ON THE PHASE-STRUCTURE OF BARYONIC MATTER

We have studied the phase structure of baryonic matter in a model which includes nucleons and delta resonances interacting with sigma- and omega-mesons. In the mean-field approximation, the existence of phase transitions to delta matter and to a baryon-antibaryon plasma was strongly dependent on the values chosen for the equilibrium effective mass and compression modulus. When vacuum fluctuations were included, the physically acceptable solutions only yielded a liquid-gas phase transition. Further, these solutions were restricted to rather large values of the effective mass and compression modulus which did not include the currently accepted values.