Linearized lattice QED

Abstract

We present a linearized formulation of lattice QED. The cutoff theory is locally gauge invariant and satisfies the associated Ward identities exactly, even though the physical transverse vector potential enters the action only linearly. The quenched version of the model is simulated and a continuous chiral symmetry breaking transition is found at strong coupling. Lattice monopoles are found to be unimportant near the transition, which supports the picture that chiral symmetry breaking is due solely to strong vector forces. The critical region of the model is very narrow and estimates of critical indices are very sensitive to which value of the critical coupling is taken. The critical index δ is 2.5(1), distinct from mean field theory.