Dimensionally regularized study of nonperturbative quenched QED

Abstract

We study the dimensionally regularized fermion propagator Dyson-Schwinger equation in quenched nonperturbative QED. We work in arbitrary covariant gauge and perform nonperturbative renormalization numerically. The nonperturbative fermion propagator is solved in D = 4 - 2 * epsilon dimensional Euclidean space for a large number of values of epsilon. Results for D=4 dimensions are then obtained by extrapolation to epsilon = 0. Here we present results using the Curtis-Penningon fermion-photon proper vertex for two values of the coupling, namely alpha=0.6 and alpha=1.5, and compare these to previous studies employing a modified ultraviolet cut-off regularization. The results using the two different regularizations are found to agree to within the numerical precision of the present calculations.