The Impact of Fluctuations on QCD Matter

TL;DR

This paper investigates how quantum and thermal fluctuations influence the phase structure of QCD matter at finite temperature and density using an extended quark-meson model with Polyakov-loop dynamics, revealing complex phase transition behaviors.

Contribution

It introduces a dynamical Polyakov-loop--extended quark-meson model that includes back-coupling effects, providing new insights into the phase transitions of QCD at finite temperature and density.

Findings

Chiral phase transition splits into two branches at high chemical potential in the chiral limit.

Transition at small chemical potential becomes a crossover for non-zero pion masses.

Discussion of systematic improvements towards full QCD modeling.

Abstract

We study the effect of quantum and thermal fluctuations as well as the mass dependence of the phase structure of QCD at finite temperature and density within a dynamical Polyakov-loop--extended quark-meson model. The glue dynamics is simulated by the Polyakov-loop potential, also including the back-coupling of the matter sector to the glue dynamics. In the chiral limit, the chiral phase transition at large chemical potential and low temperature splits into two transition branches. For non-vanishing pion masses the chiral transition at small chemical potential changes from a phase transition to a crossover. We close with a discussion of a systematical improvement of the current model towards full QCD.