THE FINITE-TEMPERATURE PHASE-TRANSITION IN LATTICE SU(2) HIGGS THEORY AT WEAK COUPLINGS

In the weak-coupling region, at beta = 8 and a lambda corresponding to an intermediate Higgs mass, the Higgs transition is studied on asymmetric thermal (N(sigma)3 X 2) lattices. A two-state signal is identified, indicating a first-order transition. Multihistogram and finite-size analysis are consistent with such a conclusion although the evidence is rather weak. The value of the Higgs condensate upsilon(T(crit)) indicates a weakly first-order transition, in qualitative accordance with partially resummed perturbation theory. On the other hand, the latent heat and the metastability temperature range deltaT/T(crit) exceed perturbative estimates by an order of magnitude. Higgs and vector boson masses are measured on symmetric lattices near the zero-temperature phase transition. The W-mass is found to be more sensitive to the lattice size than the Higgs mass. Masses and condensates are consistent with improved tree level relations within reasonable renormalized couplings.