Equation of state in the PNJL model with the entanglement interaction

Abstract

The equation of state and the phase diagram in two-flavor QCD are investigated by the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model with an entanglement vertex between the chiral condensate and the Polyakov-loop. The entanglement-PNJL (EPNJL) model reproduces LQCD data at zero and finite chemical potential better than the PNJL model. Hadronic degrees of freedom are taken into account by the free-hadron-gas (FHG) model with the volume-exclusion effect due to the hadron generation. The EPNJL+FHG model improves agreement of the EPNJL model with LQCD data particularly at small temperature. The quarkyonic phase survives, even if the correlation between the chiral condensate and the Polyakov loop is strong and hadron degrees of freedom are taken into account. However, the location of the quarkyonic phase is sensitive to the strength of the volume exclusion.