Improved Polyakov-loop potential for effective models from functional calculations

TL;DR

This paper introduces a refined Polyakov-loop potential that incorporates quark backreaction effects, resulting in a smoother transition in the thermodynamics of QCD within a Polyakov-quark-meson model.

Contribution

The study develops a quark-improved Polyakov-loop potential accounting for quark backreaction, enhancing the modeling of QCD phase transitions.

Findings

Smoother transition between hadronic and quark-gluon plasma phases.

Dependence of results on critical temperature and potential parametrization.

Impact of sigma-meson mass on thermodynamic predictions.

Abstract

We investigate the quark backreaction on the Polyakov loop and its impact on the thermodynamics of quantum chromodynamics. The dynamics of the gluons generating the Polyakov-loop potential is altered by the presence of dynamical quarks. However, this backreaction of the quarks has not yet been taken into account in Polyakov-loop extended model studies. In the present work, we show within a 2+1 flavour Polyakov-quark-meson model that a quark-improved Polyakov-loop potential leads to a smoother transition between the low-temperature hadronic phase and the high-temperature quark-gluon plasma phase. In particular, we discuss the dependence of our results on the remaining uncertainties that are the critical temperature and the parametrisation of the Polyakov-loop potential as well as the mass of the sigma-meson.