Gauge dependence of the infrared behaviour of massless QED_3

Abstract

Using the Zumino identities it is shown that in a class of non-local gauges, massless QED_3 has an infrared behaviour of a conformal field theory with a continuously varying anomalous dimension of the fermion. In the usual Lorentz gauge, the fermion propagator falls off exponentially for a large separation, but this apparent fermion mass is a gauge artifact.

Comments: 10 pages; changes made mainly to clarify the result in the usual Lorentz gauge; to appear in Phys. Lett. B