Quark Condensate and Nucleon-Antinucleon Phase Transition from Hadronic Models at Finite Temperature

We investigate different hadronic model parametrizations at high temperature regime. All the models were constructed to reproduce some observables at low temperature. At high temperature this study becomes important once a copious number of antiparticles arises playing an essential role in the high energy heavy-ion collision experiments like RHIC, SPS and LHC. In our study we observe a model dependent first-order phase transition at about 180 MeV. It was also verified that the order parameter, in-medium effective baryon mass, is very similar to the quark condensate as a function of the temperature. This result acquires importance since the quark condensate is the phase transition order parameter from hadronic (massive mesons) to chiral (massless mesons) phases.