EFFECTIVE ACTION AND CONFORMAL PHASE-TRANSITION IN 3-DIMENSIONAL QED - ART. NO. 085023

The effective action for local composite operators in QED(3) is consid ered. The effective potential is calculated in leading order in 1/N-f (N-f is the number of fermion flavors) and used to describe the featur es of the phase transition at N-f =N-cr, 3 < N-cr < 5. It is shown tha t this continuous phase transition satisfies the criteria of the confo rmal phase transition, considered recently in the literature. In parti cular, there is an abrupt change of the spectrum of light excitations at the critical point, although the phase transition is continuous, an d the structure of the equation for the divergence of the dilatation c urrent is essentially different in the symmetric and nonsymmetric phas es. The connection of this dynamics with the dynamics in QCD(4) is bri efly discussed. [S0556-2821(98)00820-0].