Phase diagram of bosonic matter with additional derivative interaction

TL;DR

This paper investigates the phase diagram of uncharged bosonic matter with derivative interactions, revealing how the interaction parameter influences phase transitions, condensate formation, and critical temperature within a mean-field scalar field model.

Contribution

It introduces a derivative interaction term into the bosonic matter model and analyzes its effects on phase transitions and condensate properties.

Findings

Ground-state binding energy decreases with increasing interaction parameter.

Critical temperature for phase transitions drops as the derivative interaction strength increases.

Liquid-gas phase transition and condensate states vanish beyond a maximum interaction value.

Abstract

Equation of state of uncharged bosonic matter is studied within a field-theoretical approach in the mean-field approximation. Interaction of bosons is described by a scalar field $\sigma$ with a Skyrme-like potential which contains both attractive and repulsive terms. Additionally we introduce the derivative interaction by including factor $(1+\lambda\sigma)^{-1}$ in the kinetic part of Lagrangian where $\lambda > 0$ is the model parameter. Numerical calculations are made for strongly interacting matter composed of $\alpha$ particles. It is shown that ground-state binding energy and equilibrium density of such matter drop with increasing $\lambda$. The liquid-gas phase transition and the Bose-Einstein condensation are studied by using different thermodynamic variables. We calculate also spinodal lines which give boundaries of metastable states. It is demonstrated that critical temperature decreases with $\lambda$. Both LGPT and bound condensate states disappear above certain maximum value of $\lambda$.