Recent progress in understanding deconfinement and chiral restoration phase transitions

TL;DR

Recent advances in gauge topology, focusing on instanton-dyons, have significantly improved understanding of deconfinement and chiral restoration phase transitions, highlighting the role of dyon ensembles and boundary conditions.

Contribution

This work reviews recent progress on instanton-dyons and their impact on phase transitions, including mean field and numerical simulation approaches, and effects of quark boundary conditions.

Findings

Dyon ensembles explain chiral symmetry breaking and deconfinement.

Non-trivial quark boundary conditions alter transition strengths.

In Z(N_c)-QCD, deconfinement is enhanced, chiral transition may be suppressed.

Abstract

Paradigme shift in gauge topology, from instantons to their constituents -- instanton-dyons -- has recently lead to very significant advances. Like instantons, they have fermionic zero modes, and their collectivization at sufficiently high density explains the chiral symmetry breaking. Unlike instantons, these objects have electric and magnetic charges. Their back reaction on the mean value of the Polyakov line (holonomy) allows to explain the deconfinement transition. The talk summarizes recent works on the dyon ensemble, done in the mean field approximation (MFA), and also by direct numerical statistical simulation. Introduction of non-trivial quark periodicity conditions leads to drastic changes in both deconfinement and chiral transitions. In particulaly, in the so called Z(N_c)-QCD model the former gets much stronger, while the latter does not seem to occur at all.