Thermodynamical phases in a PNJL model at zero temperature

TL;DR

This paper extends the PNJL model to zero temperature, introducing Polyakov loop dependence in interactions, revealing a first-order phase transition at T=0, and emphasizing the role of vector interactions in quark deconfinement.

Contribution

The study develops a zero-temperature PNJL model with Polyakov loop-dependent interactions, demonstrating a first-order phase transition and highlighting the importance of vector channels.

Findings

First-order confined/deconfined transition at T=0.

Vector interactions enable non-zero Polyakov loop solutions.

Parameter sensitivity affects quarkyonic and deconfinement phases.

Abstract

The confinement/deconfinement transition described the Polyakov-Nambu-Jona-Lasinio (PNJL) model is extended to be operative at zero temperature regime. In this study, the scalar and vector channel interaction strengths of the original PNJL model are modified by introducing a dependence on the traced Polyakov loop. In such a way the effective interactions depend on the quark phase and in turn provides a backreaction of the quarks to the gluonic sector, also at zero temperature. On general grounds from quantum chromodynamics this is an expected feature. The thermodynamics of the extended model (PNJL0) is studied in detail. It presents along with a suitable choice of the Polyakov potential, a first order confined/deconfined quark phase transition even at $T=0$. We also show that the vector channel plays an important role in order to allow $\Phi\ne0$ solutions for the PNJL0 model. Furthermore, the sensitivity of the combined quarkyonic and deconfinement phases to the vector interaction strength and the proposed parametrization of the Polyakov-loop potential at $T=0$ allowed to set a window for the bulk values of the relevant parameters.