The low-temperature behavior of the quark-meson model

TL;DR

This paper investigates the phase diagram of the two-flavor quark-meson model at low temperatures using the Functional Renormalization Group, revealing unusual phase structures and unphysical behaviors not seen in mean-field approaches.

Contribution

It introduces a non-mean-field analysis of the quark-meson model, uncovering novel phase features at low temperatures and high chemical potentials.

Findings

Unusual phase structure at low temperatures and large chemical potentials.

Identification of a regime where pressure decreases with increasing temperature.

Discussion of potential reasons for unphysical behavior in the model.

Abstract

We revisit the phase diagram of strong-interaction matter for the two-flavor quark-meson model using the Functional Renormalization Group. In contrast to standard mean-field calculations, an unusual phase structure is encountered at low temperatures and large quark chemical potentials. In particular, we identify a regime where the pressure decreases with increasing temperature and discuss possible reasons for this unphysical behavior.