Deconfinement at finite chemical potential

Abstract

In a confining, renormalisable, Dyson-Schwinger equation model of two-flavour QCD we explore the chemical-potential dependence of the dressed-quark propagator, which provides a means of determining the behaviour of the chiral and deconfinement order parameters, and low-energy pion observables. We find coincident, first order deconfinement and chiral symmetry restoration transitions at \mu_c = 375 MeV. f_\pi is insensitive to \mu until \mu \approx \mu_0 = 0.7 mu_c when it begins to increase rapidly. m_\pi is weakly dependent on \mu, decreasing slowly with \mu and reaching a minimum 6% less than its \mu=0 value at \mu=\mu_0. In a two-flavour free-quark gas at \mu=\mu_c the baryon number density would be approximately 3 \rho_0, where \rho_0=0.16 fm^{-3}; while in such a gas at \mu_0 the density is \rho_0.