Phase diagram and nucleation in the Polyakov-loop-extended Quark-Meson truncation of QCD with the unquenched Polyakov-loop potential

TL;DR

This paper investigates the phase diagram and nucleation in an unquenched Polyakov-loop extended Quark-Meson model, highlighting the impact of quark backreaction on the Polyakov-loop potential at nonzero density and its influence on phase transitions.

Contribution

It is the first study to incorporate quark backreaction on the Polyakov-loop potential at finite density, linking chiral and deconfinement transitions in the model.

Findings

Unquenching improves phase structure description.

Polyakov-loop influences all temperatures due to unquenching.

Surface tension magnitude relates to the chiral phase transition.

Abstract

Unquenching of the Polyakov-loop potential showed to be an important improvement for the description of the phase structure and thermodynamics of strongly-interacting matter at zero quark chemical potentials with Polyakov-loop extended chiral models. This work constitutes the first application of the quark backreaction on the Polyakov-loop potential at nonzero density. The observation is that it links the chiral and deconfinement phase transition also at small temperatures and large quark chemical potentials. The build up of the surface tension in the Polyakov-loop extended Quark-Meson model is explored by investigating the two and 2+1-flavour Quark-Meson model and analysing the impact of the Polyakov-loop extension. In general, the order of magnitude of the surface tension is given by the chiral phase transition. The coupling of the chiral and deconfinement transition with the unquenched Polyakov-loop potential leads to the fact that the Polyakov-loop contributes at all temperatures.