Confinement and chiral symmetry breaking, one or two critical points?

TL;DR

This paper investigates the QCD phase diagram focusing on the critical points of confinement and chiral symmetry breaking, using a quark potential model that incorporates both phenomena and examines the influence of quark masses.

Contribution

It introduces a quark potential model within the Coulomb gauge Hamiltonian formalism that includes both confinement and chiral symmetry breaking, and analyzes how quark masses affect critical point locations.

Findings

Confinement drives chiral symmetry breaking.

Both transitions are crossovers at small density and first/second order at large density.

Quark masses influence the position of the critical points.

Abstract

We study the QCD phase diagram, in particular we study the critical points of the two main QCD phase transitions, confinement and chiral symmetry breaking. Confinement drives chiral symmetry breaking, and, due to the finite quark mass, at small density both transitions are a crossover, while they are a first or second order phase transition in large density. We study the QCD phase diagram with a quark potential model including both confinement and chiral symmetry. This formalism, in the Coulomb gauge hamiltonian formalism of QCD, is presently the only one able to microscopically include both a quark-antiquark confining potential and a vacuum condensate of quark-antiquark pairs. Our order parameters are the Polyakov loop and the quark mass gap. The confining potential is extracted from the Lattice QCD data of the Bielefeld group. We scan the QCD phase diagram for different quark masses, in order to address how the quark masses affect the critical point location in the phase diagram.