan THPD066 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques A14 Advanced Concepts 4431 Figure 1: Schematic...

245

Search for pair production of scalar top quarks decaying to a tau lepton and a b quark in 1.96 TeV ppbar collisions  

SciTech Connect

I present the results of a search for pair production of scalar top quarks ({tilde t}{sub 1}) in an R-parity violating supersymmetric scenario using 322 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected by the upgraded Collider Detector at Fermilab. I assume each {tilde t}{sub 1} decays into a {tau} lepton and a b quark, with branching ratio {beta}, and search for final states containing either an electron or a muon from a leptonic {tau} decay, a hadronically decaying {tau} lepton, and two or more jets. Two candidate events pass my final selection criteria, consistent with the expectation from standard model processes. I present upper limits on the cross section times branching ratio squared {sigma}({tilde t}{sub 1}{bar {tilde t}}{sub 1}) x {beta}{sup 2} as a function of the stop mass m({tilde t}{sub 1}). Assuming {beta} = 1, I set a 95% confidence level limit m({tilde t}{sub 1}) > 153 GeV=c{sup 2}. These limits are also fully applicable to the case of a pair produced third generation scalar leptoquark that decays into a {tau} lepton and a b quark.

Khotilovich, Vadim, G.; /Texas A-M

2008-05-01T23:59:59.000Z

246

A search for close-mass lepton doublet  

SciTech Connect

Described is a search for a heavy charged lepton with an associated neutrino of nearly the same mass, together known as a close-mass lepton doublet. The search is conducted in e/sup +/e/sup/minus// annihilation data taken with the Mark II detector at a center-of-mass energy of 29 GeV. In order to suppress contamination from conventional two-photon reactions, the search applies a novel, radiative-tagging technique. Requiring the presence of an isolated, energetic photon allows exploration for lepton doublets with a mass splitting smaller than that previously accessible to experiment. No evidence for such a new lepton has been found, enabling limits to be placed on allowed mass combinations. Mass differences as low as 250-300 MeV are excluded for charged lepton masses up to 10 GeV. 78 refs., 64 figs., 8 tabs.

Riles, J.K.

1989-04-01T23:59:59.000Z

247

Radiative Transmission of Lepton Flavor Hierarchies  

E-Print Network (OSTI)

We discuss a one loop model for neutrino masses which leads to a seesaw-like formula with the difference that the charged lepton masses replace the unknown Dirac mass matrix present in the usual seesaw case. This is a considerable reduction of parameters in the neutrino sector and predicts a strong hierarchical pattern in the right handed neutrino mass matrix that is easily derived from a $U(1)_H$ family symmetry. The model is based on the left-right gauge group with an additional $Z_4$ discrete symmetry which gives vanishing neutrino Dirac masses and finite Majorana masses arising at the one loop level. Furthermore, it is one of the few models that naturally allow for large (but not necessarily maximal) mixing angles in the lepton sector. A generalization of the model to the quark sector requires three iso-spin singlet vector-like down type quarks, as in $E_6$. The model predicts an inert doublet type scalar dark matter.

Adisorn Adulpravitchai; Manfred Lindner; Alexander Merle; Rabindra N. Mohapatra

2009-08-04T23:59:59.000Z

248

Measurement of tau lepton branching fractions  

SciTech Connect

We present {tau}{sup {minus}} lepton branching fraction measurements based on data from the TPC/Two-Gamma detector at PEP. Using a sample of{tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} events, we examine the resonance structure of the K{sup {minus}}{pi}{sup +}{pi}{sup {minus}} system and obtain the first measurements of branching fractions for {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1270) and {tau}{sup {minus}} {yields} {nu}{sub {tau}}K{sub 1}{sup {minus}}(1400). We also describe a complete set of branching fraction measurements in which all the decays of the {tau}{sup {minus}} lepton are separated into classes defined by the identities of the charged particles and an estimate of the number of neutrals. This is the first such global measurement with decay classes defined by the four possible charged particle species, e, {mu}, {pi}, and K.

Nicol, N.A.

1993-09-30T23:59:59.000Z

249

Higgs. -->. four leptons at the SSC  

SciTech Connect

Detection of an intermediate mass or heavy Higgs boson through its decay into four charged leptons is studied with emphasis on background considerations and detector requirements. The intermediate mass Higgs decay via ZZ* is expected to be a difficult mode to observe due to low event rates. In addition, cuts which are needed to reduce the backgrounds reduce the signal even further. The rapidity coverage and energy resolution requirements for this mode are more severe than for the heavy Higgs. The heavy Higgs boson decay H ..-->.. Z/sup 0/Z/sup 0/ ..-->.. 4/ell//sup +-/ continues to be observable for a Higgs mass between twice the Z mass and about 600 GeV/c/sup 2/ when detector characteristics of generic large SSC detectors are included. A careful study is made of backgrounds from q/bar q/, qq ..-->.. Z + Jets and detector-related issues. It is shown that an isolation cut on the lepton candidates can be expected to reduce the background from this source to low levels. 14 refs., 12 figs., 4 tabs.

Wang, E.M.; Hanson, G.G.

1988-12-01T23:59:59.000Z

250

Update on the ILC Positron Source Study at ANL  

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

GeV THPEC036 Proceedings of IPAC'10, Kyoto, Japan 4134 03 Linear Colliders, Lepton Accelerators and New Acceleration Techniques T02 Lepton Sources beam will lose less energy...

251

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...

252

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

253

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

254

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

255

Electronic branching ratio of the. tau. lepton  

Science Conference Proceedings (OSTI)

Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio {ital R}={Gamma}({tau}{r arrow}{ital e}{bar {nu}}{sub {ital e}}{nu}{sub {tau}})/{Gamma}{sub 1}, where {Gamma}{sub 1} is the {tau} decay rate to final states with one charged particle. We find {ital R}=0.2231{plus minus}0.0044{plus minus}0.0073 where the first error is statistical and the second is systematic. Together with the measured topological one-charged-particle branching fraction, this yields the branching fraction of the {tau} lepton to electrons, {ital B}{sub {ital e}}=0.192{plus minus}0.004{plus minus}0.006.

Ammar, R.; Baringer, P.; Coppage, D.; Davis, R.; Kelly, M.; Kwak, N.; Lam, H.; Ro, S.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Perticone, D.; Poling, R.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; Romero, V.; Sun, C.R.; Wang, P.; Zoeller, M.M.; Crawford, G.; Fulton, R.; Gan, K.K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Sung, M.K.; Whitmore, J.; Wilson, P.; Butler, F.; Fu, X.; Kalbfleisch, G.; Lambrecht, M.; Skubic, P.; Snow, J.; Wang, P.; Bortoletto, D.; Brown, D.N.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Modesitt, M.; Shibata, E.I.; Schaffner, S.F.; Shipsey, I.P.J.; Battle, M.; Ernst, J.; Kroha, H.; Roberts, S.; Sparks, K.; Thorndike, E.H.; Wang, C.; Stroynowski, R.; Artuso, M.; Goldberg, M.; Haupt, T.; Horwitz, N.; Kennett, R.; Moneti, G.C.; Playfer, S.; Rozen, Y.; Rubin, P.; Skwarnicki, T.; Stone, S.; Thulasidas, M.; Yao, W.; Zhu, G.; Barnes, A.V.; Bartelt, J.; Csorna, S.E.; Jain, V.; Letson, T.; Mestayer, M.D.; Akerib, D.S.; Barish, B.; Chadha, M.; (CLEO Collaboration)

1992-06-01T23:59:59.000Z

256

Citation: K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for  

E-Print Network (OSTI)

for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Neutral Leptons, Searches for (A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons(A) Heavy Neutral Leptons Stable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton MASS LIMITSStable Neutral Heavy Lepton

257

The C-metric as a colliding plane wave space-time  

E-Print Network (OSTI)

It is explicitly shown that part of the C-metric space-time inside the black hole horizon may be interpreted as the interaction region of two colliding plane waves with aligned linear polarization, provided the rotational coordinate is replaced by a linear one. This is a one-parameter generalization of the degenerate Ferrari-Ibanez solution in which the focussing singularity is a Cauchy horizon rather than a curvature singularity.

J. B. Griffiths; R. G. Halburd

2007-01-10T23:59:59.000Z

258

Lepton flavor violation decays with the fourth generation neutrino  

E-Print Network (OSTI)

We investigate the lepton flavor violation decays, $\\tau \\to \\mu\\gamma$, $\\tau \\to e\\gamma$ and $\\mu \\to e\\gamma$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\

Huo, W J; Huo, Wu-Jun; Feng, Tai-Fu

2002-01-01T23:59:59.000Z

259

Phenomenological constraints on minimally coupled exotic lepton triplets  

Science Conference Proceedings (OSTI)

By introducing a set of new triplet leptons (with nonzero hypercharge) that can Yukawa couple to their standard model counterparts, new sources of tree-level flavor changing currents are induced via mixing. In this work, we study some of the consequences of such new contributions on processes such as the leptonic decays of gauge bosons, l{yields}3l{sup '} and l{yields}l{sup '{gamma}}, which violate lepton flavor, and {mu}-e conversion in atomic nuclei. Constraints are then placed on the parameters associated with the exotic triplets by invoking the current low-energy experimental data. Moreover, the new physics contribution to the lepton anomalous magnetic moments is calculated.

Chua, Chun-Khiang; Law, Sandy S. C. [Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan 320 (China)

2011-03-01T23:59:59.000Z

260

The small mixing angle {theta}13 and the lepton asymmetry  

SciTech Connect

We present the correlation of low energy CP phases, and the lepton asymmetry for the baryon asymmetry in the universe, for cases in which the amount of the lepton asymmetry YL turns out to be proportional to {theta}{sub 13}{sup 2}, considering the constraint between two types of CP phases and the relation of YL versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as {theta}13 varies.

Lee, Song-Haeng; Siyeon, Kim [Department of Physics, Chung-Ang University, Seoul 156-756 (Korea, Republic of)

2005-12-02T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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.


261

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

262

Measurement of the top quark mass in $p \\bar{p}$ collisions using events with two leptons  

Science Conference Proceedings (OSTI)

We present a measurement of the top quark mass (m{sub t}) in p{bar p} collisions at {radical}s = 1.96 TeV using t{bar t} events with two leptons (ee, e{mu} or {mu}{mu}) in the final state in 4.3 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider. We analyze the kinematically underconstrained dilepton events by integrating over the neutrino rapidity distributions. We reduce the dominant systematic uncertainties from jet energy calibration using a correction obtained from t{bar t} {yields} {ell} + jets events. We also correct jets in simulated events to replicate the quark flavor dependence of the jet response in data. In combination with our previous analysis, we measure m{sub t} = 174.0 {+-} 2.4(stat) {+-} 1.4(syst) GeV.

Abazov, Victor Mukhamedovich; /Dubna, JINR; Abbott, Braden Keim; /Oklahoma U.; Acharya, Bannanje Sripath; /Tata Inst.; Adams, Mark Raymond; /Illinois U., Chicago; Adams, Todd; /Florida State U.; Alexeev, Guennadi D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Augustana Coll., Sioux Falls; Alverson, George O.; /Northeastern U.; Aoki, Masato; /Fermilab; Askew, Andrew Warren; /Florida State U. /Stockholm U.

2012-01-01T23:59:59.000Z

263

INTENSE NEUTRINO BEAMS AND LEPTONIC CP VIOLATION.  

SciTech Connect

Effects of the Leptonic CP violating phase, {delta}, on 3 generation neutrino oscillation rates and asymmetries are discussed. A figure of merit argument is used to show that our ability to measure the phase 6 is rather insensitive to the value of {theta}{sub 13} (for sin{sup 2} 2{theta}{sub 13} {approx}> 0.01) as well as the detector distance (for very long oscillation baselines). Using a study of {nu}{sub {mu}} {yields} {nu}{sub e} oscillations for BNL-Homestake (2540 km) we show that a conventional horn focused wide band neutrino beam generated by an intense 1-2 MW proton source combined with a very large water Cherenkov detector (250-500 kton) should be able to determine {delta} to about {+-}15{sup o} in 5 x 10{sup 7} sec. of running. In addition, such an effort would also measure the other oscillation parameters ({theta}{sub ij}, {Delta}m{sub ij}{sup 2}) with high precision. Similar findings apply to a Fermilab-Homestake (1280 km) baseline. We also briefly discuss features of Superbeams, Neutrino Factories and Beta-Beams.

MARCIANO, W.; PARSA, Z.

2006-06-13T23:59:59.000Z

264

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

265

A measurement of the top pair production cross-section in the dilepton channel using lepton plus track selection  

Science Conference Proceedings (OSTI)

Using 1.1 fb{sup -1} of data collected by the Collider Detector at Fermilab (CDF) from Run II of the Fermilab Tevatron, they measure the t{bar t} production cross section in events with two leptons, significant missing transverse energy, and {ge} 2 jets. As the Run II dataset grows, more stringent tests of Standard Model predictions for the top quark sector are becoming possible. The dilepton channel, where both top quarks decay t {yields} Wb {yields} {ell}{nu}b, is of particular interest due to its high purity even in the absence of a b jet 'tagging' requirement. Use of an isolated track as the second lepton significant increases the dilepton acceptance, at the price of some increase in background, particular from W + jets events where one of the jets is identified as a lepton. With the amount of data available, it has been possible to improve the estimate of the contribution from that background, reflected in a reduced systematic uncertainty. Assuming a branching ratio of BR(W {yields} {ell}{nu}) = 10.8% and a top mass of m{sub t} = 175 GeV/c{sup 2}, the measured cross-section is {sigma}(p{bar p} {yields} t{bar t}) = 8.3 {+-} 1.3(stat.) {+-} 0.7(syst.) {+-} 0.5(lumi.) pb. The result is consistent with the Standard Model prediction of 6.7{sub -0.9}{sup +0.7} pb and represents a significant improvement in precision over previous results using this selection.

Mills, Corrinne Elaine; /UC, Santa Barbara

2007-06-01T23:59:59.000Z

266

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...

267

Decoupling schemes for the SSC Collider  

Science Conference Proceedings (OSTI)

A decoupling system is designed for the SSC Collider. This system can accommodate three decoupling schemes by using 44 skew quadrupoles in the different configurations. Several decoupling schemes are studied and compared in this paper.

Cai, Y.; Bourianoff, G.; Cole, B.; Meinke, R.; Peterson, J.; Pilat, F.; Stampke, S.; Syphers, M.; Talman, R.

1993-05-01T23:59:59.000Z

268

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

269

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

270

LINEAR ACCELERATOR  

DOE Patents (OSTI)

Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

Christofilos, N.C.; Polk, I.J.

1959-02-17T23:59:59.000Z

271

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

272

Search for Lepton-Number Violating Processes in B+ to h- l+ l+ Decays  

SciTech Connect

We have searched for the lepton-number violating processes B{sup +} {yields} h{sup -}{ell}{sup +}{ell}{sup +} with h{sup -} = K{sup -}/{pi}{sup -} and {ell}{sup +} = e{sup +}/{mu}{sup +}, using a sample of 471 {+-} 3 million B{bar B} events collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90% confidence level upper limits on their branching fractions B (B{sup +} {yields} {pi}{sup -}e{sup +}e{sup +}) < 2.3 x 10{sup -8}, {Beta}(B{sup +} {yields} K{sup -}e{sup +}e{sup +}) < 3.0 x 10{sup -8}, {Beta}(B{sup +} {yields} {pi}{sup -}{mu}{sup +}{mu}{sup +}) < 10.7 x 10{sup -8}, and {Beta}(B{sup +} {yields} K{sup -}{mu}{sup +}{mu}{sup +}) < 6.7 x 10{sup -8}.

Lees, J.P.

2012-05-17T23:59:59.000Z

273

Nuclear PDF for neutrino and charged lepton data  

E-Print Network (OSTI)

Neutrino Deep Inelastic Scattering on nuclei is an essential process to constrain the strange quark parton distribution functions in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions. Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton lA Deeply Inelastic Scattering and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors F_2^Fe/F_2^D for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

K. Kovarik

2010-12-13T23:59:59.000Z

274

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

275

Review of ''close-mass'' heavy lepton searches  

SciTech Connect

Results from recent searches in e/sup +/e/sup /minus// annihilation at PEP (..sqrt..s = 29 GeV) for a fourth-generation charged lepton associated with a slightly lighter neutrino partner are presented. Some emphasis is given to the most recent search, which uses a novel approach based on radiative tagging, an approach that holds promise as a general tool in searching for exotic events characterized by very low visible energy. Prospects for upcoming sequential lepton searches at SLC and LEP experiments are also discussed. 11 refs., 4 figs.

Riles, K.

1989-05-01T23:59:59.000Z

276

Non-thermal high-energy emission from colliding winds of massive stars  

E-Print Network (OSTI)

Colliding winds of massive star binary systems are considered as potential sites of non-thermal high-energy photon production. This is motivated merely by the detection of synchrotron radio emission from the expected colliding wind location. Here we investigate the properties of high-energy photon production in colliding winds of long-period WR+OB-systems. We found that in the dominating leptonic radiation process anisotropy and Klein-Nishina effects may yield spectral and variability signatures in the gamma-ray domain at or above the sensitivity of current or upcoming gamma-ray telescopes. Analytical formulae for the steady-state particle spectra are derived assuming diffusive particle acceleration out of a pool of thermal wind particles, and taking into account adiabatic and all relevant radiative losses. For the first time we include their advection/convection in the wind collision zone, and distinguish two regions within this extended region: the acceleration region where spatial diffusion is superior to convective/advective motion, and the convection region defined by the convection time shorter than the diffusion time scale. The calculation of the Inverse Compton radiation uses the full Klein-Nishina cross section, and takes into account the anisotropic nature of the scattering process. This leads to orbital flux variations by up to several orders of magnitude which may, however, be blurred by the geometry of the system. The calculations are applied to the typical WR+OB-systems WR 140 and WR 147 to yield predictions of their expected spectral and temporal characteristica and to evaluate chances to detect high-energy emission with the current and upcoming gamma-ray experiments. (abridged)

A. Reimer; M. Pohl; O. Reimer

2005-10-25T23:59:59.000Z

277

Precision Measurements of Tau Lepton Decays  

SciTech Connect

Using data collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, the branching fractions {Beta}({tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (8.83 {+-} 0.01 {+-} 0.13)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (0.273 {+-} 0.002 {+-} 0.009)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}}) = (0.1346 {+-} 0.0010 {+-} 0.0036)%, and {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}) = (1.58 {+-} 0.13 {+-} 0.12) x 10{sup -5} are measured where the uncertainties are statistical and systematic, respectively. The invariant mass distribution for the {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}, {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} decays are unfolded to correct for detector effects. A measurement of {Beta}({tau}{sup -} {yields} {phi}{pi}{sup -}{nu}{sub {tau}}) = (3.42 {+-} 0.55 {+-} 0.25) x 10{sup -5}, a measurement of {Beta}({tau}{sup -} {yields} {phi}K{sup -}{nu}{sub {tau}}) = (3.39 {+-} 0.20 {+-} 0.28) x 10{sup -5} and an upper limit on {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}[ex.{phi}]) {le} 2.5 x 10{sup -6} {at} 905 CL are determined from a binned maximum likelihood fit of the {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} K{sup +}K{sup -} invariant mass distributions. The branching ratio {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}) is measured to be (6.531 {+-} 0.056 {+-} 0.093) x 10{sup -2} from which |V{sub us}| is determined to be 0.2255 {+-} 0.0023. The branching ratio {Beta}/({tau}{sup -} {yields} {mu}{nu}{sub {tau}}{bar {nu}}{sub {mu}})/{Beta}({tau}{sup -} {yields} e{sup -} {nu}{sub {tau}}{bar {nu}}{sub e}) = (9.796 {+-} 0.016 {+-} 0.035) x 10{sup -1} is measured enabling a precision test of the Standard Model assumption of charged current lepton universality, g{sub {mu}}/g{sub e} = 1.0036 {+-} 0.0020. The branching ratios {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{nu}{sub {tau}}{bar {nu}}{sub e}) = (3.882 {+-} 0.032 {+-} 0.057) x 10{sup -2}, and {Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{nu}{sub {tau}}{bar {nu}}{sub e}) = (5.9545 {+-} 0.014 {+-} 0.061) x 10{sup -1} are measured which provide additional tests of charged current lepton universality, (g{sub {tau}}/g{sub {mu}}){sub {pi}} = 0.9856 {+-} 0.0057 and (g{sub {tau}}/g{sub {mu}}){sub K} = 0.9827 {+-} 0.0086 which can be combined to give (g{sub {tau}}/g{sub {mu}}){sub {pi}/K} = 0.9850 {+-} 0.0054. Any deviation of these measurements from the expected Standard Model values would be an indication of new physics.

Nugent, Ian M.; /Victoria U.

2010-03-16T23:59:59.000Z

278

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

279

Fermilab | Muon Collider | Reports and Papers  

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

Reports and Papers Reports and Papers Comprehensive Reports J. Gallardo, R. Palmer, A. Tollestrup, A. Sessler, A. Skrinsky et al., "μ+ μ- Collider: A Feasibility Study," DPF/DPB Summer Study on New Directions for High Energy Physics, Snow- mass, Colorado, 25 Jun - 12 Jul 1996, BNL - 52503, Fermilab - Conf - 96 - 092, LBNL - 38946, http://www.cap.bnl.gov/mumu/pubs/snowmass96.html C. Ankenbrandt et al.,"Status of muon collider research and development and future plans," Phys. Rev. ST Accel. Beams 2 (1999) 081001, http://prst-ab.aps.org/abstract/PRSTAB/v2/i8/e081001 M. M. Alsharo'a et al., "Recent progress in neutrino factory and muon collider research within the Muon Collaboration," Phys. Rev. ST Accel. Beams 6 (2003) 081001, http://prst-ab.aps.org/abstract/PRSTAB/v6/i8/e081001

280

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

Note: This page contains sample records for the topic "linear colliders lepton" 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.


281

A Lepton Universality Test at CERN NA62 Experiment  

E-Print Network (OSTI)

The NA62 experiment at CERN collected a large sample of K+ --> enu decays during a dedicated run in 2007, aiming at a precise test of lepton universality by measurement of the helicity suppressed ratio RK = BR(K+ --> enu)/BR(K+ --> munu). A preliminary result of the analysis of a partial data sample of 51089 K+ --> enu candidates is presented.

Evgueni Goudzovski

2010-05-07T23:59:59.000Z

282

Hadronic decays of the tau lepton: Theoretical outlook  

E-Print Network (OSTI)

The structure of the form factors stemmed from the hadronization of QCD currents in the energy region of the resonances can be explored through the analyses of exclusive hadronic decays of the tau lepton. I give a short review on the later theoretical progress achieved in the description of experimental data.

J. Portoles

2007-02-13T23:59:59.000Z

283

CP Violation for Leptons at Higher Energy Scales  

E-Print Network (OSTI)

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.

Cheng-Wei Chiang

2000-11-15T23:59:59.000Z

284

CP Violation for Leptons at Higher Energy Scales  

E-Print Network (OSTI)

The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.

Chiang, C W

2001-01-01T23:59:59.000Z

285

PHYSICS WITH AND PHYSICS OF COLLIDING ELECTRON BEAMS  

E-Print Network (OSTI)

contributed so much to the physics of colliding beams, theyto reap so little from the physics with colliding beams.Conference on High-Energy Physics, Vienna" September 1968 (

Pellegrini, Claudio

2008-01-01T23:59:59.000Z

286

Tune spectra in the Tevatron Collider  

SciTech Connect

A variety of transverse and longitudinal tune studies have been made in the Tevatron with both single and colliding beams. Besides measuring such typical quantities as tunes and chromaticity, beam- beam tune shifts and coherent beam-beam normal mode oscillations have been observed. A number of measurements are reported where the beam response to stimulation is studied. 13 refs., 9 figs.

Jackson, G.

1989-03-01T23:59:59.000Z

287

QCD parton model at collider energies  

Science Conference Proceedings (OSTI)

Using the example of vector boson production, the application of the QCD improved parton model at collider energies is reviewed. The reliability of the extrapolation to SSC energies is assessed. Predictions at ..sqrt..S = 0.54 TeV are compared with data. 21 references.

Ellis, R.K.

1984-09-01T23:59:59.000Z

288

The Particle Adventure | What is the world made of? | Lepton type  

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

type conservation type conservation Lepton type conservation Leptons are divided into three lepton families: the electron and its neutrino, the muon and its neutrino, and the tau and its neutrino. We use the terms "electron number," "muon number," and "tau number" to refer to the lepton family of a particle. Electrons and their neutrinos have electron number +1, positrons and their antineutrinos have electron number -1, and all other particles have electron number 0. Muon number and tau number operate analogously with the other two lepton families. One important thing about leptons, then, is that electron number, muon number, and tau number are always conserved when a massive lepton decays into smaller ones. Let's take an example decay.

289

Higgs boson and Z physics at the first muon collider  

SciTech Connect

The potential for the Higgs boson and Z-pole physics at the first muon collider is summarized, based on the discussions at the ``Workshop on the Physics at the First Muon Collider and at the Front End of a Muon Collider``.

Demarteau, M.; Han, T.

1998-01-01T23:59:59.000Z

290

A Moment Equation Approach to a Muon Collider Cooling Lattice  

E-Print Network (OSTI)

a Muon Collider Cooling Lattice C.M. Celata, A.M. Sessler,a Muon Collider Cooling Lattice C.M. Celata and A.M. SesslerMUON COLLIDER COOLING LATTICE eM. Celata and A. M. Sessler,

Celata, C.M.; Sessler, A.M.; Lee, P.B.; Shadwick, B.A.; Wurtele, S.

2008-01-01T23:59:59.000Z

291

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

292

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

293

Citation: K. Nakamura et al. (Particle Data Group), JP G 37, 075021 (2010) and 2011 partial update for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches  

E-Print Network (OSTI)

for the 2012 edition (URL: http://pdg.lbl.gov) Heavy Charged Lepton Searches Charged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITSCharged Heavy Lepton MASS LIMITS Sequential Charged Heavy Lepton (L±) MASS LIMITSSequential Charged Heavy Lepton (L±) MASS LIMITSSequential

294

A Zip-code for Quarks, Leptons and Higgs Bosons  

E-Print Network (OSTI)

The location of matter fields and the pattern of gauge symmetry in extra dimensions are crucial ingredients for string model building. We analyze realistic MSSM models from the heterotic Z6 Mini-Landscape and extract those properties that are vital for their success. We find that Higgs bosons and the top quark are not localized in extra dimensions and live in the full D=10 dimensional space-time. The first two families of quarks and leptons, however, live at specific fixed points in extra dimensional space and exhibit a (discrete) family symmetry. Within a newly constructed Z2XZ4 orbifold framework we further elaborate on these location properties and the appearance of discrete symmetries. A similar geometrical picture emerges. This particular Zip-code for quarks, leptons and Higgs bosons seems to be of more general validity and thus a useful guideline for realistic model building in string theory.

Damian Kaloni Mayorga Pena; Hans Peter Nilles; Paul-Konstantin Oehlmann

2012-09-26T23:59:59.000Z

295

Search for Charged Lepton Violation in Narrow Upsilon Decays  

SciTech Connect

Charged lepton flavor violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 10{sup 6} {Upsilon}(2S) decays and 117 x 10{sup 6} {Upsilon}(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions {Beta}({Upsilon}(nS) {yields} e{sup {+-}}{tau}{sup {-+}}) and {Beta}({Upsilon}(nS) {yields} {mu}{sup {+-}}{tau}{sup {-+}}) (n = 2, 3) at the 10{sup -6} level and use these results to place lower limits of order 1 TeV on the mass scale of charged lepton flavor violating effective operators.

Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley; Hawkes, C.M.; /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Columbus Supercond., Genova /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2011-08-19T23:59:59.000Z

296

mu+-mu? colliders: possibilities and challenges  

SciTech Connect

The current status of the mu+-mu? collider concept is reviewed and discussed. In a reference scenario, a high-intensity pulsed proton accelerator (of K-factory class) produces large numbers of secondary pi's in a nuclear target, which produce muons by decay. The muons are collected and cooled (by "ionization cooling") to form high-intensity bunches that are accelerated to high-energy collisions. High-luminosity mu+-mu? and mu?-p colliders at TeV or higher energy scales may be possible. Challenges in implementing the scenario are described. Possible variations in muon production, accumulation, and collisions are discussed; further innovations and improvements are encouraged.

David Neuffer

1994-10-01T23:59:59.000Z

297

Snowmass White Paper CMS Upgrade: Forward Lepton-Photon System  

E-Print Network (OSTI)

This White Paper outlines a proposal for an upgraded forward region to extend CMS lepton (e, mu) and photon physics reach out to 2.2

Bilki, Burak; Onel, Yasar; Winn, David R; Yetkin, Taylan

2013-01-01T23:59:59.000Z

298

Search for the Lepton-Number-Violating Decay $?^- \\to p ?^- ?^-$  

E-Print Network (OSTI)

A sensitive search for the lepton-number-violating decay $\\Xi^-\\to p \\mu^-\\mu^-$ has been performed using a sample of $\\sim10^9$ $\\Xi^-$ hyperons produced in 800 GeV/$c$ $p$-Cu collisions. We obtain $\\mathcal{B}(\\Xi^-\\to p \\mu^-\\mu^-)< 4.0\\times 10^{-8}$ at 90% confidence, improving on the best previous limit by four orders of magnitude.

HyperCP Collaboration; D. Rajaram; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. -S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. D. Jones; D. M. Kaplan; M. J. Longo; L. C. Lu; W. Luebke; K. -B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla

2005-05-12T23:59:59.000Z

299

Scaling quark gluon plasma by HBT interferometry with lepton pairs  

E-Print Network (OSTI)

We study the intensity interferometry with lepton pairs for nuclear collisions at RHIC and LHC energies. It is argued that the invariant mass dependence of HBT radii extracted from the correlation functions of dilepton pairs can be used as an efficient tool to scale the size and life time of the quark gluon plasma expected to be formed in nuclear collisions at RHIC and LHC. Quantitatively different magnitudes of HBT radii are obtained at RHIC and LHC indicating stronger radial flow at LHC.

Payal Mohanty; Jan-e Alam

2012-02-10T23:59:59.000Z

300

MEASURING LEPTONIC CP VIOLATION WITH A WATER CERENKOV  

E-Print Network (OSTI)

In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case ?13 ? 3 ? (the limit that can be reached by under-construction experiments), the signal-to-background rate for a ?-beam setup with the radioactive ions accelerated to ? = 350. 1

E. Couce

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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.


301

Electroweak Penguin and Leptonic Decays at BaBar  

SciTech Connect

Recent BABAR results on electroweak penguin and leptonic decays are reviewed. In particular, the measurements of B {yields} K{sup (*)}l{sup +}l{sup -} and the preliminary results on B {yields} X{sub s}l{sup +}l{sup -} are presented. Also summarized are the preliminary limits on B{sup +} {yields} l{sup +}{nu} (l = e,{mu}) and B{sup +} {yields} K{sup +}{nu}{bar {nu}}.

Bucci, F.; /Pisa U. /INFN, Pisa

2005-08-26T23:59:59.000Z

302

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

303

Electron Ion Collider: The Next QCD Frontier  

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

Ion Collider: Ion Collider: The Next QCD Frontier Understanding the glue that binds us all Electron Ion Collider: The Next QCD Frontier Understanding the glue that binds us all BNL-98815-2012-JA JLAB-PHY-12-1652 arXiv:1212.1701 Authors A. Accardi 14,28 , J. L. Albacete 16 , M. Anselmino 29 , N. Armesto 36 , E. C. Aschenauer 3,† , A. Bacchetta 35 , D. Boer 33 , W. Brooks 37,† , T. Burton 3 , N.-B. Chang 23 , W.-T. Deng 13,23 , A. Deshpande 25,∗,† , M. Diehl 11,† , A. Dumitru 2 , R. Dupr´ e 7 , R. Ent 28,‡ , S. Fazio 3 , H. Gao 12,† , V. Guzey 28 , H. Hakobyan 37 , Y. Hao 3 , D. Hasch 15 , R. Holt 1,† , T. Horn 5,† , M. Huang 23 , A. Hutton 28,† , C. Hyde 20 , J. Jalilian-Marian 2 , S. Klein 17 , B. Kopeliovich 37 , Y. Kovchegov 19,† , K. Kumar 24,† , K. Kumeriˇ cki 40 , M. A. C. Lamont 3 , T. Lappi 34 , J.-H. Lee 3 , Y. Lee 3 , E. M. Levin 26,37 , F.-L. Lin 28 , V. Litvinenko 3 , T. W. Ludlam 3,‡ , C. Marquet

304

Muon Collider Machine-Detector Interface  

SciTech Connect

In order to realize the high physics potential of a Muon Collider (MC) a high luminosity of {mu}{sup +}{mu}{sup -}-collisions at the Interaction Point (IP) in the TeV range must be achieved ({approx}10{sup 34} cm{sup -2}s{sup -1}). To reach this goal, a number of demanding requirements on the collider optics and the IR hardware - arising from the short muon lifetime and from relatively large values of the transverse emittance and momentum spread in muon beams that can realistically be obtained with ionization cooling should be satisfied. These requirements are aggravated by limitations on the quadrupole gradients as well as by the necessity to protect superconducting magnets and collider detectors from muon decay products. The overall detector performance in this domain is strongly dependent on the background particle rates in various sub-detectors. The deleterious effects of the background and radiation environment produced by the beam in the ring are very important issues in the Interaction Region (IR), detector and Machine-Detector Interface (MDI) designs. This report is based on studies presented very recently.

Mokhov, Nikolai V.; /Fermilab

2011-08-01T23:59:59.000Z

305

Nuclear PDF for neutrino and charged lepton data  

SciTech Connect

Neutrino Deep Inelastic Scattering (DIS) on nuclei is an essential process to constrain the strange quark parton distribution functions (PDF) in the proton. The critical component on the way to using the neutrino DIS data in a proton PDF analysis is understanding the nuclear effects in parton distribution functions. We parametrize these effects by nuclear parton distribution functions (NPDF). Here we compare results from two analysis of NPDF both done at next-to-leading order in QCD. The first uses neutral current charged-lepton (l{sup {+-}A}) Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets and the second uses neutrino-nucleon DIS data. We compare the nuclear corrections factors (F{sub 2}{sup Fe}/F{sub 2}{sup D}) for the charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

Kovarik, K. [Institute for Theoretical Physics, Karlsruhe Institute of Technology, Karlsruhe, D-76128 (Germany)

2011-10-06T23:59:59.000Z

306

Linear Quadratic  

E-Print Network (OSTI)

The proposal of Reshef et. al. (MIC) is an interesting new approach for discovering non-linear dependencies among pairs of measurements in exploratory data mining. However, it has a potentially serious drawback. The authors laud the fact that MIC has no preference for some alternatives over others, but as the authors know, there is no free lunch in Statistics: tests which strive to have high power against all alternatives can have low power in many important situations. To investigate this, we ran simulations to compare the power of MIC to that of standard Pearson correlation and distance correlation (dcor) Szkely & Rizzo (2009). We simulated pairs of variables with different relationships (most of which were considered by the Reshef et. al.), but with varying levels of noise added. To determine proper cutoffs for testing the independence hypothesis, we simulated independent data with the appropriate marginals. As one can see from the Figure, MIC has lower power than dcor, in every case except the somewhat pathological

Noah Simon; Robert Tibshirani; Noah Simon; Robert Tibshirani

2011-01-01T23:59:59.000Z

307

Chromaticity correction for a muon collider optics  

Science Conference Proceedings (OSTI)

Muon Collider (MC) is a promising candidate for the next energy frontier machine. However, in order to obtain peak luminosity in the 10{sup 34} cm{sup 2}s{sup -1} range the collider lattice designmust satisfy a number of stringent requirements. In particular the expected large momentum spread of the muon beam and the very small {beta}* call for a careful correction of the chromatic effects. Here we present a particular solution for the interaction region (IR) optics whose distinctive feature is a three-sextupole local chromatic correction scheme. The scheme may be applied to other future machines where chromatic effects are expected to be large. The expected large muon energy spread requires the optics to be stable over a wide range of momenta whereas the required luminosity calls for {beta}* in the mm range. To avoid luminosity degradation due to hour-glass effect, the bunch length must be comparatively small. To keep the needed RF voltage within feasible limits the momentum compaction factor must be small over the wide range of momenta. A low {beta}* means high sensitivity to alignment and field errors of the Interaction Region (IR) quadrupoles and large chromatic effects which limit the momentum range of optics stability and require strong correction sextupoles, which eventually limit the Dynamic Aperture (DA). Finally, the ring circumference should be as small as possible, luminosity being inversely proportional to the collider length. A promising solution for a 1.5 TeV center of mass energy MC with {beta}* = 1 m in both planes has been proposed. This {beta}* value has been chosen as a compromise between luminosity and feasibility based on the magnet design and energy deposition considerations. The proposed solution for the IR optics together with a new flexible momentum compaction arc cell design allows to satisfy all requirements and is relatively insensitive to the beam-beam effect.

Alexahin, Y.; Gianfelice-Wendt, E.; Kapin, V.; /Fermilab

2011-03-01T23:59:59.000Z

308

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

309

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

310

Two gauge boson physics at future colliders  

SciTech Connect

Electroweak unification suggests that there should be WW and ZZ physics analogous to {gamma}{gamma} physics. Indeed, WW and ZZ collisions will provide an opportunity to search for the Higgs boson at future high energy colliders. Cross sections in the picobarn range are predicted for Higgs boson production at the proposed 40-TeV SSC. While other states may be produced by WW and ZZ collisions, it is the Higgs boson that looms as the most attractive objective. 31 refs., 5 figs.

Cahn, R.N.

1988-05-13T23:59:59.000Z

311

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

312

RHIC | Physics of the Relativistic Heavy Ion Collider  

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

The Physics of RHIC Physicists from around the world are using the Relativistic Heavy Ion Collider to explore some of Nature's most basic -- and intriguing -- ingredients and...

313

Far Future Colliders and Required R&D Program  

Science Conference Proceedings (OSTI)

Particle colliders for high energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the collider has progressed immensely, while the beam energy, luminosity, facility size and the cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but its pace of progress has greatly slowed down. In this paper we very briefly review the R&D toward near future colliders and make an attempt to look beyond the current horizon and outline the changes in the paradigm required for the next breakthroughs.

Shiltsev, V.; /Fermilab

2012-06-01T23:59:59.000Z

314

Searches for Leptonic B Decays at BaBar  

SciTech Connect

Measurements of the branching fractions of purely leptonic decays of B-mesons translate into constraints in the plane of the charged Higgs mass versus tan {beta} which are relatively insensitive to the particular theoretical model. Using the full BABAR dataset of 450 million B-decays we search for these decays. No significant signal is found in the decays into electrons or muons and we set upper limits on the branching fractions of the order of a 10{sup -6} at 90% confidence level. We measure the branching fraction of B {yields} {tau}{mu} to be (1.7 {+-} 0.6) x 10{sup -4}.

Nelson, Silke; /SLAC

2012-04-25T23:59:59.000Z

315

Measuring Leptonic CP Violation with a Water Cerenkov  

E-Print Network (OSTI)

In this talk, we present the physics case for a megaton Water Cerenkov detector in addressing some of the still pending questions in neutrino oscillations physics, particularly the measurement of leptonic CP violation. We compare different future beams that could profit from a water detector and analyse, for the case $\\theta_{13} \\approx 3^\\circ$ (the limit that can be reached by under-construction experiments), the signal-to-background rate for a $\\beta$-beam setup with the radioactive ions accelerated to $\\gamma = 350$.

E. Couce

2006-07-01T23:59:59.000Z

316

Search for the Rare Leptonic Decays B^+ \\to l^+ \  

SciTech Connect

We have performed a search for the rare leptonic decays B{sup +} {yields} {ell}{sup +} {nu}{sub {ell}}({ell} = e,{mu}), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468 x 10{sup 6} B{bar B} pairs we find no evidence for a signal and set an upper limit on the branching fractions B(B{sup +} {yields} e{sup +}{nu}{sub e}) < 1.9 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.

Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

2009-06-19T23:59:59.000Z

317

Advances in Beam Cooling for Muon Colliders  

DOE Green Energy (OSTI)

A six-dimensional (6D) ionization cooling channel based on helical magnets surrounding RF cavities filled with dense hydrogen gas is the basis for the latest plans for muon colliders. This helical cooling channel (HCC) has solenoidal, helical dipole, and helical quadrupole magnetic fields, where emittance exchange is achieved by using a continuous homogeneous absorber. Momentum-dependent path length differences in the dense hydrogen energy absorber provide the required correlation between momentum and ionization loss to accomplish longitudinal cooling. Recent studies of an 800 MHz RF cavity pressurized with hydrogen, as would be used in this application, show that the maximum gradient is not limited by a large external magnetic field, unlike vacuum cavities. Two new cooling ideas, Parametric-resonance Ionization Cooling and Reverse Emittance Exchange, will be employed to further reduce transverse emittances to a few mm-mr, which allows high luminosity with fewer muons than previously imagined. We describe these new ideas as well as a new precooling idea based on a HCC with z dependent fields that is being developed for an exceptional 6D cooling demonstration experiment. The status of the designs, simulations, and tests of the cooling components for a high luminosity, low emittance muon collider will be reviewed.

R.P. Johnson, Y.S. Derbenev

2006-09-01T23:59:59.000Z

318

Ionization cooling in the muon collider  

SciTech Connect

The muon beams in a high luminosity muon collider are produced with a very large emittance. The process of ionization cooling offers a method for reducing the 6-dimensional normalized emittance of the beam by a factor of {approx} 10{sup 6}. A simple analytic theory has been developed that demonstrates the dependence of the net cooling on various experimental parameters. The simple theory has been checked and realistic arrangements have been examined using Monte Carlo simulations. Transverse cooling of the initial beam can be achieved using passive Li absorbers in a FOFO lattice. The last factor of 10 in transverse cooling probably requires the use of current-carrying Li lenses. Efficient longitudinal cooling requires the use of wedge shaped absorbers in a dispersive section of the beam line. An example, multi-stage cooling scenario has been developed that meets the requirements of the muon collider. Preliminary designs have been made of solenoids for use in the FOFO lattice and of solenoids and dipoles for use in the emittance exchange sections. Detailed simulation work, farther optimization, and preparations for experimental demonstrations of critical components are currently in progress.

Fernow, R.C.; Gallardo, J.C.; Kirk, H.G.; Palmer, R.B. [and others

1996-10-01T23:59:59.000Z

319

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

320

Charged lepton electric dipole moments with the localized leptons and the new Higgs doublet in the two Higgs doublet model  

E-Print Network (OSTI)

We study the lepton electric dipole moments in the split fermion scenario, in the two Higgs doublet model, where the new Higgs scalars are localized around the origin in the extra dimension, with the help of the localizer field. We observe that the numerical value of the electron (muon, tau) electric dipole moment is at the order of the magnitude of 10^{-31} (10^{-24}, 10^{-22}) (e-cm) and this quantity is sensitive the new Higgs localization in the extra dimension.

Erhan Onur Iltan

2005-11-20T23:59:59.000Z

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321

Polarization Effects In The Charged Lepton Pair Production By A Neutrino (Antineutrino) In A Magnetic Field  

Science Conference Proceedings (OSTI)

The probability of the process of the charged lepton pair production by a neutrino (an antineutrino) with allowance for the longitudinal and transverse polarizations of the charged leptons in a magnetic field is presented. The dependence of the probability of the process on the spin variables of the charged leptons and on the azimuthal and polar angles of the initial and final neutrinos (antineutrinos) are investigated. It is shown that the probability of the process is sensitive to the spin variables of the charged leptons and to the direction of the neutrino (antineutrino) momentum. It is determined that the neutrino (antineutrino) energy and momentum loss through the production of a charged lepton pair happens asymmetrically.

Huseynov, Vali A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Ahmad, Ali S. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

2007-06-13T23:59:59.000Z

322

Cosmological lepton asymmetry with a nonzero mixing angle $\\theta_{13}$  

E-Print Network (OSTI)

While the baryon asymmetry of the Universe is nowadays well measured by cosmological observations, the bounds on the lepton asymmetry in the form of neutrinos are still significantly weaker. We place limits on the relic neutrino asymmetries using some of the latest cosmological data, taking into account the effect of flavor oscillations. We present our results for two different values of the neutrino mixing angle \\theta_{13}, and show that for large \\theta_{13} the limits on the total neutrino asymmetry become more stringent, diluting even large initial flavor asymmetries. In particular, we find that the present bounds are still dominated by the limits coming from Big Bang Nucleosynthesis, while the limits on the total neutrino mass from cosmological data are essentially independent of \\theta_{13}. Finally, we perform a forecast for COrE, taken as an example of a future CMB experiment, and find that it could improve the limits on the total lepton asymmetry approximately by up to a factor 5.

Castorina, Emanuele; Lattanzi, Massimiliano; Lesgourgues, Julien; Mangano, Gianpiero; Melchiorri, Alessandro; Pastor, Sergio

2012-01-01T23:59:59.000Z

323

Neutrino masses and heavy triplet leptons at the LHC: Testability of the type III seesaw mechanism  

Science Conference Proceedings (OSTI)

We study LHC signatures of the type III seesaw mechanism in which SU(2){sub L} triplet leptons are introduced to supply the heavy seesaw masses. To detect the signals of these heavy triplet leptons, one needs to understand their decays to standard model particles which depend on how light and heavy leptons mix with each other. We concentrate on the usual solutions with small light and heavy lepton mixing of the order of the square root of the ratio of light and heavy masses, (m{sub {nu}}/M{sub {nu}}{sub {sub R}}){sup 1/2}. This class of solutions can lead to a visible displaced vertex detectable at the LHC which can be used to distinguish small mixing and large mixing between light and heavy leptons. We show that, in this case, the couplings of light and heavy triplet leptons to gauge and Higgs bosons, which determine the decay widths and branching ratios, can be expressed in terms of light neutrino masses and their mixing. Using these relations, we study heavy triplet lepton decay patterns and production cross section at the LHC. If these heavy triplet leptons are below a TeV or so, they can be easily produced at the LHC due to their gauge interactions from being nontrivial representations of SU(2){sub L}. We consider two ideal production channels, (1) E{sup +}E{sup -}{yields}l{sup +}l{sup +}l{sup -}l{sup -}jj (l=e, {mu}, {tau}) and (2) E{sup {+-}}N{yields}l{sup {+-}}l{sup {+-}}jjjj in detail. For case 1, we find that with one or two of the light leptons being {tau} it can also be effectively studied. With judicious cuts at the LHC, the discovery of the heavy triplet leptons as high as a TeV can be achieved with 100 fb{sup -1} integrated luminosity.

Li Tong [Center for High Energy Physics, Peking University, Beijing, 100871 (China); He Xiaogang [Center for High Energy Physics, Peking University, Beijing, 100871 (China); Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China)

2009-11-01T23:59:59.000Z

324

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab  

Science Conference Proceedings (OSTI)

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very beginning, the design studies at Jefferson Lab have focused on achieving high collider performance, particularly ultrahigh luminosities up to 10{sup 34} cm{sup -2}s{sup -1} per detector with large acceptance, while maintaining high polarization for both the electron and light-ion beams. These are the two key performance requirements of a future electron-ion collider facility as articulated by the NSAC Long Range Plan. In MEIC, a new ion complex is designed specifically to deliver ion beams that match the high bunch repetition and highly polarized electron beam from CEBAF. During the last two years, both development of the science case and optimization of the machine design point toward a medium-energy electron-ion collider as the topmost goal for Jefferson Lab. The MEIC, with relatively compact collider rings, can deliver a luminosity above 10{sup 34} cm{sup -2}s{sup -1} at a center-of-mass energy up to 65 GeV. It offers an electron energy up to 11 GeV, a proton energy up to 100 GeV, and corresponding energies per nucleon for heavy ions with the same magnetic rigidity. This design choice balances the scope of the science program, collider capabilities, accelerator technology innovation, and total project cost. An energy upgrade could be implemented in the future by adding two large collider rings housed in another large tunnel to push the center-of-mass energy up to or exceeding 140 GeV. After careful consideration of an alternative electron energy recovery linac on ion storage ring approach, a ring-ring collider scenario at high bunch repetition frequency was found to offer fully competitive performance while eliminating the uncertainties of challenging R&D on ampere-class polarized electron sources and many-pass energy-recovery linacs (ERLs). The essential new elements of an MEIC facility at Jefferson Lab are an electron storage ring and an entirely new, modern ion acceleration and storage complex. For the high-current electron collider ring, the upgraded 12 GeV CEBAF SRF linac will serve as a full-energy injector, and, if needed, provide top

Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B

2012-08-01T23:59:59.000Z

325

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

326

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

327

Optimal, real-time control--colliders  

Science Conference Proceedings (OSTI)

With reasonable definitions, optimal control is possible for both classical and quantal systems with new approaches called PISC(Parallel) and NISC(Neural) from analogy with RISC (Reduced Instruction Set Computing). If control equals interaction, observation and comparison to some figure of merit with interaction via external fields, then optimization comes from varying these fields to give design or operating goals. Structural stability can then give us tolerance and design constraints. But simulations use simplified models, are not in real-time and assume fixed or stationary conditions, so optimal control goes far beyond convergence rates of algorithms. It is inseparable from design and this has many implications for colliders. 12 refs., 3 figs.

Spencer, J.E.

1991-05-01T23:59:59.000Z

328

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

329

Linear Thermite Charge  

The Linear Thermite Charge (LTC) is designed to rapidly cut through concrete and steel structural components by using extremely high temperature thermite reactions jetted through a linear nozzle.

330

Lepton Mixing Predictions from Delta(6n^2) Family Symmetry  

E-Print Network (OSTI)

We obtain predictions of lepton mixing parameters for direct models based on Delta(6n^2) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Delta(6n^2), we find many new candidates for large n able to yield reactor angle predictions within 3 sigma of recent global fits. We show that such Delta(6n^2) models with Majorana neutrinos predict trimaximal mixing with reactor angle theta_{13} fixed up to a discrete choice, an oscillation phase of either zero or pi and the atmospheric angle sum rules theta_{23}=45 degrees -/+ theta_{13}/sqrt{2}, respectively, which are consistent with recent global fits and will be tested in the near future.

King, Stephen F; Stuart, Alexander J

2013-01-01T23:59:59.000Z

331

Lepton Mixing Predictions from Delta(6n^2) Family Symmetry  

E-Print Network (OSTI)

We obtain predictions of lepton mixing parameters for direct models based on Delta(6n^2) family symmetry groups for arbitrarily large n in which the full Klein symmetry is identified as a subgroup of the family symmetry. After reviewing and developing the group theory associated with Delta(6n^2), we find many new candidates for large n able to yield reactor angle predictions within 3 sigma of recent global fits. We show that such Delta(6n^2) models with Majorana neutrinos predict trimaximal mixing with reactor angle theta_{13} fixed up to a discrete choice, an oscillation phase of either zero or pi and the atmospheric angle sum rules theta_{23}=45 degrees -/+ theta_{13}/sqrt{2}, respectively, which are consistent with recent global fits and will be tested in the near future.

Stephen F. King; Thomas Neder; Alexander J. Stuart

2013-05-14T23:59:59.000Z

332

Linear Collider Collaboration Tech Notes LCC-0140 SLAC-TN-04-041  

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

0 0 SLAC-TN-04-041 June 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Sensitivity to Nano-Tesla Scale Stray Magnetic Fields J. Frisch, T.O. Raubenheimer, P. Tenenbaum

333

Linear Collider Collaboration Tech Notes LCC-0139 SLAC-TN-04-042  

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

9 9 SLAC-TN-04-042 May 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Alternative Main Linac BNS Configurations for Reduced Energy Spread Andrei Seryi and Peter Tenenbaum

334

Linear Collider Collaboration Tech Notes LCC-0130 CBP Tech Note-302  

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

30 30 CBP Tech Note-302 March 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Research and Development Issues for NLC Damping Rings 2003-2004 A. Wolski Lawrence Berkeley National Laboratory

335

Linear Collider Collaboration Tech Notes LCC-0132 SLAC-PUB-10229  

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

2 2 SLAC-PUB-10229 November 2003 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Transverse Deflections in a Cavity Due to the Short-range Longitudinal Wake K. L. F. Bane, T. O. Raubenheimer, G. Stupakov, J. Wu

336

Linear Collider Collaboration Tech Notes LCC-0105 CBP Tec Note-266  

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

5 5 CBP Tec Note-266 October 2002 Effects of Systematic Multipole Errors on the Dynamic Aperture of the NLC Main Damping Rings A. Wolski, J.-Y. Jung Lawrence Berkeley National Laboratory University of California Berkeley, CA Abstract: Recent work on designs of dipoles, quadrupoles and sextupoles for the NLC Main Damping Ring has led to estimates of the systematic multipole components in the fields of these magnets. We report on studies of the effects of these multipoles on the dynamic aperture of the damping ring, and show that the systematic multipole components in the present magnet designs are unlikely to be a severe limitation. LCC-0105 CBP Tech Note-266 Effects of Systematic Multipole Errors on the Dynamic

337

Linear Collider Collaboration Tech Notes LCC-0080 CBP Tech Note-244  

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

0 0 CBP Tech Note-244 May 2002 Estimates of Collective Effects in the NLC Main Damping Rings A. Wolski and S. de Santis Lawrence Berkeley National Laboratory Berkeley, California Abstract: Damping Ring performance depends on the ability to store the design beam current, and extract the beam with the specified low transverse emittance. Given the high bunch charge and moderate energy, a variety of collective effects could play a significant role, in either limiting the bunch current, or increasing the emittance. Here, we estimate the consequences of various effects, based on current theories and understanding. LCC-0080 CBP Tech Note-244 Estimates of Collective Effects in the NLC Main Damping Rings A. Wolski and S. de Santis Lawrence Berkeley National Laboratory

338

Linear Collider Collaboration Tech Notes LCC-0150 CBP Tech Note-321  

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

0 0 CBP Tech Note-321 June 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Research and Development Issues for NLC Damping Rings 2004-2005 A. Wolski June 2004

339

Linear Collider Collaboration Tech Notes LCC-0155 CBP Tech Note-326  

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

5 5 CBP Tech Note-326 July 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Spin-Tracking Studies for Beam Polarization Preservation in the NLC Main Damping Rings

340

Linear Collider Collaboration Tech Notes LCC-0151 SLAC-TN-0-048  

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

of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion...

Note: This page contains sample records for the topic "linear colliders lepton" 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

International workshop on final focus and interaction regions of next generation linear colliders: Proceedings  

SciTech Connect

The first day of the workshop was devoted to four plenary issues'' talks, one for each working group: Beam-Beam Interaction, Detector, Hardware, and Optical Design. The last day was devoted to plenary talks summarizing the activities of the working groups. Each of the three remaining days there,was a short morning plenary devoted to a brief summary of the preceding day and an announcement of planned working group discussions for that day. The transparencies for the issues'' and summary'' talks are included in this volume, along with some remarks from the working group chairpersons. Very briefly, the beam-beam group continued to address the quantitative study of QED induced backgrounds, and attempted to better understand the nature and prevalence of QCD millijets. The detector group attempted to identify the impact on masking and detector design of the beam-beam backgrounds, the synchrotron radiation induced backgrounds from beam halos and muon backgrounds produced primarily in collimators. Nanosecond timing elements needed in conjunction with multi-bunch operation were discussed. The hardware group addressed the problem of magnet design and support, especially the final doublet magnets suspended within the detector environment, and instrumentation issues, such as high resolution beam position monitors. The optics group discussed new final focus system ideas, collimator design, and improvement of beamline tolerances. If you were not here to participate, we hope that this volume will help you in your orientation to these problems.

1992-01-01T23:59:59.000Z

342

International workshop on final focus and interaction regions of next generation linear colliders: Proceedings  

SciTech Connect

The first day of the workshop was devoted to four plenary ``issues`` talks, one for each working group: Beam-Beam Interaction, Detector, Hardware, and Optical Design. The last day was devoted to plenary talks summarizing the activities of the working groups. Each of the three remaining days there,was a short morning plenary devoted to a brief summary of the preceding day and an announcement of planned working group discussions for that day. The transparencies for the ``issues`` and ``summary`` talks are included in this volume, along with some remarks from the working group chairpersons. Very briefly, the beam-beam group continued to address the quantitative study of QED induced backgrounds, and attempted to better understand the nature and prevalence of QCD millijets. The detector group attempted to identify the impact on masking and detector design of the beam-beam backgrounds, the synchrotron radiation induced backgrounds from beam halos and muon backgrounds produced primarily in collimators. Nanosecond timing elements needed in conjunction with multi-bunch operation were discussed. The hardware group addressed the problem of magnet design and support, especially the final doublet magnets suspended within the detector environment, and instrumentation issues, such as high resolution beam position monitors. The optics group discussed new final focus system ideas, collimator design, and improvement of beamline tolerances. If you were not here to participate, we hope that this volume will help you in your orientation to these problems.

1992-11-01T23:59:59.000Z

343

A Test-bed for Future Linear Collider Technology: Argonne Wakefield...  

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

U.S.A. Abstract Research at the AWA Facility has been focused on the development of electron beam driven wakefield structures. Accelerating gradients of up to 100 MVm have been...

344

International Linear Collider Reports | U.S. DOE Office of Science...  

Office of Science (SC) Website

Facebook Facebook External link Share with Twitter Twitter External link Share with Google Bookkmarks Google Bookmarks External link Email a Friend Email link to: send...

345

Linear Collider Collaboration Tech Notes LCC-0147 CBP Tech Note-319  

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

7 7 CBP Tech Note-319 June 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Intrabeam Scattering in the NLC Main Damping Rings A. Wolski June 2004 Lawrence Berkeley National Laboratory

346

Linear Collider Collaboration Tech Notes LCC-0157 SLAC-PUB-10985  

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

plate (5) Rack and pinion travel (6) Sample plate stage (7) XYZ Omniax T M manipulator (8) Sample on XYZ (9) Electrostatic energy analyzer (10) X-ray source (11) SEY...

347

Linear Collider Collaboration Tech Notes LCC-0141 SLAC-TN-04-040  

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

1 1 SLAC-TN-04-040 May 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Availability and Failure Effects of NLC Main Linac Mechanical Movers T. M. Himel, C. Spencer, Peter Tenenbaum

348

PDF Nuclear Corrections for Charged Lepton and Neutrino Deep Inelastic Scattering Processes  

E-Print Network (OSTI)

We perform a \\chi^2-analysis of Nuclear Parton Distribution Functions (NPDFs) using neutral current charged-lepton Deeply Inelastic Scattering (DIS) and Drell-Yan data for several nuclear targets. The nuclear A dependence of the NPDFs is extracted in a next-to-leading order fit. We compare the nuclear corrections factors F2(Fe)/F2(D) for this charged-lepton data with other results from the literature. In particular, we compare and contrast fits based upon the charged-lepton DIS data with those using neutrino-nucleon DIS data.

I. Schienbein; J. Y. Yu; K. Kovarik; C. Keppel; J. G. Morfin; F. Olness; J. F. Owens

2009-07-14T23:59:59.000Z

349

Unconventional fermions: The Price of Quark-Lepton Unification at TeV Scales  

E-Print Network (OSTI)

The early petite unification (PUT) of quarks and leptons at TeV scales with sin^2 theta_W(M^2_Z) used as a constraint, necessitates the introduction of extra quarks and leptons with unconventional electric charges (up to 4/3 for the quarks and 2 for the leptons). This talk, in honor of Paul Frampton's 60th birthday, will be devoted to the motivation and construction of models of early unification and to their implications, including the issues of rare decays and unconventional fermions.

P. Q. Hung

2004-06-23T23:59:59.000Z

350

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

351

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

352

Probing the Quark Sea and Gluons: the Electron-Ion Collider Projects  

Science Conference Proceedings (OSTI)

EIC is the generic name for the nuclear science-driven Electron-Ion Collider presently considered in the US. Such an EIC would be the worlds first polarized electron-proton collider, and the worlds first e-A collider. Very little remains known about the dynamical basis of the structure of hadrons and nuclei in terms of the fundamental quarks and gluons of Quantum Chromodynamics (QCD). A large community effort to sharpen a compelling nuclear science case for an EIC occurred during a ten-week program taking place at the Institute for Nuclear Theory (INT) in Seattle from September 13 to November 19, 2010. The critical capabilities of a stage-I EIC are a range in center-of-mass energies from 20 to 70 GeV and variable, full polarization of electrons and light ions (the latter both longitudinal and transverse), ion species up to A=200 or so, multiple interaction regions, and a high luminosity of about 10{sup 34} electron-nucleons per cm{sup 2} and per second. The physics program of such a stage-I EIC encompass inclusive measurements (ep/A{yields}e'+X), which require detection of the scattered lepon and/or the full scattered hadronic debris with high precision, semi-inclusive processes (ep/A{yields}e'+h+X), which require detection in coincidence with the scattered lepton of at least one (current or target region) hadron; and exclusive processes (ep/A{yields}e'+N'/A'+{gamma}/m), which require detection of all particles in the reaction. The main science themes of an EIC are to i) map the spin and spatial structure of quarks and gluons in nucleons, ii) discover the collective effects of gluons in atomic nuclei, and (iii) understand the emergence of hadronic matter from color charge. In addition, there are opportunities at an EIC for fundamental symmetry and nucleon structure measurements using the electroweak probe. To truly make headway to image the sea quarks and gluons in nucleons and nuclei, the EIC needs high luminosity over a range of energies as more exclusive scattering probabilities are small, and any integrated detector/interaction region design needs to provide uniform coverage to detect spectator and diffractive products. This is because e-p and even more e-A colliders have a large fraction of their science related to what happens to the nucleon or ion beams. As a result, the philosophy of integration of complex detectors into an extended interaction region faces challenging constraints. Designs feature crossing angles between the protons or heavy ions during collisions with electrons, to remove potential problems for the detector induced by synchrotron radiation. Designs allocate quite some detector space before the final-focus ion quads, at the cost of luminosity, given that uniform detection coverage is a must for deep exclusive and diffractive processes. The integrated EIC detector/interaction region design at JLab focused on establishing full acceptance for such processes over a wide range of proton energies (20-100 GeV) with well achievable interaction region magnets. The detector design at BNL uses the higher ion beam energies to achieve good detection efficiency for instance for protons following a DVCS reaction, for proton beam energies starting from 100 GeV. Following a recommendation of the 2007 US Nuclear Science Long-Range Planning effort, the DOE Office of Nuclear Physics (DOE/NP) has allocated accelerator R&D funds to lay the foundation for a polarized EIC. BNL, in association with JLab and DOE/NP, has also established a generic detector R&D program to address the scientific requirements for measurements at a future EIC.

Rolf Ent

2012-04-01T23:59:59.000Z

353

Phase and amplitude detection system for the Stanford Linear Accelerator  

Science Conference Proceedings (OSTI)

A computer controlled phase and amplitude detection system to measure and stabilize the rf power sources in the Stanford Linear Accelerator is described. This system measures the instantaneous phase and amplitude of a 1 microsecond 2856 MHz rf pulse and will be used for phase feedback control and for amplitude and phase jitter detection. This paper discusses the measurement system performance requirements for the operation of the Stanford Linear Collider, and the design and implementation of the phase and amplitude detection system. The fundamental software algorithms used in the measurement are described, as is the performance of the prototype phase and amplitude detector system.

Fox, J.D.; Schwarz, H.D.

1983-01-01T23:59:59.000Z

354

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

355

Brookhaven National Laboratory The Relativistic Heavy Ion Collider (RHIC)  

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

Relativistic Heavy Ion Collider (RHIC) Relativistic Heavy Ion Collider (RHIC) An Exciting Beginning and a Compelling Future At the Relativistic Heavy Ion Collider (RHIC), a world-class particle accelerator at Brookhaven National Laboratory, physicists are exploring the most fundamental forces and properties of matter and the early universe, with important implications for our understanding of the world around us. Operated with funding from the U.S. Department of Energy's Office of Science, the Relativistic Heavy Ion Collider (RHIC), was designed to recreate a state of matter thought to have existed immediately after the Big Bang some 13 billion years ago, and to investigate how the proton gets its spin and intrinsic magnetism from its quark and gluon constituents. Large detectors located

356

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,...

357

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,...

358

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

359

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

360

Neutrino Factory and Muon Collider R&D  

E-Print Network (OSTI)

European, Japanese, and US Neutrino Factory designs are presented. The main R&D issues and associated R&D programs, future prospects, and the additional issues that must be addressed to produce a viable Muon Collider design, are discussed.

Steve Geer

2001-11-05T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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

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

362

Higgs boson decay into heavy quarks and heavy leptons: higher order corrections  

E-Print Network (OSTI)

Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_HHiggs boson into bb and tau+tau- are discussed.

Kim, Victor T

2010-01-01T23:59:59.000Z

363

Yukawaon Model with Anomaly Free Set of Quarks and Leptons in a U(3) Family Symmetry  

E-Print Network (OSTI)

In the so-called "yukawaon" model, the (effective) Yukawa coupling constants $Y_f^{eff}$ are given by vacuum expectation values (VEVs) of scalars $Y_f$ (yukawaons) with $3\\times 3$ components. So far, yukawaons $Y_f$ have been assigned to ${\\bf 6}$ or ${\\bf 6}^*$ of U(3) family symmetry, so that quarks and leptons were not anomaly free in U(3). In this paper, yukawaons are assigned to ${\\bf 8}+{\\bf 1}$ of U(3), so that quarks and leptons are anomaly free. Since VEV relations among yukawaons are also considerably changed, parameter fitting of the model is renewed. After fixing our free parameters by observed mass ratios, we have only two and one remaining free parameters for quark and lepton mixings, respectively. We obtain successful predictions for the quark and lepton mixing parameters including magnitudes of $CP$ violation. The effective Majorana neutrino mass is also predicted.

Yoshio Koide; Hiroyuki Nishiura

2013-08-09T23:59:59.000Z

364

Selection of tau leptons with the CDF Run 2 trigger system  

SciTech Connect

We have implemented triggers for hadronically decaying tau leptons within a framework of the CDF Run 2 trigger system. We describe the triggers, along with their physics motivations, and report on their initial performance.

A. Anastassov; S. Baroiant; M. Chertok

2003-07-01T23:59:59.000Z

365

The energy spectrum of tau leptons induced by the high energy Earth-skimming neutrinos  

E-Print Network (OSTI)

We present a semi-analytic calculation of the tau-lepton flux emerging from the Earth, induced by the incident high energy neutrinos interacting inside the Earth for $10^{5} \\leq E_{\

J. -J. Tseng; T. -W. Yeh; H. Athar; M. A. Huang; F. -F. Lee; G. -L. Lin

2003-05-27T23:59:59.000Z

366

Ion polarization in the MEIC figure-8 ion collider ring  

SciTech Connect

The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally/ transversely polarized protons/ deuterons/ light ions. We present a scheme that provides the required ion polarization arrangement in the MEIC's ion collider ring.

V.S. Morozov, Ya.S. Derbenev, Y. Zhang, P. Chevtsov, A.M. Kondratenko, M.A. Kondratenko, Yu.N. Filatov

2012-07-01T23:59:59.000Z

367

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

368

Test of Lepton Flavour Universality in K+ --> l+nu Decays  

E-Print Network (OSTI)

A precision test of lepton flavour universality has been performed by measuring the ratio RK of kaon leptonic decay rates K+ --> e+nu and K+ --> mu+nu in a sample of 59813 reconstructed K+ --> e+nu candidates with (8.71 +- 0.24)% background contamination. The result RK = (2.487 +- 0.013) * 10^{-5} is in agreement with the Standard Model expectation.

C. Lazzeroni et al.

2011-01-25T23:59:59.000Z

369

Physical model of leptons : Massive electrons, muons, tauons and their massless neutrons  

E-Print Network (OSTI)

The physical model (PhsMdl) of the leptons is offered by means of the PhsMdls of the vacuum and electron,described in our recent works. It is assumed that the vacuum is consistent by dynamides, streamlined in junctions of some tight crystalline lattice. Every dynamide contains a neutral pair of massless point-like (PntLk) contrary elementary electric charges (ElmElcChrgs): electrino $(-)$ and positrino $(+)$. The PntLk ElmElcChrgs of the massless electrino and positrino of some dynamide in the fluctuated vacuum may been excited or deviated by means of some energy, introduced by some photon or other micro particles (MicrPrts). The massless leptons (neutrinos) are neutral long-living solitary spherical vortical oscillation excitations of the uncharged fluctuating vacuum. The massive leptons are charged long-living solitary spherical vortical excitations of its fine spread (FnSpr) elementary electric charge (ElmElcChrg). So-called zitterbewegung is self-consistent strong-correlated vortical harmonic oscillation motion of the FnSpr ElmElcChrg of massive leptons. Different leptons have different self-consistent strong-correlated vortical harmonic oscillation motion of different sizes of their FnSpr ElmElcChrg, which is determined by their Kompton length $\\lambda =\\frac{h}{m C} $, where $m$ is the mass of the massive leptons. At mutual transition of one massive lepton into another massive lepton its PntLk ElmElcChrg move up by dint of weak interaction in the form of the charged intermediate vector meson $W$ from one self-consistent strong-correlated vortical harmonic oscillation motion of one size into another self-consistent strong-correlated vortical harmonic oscillation motion of another size.

Josiph Mladenov Rangelov

2000-03-07T23:59:59.000Z

370

Search for Pair Production of a Heavy Up-Type Quark Decaying to a W Boson and a b Quark in the lepton plus jets Channel with the ATLAS Detector  

Science Conference Proceedings (OSTI)

A search is presented for production of a heavy up-type quark (t{prime}) together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t{prime}{bar t}{prime} {yields} W{sup +}bW{sup -}{bar b}. The search is based on 1.04 fb{sup -1} of proton-proton collisions at {radical}s = 7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum, and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit of 404 GeV is set for the mass of the t{prime} quark.

Aad G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; et al.

2012-06-25T23:59:59.000Z

371

Measurement of Cabibbo suppressed decays of the $\\tau$ lepton  

E-Print Network (OSTI)

Branching ratios for the dominant Cabibbo-suppressed decays of the \\tau lepton have been measured by CLEO~II in e^+ e^- annihilation at CESR (\\sqrt{s} \\sim 10.6~GeV) using kaons with momenta below 0.7\\ \\rm GeV/c. The inclusive branching ratio into one charged kaon is (1.60 \\pm 0.12 \\pm 0.19)\\%. For the exclusive decays, B(\\tau \\to K^-) = (0.66 \\pm 0.07 \\pm 0.09)\\%, B(\\tau \\to K^- \\pi^0) = (0.51 \\pm 0.10 \\pm 0.07)\\%, and, based on three events, B(\\tau \\to K^- \\pi^0 \\pi^0) < 0.3\\% at the 90\\% confidence level. These represent significant improvements over previous results. B(\\tau\\to K^- \\pi^0) is measured for the first time with exclusive \\pi^0 reconstruction. hardcopies with figures can be obtained by writing to: Pam Morehouse preprint secretary Newman Lab Cornell University Ithaca, NY 14853 or by sending mail to: preprints@lns62.lns.cornell.edu

Battle, M; Kwon, Y; Roberts, S; Thorndike, E H; Wang, C H; Dominick, J; Lambrecht, M; Sanghera, S; Shelkov, V; Skwarnicki, T; Stroynowski, R; Volobuev, I P; Wei, G; Zadorozhny, P; Artuso, M; Goldberg, M; He, D; Horwitz, N; Kennett, R; Mountain, R; Moneti, G C; Muheim, F; Mukhin, Y; Playfer, S; Rozen, Y; Stone, S; Thulasidas, M; Vasseur, G; Zhu, G; Bartelt, J; Csorna, S E; Egyed, Z; Jain, V; Kinoshita, K; Edwards, K W; Ogg, M; Britton, D I; Hyatt, E R F; MacFarlane, D B; Patel, P M; Akerib, D S; Barish, B C; Chadha, M; Chan, S; Cowen, D F; Eigen, G; Miller, J S; O'Grady, C; Urheim, J; Weinstein, A J; Acosta, D; Athanas, M; Masek, G E; Paar, H P; Sivertz, M; Gronberg, J B; Kutschke, R; Menary, S R; Morrison, R J; Nakanishi, S; Nelson, H N; Nelson, T K; Qiao, C; Richman, J D; Ryd, A; Tajima, H; Sperka, D; Witherell, M S; Procario, M; Balest, R; Cho, K; Daoudi, M; Ford, W T; Johnson, D R; Lingel, K; Lohner, M; Rankin, P; Smith, J G; Alexander, J P; Bebek, C; Berkelman, K; Bloom, K; Browder, T E; Cassel, David G; Cho, H A; Coffman, D M; Drell, P S; Ehrlich, R; Gaidarev, P B; Galik, R S; Garca-Sciveres, M; Geiser, B; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Jones, C D; Jones, S L; Kandaswamy, J; Katayama, N; Kim, P C; Kreinick, D L; Ludwig, G S; Masui, J; Mevissen, J; Mistry, N B; Ng, C R; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Salman, S; Sapper, M; Wrthwein, F; Avery, P; Freyberger, A P; Rodrguez, J; Stephens, R; Yang, S; Yelton, J; Cinabro, D; Henderson, S; Liu, T; Saulnier, M; Wilson, R; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Gollin, G; Ong, B; Palmer, M; Selen, M; Thaler, J J; Sadoff, A J; Ammar, R; Ball, S; Baringer, P; Bean, A; Besson, D; Coppage, D; Copty, N K; Davis, R; Hancock, N; Kelly, M; Kwak, N; Lam, H; Kubota, Y; Lattery, M; Nelson, J K; Patton, S; Perticone, D; Poling, R A; Savinov, V; Schrenk, S; Wang, R; Alam, M S; Kim, I J; Nemati, B; O'Neill, J J; Severini, H; Sun, C R; Zoeller, M M; Crawford, G; Daubenmier, C M; Fulton, R; Fujino, D; Gan, K K; Honscheid, K; Kagan, H; Kass, R; Lee, J; Malchow, R L; Skovpen, Y; Sung, M; White, C; Butler, F; Fu, X; Kalbfleisch, G R; Ross, W R; Skubic, P L; Snow, J; Wang, P L; Wood, M; Brown, D N; Fast, J; McIlwain, R L; Miao, T; Miller, D H; Modesitt, M; Payne, D; Shibata, E I; Shipsey, I P J; Wang Pei Ning

1994-01-01T23:59:59.000Z

372

Lepton Flavor Violation in Predictive Supersymmetric GUT Models  

E-Print Network (OSTI)

There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially $\\sin^2 2\\theta_{13}$, are obtained, charged lepton flavor violation (LFV) experiments are able to differentiate even further among the models. In this paper, we investigate various rare LFV processes, such as $\\ell_{i} \\to \\ell_{j} + \\gamma$ and $\\mu-e$ conversion, in five predictive supersymmetric (SUSY) SO(10) models and their allowed soft-SUSY breaking parameter space in the constrained minimal SUSY standard model. Utilizing the Wilkinson Microwave Anisotropy Probe dark matter constraints, we obtain lower bounds on the branching ratios of these rare processes and find that at least three of the five models we consider give rise to predictions for $\\mu \\to e + \\gamma$ that will be tested by the MEG Collaboration at PSI. In addition, the next generation $\\mu-e$ conversion experiment has sensitivity to the predictions of all five models, making it an even more robust way to test these models. While generic studies have emphasized the dependence of the branching ratios of these rare processes on the reactor neutrino angle $\\theta_{13}$ and the mass of the heaviest right-handed neutrino $M_3$, we find very massive $M_3$ is more significant than large $\\theta_{13}$ in leading to branching ratios near to the present upper limits.

Carl H. Albright; Mu-Chun Chen

2008-02-28T23:59:59.000Z

373

Lepton Flavor Violation in Predictive SUSY-GUT Models  

SciTech Connect

There have been many theoretical models constructed which aim to explain the neutrino masses and mixing patterns. While many of the models will be eliminated once more accurate determinations of the mixing parameters, especially sin{sup 2} 2{theta}{sub 13}, are obtained, charged lepton flavor violation (LFV) experiments are able to differentiate even further among the models. In this paper, they investigate various rare LFV processes, such as {ell}{sub i} {yields} {ell}{sub j} + {gamma} and {mu} - e conversion, in five predictive SUSY SO(10) models and their allowed soft SUSY breaking parameter space in the constrained minimal SUSY standard model (CMSSM). Utilizing the WMAP dark matter constraints, they obtain lower bounds on the branching ratios of these rare processes and find that at least three of the five models they consider give rise to predictions for {mu} {yields} e + {gamma} that will be tested by the MEG collaboration at PSI. in addition, the next generation {mu} - e conversion experiment has sensitivity to the predictions of all five models, making it an even more robust way to test these models. While generic studies have emphasized the dependence of the branching ratios of these rare processes on the reactor neutrino angle, {theta}{sub 13}, and the mass of the heaviest right-handed neutrino, M{sub 3}, they find very massive M{sub 3} is more significant than large {theta}{sub 13} in leading to branching ratios near to the present upper limits.

Albright, Carl H.; /Northern Illinois U. /Fermilab; Chen, Mu-Chun; /UC, Irvine

2008-02-01T23:59:59.000Z

374

Searches for the baryon- and lepton-number violating decays B[superscript 0]-->Lambda c+l-, B--->Lambda l-, and B--->Lambda[over-bar] l- l-  

E-Print Network (OSTI)

Searches for B mesons decaying to final states containing a baryon and a lepton are performed, where the baryon is either ?c or ? and the lepton is a muon or an electron. These decays violate both baryon and lepton number ...

Cowan, Ray Franklin

375

When Galaxies Collide: Ripples Indicate Recent Impact Close to Home |  

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

When Galaxies Collide: Ripples Indicate Recent Impact Close to Home When Galaxies Collide: Ripples Indicate Recent Impact Close to Home When Galaxies Collide: Ripples Indicate Recent Impact Close to Home June 28, 2012 - 11:16am Addthis This is a graphic representation of the Milky Way, the galaxy in which Earth is contained. Scientists know of more than 20 visible satellite galaxies that circle the center of the Milky Way, with masses ranging from one million to one billion solar masses. Occasionally, one of these orbiting galaxies pass through the Milky Way making waves for millennia. | Graphic courtesy of NASA This is a graphic representation of the Milky Way, the galaxy in which Earth is contained. Scientists know of more than 20 visible satellite galaxies that circle the center of the Milky Way, with masses ranging from

376

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

377

The Relativistic Heavy Ion Collider (RHIC) - the nation's only remaining  

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

Collider (RHIC) - the nation's only remaining Collider (RHIC) - the nation's only remaining particle collider, located at Brookhaven National Laboratory - has made a series of landmark discoveries and continuing breakthroughs in science and technology. One major accomplishment has been RHIC's ability to recreate and study in detail a type of matter that last existed at the beginning of the universe to better understand the strongest force in nature - the force that holds together the fundamental particles that make up 99 percent of visible matter in the universe today, everything from stars to planets to people. In addition to giving us a new way to explore and understand the nature of the early universe and the force that holds together ordinary matter, research at RHIC has revealed stunning

378

When Galaxies Collide: Ripples Indicate Recent Impact Close to Home |  

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

When Galaxies Collide: Ripples Indicate Recent Impact Close to Home When Galaxies Collide: Ripples Indicate Recent Impact Close to Home When Galaxies Collide: Ripples Indicate Recent Impact Close to Home June 28, 2012 - 11:16am Addthis This is a graphic representation of the Milky Way, the galaxy in which Earth is contained. Scientists know of more than 20 visible satellite galaxies that circle the center of the Milky Way, with masses ranging from one million to one billion solar masses. Occasionally, one of these orbiting galaxies pass through the Milky Way making waves for millennia. | Graphic courtesy of NASA This is a graphic representation of the Milky Way, the galaxy in which Earth is contained. Scientists know of more than 20 visible satellite galaxies that circle the center of the Milky Way, with masses ranging from

379

Massive Stars in Colliding Wind Systems: the GLAST Perspective  

SciTech Connect

Colliding winds of massive stars in binary systems are considered as candidate sites of high-energy non-thermal photon emission. They are already among the suggested counterparts for a few individual unidentified EGRET sources, but may constitute a detectable source population for the GLAST observatory. The present work investigates such population study of massive colliding wind systems at high-energy gamma-rays. Based on the recent detailed model (Reimer et al. 2006) for non-thermal photon production in prime candidate systems, we unveil the expected characteristics of this source class in the observables accessible at LAT energies. Combining the broadband emission model with the presently cataloged distribution of such systems and their individual parameters allows us to conclude on the expected maximum number of LAT-detections among massive stars in colliding wind binary systems.

Reimer, Anita; Reimer, Olaf; /Stanford U., HEPL /KIPAC, Menlo Park

2011-11-29T23:59:59.000Z

380

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

Note: This page contains sample records for the topic "linear colliders lepton" 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
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381

Structure Functions in Deep Inelastic Lepton Scattering: Data from DOE laboratory experiments as compiled in data reviews by the Durham High Energy Physics Database Group  

DOE Data Explorer (OSTI)

Gehrmann, Roberts, and Whalley in their 1999 paper, A Compilation of Structure Functions in Deep Inelastic Scattering, published in volume 25 of Journal of Physics G (Nuclear and Particle Physics) note that these data will continue to be relevant to the next generation of hadron colliders. They present data on the unpolarized structure functions F2 and xF3, R D ._L=_T /, the virtual photon asymmetries A1 and A2 and the polarized structure functions g1 and g2, from deep inelastic lepton scattering off protons, deuterium and nuclei. Data are presented in both tabular and graphical format and include predictions based on the MRST98 and CTEQ4 parton distribution functions as well. The data gathered from the relevant collaborations at DOE's Fermilab, SLAC, and JLAB are available, and so are data from related collaborations based at CERN and DESY. The Durham High Energy Physics (HEP) Database Group makes these data, extracted from papers and data reviews, available in one place in an easy-to-access format. These data are also include in the Durham HEP Reaction Data Database which can be searched at http://durpdg.dur.ac.uk/spires/hepdata/reac.html

Gehrmann, T; Roberts, R. G.; Whalley, M. R.; Durham HEP Database Group

382

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

383

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

384

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

385

Charge recombination in the muon collider cooling channel  

SciTech Connect

The final stage of the ionization cooling channel for the muon collider must transversely recombine the positively and negatively charged bunches into a single beam before the muons can be accelerated. It is particularly important to minimize any emittance growth in this system since no further cooling takes place before the bunches are collided. We have found that emittance growth could be minimized by using symmetric pairs of bent solenoids and careful matching. We show that a practical design can be found that has transmission {approx}99%, emittance growth less than 0.1%, and minimal dispersion in the recombined bunches.

Fernow, R. C.; Palmer, R. B. [Physics Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)

2012-12-21T23:59:59.000Z

386

R&D Toward a Neutrino Factory and Muon Collider  

SciTech Connect

Significant progress has been made in recent years in R&D towards a neutrino factory and muon collider. The U.S. Muon Accelerator Program (MAP) has been formed recently to expedite the R&D efforts. This paper will review the U.S. MAP R&D programs for a neutrino factory and muon collider. Muon ionization cooling research is the key element of the program. The first muon ionization cooling demonstration experiment, MICE (Muon Ionization Cooling Experiment), is under construction now at RAL (Rutherford Appleton Laboratory) in the UK. The current status of MICE will be described.

Zisman, Michael S

2011-03-20T23:59:59.000Z

387

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.

388

Detroit as linear city.  

E-Print Network (OSTI)

??Detroit is a city in decline. Through strategic withdrawal into a linear city its main artery -Woodward Avenue- becomes an assembly line that holds different (more)

Kuys, J.I.

2012-01-01T23:59:59.000Z

389

Linear phase compressive filter  

DOE Patents (OSTI)

A phase linear filter for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass filters with each low pass filter having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear filter. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.

McEwan, Thomas E. (Livermore, CA)

1995-01-01T23:59:59.000Z

390

Focusing in Linear Accelerators  

DOE R&D Accomplishments (OSTI)

Review of the theory of focusing in linear accelerators with comments on the incompatibility of phase stability and first-order focusing in a simple accelerator.

McMillan, E. M.

1950-08-24T23:59:59.000Z

391

Linear Graphene Plasmons  

Science Conference Proceedings (OSTI)

The coupling of the plasmon spectra of graphene and a nearby thick plasma is examined here in detail. The coupled modes include linear plasmons. Keywords: Graphene, plasmons, surface

N. J.M. Horing

2010-11-01T23:59:59.000Z

392

Search for anomalous production of multiple leptons in association with $W$ and $Z$ bosons at CDF  

Science Conference Proceedings (OSTI)

This paper presents a search for anomalous production of multiple low-energy leptons in association with a W or Z boson using events collected at the CDF experiment corresponding to 5.1 fb{sup -1} of integrated luminosity. This search is sensitive to a wide range of topologies with low-momentum leptons, including those with the leptons near one another. The observed rates of production of additional electrons and muons are compared with the standard model predictions. No indications of phenomena beyond the standard model are found. A 95% confidence level limit is presented on the production cross section for a benchmark model of supersymmetric hidden-valley Higgs production. Particle identification efficiencies are also provided to enable the calculation of limits on additional models.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U.; Artikov, A.; /Dubna, JINR /Texas A-M

2012-02-01T23:59:59.000Z

393

On the origin of families of quarks and leptons - predictions for four families  

E-Print Network (OSTI)

The approach unifying all the internal degrees of freedom--proposed by one of us--is offering a new way of understanding families of quarks and leptons: A part of the starting Lagrange density in d(=1+13), which includes two kinds of spin connection fields--the gauge fields of two types of Clifford algebra objects--transforms the right handed quarks and leptons into the left handed ones manifesting in d=1+3 the Yukawa couplings of the Standard model. We study the influence of the way of breaking symmetries on the Yukawa couplings and estimate properties of the fourth family--the quark masses and the mixing matrix, investigating the possibility that the fourth family of quarks and leptons appears at low enough energies to be observable with the new generation of accelerators.

G. Bregar; M. Breskvar; D. Lukman; N. S. Mankoc Borstnik

2007-08-21T23:59:59.000Z

394

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

395

Spin Asymmetries Arising In Neutrino-Lepton Processes In A Magnetic Field And Their Macroscopic Appearance  

Science Conference Proceedings (OSTI)

We present expressions that determine the differential cross sections and energy and momentum losses for the neutrino-lepton processes {nu}le- {yields} {nu}le-, {nu}-tildele- {yields} {nu}-tildele-, {nu}l{nu}-tildel {yields} e-e+, {nu}l{nu}-tildee {yields} l-e+, {nu}le- {yields} {nu}el- in a magnetic field with allowance for the longitudinal and transverse polarizations of the charged leptons and antileptons and the results on the spin asymmetries arising in these processes.

Huseynov, Vali A. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan); Laboratory of Physical Research, Nakhchivan Division of Azerbaijan National Academy of Sciences, AZ 7000, Nakhchivan (Azerbaijan); Gasimova, Rasmiyya E.; Akbarova, Nurida Y.; Hajiyeva, Billura T. [Department of General and Theoretical Physics, Nakhchivan State University, AZ 7000, Nakhchivan (Azerbaijan)

2007-06-13T23:59:59.000Z

396

Implications of texture 4 zero lepton mass matrices for U_{e3}  

E-Print Network (OSTI)

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \\Delta m_{12}^2 constrained by SNP and s_{23} and \\Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\

Randhawa, M; Sen-Gupta, M; Randhawa, Monika; Ahuja, Gulsheen; Gupta, Manmohan

2002-01-01T23:59:59.000Z

397

Implications of texture 4 zero lepton mass matrices for U_{e3}  

E-Print Network (OSTI)

Lepton mass matrices similar to texture 4 zero quark mass matrices, known to be quite successful in explaining the CKM phenomenology, have been considered for finding the mixing matrix element U_{e3} (\\equiv s_{13}) respecting the CHOOZ constraint, with s_{12} and \\Delta m_{12}^2 constrained by SNP and s_{23} and \\Delta m_{23}^2 constrained by ANP. Taking charged lepton mass matrix M_l to be diagonal, we find that the ranges of s_{13} corresponding to different SNP solutions very well include the corresponding values of s_{13} found by Akhmedov et al. by considering neutrino mass matrix M_{\

Monika Randhawa; Gulsheen Ahuja; Manmohan Gupta

2002-03-12T23:59:59.000Z

398

Neutrinos and Lepton Flavour Violation in the Left-Right Twin Higgs Model  

E-Print Network (OSTI)

We analyse the lepton sector of the Left-Right Twin Higgs Model. This model offers an alternative way to solve the "little hierarchy" problem of the Standard Model. We show that one can achieve an effective see-saw to explain the origin of neutrino masses and that this model can accommodate the observed neutrino masses and mixings. We have also studied the lepton flavour violation process l_1 -> l_2 \\gamma and discussed how the experimental bound from these branching ratios constrains the scale of symmetry breaking of this Twin Higgs model.

Asmaa Abada; Irene Hidalgo

2007-11-08T23:59:59.000Z

399

Origin of quark-lepton flavor in SO(10) with type II seesaw mechanism  

SciTech Connect

Diverse mass and mixing patterns between the quarks and leptons makes it challenging to construct a simple grand unified theory of flavor. We show that SO(10) supersymmetry grand unified theories with type II seesaw mechanism giving neutrino masses provide a natural framework for addressing this issue. A simple ansatz that the dominant Yukawa matrix (the 10-Higgs coupling to matter) has rank one appears to simultaneously explain both the large lepton mixings as well as the observed quark flavor hierarchy in these models. A testable prediction of this ansatz is the neutrino mixing, U{sub e3}, which should be observable in planned long baseline experiments.

Dutta, Bhaskar [Department of Physics, Texas A and M University, College Station, Texas 77843-4242 (United States); Mimura, Yukihiro; Mohapatra, R. N. [Maryland Center for Fundamental Physics and Department of Physics, University of Maryland, College Park, Maryland, 20742 (United States)

2009-11-01T23:59:59.000Z

400

Search for quark-lepton compositeness in the dimuon final state at D0  

SciTech Connect

We used the upgraded D0 detector at the Tevatron at {radical}s = 1.96 TeV to collect data in a search for a compositeness signature of quarks and leptons. This analysis uses an integrated luminosity of 400 pb{sup -1}. The high-mass dimuon mass spectrum is compared with that predicted by Drell-Yan (DY) scattering, modified by a contact interaction. This interaction is parameterized by a compositeness energy scale factor {Lambda}. Preliminary limits on {lambda} are set at the 95% confidence level for constructive and destructive interference between the DY amplitude and the contact interaction for various quark and lepton chiralities.

Xuan, Nguyen Phuoc; /Notre Dame U.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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

NMSSM in disguise: Discovering singlino dark matter with soft leptons at the LHC  

E-Print Network (OSTI)

, cuts on lepton transverse momentum of even 10 GeV will remove the wast majority of events for points BE, and hence remove the one remaining clue to the non-minimal nature of the scenario. However, one should also notice that the distributions have... benchmark point, corresponding to 10 fb?1 of data. For the SM background we have generated a wide variety of samples that in addition to two, possibly soft, OSSF isolated leptons at low invariant mass, could potentially yield the hard jets and missing energy...

Kraml, S; Raklev, Are R; White, Martin J

402

Energy-Scale Dependence of the Lepton-Flavor-Mixing Matrix hep-ph/9904292  

E-Print Network (OSTI)

We study an energy-scale dependence of the lepton-flavor-mixing matrix in the minimal supersymmetric standard model with the effective dimension-five operators which give the masses of neutrinos. We analyze the renormalization group equations of ?ijs which are coefficients of these effective operators under the approximation to neglect the corrections of O(?2). As a consequence, we find that all phases in ? do not depend on the energy-scale, and that only ng ? 1 (ng: generation number) real independent parameters in the lepton-flavor-mixing matrix depend on the energyscale.

N. Haba; Y. Matsui; N. Okamura; M. Sugiura

1999-01-01T23:59:59.000Z

403

Atomic Physics Aspects of a Relativistic Nuclear Collider  

DOE Green Energy (OSTI)

Atomic collision cross sections involving bare uranium nuclei are large at relativistic energies and will affect the design and operation of a relativistic nuclear collider (RNC). The most significant may be production of electron-positron pairs and muon pairs ({approx} 10{sup 8} per sec. and 2000 per sec. respectively for a 100 GeV/nucleon collider with a luminosity of 10{sup 27} cm{sup 2} s{sup -1}). Although the pair production is a direct measure of the luminosity it is also a large source of background and capture of an electron from the pair by one of the nuclei will result in the loss of the ion. Another important loss mechanism is Coulomb excitation of the giant nuclear dipole and giant nuclear quadrupole resonances. Storing and colliding bare and highly-stripped uranium opens up new possibilities for novel atomic physics experiments and an alternate approach for present experiments. As examples, the use of a collider for experiments to study spontaneous decay of the super-critical state (both positron production and x-ray production) of quasi-atoms of atomic number Z > 172, and a storage-ring measurement of the ground state hyperfine structure of hydrogen like thallium as a test of quantum electrodynamics (QED) are discussed.

Gould, R.

1984-11-01T23:59:59.000Z

404

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

405

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

406

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

407

Details of Colliding Thunderstorm Outflows as Observed by Doppler Lidar  

Science Conference Proceedings (OSTI)

Three cases of colliding outflow boundaries are examined using data collected from the NOAA Doppler lidar and a meteorological tower during the summer of 1986 near Boulder, Colorado. The data are unique because the lidar and the 300 m tower were ...

J. M. Intrieri; A. J. Bedard Jr.; R. M. Hardesty

1990-05-01T23:59:59.000Z

408

A comparison of collider searches for new gauge bosons  

SciTech Connect

We compare and contrast the search capabilities during the next decade of e{sup +}e{sup {minus}}, ep, and {bar p}p colliders for new neutral gauge bosons in several extended versions of the Standard Model. 7 refs., 3 figs., 1 tab.

Hewett, J.L. (Wisconsin Univ., Madison, WI (USA). Dept. of Physics); Rizzo, T.G. (Wisconsin Univ., Madison, WI (USA). Dept. of Physics Iowa State Univ. of Science and Technology, Ames, IA (USA))

1990-01-01T23:59:59.000Z

409

MERCURY HANDLING FOR THE TARGET SYSTEM FOR A MUON COLLIDER  

E-Print Network (OSTI)

Cryostat 1. Remote handling The high radiation levels and presence of hazardous, ac- tivated mercury vaporsMERCURY HANDLING FOR THE TARGET SYSTEM FOR A MUON COLLIDER Van Graves , ORNL, Oak Ridge, TN 37830 placement within the Shielding Module in a remote environment. · Providing double containment of the mercury

McDonald, Kirk

410

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

411

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

412

QED peripheral mechanism of pair production at colliders  

Science Conference Proceedings (OSTI)

Cross sections of the processes of production of neutral pions and pairs of charged fermions and bosons in peripheral interaction of leptons and photons are calculated in the main logarithmic approximation. We investigate the phase volumes and differential cross sections. The differential cross sections of production of a few neutral pions and a few pairs are written down explicitly. Considering the academic problem of summation over a number of pairs for massless particles we reproduce the known results obtained in the 1970s. The possibility of constructing the generator for Monte Carlo modeling of these processes based on these results is discussed.

Ahmadov, A. I.; Galynskii, M. V.; Bystritskiy, Yu. M.; Kuraev, E. A.; Shatnev, M. G. [Joint Institute for Nuclear Research, Dubna, Russia, and Institute of Physics, Azerbaijan National Academy of Sciences, Baku (Azerbaijan); Institute of Physics, Minsk (Belarus); Joint Institute for Nuclear Research, Dubna (Russian Federation); Kharkov Institute of Physics and Technology, Kharkov, 61108 (Ukraine)

2008-10-01T23:59:59.000Z

413

Search for [ital B][sup 0] decays to two charged leptons  

Science Conference Proceedings (OSTI)

We have searched for [ital B][sup 0] decays to two charged leptons and set 90% confidence level upper limits on the branching fractions: [ital B]([ital B][sup 0][r arrow][ital e][sup +][ital e][sup [minus

Ammar, R.; Ball, S.; Baringer, P.; Bean, A.; Besson, D.; Coppage, D.; Copty, N.; Davis, R.; Hancock, N.; Kelly, M.; Kwak, N.; Lam, H.; Kubota, Y.; Lattery, M.; Nelson, J.K.; Patton, S.; Perticone, D.; Poling, R.; Savinov, V.; Schrenk, S.; Wang, R.; Alam, M.S.; Kim, I.J.; Nemati, B.; O'Neill, J.J.; Severini, H.; Sun, C.R.; Zoeller, M.M.; Crawford, G.; Daubenmier, C.M.; Fulton, R.; Fujino, D.; Gan, K.K.; Honscheid, K.; Kagan, H.; Kass, R.; Lee, J.; Malchow, R.; Morrow, F.; Skovpen, Y.; Sung, M.; White, C.; Butler, F.; Fu, X.; Kalbfleisch, G.; Ross, W.R.; Skubic, P.; Snow, J.; Wang, P.L.; Wood, M.; Brown, D.N.; Fast, J.; McIlwain, R.L.; Miao, T.; Miller, D.H.; Modesitt, M.; Payne, D.; Shibata, E.I.; Shipsey, I.P.J.; Wang, P.N.; Battle, M.; Ernst, J.; Kwon, Y.; Roberts, S.; Thorndike, E.H.; Wang, C.H.; Dominick, J.; Lambrecht, M.; Sanghera, S.; Shelkov, V.; Skwarnicki, T.; Stroynowski, R.; Volobouev, I.; Wei, G.; Zadorozhny, P.; Artuso, M.; Goldberg, M.; He, D.; Horwitz, N.; Kennett, R.; M; (CLEO Collaboration)

1994-06-01T23:59:59.000Z

414

Search for the rare leptonic decays B+-->l+ nu l (l=e,mu)  

E-Print Network (OSTI)

We have performed a search for the rare leptonic decays B+-->?+nu ?(l=e,mu), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468106 BB[over-bar] pairs we find ...

Zhao, M.

415

Novel inclusive search for the Higgs boson in the four-lepton final state at CDF  

E-Print Network (OSTI)

An inclusive search for the standard model Higgs boson using the four-lepton final state in proton-antiproton collisions produced by the Tevatron at ?s=1.96??TeV is conducted. The data are recorded by the CDF II detector ...

Gomez-Ceballos, Guillelmo

416

Early Discoveries of New Gauge Bosons W' and Z' in Leptonic Decay Channels at ATLAS  

E-Print Network (OSTI)

We present the potential of the ATLAS detector to discover new massive gauge bosons in their leptonic decay channels: W' -> l nu_l and Z' -> l+ l-. Emphasis is placed on early data-taking at the LHC with low luminosity (up to 1 fb^-1).

E. N. Thompson; for the ATLAS Collaboration

2008-10-16T23:59:59.000Z

417

Search for narrow resonances in the lepton final state at CMS  

E-Print Network (OSTI)

We discuss the results of searches for high-mass narrow resonances decaying into pairs of leptons using pp collisions at 7 TeV delivered by LHC and collected with the CMS detector in 2010 and 2011. These include searches for the Z' bosons and RS gravitons.

Gennadiy Kukartsev; for the CMS Collaboration

2011-10-13T23:59:59.000Z

418

Search for narrow resonances in the lepton final state at CMS  

E-Print Network (OSTI)

We discuss the results of searches for high-mass narrow resonances decaying into pairs of leptons using pp collisions at 7 TeV delivered by LHC and collected with the CMS detector in 2010 and 2011. These include searches for the Z' bosons and RS gravitons.

Kukartsev, Gennadiy

2011-01-01T23:59:59.000Z

419

North Linear Accelerator  

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

North Linear Accelerator North Linear Accelerator Building Exterior Beam Enclosure Level Walk to the North Spreader North Recombiner Extras! North Linear Accelerator The North Linear Accelerator is one of the two long, straight sections of Jefferson Lab's accelerator. Electrons gain energy in this section by passing through acceleration cavities. There are 160 cavities in this straightaway, all lined up end to end. That's enough cavities to increase an electron's energy by 400 million volts each time it passes through this section. Electrons can pass though this section as many as five times! The cavities are powered by microwaves that travel down the skinny rectangular pipes from the service buildings above ground. Since the cavities won't work right unless they are kept very cold, they

420

Linear Motor Powered Transportation  

E-Print Network (OSTI)

This special issue on linear-motor powered transportation covers both supporting technologies and innovative transport systems in various parts of the World, as this technology moves from the lab to commercial operations. ...

Thornton, Richard D.

Note: This page contains sample records for the topic "linear colliders lepton" 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

Edges and linearization  

E-Print Network (OSTI)

This thesis is concerned with how grammar determines the phonological consequence of syntactic dislocation. It centers on a hypothesis regarding the linearization of movement chains - the Edge Condition on Copy Deletion, ...

Trinh, Tue H. (Tue Huu)

2011-01-01T23:59:59.000Z

422

Proceedings of the 1992 workshops on high-energy physics with colliding beams. Volume 1, Search for new phenomena at colliding-beam facilities  

SciTech Connect

This report contains brief papers and viewgraphs on high energy topics like: supersymmetry; new gauge bosons; and new high energy colliders.

Rogers, J. [ed.

1992-12-31T23:59:59.000Z

423

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

424

Search for the Higgs boson in its decay into tau leptons at CMS  

E-Print Network (OSTI)

A search for the Standard Model Higgs boson in the H --> rr channel is presented. The search is performed on proton collision data collected by the Compact Muon Solenoid at the Large Hadron Collider. The data corresponds ...

Chan, Matthew Hans

2013-01-01T23:59:59.000Z

425

Measurement of the top quark pair production cross section in the dilepton channel using lepton+track selection  

SciTech Connect

The production cross section for t{bar t} pairs decaying into two lepton final states was measured using data from the D0 detector at Fermilab. The measurement was made using a lepton+track selection, where one lepton is fully identified and the second lepton is observed as an isolated track. This analysis is designed to complement similar studies using two fully identified leptons [1]. The cross section for the lepton+track selection was found to be {sigma} = 5.2{sub -1.4}{sup +1.6}(stat){sub -0.8}{sup +0.9}(syst) {+-} 0.3(lumi) pb. The combined cross section using both the lepton+track data and the data from the electron+electron, electron+muon, and muon+muon samples is: {sigma} = 6.4{sub -0.9}{sup +0.9}(stat){sub -0.7}{sup +0.8}(syst) {+-} 0.4(lumi) pb.

Wagner, Robert Emil; /Princeton U.

2008-09-01T23:59:59.000Z

426

Microsoft Word - 2003-0820 RHIC collider projections.doc  

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

RHIC Collider Projections (FY2004 - FY2008) RHIC Collider Projections (FY2004 - FY2008) Thomas Roser, Wolfram Fischer Last update: August 20, 2003 This note discusses in Part I possible operating modes for the RHIC Run-4 (FY2004) running period including constraints from cryogenic cool-down, machine set-up and beam commissioning. In Part II a 5-year projection is given for gold-gold and polarized proton collisions. Part I - Run-4 Projections Cryogenic operation - After the summer shutdown the two RHIC rings will be at room temperature. They will be first brought to liquid nitrogen temperature, in about 10 days. Then, two weeks will be required to cool down to 4 Kelvin. At the end of the run, one week of refrigerator operation is required for the warm-up to 80 Kelvin. Running modes - A number of running modes are considered in RHIC, such as Au-Au

427

Relativistic Heavy Ion Collider | The Case for Continuing Operations  

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

The Case for Continuing RHIC Operations The Case for Continuing RHIC Operations The Relativistic Heavy Ion Collider (RHIC) - the nation's only remaining particle collider, located at Brookhaven National Laboratory - has made a series of landmark discoveries and continuing breakthroughs in science and technology. One major accomplishment has been RHIC's ability to recreate and study in detail a type of matter that last existed at the beginning of the universe to better understand the strongest force in nature - the force that holds together the fundamental particles that make up 99 percent of visible matter in the universe today, everything from stars to planets to people. In addition to giving us a new way to explore and understand the nature of the early universe and the force that holds together ordinary matter, research at RHIC has revealed stunning

428

Observation of snake resonances at Relativistic Heavy Ion Collider  

SciTech Connect

The Siberian snakes are powerful tools in preserving polarization in high energy accelerators has been demonstrated at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the Siberian snakes also introduce a new set of depolarization resonances, i.e. snake resonances as first discovered by Lee and Tepikian. The intrinsic spin resonances above 100 GeV are about a factor of two stronger than those below 100 GeV which raises the challenge to preserve the polarization up to 250 GeV. In 2009, polarized protons collided for the first time at the RHIC design store energy of 250 GeV. This paper presents the experimental measurements of snake resonances at RHIC. The plan for avoiding these resonances is also presented.

Bai, M.; Ahrens, L.; Alekseev, I.G.; Alessi, J.; et al

2010-09-27T23:59:59.000Z

429

Black Holes at Future Colliders and Beyond: a Topical Review  

E-Print Network (OSTI)

One of the most dramatic consequences of low-scale (~1 TeV) quantum gravity in models with large or warped extra dimension(s) is copious production of mini black holes at future colliders and in ultra-high-energy cosmic ray collisions. Hawking radiation of these black holes is expected to be constrained mainly to our three-dimensional world and results in rich phenomenology. In this topical review we discuss the current status of astrophysical observations of black holes and selected aspects of mini black hole phenomenology, such as production at colliders and in cosmic rays, black hole decay properties, Hawking radiation as a sensitive probe of the dimensionality of extra space, as well as an exciting possibility of finding new physics in the decays of black holes.

Greg Landsberg

2006-07-26T23:59:59.000Z

430

Baseline scenario(s) for muon collider proton driver  

DOE Green Energy (OSTI)

This paper gives an overview of the various muon collider scenarios and the requirements they put on the Proton Driver. The required proton power is about 4-6MW in all the scenarios, but the bunch repetition rate varies between 12 and 65Hz. Since none of the muon collider scenarios have been simulated end-to-end, it would be advisable to plan for an upgrade path to around 10MW. Although the proton driver energy is flexible, cost arguments seems to favor a relatively low energy. In particular, at Fermilab 8GeV seems most attractive, partly due to the possibility of reusing the three existing fixed energy storage rings for bunch manipulations.

Jansson, Andreas; /Fermilab

2008-07-01T23:59:59.000Z

431

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

432

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

433

High energy accelerator and colliding beam user group  

Science Conference Proceedings (OSTI)

This report discusses the following topics: OPAL experiment at LEP; D{phi} experiment at Fermilab; deep inelastic muon interactions at TEV II; CYGNUS experiment; final results from {nu}{sub e}{sup {minus}e} elastic scattering; physics with CLEO detector at CESR; results from JADE at PETRA; rare kaon-decay experiment at BNL; search for top quark; and super conducting super collider activities.

Not Available

1990-09-01T23:59:59.000Z

434

New Results for a Photon-Photon Collider  

SciTech Connect

We present new results from studies in progress on physics at a two-photon collider. We report on the sensitivity to top squark parameters of MSSM Higgs boson production in two-photon collisions; Higgs boson decay to two photons; radion production in models of warped extra dimensions; chargino pair production; sensitivity to the trilinear Higgs boson coupling; charged Higgs boson pair production; and we discuss the backgrounds produced by resolved photon-photon interactions.

Asner, D; Grzadkowski, B; Gunion, J F; Logan, H E; Martin, V; Schmitt, M; Velasco, M M

2002-08-23T23:59:59.000Z

435

New results for a photon-photon collider  

SciTech Connect

We present new results from studies in progress on physics at a two-photon collider. We report on the sensitivity to top squark parameters of MSSM Higgs boson production in two-photon collisions; Higgs boson decay to two photons; radion production in models of warped extra dimensions; chargino pair production; sensitivity to the trilinear Higgs boson coupling; charged Higgs boson pair production; and we discuss the backgrounds produced by resolved photon-photon interactions.

David Asner et al.

2002-09-26T23:59:59.000Z

436

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

437

Ion effects in future circular and linear accelerators  

SciTech Connect

In this paper, the author discusses ion effects relevant to future storage rings and linear colliders. The author first reviews the conventional ion effects observed in present storage rings and then discusses how these effects will differ in the next generation of rings and linacs. These future accelerators operate in a new regime because of the high current long bunch trains and the very small transverse beam emittances. Usually, storage rings are designed with ion clearing gaps to prevent ion trapping between bunch trains or beam revolutions. Regardless, ions generated within a single bunch train can have significant effects. The same is true in transport lines and linacs, where typical vacuum pressures are relatively high. Amongst other effects, the author addresses the tune spreads due to the ions and the resulting filamentation which can severely limit emittance correction techniques in future linear colliders, the bunch-to-bunch coupling due to the ions which can cause a multi-bunch instability with fast growth rates, and the betatron coupling and beam halo creation which limit the vertical emittance and beam lifetimes.

Raubenheimer, T.O.

1995-05-01T23:59:59.000Z

438

Experimental Study of W Z Intermediate Bosons Associated Production with the CDF Experiment at the Tevatron Collider  

Science Conference Proceedings (OSTI)

Studying WZ associated production at the Fermilab Tevatron Collider is of great importance for two main reasons. On the one hand, this process would be sensitive to anomalies in the triple gauge couplings such that any deviation from the value predicted by the Standard Model would be indicative of new physics. In addition, by choosing to focus on the final state where the Z boson decays to b{bar b} pairs, the event topology would be the same as expected for associated production of a W and a Standard Model light Higgs boson (m{sub H} {approx}< 135 GeV) which decays into b{bar b} pairs most of times. The process WH {yields} W b{bar b} has an expected {sigma} {center_dot} B about five times lower than WZ {yields} Wb{bar b} for m{sub H} {approx_equal} 120 GeV. Therefore, observing this process would be a benchmark for an even more difficult search aiming at discovering the light Higgs in the WH {yields} Wb{bar b} process. After so many years of Tevatron operation only a weak WZ signal was recently observed in the full leptonic decay channel, which suffers from much less competition from background. Searching for the Z in the b{bar b} decay channel in this process is clearly a very challenging endeavour. In the work described in this thesis, WZ production is searched for in a final state where the W decays leptonically to an electron-neutrino pair or a muon-neutrino pair, with associated production of a jet pair consistent with Z decays. A set of candidate events is obtained by applying appropriate cuts to the parameters of events collected by wide acceptance leptonic triggers. To improve the signal fraction of the selected events, an algorithm was used to tag b-flavored jets by means of their content of long lived b-hadrons and corrections were developed to the jet algorithm to improve the b-jet energy resolution for a better reconstruction of the Z mass. In order to sense the presence of a signal one needs to estimate the amount of background. The relative content of heavy flavor jets in the dominant W+multijet background is assumed as predicted by theory. This technique was originally developed in CDF to measure the t{bar t} production cross section in the final state with W + 3 or more jets. This thesis was conceived as the first attempt within CDF to apply a customized version of it to look for evidence of diboson production in the final state with aW and two jets. Extracting the signal in this channel is very hard since with such a small number of jets the background is two orders of magnitude greater than the signal. Moreover, since the signal to background ratio is very small, the expected sensitivity depends critically on the theoretical uncertainties on the amount of background. While work is in progress to understand this background more reliably, this analysis provides an estimate of the achievable upper limit on the WZ production cross section.

Pozzobon, Nicola; /Pisa U.

2007-09-01T23:59:59.000Z

439

Portable Linear Accelerator Development  

Science Conference Proceedings (OSTI)

This report describes Minac-3, a miniaturized linear accelerator system. It covers the current equipment capabilities and achievable modifications, applications information for prospective users, and technical information on high-energy radiography that is useful for familiarization and planning. The design basis, development, and applications history of Minac are also summarized.

1982-12-01T23:59:59.000Z

440

Radio frequency pulse compression experiments at SLAC (Stanford Linear Accelerator Center)  

Science Conference Proceedings (OSTI)

Proposed future positron-electron linear colliders would be capable of investigating fundamental processes of interest in the 0.5--5 TeV beam-energy range. At the SLAC Linear Collider (SLC) gradient of about 20 MV/m this would imply prohibitive lengths of about 50--250 kilometers per linac. We can reduce the length by increasing the gradient but this implies high peak power, on the order of 400-- to 1000-MW at X-Band. One possible way to generate high peak power is to generate a relatively long pulse at a relatively low power and compress it into a short pulse with higher peak power. It is possible to compress before DC to RF conversion, as is done using magnetic switching for induction linacs, or after DC to RF conversion, as is done for the SLC. Using RF pulse compression it is possible to boost the 50-- to 100-MW output that has already been obtained from high-power X-Band klystrons the levels required by the linear colliders. In this note only radio frequency pulse compression (RFPC) is considered.

Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Miller, R.H.; Nantista, C.; Spalek, G.; Wilson, P.B.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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

Electric dipole moments of charged leptons in the split fermion scenario in the two Higgs doublet model  

E-Print Network (OSTI)

We predict the charged lepton electric dipole moments in the split fermion scenario in the framework of the two Higgs doublet model. We observe that the numerical value of the muon (tau) electric dipole moment is at the order of the magnitude of $10^{-22} (e-cm)$ ($10^{-20} (e-cm)$) and there is an enhancement in the case of two extra dimensions, especially for the tau lepton electric dipole moment.

E. O. Iltan

2005-02-28T23:59:59.000Z

442

Spin Polarized Photons and Di-leptons from Axially Charged Plasma  

E-Print Network (OSTI)

Axial charge in a QCD plasma is P- and CP-odd. We propose and study P- and CP-odd observables in photon and di-lepton emissions from an axially charged QCD plasma, which may provide possible experimental evidences of axial charge fluctuation and triangle anomaly in the plasma created in heavy-ion collisions. Our observables measure spin alignments of the emitted photons and di-leptons, and are shown to be related to the imaginary part of chiral magnetic conductivity at finite frequency-momentum, which ultimately arises from the underlying triangle anomaly of the QCD plasma with a finite axial charge density. We present an exemplar computation of these observables in strongly coupled regime using AdS/CFT correspondence.

Kiminad A. Mamo; Ho-Ung Yee

2013-07-30T23:59:59.000Z

443

Spin Polarized Photons and Di-leptons from Axially Charged Plasma  

E-Print Network (OSTI)

Axial charge in a QCD plasma is P- and CP-odd. We propose and study P- and CP-odd observables in photon and di-lepton emissions from an axially charged QCD plasma, which may provide possible experimental evidences of axial charge fluctuation and triangle anomaly in the plasma created in heavy-ion collisions. Our observables measure spin alignments of the emitted photons and di-leptons, and are shown to be related to the imaginary part of chiral magnetic conductivity at finite frequency-momentum, which ultimately arises from the underlying triangle anomaly of the QCD plasma with a finite axial charge density. We present an exemplar computation of these observables in strongly coupled regime using AdS/CFT correspondence.

Mamo, Kiminad A

2013-01-01T23:59:59.000Z

444

Transverse self-modulation of ultra-relativistic lepton beams in the plasma wakefield accelerator  

SciTech Connect

The transverse self-modulation of ultra-relativistic, long lepton bunches in high-density plasmas is explored through full-scale particle-in-cell simulations. We demonstrate that long SLAC-type electron and positron bunches can become strongly radially self-modulated over centimeter distances, leading to wake excitation in the blowout regime with accelerating fields in excess of 20 GV/m. We show that particles energy variations exceeding 10 GeV can occur in meter-long plasmas. We find that the self-modulation of positively and negatively charged bunches differs when the blowout is reached. Seeding the self-modulation instability mitigates the effect of the competing hosing instability. This work reveals that a proof-of-principle experiment to test the physics of bunch self-modulation can be performed with available lepton bunches and with existing experimental apparatus and diagnostics.

Vieira, J.; Silva, L. O. [GoLP/Instituto de Plasmas e Fusao Nuclear, Laboratorio Associado Instituto Superior Tecnico, Technical University of Lisbon, Lisboa (Portugal); Fang, Y. [University of Southern California, Los Angeles, California 90089 (United States); Mori, W. B. [University of California, Los Angeles, California 90095 (United States); Muggli, P. [University of Southern California, Los Angeles, California 90089 (United States); Max Planck Institute for Physics, Munich (Germany)

2012-06-15T23:59:59.000Z

445

The 5D to 4D projection model applied as a Lepton to Galaxy Creation model  

E-Print Network (OSTI)

The 5D to 4D projection is presented in a simple geometry giving the Perelman Theorem, resulting in a 3D doughnut structure for the space manifold of the Lorentz space-time. It is shown that in the lowest quantum state, this Lorentz manifold confines and gives the de Broglie leptons from the massless 5D e-trinos. On the scale of the universe, it allows for a model for the creation of galaxies.

Kai-Wai Wong; Gisela A. M. Dreschhoff; Hgne Jungner

2013-06-02T23:59:59.000Z

446

An SO(10)XS4 Model of Quark-Lepton Complementarity  

E-Print Network (OSTI)

The present observations of Cabbibo angle and solar mixing angle satisfy the empirical relation called Quark-Lepton Complementarity(QLC), namely $\\theta_{12}^l\\sim \\pi/4-\\theta_C$. It suggests the existence of correlation between quarks and leptons which is supported by the idea of grand unification. We propose a specific ansatz for the structure of Yukawa matrices in SO(10) unified theory which leads to such relation if neutrinos get masses through type-II seesaw mechanism. Viability of this ansatz is discussed through detailed analysis of fermion masses and mixing angles all of which can be explained in a model which uses three Higgs fields transforming as 10 and one transforming as $\\bar{126}$ representations under SO(10). It is shown that the proposed ansatz can be derived from an extended model based on the two pairs of 16-dimensional vector-like fermions and an $S_4$ flavor symmetry. The model leads to the lepton mixing matrix that is dominantly bimaximal with ${\\cal O}(\\theta_C)$ corrections related to quark mixing. A generic prediction of the model is the reactor angle $\\theta_{13}^l\\sim \\theta_C/\\sqrt{2}$ which is close to its present experimental upper bound.

Ketan M. Patel

2010-08-30T23:59:59.000Z

447

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

448

Linear induction accelerator  

DOE Patents (OSTI)

A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

Buttram, M.T.; Ginn, J.W.

1988-06-21T23:59:59.000Z

449

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

450

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

451

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

452

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

453

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

454

Crab Crossing Schemes and Studies for Electron Ion Collider  

Science Conference Proceedings (OSTI)

This report shows our progress in crab crossing consideration for future electron-ion collider envisioned at JLab. In this design phase, we are evaluating two crabbing schemes viz., the deflecting and dispersive. The mathematical formulations and lattice design for these schemes are discussed in this paper. Numerical simulations involving particle tracking through a realistic deflecting RF cavity and optics illustrate the desired crab tilt of 25 mrad for 1.35 MV. Evolution of beam propagation are shown which provides the physical insight of the crabbing phenomenon.

S. Ahmed, Y. Derbenev, V. Morozov, A. Castilla, G.A. Krafft, B. Yunn, Y. Zhang, J.R. Delayen

2011-09-01T23:59:59.000Z

455

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

456

Development of High Average Power Lasers for the Photon Collider  

SciTech Connect

The laser and optics system for the photon collider seeks to minimize the required laser power by using an optical stacking cavity to recirculate the laser light. An enhancement of between 300 to 400 is desired. In order to achieve this the laser pulses which drive the cavity must precisely match the phase of the pulse circulating within the cavity. We report on simulations of the performance of a stacking cavity to various variations of the drive laser in order to specify the required tolerances of the laser system.

Gronberg, Jeff; /LLNL, Livermore; Stuart, Brent; /LLNL, Livermore; Seryi, Andrei; /SLAC

2012-07-05T23:59:59.000Z

457

Linear Solar Models  

E-Print Network (OSTI)

We present a new approach to study the properties of the sun. We consider small variations of the physical and chemical properties of the sun with respect to Standard Solar Model predictions and we linearize the structure equations to relate them to the properties of the solar plasma. By assuming that the (variation of) the present solar composition can be estimated from the (variation of) the nuclear reaction rates and elemental diffusion efficiency in the present sun, we obtain a linear system of ordinary differential equations which can be used to calculate the response of the sun to an arbitrary modification of the input parameters (opacity, cross sections, etc.). This new approach is intended to be a complement to the traditional methods for solar model calculation and allows to investigate in a more efficient and transparent way the role of parameters and assumptions in solar model construction. We verify that these Linear Solar Models recover the predictions of the traditional solar models with an high...

Villante, F L

2009-01-01T23:59:59.000Z

458

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

459

JILA/NIST Scientists Get a Grip on Colliding Fermions to ...  

Science Conference Proceedings (OSTI)

... not supposed to collide when in identical energy states ... accurate than the results reported last year, so that ... 1 second in more than 300 million years. ...

2010-10-05T23:59:59.000Z

460

Laser triggered injection of electrons in a laser wakefield accelerator with the colliding pulse method  

E-Print Network (OSTI)

Laser Triggered Injection ofElectrons in a Laser Wake?eld Accelerator with the CollidingAn injection scheme for a laser wake?eld accelerator that

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "linear colliders lepton" 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

Successful observation of Schottky signals at the Tevatron collider  

SciTech Connect

We have constructed a Schottky detector for the Tevatron collider in the form of a high-Q ({approx}5000) cavity which operates at roughly 2 GHz, well above the frequency at which the Tevatron's single-bunch frequency spectrum begins to roll off. Initial spectra obtained from the detector show clearly observable Schottky betatron lines, free of coherent contaminants; also seen are the common-mode'' longitudinal signals due to the offset of the beam from the detector center. The latter signals indicate that at 2 GHz, the coherent single-bunch spectrum from the detector is reduced by >80 dB; therefore, in normal collider operation, the Schottky betatron lines are >40 dB greater than their coherent counterparts. We describe how the data we have obtained give information on transverse and longitudinal emittances, synchrotron frequency, and betatron tunes, as well as reveal what may be previously unobserved phenomena. Space limitations restrict us to presenting only as much data as should be necessary to convince even the skeptical reader of the validity of the claim made in the paper's title. 3 refs., 2 figs.

Goldberg, D.A.; Lambertson, G.R.

1989-08-01T23:59:59.000Z

462

Open-Midplane Dipoles for a Muon Collider  

SciTech Connect

For a muon collider with copious decay particles in the plane of the storage ring, open-midplane dipoles (OMD) may be preferable to tungsten-shielded cosine-theta dipoles of large aperture. The OMD should have its midplane completely free of material, so as to dodge the radiation from decaying muons. Analysis funded by a Phase I SBIR suggests that a field of 10-20 T should be feasible, with homogeneity of 1 x 10{sup -4} and energy deposition low enough for conduction cooling to 4.2 K helium. If funded, a Phase II SBIR would refine the analysis and build and test a proof-of-principle magnet. A Phase I SBIR has advanced the feasibility of open-midplane dipoles for the storage ring of a muon collider. A proposed Phase II SBIR would refine these predictions of stresses, deformations, field quality and energy deposition. Design optimizations would continue, leading to the fabrication and test, for the first time, of a proof-of-principle dipole of truly open-midplane design.

Weggel, R.; Gupta, R.; Kolonko, J., Scanlan, R., Cline, D., Ding, X., Anerella, M., Kirk, H., Palmer, B., Schmalzle, J.

2011-03-28T23:59:59.000Z

463

X-ray emission from colliding laser plasmas  

SciTech Connect

Colliding Au, CD and Ti-Cr plasmas have been generated by illuminating two opposing foils each with a {approximately} 100J, 0.5 nsec, 2{omega} Nd-glass laser beam from the Trident laser facility at Los Alamos. The plasmas are being used to study plasma interactions which span the parameter regime from interpenetrating to collisional stagnation. X-ray emission during the laser target interaction and the subsequent collision is used to diagnose the initial plasma conditions and the colliding plasma properties. X-ray instrumentation consists of a 100 ps gated x-ray pinhole imager, a time-integratcd bremsstrahlung x-ray spectrograph and a gated x-ray spectrograph used to record isoelectronic spectra from the Ti-Cr plasmas. The imager has obtained multi-frame images of the collision and therefore, a measure of the stagnation length which is a function of the ion charge state and density and a strong function of the electron temperature. Other instrumentation includes a Thomson scattering spectrometer with probe beam, neutron detectors used to monitor the CD coated foil collisions and an ion spectrometer. We will describe the current status of the experiments and current results with emphasis on the x-ray emission diagnostics. We will also briefly describe the modeling using Lasnex and ISIS, a particle-in-cell code with massless fluid electrons and inter particle (classical) collisions.

Wilke, M.; Obst, A.W.; Winske, D. [and others

1995-09-01T23:59:59.000Z

464

Optical linear algebra  

SciTech Connect

Many of the linear algebra operations and algorithms possible on optical matrix-vector processors are reviewed. Emphasis is given to the use of direct solutions and their realization on systolic optical processors. As an example, implicit and explicit solutions to partial differential equations are considered. The matrix-decomposition required is found to be the major operation recommended for optical realization. The pipelining and flow of data and operations are noted to be key issues in the realization of any algorithm on an optical systolic array processor. A realization of the direct solution by householder qr decomposition is provided as a specific case study. 19 references.

Casasent, D.; Ghosh, A.

1983-01-01T23:59:59.000Z

465

Instrumentation of the Very Forward Region at Future Linear Colliders - design and R&D by the FCAL Collaboration  

E-Print Network (OSTI)

Two finely segmented and very compact calorimeters are foreseen for the instrumentation of the very forward region of the ILC and the CLIC detectors; a luminometer to measure the rate of low angle Bhabha scattering events with a precision better than $10^{-3}$ and, at lower polar angles, a detector for fast luminosity estimate. Both devices will improve the hermeticity of the detector in searches for new particles. Due to the expected high occupancy, fast front-end electronics is needed. The calorimeter closest to the beampipe will be hit by a large amount of beamstrahlung remnants, so that radiation hard sensors are required. Results on the performance of the sensor and readout electronics prototypes are summarized.

Iftach Sadeh

2010-11-01T23:59:59.000Z

466

2005 International Linear Collider Workshop- Stanford, U.S.A. Frequency Scanned Interferometry for ILC Tracker Alignment  

E-Print Network (OSTI)

In this paper, we report high-precision absolute distance and vibration measurements performed with frequency scanned interferometry using a pair of single-mode optical fibers. Absolute distance was determined by counting the interference fringes produced while scanning the laser frequency. A high-finesse Fabry-Perot interferometer was used to determine frequency changes during scanning. Two multiple-distance-measurement analysis techniques were developed to improve distance precision and to extract the amplitude and frequency of vibrations. Under laboratory conditions, measurement precision of ? 50 nm was achieved for absolute distances ranging from 0.1 meters to 0.7 meters by using the first multiple-distance-measurement technique. The second analysis technique has the capability to measure vibration frequencies ranging from 0.1 Hz to 100 Hz with amplitude as small as a few nanometers, without a priori knowledge. A possible optical alignment system for a silicon tracker is also presented. 1.

Hai-jun Yang; Sven Nyberg; Keith Riles

2005-01-01T23:59:59.000Z

467

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

468

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

469

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

470

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

471

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

472

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

473

Piecewise Linear Modeling and Analysis  

Science Conference Proceedings (OSTI)

From the Publisher:Piecewise Linear Modeling and Analysis explains in detail all possible model descriptions to efficiently store piecewise linear functions starting with the Chua descriptions. Detailed explanation on how the model parameter can be obtained ...

Domine M. W. Leenaerts; Wim M. Van Bokhoven

1998-07-01T23:59:59.000Z

474

History of Proton Linear Accelerators  

DOE R&D Accomplishments (OSTI)

Some personal recollections are presented that relate to the author`s experience developing linear accelerators, particularly for protons. (LEW)

Alvarez, L. W.

1987-01-00T23:59:59.000Z

475

Home of eRHIC: the Electron-Ion-Collider at BNL  

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

Electron Ion Collider (EIC) Project Web Page Electron Ion Collider (EIC) Project Web Page This webpage is perpetually under construction October 26, 2007 (Maintained by Abhay Deshpande) A high luminosity polarized e-p/He and unpolarized e-A collider to study the hyperfine structure of the nucleon including (spin and flavor) and to explore nuclear matter at high parton densities. EIC Collaboration WebPage EIC Meeting at SBU, December 7-8, 2007 The most recent meeting: EICC meeting at MIT, May 2007 A Joint EIC2006 (Third Electron Ion Collider) and Hot-QCD Workshop hosted by BNL, July 17-22, 2006 eRHIC Related Papers and other Material White Papers & other information and documents for NSAC Long Range Planning 2007 Study of fundamental structure of matter with an electron-ion collider, A.

476

Recent Results on Muon Capture for a Neutrino Factory and Muon Collider  

SciTech Connect

Scenarios for capture, bunching and phase-energy rotation of {mu}'s from a proton source have been developed. The goal is capture of a maximal number of muons in a string of rf bunches with applications in neutrino factories and {mu}{sup +}-{mu}{sup -} colliders. In this note we begin with the bunching, phase rotation and cooling scenario used in neutrino factory study 2B and adapted by R. Palmer as the initial stage of a {mu}{sup +}-{mu}{sup -} collider scenario. However the scenario produces a relatively large number of bunches that must be recombined for maximal collider luminosity. In this paper we modify the scenario to obtain a smaller number of bunches, and, after some optimization, obtain cases that are better for both n-factory and collider scenarios. We describe these examples and consider some variations toward an optimal {nu}-factory + collider scenario.

Neuffer, David; /Fermilab

2008-01-01T23:59:59.000Z

477

High energy particle colliders: past 20 years, next 20 years and beyond  

Science Conference Proceedings (OSTI)

Particle colliders for high energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the collider has progressed immensely, while the beam energy, luminosity, facility size and the cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but its pace of progress has greatly slowed down. In this paper we very briefly review the method and the history of colliders, discuss in detail the developments over the past two decades and the directions of the R and D toward near future colliders which are currently being explored. Finally, we make an attempt to look beyond the current horizon and outline the changes in the paradigm required for the next breakthroughs.

Shiltsev, Vladimir D.; /Fermilab

2012-04-01T23:59:59.000Z

478

Linearized Additive Classifiers  

E-Print Network (OSTI)

We revisit the additive model learning literature and adapt a penalized spline formulation due to Eilers and Marx, to train additive classifiers efficiently. We also propose two new embeddings based two classes of orthogonal basis with orthogonal derivatives, which can also be used to efficiently learn additive classifiers. This paper follows the popular theme in the current literature where kernel SVMs are learned much more efficiently using a approximate embedding and linear machine. In this paper we show that spline basis are especially well suited for learning additive models becau