On the nature of thermal QCD phase transitions

TL;DR

This paper proposes that the chiral and deconfinement phase transitions in finite temperature QCD are unified as a single crossover driven by a mixed scalar field, explaining the entire QCD phase diagram.

Contribution

It introduces a unified framework for understanding QCD phase transitions as a single crossover influenced by scalar field mixing and level repulsion.

Findings

Unified description of chiral and deconfinement transitions

Characterization of the QCD phase diagram in temperature-quark mass plane

Mechanism based on scalar field mixing and level repulsion

Abstract

We argue that the chiral phase transition and the deconfinement phase transition in finite temperature QCD are just different limits of a single crossover phase transition driven by the lightest scalar field which is a mixture of the glueball and the sigma meson. The key mechanism, the level repulsion between the sigma and the glueball, gives not only a unified description of the finite temperature phase transitions, but also a consistent characterization of the entire QCD phase diagram in the temperature-quark mass plane.