Chiral-spin symmetry of the meson spectral function above Tc

Abstract

Recently, via calculation of spatial correlators of J=0,1 isovector operators using a chirally symmetric Dirac operator within NF=2 QCD, it has been found that QCD at temperatures Tc−3Tc is approximately SU(2)CS and SU(4) symmetric. The latter symmetry suggests that the physical degrees of freedom are chirally symmetric quarks bound by the chromoelectric field into color singlet objects without chromomagnetic effects. This regime of QCD has been referred to as a Stringy Fluid. Here we calculate correlators for propagation in time direction at a temperature slightly above Tc and find the same approximate symmetries. This means that the meson spectral function is chiral-spin and SU(4) symmetric in the same temperature range. Keywords: Lattice QCD, High temperature, Chiral and chiral-spin symmetries, Stringy fluid