QCD inequalities, the high temperature phase of QCD, and U(1)Asymmetry

Inequalities for QCD functional integrals are used to establish that if the QCD functional integral does not get contributions from a set of zero measure, then the high-temperature chirally restored phase of QCD is effectively symmetric under U(${\mathit{N}}_{\mathit{f}}$)×U(${\mathit{N}}_{\mathit{f}}$) rather than SU(${\mathit{N}}_{\mathit{f}}$)×SU(${\mathit{N}}_{\mathit{f}}$). If this assumption is correct, there are no effects due to anomalous breaking of U(1${)}_{\mathit{A}}$ on correlation functions in this phase. © 1996 The American Physical Society.