Scalar-pseudoscalar meson behavior and restoration of symmetries in SU(3) PNJL model

TL;DR

This paper investigates how mesonic properties change in a hot medium using the SU(3) PNJL model, highlighting the importance of the Polyakov loop in reproducing lattice results and understanding symmetry restoration.

Contribution

It demonstrates that the Polyakov loop significantly influences mesonic observables and symmetry restoration, providing a better match with lattice data compared to the NJL model.

Findings

Faster partial chiral symmetry restoration in the PNJL model.

Polyakov loop effects are crucial for lattice consistency.

Topological susceptibility aligns with lattice results around T/Tc ≈ 1.0.

Abstract

The modification of mesonic observables in a hot medium is analyzed as a tool to investigate the restoration of chiral and axial symmetries in the context of the Polyakov-loop extended Nambu--Jona-Lasinio model. The results of the extended model lead to the conclusion that the effects of the Polyakov loop are fundamental for reproducing lattice findings. In particular, the partial restoration of the chiral symmetry is faster in the PNJL model than in the NJL one, and it is responsible for several effects: the meson-quark coupling constants show a remarkable difference in both models, there is a faster tendency to recover the Okubo-Zweig-Iizuka rule, and finally the topological susceptibility nicely reproduces the lattice results around $T/T_c\approx 1.0$.