Phase transition of the nucleon-antinucleon plasma at different ratios

TL;DR

This paper explores phase transitions in the Walecka model at high temperatures with non-zero chemical potential, revealing coexistence of phases with varying antinucleon-nucleon ratios and baryon densities.

Contribution

It extends previous studies by analyzing phase coexistence in the Walecka model at non-zero chemical potential, providing new phase diagrams and insights.

Findings

Identification of phase coexistence regions with different antinucleon-nucleon ratios.

Temperature versus baryon density phase diagrams showing coexistence.

Phase diagrams illustrating the effects of chemical potential on phase transitions.

Abstract

We investigate phase transitions for the Walecka model at very high temperatures. As is well known, depending on the parametrization of this model and for the particular case of a zero chemical potential ($ \mu $), a first order phase transition is possible \cite{theis}. We investigate this model for the case in which $ \mu \ne 0 $. It turns out that, in this situation, phases with different values of antinucleon-nucleon ratios and net baryon densities may coexist. We present the temperature versus antinucleon-nucleon ratio as well as the temperature versus the net baryon density for the coexistence region. The temperature versus chemical potential phase diagram is also presented.