PHASE-TRANSITION AND THERMODYNAMICS OF A HOT AND DENSE SYSTEM IN A SCALED NJL MODEL

The chiral phase transition of a hot and dense system of quarks is stu died within a modified SU(3) NJL Lagrangian that implements the QCD sc ale anomaly. The u- and s-quark condensates can or can not feel the sa me chiral restoration depending on the considered region of the three- dimensional space (T-c, mu(uc), mu(sc)) The temperature behaviour of t he pressure and the energy and entropy densities of the u- and s-quark system is investigated. At high temperature, the nonvanishing bare s- quark mass only modifies slightly the usual behaviour associated with an ideal quark gas.