1,348 research outputs found
The International Linear Collider
In this article, we describe the key features of the recently completed
technical design for the International Linear Collider (ILC), a 200-500 GeV
linear electron-positron collider (expandable to 1 TeV) that is based on 1.3
GHz superconducting radio-frequency (SCRF) technology. The machine parameters
and detector characteristics have been chosen to complement the Large Hadron
Collider physics, including the discovery of the Higgs boson, and to further
exploit this new particle physics energy frontier with a precision instrument.
The linear collider design is the result of nearly twenty years of R&D,
resulting in a mature conceptual design for the ILC project that reflects an
international consensus. We summarize the physics goals and capability of the
ILC, the enabling R&D and resulting accelerator design, as well as the concepts
for two complementary detectors. The ILC is technically ready to be proposed
and built as a next generation lepton collider, perhaps to be built in stages
beginning as a Higgs factory.Comment: 41 page
An Empirical Analysis of the Financial Impact of Supply Chain Management on Small Firms
In this article we test the value proposition hypothesis of supply chain management (SCM) by examining survey results of 570 US managers. First, we find that large firms use SCM initiatives significantly more than small firms. Second, in univariate and multivariate tests, we find that SCM leads to significant improvements in asset utilization, revenue generation, and competitive performance, regardless of firm size. These two major findings suggest that managers at small firms that are not actively engaged in SCM should reevaluate their opportunity to capture the competitive benefits of SCM that many large firms currently enjoy
Baryon spectra with instanton induced forces
Except the vibrational excitations of and mesons, the main features
of spectra of mesons composed of quarks , , and can be quite well
described by a semirelativistic potential model including instanton induced
forces. The spectra of baryons composed of the same quarks is studied using the
same model. The results and the limitations of this approach are described.
Some possible improvements are suggested.Comment: 5 figure
The International Linear Collider Technical Design Report - Volume 4: Detectors
The International Linear Collider Technical Design Report (TDR) describes in
four volumes the physics case and the design of a 500 GeV centre-of-mass energy
linear electron-positron collider based on superconducting radio-frequency
technology using Niobium cavities as the accelerating structures. The
accelerator can be extended to 1 TeV and also run as a Higgs factory at around
250 GeV and on the Z0 pole. A comprehensive value estimate of the accelerator
is give, together with associated uncertainties. It is shown that no
significant technical issues remain to be solved. Once a site is selected and
the necessary site-dependent engineering is carried out, construction can begin
immediately. The TDR also gives baseline documentation for two high-performance
detectors that can share the ILC luminosity by being moved into and out of the
beam line in a "push-pull" configuration. These detectors, ILD and SiD, are
described in detail. They form the basis for a world-class experimental
programme that promises to increase significantly our understanding of the
fundamental processes that govern the evolution of the Universe.Comment: See also http://www.linearcollider.org/ILC/TDR . The full list of
signatories is inside the Repor
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
Low energy theorems and the unitarity bounds in the extra U(1) superstring inspired E6 models
The conventional method using low energy theorems [3] does not seem to lead
to an explicit unitarity limit in the scattering processes of longitudinally
polarized gauge bosons for the high energy case in the extra U(1) superstring
inspired models, commonly known as eta model, emanating from E6 group of
superstring theory. We have made use of an alternative procedure given in [14],
which is applicable to SUSY GUT. Explicit unitarity bounds on the Yukawa
couplings are obtained from both using unitarity constraints as well as using
RGE analysis at one-loop level utilizing critical couplings concepts implying
divergence of scalar coupling at MG. These are found to be consistent with
finiteness over the entire range MZ<=sqrt(s)<=MG. For completeness, the similar
approach has been made use of in other models, i.e., chi, psi, and nu models
emanating from E6 and it has been noticed that at weak scale, the unitarity
bounds on Yukawa couplings do not differ among E6 extra U(1) models
significantly except for the case of chi model in 16 representations.
Theoretically we have obtained the upper bounds on top quark and lightest
neutral higgs boson mass using the unitarity constrained superpotential
couplings and also obtained the D-quark mass as a function of MZ2 is O(3 TeV)
for MZ2 is O(1 TeV). The obtained bounds on these physical parameters are found
consistent with the present day experimental precision measurements.Comment: 57 Pages, 13 Tables, 7 Figs.; PACS: 12.10.Dm, 12.60.Cn;
http://link.aps.org/abstract/PRD/v72/e09501
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