CHIRAL SYMMETRY-BREAKING AND SCALING PROPERTIES OF (2+1)-DIMENSIONL QED WITH 4-FERMION INTERACTIONS

We study the chiral symmetry-breaking (2 + 1)-dimensional quantum electrodynamics with four-fermion interactions. Solving the Dyson-Schwinger equation with a boundary condition identical to an _equation of state, we determine the phase diagram of this model and obtain a large anomalous dimension of the operator psipsiBAR. By substituting a symmetry-breaking solution in the equation of state, we find the critical exponents and show that they satisfy the hyperscaling laws. Some comments are given on the equation of hierarchy between the chiral symmetry-breaking scale and the fundamental scale in our model.