Non-ladder extended renormalization group analysis of the dynamical chiralsymmetry breaking

The order parameters of dynamical, chiral symmetry breaking in QCD, the dyn amical mass of quarks and the chiral condensates, are evaluated by numerica lly solving the non-perturbative renormalization group (NPRG) equations. We employ an approximation scheme beyond "the ladder", that is, beyond the (i mproved) ladder Schwinger-Dyson equations. The chiral condensates are enhan ced in comparison with the ladder approximation, which is phenomenologicall y favorable. The gauge dependence of the order parameters is reduced signif icantly in this scheme.