Non-Perturbative Renormalization Group Analysis of the Chiral Critical Behaviors in QED

Abstract

We study the chiral critical behaviors of QED by using Non-Perturbative Renormalization Group (NPRG). Taking account of the non-ladder contributions, our flow equations are free from the gauge parameter ($\alpha$) dependence. We clarify the chiral phase structure, and calculate the anomalous dimension of $\bar{\psi }\psi$, which is enhanced compared to the ladder approximation. We find that the cutoff scheme dependence of the physical results is very small.

Comments: 14 pages, latex, 7 figures; misprints corrected