Degeneracy of vector-channel spatial correlators in high temperature QCD

TL;DR

This study investigates spatial meson correlators in high-temperature QCD, revealing unexpected degeneracies that suggest emergent symmetries beyond known chiral and axial symmetries.

Contribution

It provides evidence for emergent $SU(2)_{CS}$ and $SU(4)$ symmetries in high-temperature QCD through lattice measurements of spatial correlators.

Findings

Approximate degeneracy of correlators above $T_c$

Evidence for emergent $SU(2)_{CS}$ symmetry

Indication of $SU(4)$ symmetry at high temperature

Abstract

We study spatial isovector meson correlators in $N_f=2$ QCD with dynamical domain-wall fermions on $32^3\times 8$ lattices at temperatures up to 380 MeV with various quark masses. We measure the correlators of spin-one isovector operators including vector, axial-vector, tensor and axial-tensor. At temperatures above $T_c$ we observe an approximate degeneracy of the correlators in these channels, which is unexpected because some of them are not related under $SU(2)_L \times SU(2)_R$ nor $U(1)_A$ symmetries. The observed approximate degeneracy suggests emergent $SU(2)_{CS}$ (chiral-spin) and $SU(4)$ symmetries at high $T$.