Critical surface of theSU(3)L×SU(3)Rchiral quark model at nonzero baryon density

Abstract

The boundary of the first order chiral phase transition region is studied in the ${m}_{\ensuremath{\pi}}\ensuremath{-}{m}_{K}\ensuremath{-}{\ensuremath{\mu}}_{B}$ space using the one-loop optimized perturbation theory for the resummation of the perturbative series. Chiral perturbation theory for mesons and baryons is used for the $T=0$ parametrization of the model. The surface of second order transition points bends with increasing ${\ensuremath{\mu}}_{B}$ towards the physical point of the ${m}_{\ensuremath{\pi}}\ensuremath{-}{m}_{K}$ mass plane allowing for the existence of the critical end point in the ${\ensuremath{\mu}}_{B}\ensuremath{-}T$ plane at the physical point. The location and scaling region of the CEP is explored.