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Tevatron results on the discovery of sigma^(*)_b, b_s oscillations and the measurement of delta m_s, the lifetime difference delta gamma_s and the cp-violating phase phi

Description: The author discusses results from the Tevatron experiments on mixing and CP-violation in B{sub s} mesons, including the observation of B{sub s} oscillations and the first precision measurement of the mixing frequency, as well as a measurement of the lifetime difference {Delta}{Lambda}{sub s} and the first measurement of the CP-violating phase {delta}{sub s}. The author also briefly reports on the observation of four new bottom baryons at CDF.
Date: October 1, 2007
Creator: Heijboer, Aart
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Plasma Suppression of Large Scale Structure Formation in the Universe

Description: We point out that during the reionization epoch of the cosmic history, the plasma collective effect among the ordinary matter would suppress the large scale structure formation. The imperfect Debye shielding at finite temperature would induce a residual long-range electrostatic potential which, working together with the baryon thermal pressure, would counter the gravitational collapse. As a result the effective Jean's length, {tilde {lambda}}{sub J}, is increased by a factor, {tilde {lambda}}{s… more
Date: December 10, 2007
Creator: Chen, Pisin & Lai, Kwang-Chang
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Partner: UNT Libraries Government Documents Department
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Charm Spectroscopy at BaBar

Description: We present a mini-review on charm spectroscopy at the BABAR experiment. We first report on the c{bar s} meson spectrum, and present precise measurements of the D{sub s1}(2536) meson as well as the properties of the many new states discovered since 2003 (D*{sub s0}(2317), D{sub s1}(2460), D*{sub sJ}(2860), and D{sub sJ}(2700) mesons). We then discuss about charmed baryons observed recently in the BABAR experiment: {Omega}{sub c}{sup 0} and {Omega}*{sub c}{sup 0} css baryons, {Lambda}{sub c}(2940… more
Date: December 21, 2007
Creator: Poireau, Vincent
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Partner: UNT Libraries Government Documents Department
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Recent results on B spectroscopy at the Tevatron

Description: The Tevatron collider at Fermilab provides a rich environment for B spectroscopy. Recently the first direct observation of the B{sub c} meson has reduced its mass uncertainty by two orders of magnitude. A search for {eta}{sub b} mesons provides the best limit on its production in p{bar p} colliders. In studies on orbitally excited B{sub d} mesons for the first time the narrow states could be separated from each other. The orbitally excited B{sub s} mesons have been observed for the first time. … more
Date: November 1, 2007
Creator: Heck, Martin
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Partner: UNT Libraries Government Documents Department
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Baryon Triality And Neutrino Masses From An Anomalous FlavorU(1)

Description: We construct a concise U(1){sub X} Froggatt-Nielsen model in which baryon triality, a discrete gauge Z{sub 3}-symmetry, arises from U(1){sub X} breaking. The proton is thus stable, however, R-parity is violated. With the proper choice of U(1){sub X} charges we can obtain neutrino masses and mixings consistent with an explanation of the atmospheric and solar neutrino anomalies in terms of neutrino oscillations, with no right-handed neutrinos required. The only mass scale apart from M{sub grav} i… more
Date: August 15, 2007
Creator: Dreiner, Herbi K.; Luhn, Christoph; Murayama, Hitoshi & Thormeier,Marc
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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D and B meson spectroscopy, new states, baryons at the Tevatron

Description: We review recent results in heavy quark hadron spectroscopy at the Tevatron. With increasing data samples, the Tevatron experiments start to uncover information on the spectroscopy of b-hadrons. Most important are the first observations of the narrow B**{sub s}{sup 0} as well as {Sigma}{sub b}{sup {+-}}, {Sigma}*{sub b}{sup {+-}} and {Xi}{sub b}{sup -} baryons. In addition we present updated results on the narrow B**{sup 0} and B{sub c} mesons.
Date: December 1, 2007
Creator: Kreps, Michal & U., /Karlsruhe
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Partner: UNT Libraries Government Documents Department
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BULK THERMODYNAMICS AND CHARGE FLUCTUATIONS AT NON-VANISHING BARYON DENSITY.

Description: We present results on bulk thermodynamic quantities as well as net baryon number, strangeness and electric charge fluctuations in QCD at non-zero density and temperature obtained from lattice calculations with almost physical quark masses for two values of the lattice cut-off aT = 1/4 and 1/6. We show that with our improved p4fa3-action the cut-off effects are under control when using lattices with a temporal extent of 6 or larger and that the contribution to the equation of state, which is due… more
Date: July 30, 2007
Creator: MIAO,C. & SCHMIDT, C.
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Partner: UNT Libraries Government Documents Department
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MODEL STUDY OF THE SIGN PROBLEM IN A MEAN-FIELD APPROXIMATION.

Description: We study the sign problem of the fermion determinant at nonzero baryon chemical potential. For this purpose we apply a simple model derived from Quantum Chromodynamics, in the limit of large chemical potential and mass. For SU(2) color, there is no sign problem and the mean-field approximation is similar to data from the lattice. For SU(3) color the sign problem is unavoidable, even in a mean-field approximation. We apply a phase-reweighting method, combined with the mean-field approximation, t… more
Date: July 30, 2007
Creator: Hidaka, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Mass, quark-number, and sqrt sNN dependence of the second andfourth flow harmonics in ultra-relativistic nucleus-nucleuscollisions

Description: We present STAR measurements of the azimuthal anisotropyparameter v_2 for pions, kaons, protons, Lambda, bar Lambda, Xi+bar Xi,and \Omega + bar Omega, along with v_4 for pions, kaons, protons, andLambda + bar Lambda at mid-rapidity for Au+Au collisions at sqrt sNN=62.4and 200 GeV. The v_2(p_T) values for all hadron species at 62.4 GeV aresimilar to those observed in 130 and 200 GeV collisions. For observedkinematic ranges, v_2 values at 62.4, 130, and 200 GeV are as little as10 percent-15 perce… more
Date: January 6, 2007
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett,J.; Anderson, B. D. et al.
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Partner: UNT Libraries Government Documents Department
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Nucleon Structure and Hyperon Form Factors from Lattice QCD.

Description: In this work, I report the latest lattice QCD calculations of nucleon and hyperon structure from chiral fermions in 2+1-flavor dynamical simulations. All calculations are done with a chirally symmetric fermion action, domain-wall fermions, for valence quarks. I begin with the latest lattice results on the nucleon structure, focusing on results from RBC/UKQCD using 2+1-flavor chiral fermion actions. We find the chiral-extrapolated axial coupling constant at physical pion mass point. to be 1.23(5… more
Date: June 11, 2007
Creator: Lin, H. W.
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Partner: UNT Libraries Government Documents Department
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First Observation of An Excited Charm Baryon Decaying to Omega Charm Baryon at the BaBar Experiment

Description: We have carried out a search for a charmed baryon {Omega}{sup *}{sub c} decaying to {Omega}{sup 0}{sub c} and a {gamma} where {Omega}{sub c} candidates are reconstructed using decay modes {Omega}{sup -}{pi}{sup +}(c1), {Omega}{sup -}{pi}{sup +}{pi}{sup 0}(c2), {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}(c3) and {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +}(c4). This search is performed by analyzing integrated luminosity of 230.7 fb{sup -1} data collected by the BABAR detector at the Stanford Li… more
Date: November 26, 2007
Creator: Bula, Rahmi & /SUNY, Albany
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Cosmology with X-ray Cluster Baryons

Description: X-ray cluster measurements interpreted with a universal baryon/gas mass fraction can theoretically serve as a cosmological distance probe. We examine issues of cosmological sensitivity for current (e.g., Chandra X-ray Observatory, XMM-Newton) and next generation (e.g., Con-X, XEUS) observations, along with systematic uncertainties and biases. To give competitive next generation constraints on dark energy, we find that systematics will need to be controlled to better than 1percent and any evolut… more
Date: April 10, 2007
Creator: Linder, Eric V.
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Partner: UNT Libraries Government Documents Department
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Theory Challenges of the Accelerating Universe

Description: The accelerating expansion of the universe presents an exciting, fundamental challenge to the standard models of particle physics and cosmology. I highlight some of the outstanding challenges in both developing theoretical models and interpreting without bias the observational results from precision cosmology experiments in the next decade that will return data to help reveal the nature of the new physics. Examples given focus on distinguishing a new component of energy from a new law of gravit… more
Date: March 5, 2007
Creator: Linder, Eric V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hyperon AND Hyperon Resonance Properties From Charm Baryon Decays At BaBar

Description: This report describes studies of hyperons and hyperon resonances produced in charm baryon decays at BABAR. Using two-body decays of the {Xi}{sub c}{sup 0} and {Omega}{sub c}{sup 0}, it is shown, for the first time, that the spin of the {omega}{sup -} is 3/2. The {Omega}{sup -} analysis procedures are extended to three-body final states and properties of the {Xi}(1690){sup 0} are extracted from a detailed isobar model analysis of the {Lambda}{sub c}{sup +} {yields} {Lambda}{bar K}{sup 0}K{sup +}… more
Date: July 3, 2007
Creator: Ziegler, Veronique
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charm and Charmonium Spectroscopy at B-factories

Description: Since a few years, charm and charmonium spectroscopy has revived, both from experimental and theoretical point of views. Many new states have been discovered triggering numerous theoretical publications. The B-factories with their large enriched charm sample have played a leading role on the experimental side with the observation and study of most of the new states. Other experiments such as CLEO and CDF have also contributed. Classical hadron spectroscopy predicted some of these new states, bu… more
Date: May 18, 2007
Creator: Grenier, Philippe & /SLAC /Ecole Normale Superieure, CNRS
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hadronic Charm Decays From B Factories

Description: The B factories, KEKB and PEPII, provide enormous samples of charmed mesons and baryons as well as B{bar B} events. The BELLE and BaBar collaborations have discovered many new particles containing charm quarks in the last few years and have measured their properties with increasing precision. The current status and most recent studies of these charm particle properties is briefly reviewed.
Date: November 9, 2007
Creator: Band, H. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Conformal Template and New Perspectives for Quantum Chromodynamics

Description: Conformal symmetry provides a systematic approximation to QCD in both its perturbative and nonperturbative domains. One can use the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. For example, there is an exact correspondence between the fifth-dimensional coordinate of AdS space and a specific impact variable which measures the separation of the q… more
Date: March 6, 2007
Creator: Brodsky, Stanley J.
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Partner: UNT Libraries Government Documents Department
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Novel QCD Phenomena

Description: I discuss a number of novel topics in QCD, including the use of the AdS/CFT correspondence between Anti-de Sitter space and conformal gauge theories to obtain an analytically tractable approximation to QCD in the regime where the QCD coupling is large and constant. In particular, there is an exact correspondence between the fifth-dimension coordinate z of AdS space and a specific impact variable {zeta} which measures the separation of the quark constituents within the hadron in ordinary space-t… more
Date: July 6, 2007
Creator: Brodsky, Stanley J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Resolving the Formation of Protogalaxies. III.Feedback from the First Stars

Description: The first stars form in dark matter halos of masses {approx}10{sup 6}M{sub {circle_dot}} as suggested by an increasing number of numerical simulations. Radiation feedback from these stars expels most of the gas from their shallow potential well of their surrounding dark matter halos. We use cosmological adaptive mesh refinement simulations that include self-consistent Population III star formation and feedback to examine the properties of assembling early dwarf galaxies. Accurate radiative tran… more
Date: October 30, 2007
Creator: Wise, John H.; Abel, Tom & /KIPAC, Menlo Park
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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CDF Hot Topics

Description: We present recent CDF results based on approximately 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV delivered at Fermilab Tevatron. Results shown include the observation of the B{sub s} oscillation frequency, the first observation of bottom baryon {Sigma}{sub b}{sup (*){+-}} states, updates on B hadrons lifetimes, and searches for rare decays in the b {yields} s{mu}{sup +}{mu}{sup -} transition and in charmless two-body B decays.
Date: June 1, 2007
Creator: Casal, Bruno
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Discovery and measurement of excited b hadrons at the Collider Detector at Fermilab

Description: This thesis presents evidence for the B**{sup 0} and {Sigma}{sub b}{sup (*){+-}} hadrons in proton-antiproton collisions at a center of mass energy of 1.96 TeV, using data collected by the Collider Detector at Fermilab. In the search for B**{sup 0} {yields} B{sup {+-}} {pi}{sup {-+}}, two B{sup {+-}} decays modes are reconstructed: B{sup {+-}} {yields} J/{Upsilon}K{sup {+-}}, where J/{Upsilon} {yields} {mu}{sup +}{mu}{sup -}, and B{sup {+-}} {yields} {bar D}{sup 0}{pi}{sup {+-}}, where {bar D}{… more
Date: June 1, 2007
Creator: Pursley, Jennifer Marie
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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TECHNICAL DESIGN REPORT OF THE FORWARD SILICON VERTEX (FVTX)

Description: The main goal of the RHIC heavy ion program is the discovery of the novel ultra-hot high-density state of matter predicted by the fundamental theory of strong interactions and created in collisions of heavy nuclei, the Quark-Gluon Plasma (QGP). From measurements of the large elliptic flow of light mesons and baryons and their large suppression at high transverse momentum pT that have been made at RHIC, there is evidence that new degrees of freedom, characteristic of a deconfined QCD medium, dri… more
Date: August 1, 2007
Creator: EXPERIMENT, PHENIX; OBRIEN,E.; PAK, R.; DREES, K.A. & COLLABORATORS), (PHENIX EXPERIMENT
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Study of Bbar to Xi_c Lambda_c^- and Bbar to Lambda_c^+ Lambda_c^- Kbar Decays at \babar

Description: We report measurements of B-meson decays into two- and three-body final states containing two charmed baryons using a sample of 230 million {Upsilon}(4S) {yields} B{bar B} decays. We find significant signals in two modes, measuring branching fractions {beta}(B{sup -} {yields} {Lambda}{sub c}{sup +}{Lambda}{sub c}{sup -}K{sup -}) = (1.14 {+-} 0.15 {+-} 0.17 {+-} 0.60) x 10{sup -3} and {beta}(B{sup -}{yields} {Xi}{sup 0}{sub c}{bar {Lambda}}{sub c}{sup -}) x {beta}({Xi}{sup 0}{sub c} {yields} {Xi… more
Date: November 7, 2007
Creator: Aubert, B.
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Partner: UNT Libraries Government Documents Department
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Parameterization of the Angular Distribution of Gamma Rays Produced by P-P Interaction in Astronomical Environment

Description: We present the angular distribution of gamma rays produced by proton-proton interactions in parameterized formulae to facilitate calculations in astrophysical environments. The parameterization is derived from Monte Carlo simulations of the up-to-date proton-proton interaction model by Kamae et al. (2005) and its extension by Kamae et al. (2006). This model includes the logarithmically rising inelastic cross section, the diffraction dissociation process and Feynman scaling violation. The extens… more
Date: September 24, 2007
Creator: Karlsson, Niklas & Kamae, Tuneyoshi
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Partner: UNT Libraries Government Documents Department
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