Phase diagram of alpha matter with Skyrme-like scalar interaction

Abstract

The equation of state and phase diagram of strongly interacting matter composed of $\hat{I}\pm$ particles are studied in the mean-field approximation. The particle interactions are included via a Skyrme-like mean field, containing both attractive and repulsive terms. The model parameters are found by fitting known values of binding energy and baryon density in the ground state of $\hat{I}\pm$ matter, obtained from microscopic calculations by Clark and Wang. Thermodynamic quantities of $\hat{I}\pm$ matter are calculated in the broad domains of temperature and baryon density, which can be reached in heavy-ion collisions at intermediate energies. The model predicts both first-order liquid-gas phase transition and Bose-Einstein condensation of $\hat{I}\pm$ particles. We present the profiles of scaled variance, sound velocity and isochoric heat capacity along the isentropic trajectories of $\hat{I}\pm$ matter. Strong density fluctuations are predicted in the vicinity of the critical point at temperature $T_c\approx 14\text{MeV}$ and density $n_c\approx 0.012{\text{fm}}^{-3}$.

29 pages, 11 figures