78,096 research outputs found

    Thermodynamical quantities of lattice full QCD from an efficient method

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    I extend to QCD an efficient method for lattice gauge theory with dynamical fermions. Once the eigenvalues of the Dirac operator and the density of states of pure gluonic configurations at a set of plaquette energies (proportional to the gauge action) are computed, thermodynamical quantities deriving from the partition function can be obtained for arbitrary flavor number, quark masses and wide range of coupling constants, without additional computational cost. Results for the chiral condensate and gauge action are presented on the 10410^4 lattice at flavor number Nf=0N_f=0, 1, 2, 3, 4 and many quark masses and coupling constants. New results in the chiral limit for the gauge action and its correlation with the chiral condensate, which are useful for analyzing the QCD chiral phase structure, are also provided.Comment: Latex, 11 figures, version accepted for publicatio

    Probing the QCD Critical Point with Higher Moments of Net-proton Multiplicity Distributions

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    Higher moments of event-by-event net-proton multiplicity distributions are applied to search for the QCD critical point in the heavy ion collisions. It has been demonstrated that higher moments as well as moment products are sensitive to the correlation length and directly connected to the thermodynamic susceptibilities computed in the Lattice QCD and Hadron Resonance Gas (HRG) model. In this paper, we will present measurements for kurtosis (κ\kappa), skewness (SS) and variance (σ2\sigma^{2}) of net-proton multiplicity distributions at the mid-rapidity (y<0.5|y|<0.5) and 0.4<pT<0.80.4<p_{T}<0.8 GeV/cc for Au+Au collisions at sNN\sqrt{s_{NN}}=19.6, 39, 62.4, 130 and 200 GeV, Cu+Cu collisions at sNN\sqrt{s_{NN}}=22.4, 62.4 and 200 GeV, d+Au collisions at sNN\sqrt{s_{NN}}=200 GeV and p+p collisions at sNN\sqrt{s_{NN}}=62.4 and 200 GeV. The moment products κσ2\kappa \sigma^{2} and SσS \sigma of net-proton distributions, which are related to volume independent baryon number susceptibility ratio, are compared to the Lattice QCD and HRG model calculations. The κσ2\kappa \sigma^{2} and SσS \sigma of net-proton distributions are consistent with Lattice QCD and HRG model calculations at high energy, which support the thermalization of the colliding system. Deviations of κσ2\kappa \sigma^{2} and SσS \sigma for the Au+Au collisions at low energies from HRG model calculations are also observed.Comment: 10 pages, 8 figures, Proceedings of 27th Winter Workshon on Nuclear Dynamics. Feb. 6-13 (2011

    Nonlinear Realization of Spontaneously Broken N=1 Supersymmetry Revisited

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    This paper revisits the nonlinear realization of spontaneously broken N=1 supersymmetry. It is shown that the constrained superfield formalism can be reinterpreted in the language of standard realization of nonlinear supersymmetry via a new and simpler route. Explicit formulas of actions are presented for general renormalizable theories with or without gauge interactions. The nonlinear Wess-Zumino gauge is discussed and relations are pointed out for different definitions of gauge fields. In addition, a general procedure is provided to deal with theories of arbitrary Kahler potentials.Comment: 1+18 pages, LaTe