We have examined the phase structure of a nucleon-antinucleon plasma in Walecka’s relativistic mean-field approximation originally due to Theis et al. who have shown that the nuclear-matter system exhibits a phase transition at $T_c$≃200 MeV for zero baryon density. It is found that the inclusion of a small nonvanishing chemical potential which, in turn, implies a nonzero baryon density does not negate this result.

• Received 30 January 1987

DOI:https://doi.org/10.1103/PhysRevD.35.3530