CHIRAL PHASE-TRANSITION IN A LATTICE FERMION-GAUGE-SCALAR MODEL WITH U(1) GAUGE-SYMMETRY

The chiral phase transition induced by a charged scalar field is inves tigated numerically in a lattice fermion-gauge-scalar model with U(1) gauge symmetry, proposed recently as a model for dynamical fermion mas s generation. For very strong gauge coupling the transition is of seco nd order and its scaling properties are very similar to those of the N ambu-Jona-Lasinio model. However, in the vicinity of the tricritical p oint at somewhat weaker coupling, where the transition changes the ord er, the scaling behavior is different. Therefore it is worthwhile to i nvestigate the continuum limit of the model at this point.