Chiral symmetry in hot QCD

Abstract

Recent lattice calculations of static hadronic-screening lengths and the quark-number susceptibility are interpreted in terms of a simple constituent quark model. The conclusion is that just above ${\mathit{T}}_{\mathit{c}}$ the nature of the hadronic modes is rather well described in terms of elementary \ensuremath{\pi} and \ensuremath{\sigma}, as well as light-quark, modes. Hence chiral symmetry in the absence of symmetry-breaking terms is realized through massless quarks rather than through parity doubling.