Thermodynamics of dense hadronic matter in a parity doublet model

We study thermodynamics of nuclear matter in a two-flavored parity doublet model within the mean-field approximation. Parameters of the model are chosen to reproduce correctly the properties of the nuclear ground state. The model predicts two phase transitions in nuclear matter, a liquid-gas phase transition at normal nuclear density and a chiral transition at higher density. At finite temperature the pion decay constant exhibits a considerable reduction at intermediate values of chemical potential, which is traced back to the presence of the liquid-gas transition, and approaches zero at higher chemical potential associated with the chiral symmetry restoration. A transition from meson-rich to baryon-rich matter is also discussed.