STRONGLY COUPLED LATTICE GAUGE-THEORY WITH DYNAMICAL FERMION MASS GENERATION IN 3 DIMENSIONS - ART. NO. 074507

We investigate the critical behavior of a three-dimensional lattice ch i U phi(3) model in the chiral limit. The model consists of a staggere d fermion field, a U(1) gauge field (with coupling parameter beta) and a complex scalar field (with hopping parameter kappa). Two different methods are used: (1) fits of the chiral condensate and the mass of th e neutral unconfined composite fermion to an equation of state and (2) finite size scaling investigations of the Lee-Yang zeros of the parti tion function in the complex fermion mass plane. For strong gauge coup ling (beta<1) the critical exponents for the chiral phase transition a re determined. We find strong indications that the chiral phase transi tion is in one universality class in this beta interval: that of the t hree-dimensional Gross-Neveu model with two fermions. Thus the continu um limit of the chi U phi(3) model defines here a nonperturbatively re normalizable gauge theory with dynamical mass generation. At weak gaug e coupling and small kappa, we explore a region in which the mass in t he neutral fermion channel is large but the chiral condensate on finit e lattices very small. If it does not vanish in the infinite volume li mit, then a continuum limit with a massive unconfined fermion might be possible in this region, too. [S0556-2821(98)06917-3].