Physical interpretation of the dressed Polyakov loop in the Nambu--Jona-Lasinio model

TL;DR

This paper explores how the dressed Polyakov loop's temperature-dependent behavior in the NJL model is actually a reflection of chiral transition rather than true confinement-deconfinement transition as in QCD.

Contribution

It clarifies the physical interpretation of the dressed Polyakov loop in the NJL model, linking its behavior to chiral symmetry restoration instead of confinement.

Findings

The dressed Polyakov loop rises rapidly with temperature in the NJL model.

This behavior is shown to be a remnant of the chiral transition, not a deconfinement transition.

In the NJL model, the Polyakov loop does not directly indicate confinement.

Abstract

We investigate the rapid rise of the dressed Polyakov loop in the Nambu--Jona-Lasinio (NJL) model as a function of temperature. In QCD such a behaviour is interpreted as a confinement- deconfinement phase transition. However, we demonstrate that in the NJL model this is simply a remnant of the chiral transition.