K. Ogure et J. Sato, CRITICAL PROPERTIES OF THE O(N) INVARIANT SCALAR MODEL USING THE AUXILIARY-MASS METHOD AT FINITE-TEMPERATURE - ART. NO. 085010, Physical review. D. Particles and fields, 5808(8), 1998, pp. 5010
Using the auxiliary-mass method, the O(N) invariant scalar model is in
vestigated at finite temperature. This mass and an evolution equation
allow us to calculate an effective potential without an infrared diver
gence. A second order phase transition is indicated by the effective p
otential. The critical exponents are determined numerically. [S0556-28
21(98)09418-1].