Color-flavor unlocking and phase diagram with self-consistently determined strange-quark masses

The phase diagram of strongly interacting matter at nonzero temperature and baryon chemical potential is calculated within a three-flavor NJL-type quark model with realistic quark masses. The model exhibits spontaneous chiral symmetry breaking as well as diquark condensation in the two-flavor color-superconducting phase and in the color-flavor-locked phase. We investigate the color-flavor-unlocking phase transition, taking into account self-consistently calculated effective quark masses. We find that it is mainly triggered by a first-order phase transition with respect to the strangequark mass. It takes place at much higher values of the chemical potential than the transition to the hadronic phase such that we find a relatively large region in the phase diagram where the two-flavor color-superconductor seems to be the most favored state. (C) 2002 Elsevier Science B.V. All rights reserved.