Symmetries of temporal correlators and the nature of hot QCD

TL;DR

This paper explores the symmetries of correlators in hot QCD, revealing an intermediate 'stringy fluid' phase characterized by approximate chiral spin symmetry between the chiral restoration and deconfinement transitions.

Contribution

It identifies a new intermediate regime in hot QCD with approximate chiral spin symmetry, bridging the chiral restoration and deconfinement phases, based on symmetry analysis of correlators.

Findings

Existence of an intermediate 'stringy fluid' regime in hot QCD.

Chiral spin symmetry approximately holds in this intermediate regime.

Transition to QGP involves Debye screening and magnetic confinement.

Abstract

The temperature of the chiral restoration phase transition at 130 MeV as well as the temperature of the center symmetry ("deconfinement") phase transition in a pure glue theory at 300 MeV are two independent temperatures and their interplay determines a structure of different regimes of hot QCD. Given a chiral spin symmetry of the color charge and of the chromoelectric interaction we can conclude from observed symmetries of spatial and temporal correlators of N_F=2 QCD with domain wall Dirac operator at physical quark masses that above the chiral symmetry restoration crossover around T_pc but below rougly 3T_pc there should exist an intermediate regime (the stringy fluid) of hot QCD that is characterized by approximate chiral spin symmetry and where degrees of freedom are chirally symmetric quarks bound into color singlet objects by the chromoelectric field. Above this intermediate regime the color charge and the chromoelectric field are Debye screened and one observes a transition to QGP with magnetic confinement.