29,081 research outputs found

    Deconfinement and Chiral Restoration in Hot and Dense Matter

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    We propose a picture that the chiral phase transition at zero quark mass and the deconfinement transition at infinite quark mass are continuously connected. This gives a simple interpretation on the coincidence of the pseudo-critical temperatures observed in lattice QCD. We discuss a possible dynamical mechanism behind the simultaneous crossovers and show the results in a model study.Comment: Contributed to the XXII International Symposium on Lattice Field Theory (Lattice2004(nonzero)), Batavia, Illinois, Jun 21-26, 200

    Relation between color-deconfinement and chiral restoration

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    We discuss the relation between the Polyakov loop and the chiral order parameter at finite temperature by using an effective model. We clarify why and how the pseudo-critical temperature associated with the Polyakov loop should coincide with that of the chiral condensate.Comment: Contributed to the XXI International Symposium on Lattice Field Theory (Lattice2003(nonzero)), Tsukuba, July 15-19, 200

    A New Method of the High Temperature Series Expansion

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    We formulate a new method of performing high-temperature series expansions for the spin-half Heisenberg model or, more generally, for SU(nn) Heisenberg model with arbitrary nn. The new method is a novel extension of the well-established finite cluster method. Our method emphasizes hidden combinatorial aspects of the high-temperature series expansion, and solves the long-standing problem of how to efficiently calculate correlation functions of operators acting at widely separated sites. Series coefficients are expressed in terms of cumulants, which are shown to have the property that all deviations from the lowest-order nonzero cumulant can be expressed in terms of a particular kind of moment expansion. These ``quasi-moments'' can be written in terms of corresponding ``quasi-cumulants'', which enable us to calculate higher-order terms in the high-temperature series expansion. We also present a new technique for obtaining the low-order contributions to specific heat from finite clusters.Comment: 20 pages, 30 figures, to appear in J. Stat. Phy

    Characteristics of the eigenvalue distribution of the Dirac operator in dense two-color QCD

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    We exposit the eigenvalue distribution of the lattice Dirac operator in Quantum Chromodynamics with two colors (i.e. two-color QCD). We explicitly calculate all the eigenvalues in the presence of finite quark chemical potential \mu for a given gauge configuration on the finite-volume lattice. First, we elaborate the Banks-Casher relations in the complex plane extended for the diquark condensate as well as the chiral condensate to relate the eigenvalue spectral density to the physical observable. Next, we evaluate the condensates and clarify the characteristic spectral change corresponding to the phase transition. Assuming the strong coupling limit, we exhibit the numerical results for a random gauge configuration in two-color QCD implemented by the staggered fermion formalism and confirm that our results agree well with the known estimate quantitatively. We then exploit our method in the case of the Wilson fermion formalism with two flavors. Also we elucidate the possibility of the Aoki (parity-flavor broken) phase and conclude from the point of view of the spectral density that the artificial pion condensation is not induced by the density effect in strong-coupling two-color QCD.Comment: 19 pages, 9 figures, reference added, some more clarificatio

    Lexus Group Consultancy in Tokyo, Japan: 5 Big Retirement Money Mistakes to Avoid

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    It’s never too late to start getting smart about money. Maybe you’ve made it this far with few problems … you’ve done pretty well all alone just by winging it. Good for you. But retirement planning isn’t about the past 30 years of your life — it’s about the next 30. And that’s harder. There are decisions you can’t undo, and mistakes are tougher to recover from when you don’t have a paycheck to back you up

    Recent Results from Telescope Array

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    The Telescope Array (TA) is an experiment to observe Ultra-High Energy Cosmic Rays (UHECRs). TA's recent results, the energy spectrum and anisotropy based on the 6-year surface array data, and the primary composition obtained from the shower maximum Xmax are reported. The spectrum demonstrates a clear dip and cutoff. The shape of the spectrum is well described by the energy loss of extra-galactic protons interacting with the cosmic microwave background (CMB). Above the cutoff, a medium-scale (20 degrees radius) flux enhancement was observed near the Ursa-Major. A chance probability of creating this hotspot from the isotropic flux is 4.0 sigma. The measured Xmax is consistent with the primary being proton or light nuclei for energies 10^18.2 eV - 10^19.2 eV.Comment: 8 pages, 15 figures, ISVHECRI2014, CERN, August 18th-22nd, 201
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