STRONGLY COUPLED COMPACT LATTICE QED WITH STAGGERED FERMIONS

We explore the compact U(1) lattice gauge theory with staggered fermio ns and gauge field action - Sigma(p)[beta cos(Theta p) + gamma cos(2 T heta p)], both for dynamical fermions and in the quenched approximatio n. (Theta p denotes the plaquette angle.) In simulations with dynamica l fermions at various gamma less than or equal to -0.2 on 6(4) lattice s we find the energy gap at the phase transition of a size comparable to the pure gauge theory for gamma less than or equal to 0 on the same lattice, diminishing with decreasing gamma. This suggests a second-or der transition in the thermodynamic limit of the theory with fermions for gamma below some finite negative value. Studying the theory on lar ge lattices at gamma = -0.2 in the quenched approximation by means of the equation of state we find non-Gaussian values of the critical expo nents associated with the chiral condensate, beta(chi) similar or equa l to 0.32 and delta similar or equal to 1.8, and determine the scaling function. Furthermore, we evaluate the meson spectrum and study the P CAC relation. (C) 1998 Elsevier Science B.V.