Observation of approximate SU(2) and SU(2n) symmetries in high temperature lattice QCD

We study spatial isovector J = 1 meson correlators in nf = 2 QCD with dynamical domain-wall fermions on 323 × 8 lattices at temperatures T = 220–380 MeV. We observe an approximate degeneracy of all considered correlators with increasing temperature. This approximate degeneracy suggests emergent SU(2)CS and SU(2nf) symmetries at high temperatures, that mix left- and right-handed quarks. Since these symmetries are symmetries of the chromo-electric interaction in QCD we conclude that at 2Tc temperature the elementary objects are quarks with a definite chirality connected by the chromo-electric field.