Symmetries and symmetry breaking patterns in QCD: chiral and deconfinement transitions

TL;DR

This paper explores the relationship between chiral symmetry breaking and deconfinement in QCD, using a schematic model and lattice results, and discusses implications at non-zero baryon chemical potential.

Contribution

It demonstrates the entanglement of chiral and center symmetry breaking patterns in QCD through a schematic PNJL model and compares with lattice QCD results.

Findings

Chiral and deconfinement transitions are interconnected in QCD.

The PNJL model captures key features of symmetry breaking.

Extensions to finite chemical potential are discussed.

Abstract

The symmetry breaking pattern of QCD features two seemingly disconnected phenomena: the spontaneous breakdown of the Z(3) center symmetry in the deconfinement transition of pure-gauge QCD, and the spontaneous breaking of chiral SU(N_f)xSU(N_f) symmetry in the limit of N_f massless quark flavours. The dynamical entanglement of these symmetries is displayed in the framework of a schematic model (the PNJL model) in comparison with results from Lattice QCD. Extensions to non-zero baryon chemical potential are discussed.