Calculating the Critical Exponents of the Chiral Phase Transition

We calculate the critical exponents of the chiral phase transition at nonzero temperature using the thermal and chiral susceptibilities. We show that within a class of confining Dyson–Schwinger equation (DSE) models the transition is mean field, and that an accurate determination of the critical exponents requires extremely small values of the current-quark mass, several order of magnitude smaller than realistic upand down-quark masses. In general, rainbow truncation models of QCD exhibit mean field exponents as a result of the gap equation’s fermion substructure.