Effects of entanglement and instanton suppression at finite temperature in a SU(2) EPNJL model with anomaly

TL;DR

This paper studies how entanglement and instanton suppression affect phase transitions related to deconfinement and symmetry restoration at finite temperature within SU(2) EPNJL models, highlighting the need for temperature-dependent couplings.

Contribution

It introduces temperature-dependent couplings in SU(2) EPNJL models to better describe symmetry restoration and phase transition thermodynamics at finite temperature.

Findings

Effective U_A(1) symmetry restoration requires temperature-dependent couplings.

Entanglement modifies the meson spectrum and phase transition behavior.

Topological susceptibility decreases with temperature, indicating symmetry restoration.

Abstract

We investigate the phase transitions characterized by deconfinement and restoration of chiral and axial symmetries,at finite temperature, in the framework of QCD inspired models. We compare the results obtained in the SU(2) Polyakov-Nambu-Jona-Lasinio model with anomaly and in its extended version, the Entangled Polyakov-Nambu-Jona-Lasinio model. In the last version, four-quark vertices with entanglement between the chiral condensate and the Polyakov loop are considered. The thermodynamics of the phase transitions, the meson spectrum, and in particular the convergence of axial and chiral partners, will be analyzed, as well as the topological susceptibility. We find that an explicit temperature dependence of the coupling vertices is necessary in both models in order to have effective restoration of the U$_A$(1) symmetry.