QCD confinement and chiral crossovers, 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 informed by lattice QCD data to understand phase transitions at different densities.

Contribution

It introduces a quark potential model that incorporates both confinement and chiral symmetry breaking, utilizing lattice QCD data within the Coulomb gauge Hamiltonian framework.

Findings

Confinement drives chiral symmetry breaking.

Finite quark mass turns phase transitions into crossovers at small density.

Model successfully addresses excited hadrons and chiral symmetry breaking.

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. We present the confinement of quark fields into a flux tube, obtained in SU(3) quenched lattice QCD, to illustrate the importance of the confining quark-antiquark potential. Our finite temperature con-fining potential is extracted from the Lattice QCD data of the Bielefeld group. Our formalism, the Coulomb gauge hamiltonian 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. This model is able to address all the excited hadrons, and chiral symmetry breaking, at the same token. Our order parameters are the Polyakov loop and the quark mass gap. We address how the quark masses affect the critical point location in the phase diagram.