Phase Diagrams of Relativistic Selfinteracting Boson System

Within the Canonical Ensemble, we investigate a system of interacting relativistic bosons at finite temperatures and finite isospin densities in a mean-field approach. The mean field contains both attractive and repulsive terms. Temperature and isospin-density dependencies of thermodynamic quantities were obtained. It is shown that in the case of attraction between particles in a bosonic system, a liquid-gas phase transition develops against the background of the Bose-Einstein condensate. The corresponding phase diagrams are given. We explain the reasons why the presence of a Bose condensate significantly increases the critical temperature of the liquid-gas phase transition compared to that obtained for the same system within the framework of the Boltzmann statistics. Our results may have implications for the interpretation of experimental data, in particular, how sensitive the critical point of the mixed phase is to the presence of the Bose-Einstein condensate.