Nonlocal counterterms in QED?

Abstract

The Leibbrandt-Mandelstam prescription is used to investigate ordinary QED in a general axial gauge. It is shown that the usual renormalization program is applicable at one-loop order without difficulties. For n 2≠0 the individual four-fermion 1PI graphs develop non-polynomial divergent structures. The sum of these contributions, however, vanishes, yielding a finite four-point vertex. For n 2 = 0 we recover the well-known results, whereas the limits n 0→0 or n→0 show an unexpected behaviour.