Non-ladder Extended Renormalization Group Analysis of the Dynamical Chiral Symmetry Breaking

TL;DR

This paper introduces a non-ladder approximation scheme in the non-perturbative renormalization group analysis of QCD, leading to improved estimates of chiral symmetry breaking parameters with reduced gauge dependence.

Contribution

It develops a non-ladder NPRG approach beyond the ladder approximation, providing more accurate and gauge-independent evaluations of chiral order parameters in QCD.

Findings

Chiral condensates are enhanced compared to ladder approximations.

Gauge dependence of order parameters is significantly reduced.

The method offers a more phenomenologically consistent description of chiral symmetry breaking.

Abstract

The order parameters of dynamical chiral symmetry breaking in QCD, the dynamical mass of quarks and the chiral condensates, are evaluated by numerically solving the Non-Perturbative Renormalization Group (NPRG) equations. We employ an approximation scheme beyond ``the ladder'', that is, beyond the (improved) ladder Schwinger-Dyson equations. The chiral condensates are enhanced compared with the ladder ones, which is phenomenologically favorable. The gauge dependence of the order parameters is fairly reduced in this scheme.