Propagators and phase structure of Nf=2 and Nf=2+1 QCD

We investigate the phase structure of QCD at finite temperature and chemical potential by solving a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagator. In contrast to previous calculations we take into account the full back-reaction of the quarks onto the Yang-Mills sector and we include the effects of strange quarks. We discuss the resulting thermal mass of the unquenched gluon propagator and extract order parameters for the chiral and deconfinement transition from the quarks. Our result for the temperature dependence of the quark condensate at zero chemical potential agrees well with corresponding lattice calculations. We determine the phase diagram at finite chemical potential and find a potential critical endpoint at (mu(EP)(q), T-EP)approximate to(190, 100) MeV. (C) 2012 Elsevier B.V. All rights reserved.