Observable Consequences of Crossover-type Deconfinement Phase Transition

Abstract

Equation of State (EoS) for hot and dense nuclear matter with a quark-hadron phase transition is constructed within a statistical mixed-phase model assuming coexistence of unbound quarks in nuclear surrounding. This model predicts the deconfinement phase transition of the crossover type. The so-called "softest point" effect of EoS is analyzed and confronted to that for other equations of state which exhibit the first order phase transition (two-phase bag model) or no transition at all (hadron resonance gas). It is demonstrated that the beam energy dependence of the directed flow is a smooth function in the whole range from SIS till SPS energies and allows to disentangle different EoS, being in good agreement with experimental data for the statistical mixed-phase model. In contrast, excitation functions for relative strangeness abundance turn out to be insensitive to the order of phase transition.