3-D lattice simulation of the electroweak phase transition at small Higgs mass

We study the electroweak phase transition by lattice simulations of an effective 3-dimensional theory, for a Higgs mass of about $35 GeV$. In the broken symmetry phase our results on masses and the Higgs condensate are consistent with 2-loop perturbative results. However, we find a non-perturbative lowering of the transition temperature, similar to the one previously found at $m_H = 80 GeV$. For the symmetric phase, bound state masses and the static force are determined and compared with results for pure $SU(2)$ theory.Comment: 11 pages, uuencoded ps-file, 5 postscript figures include

Physics of the Electroweak Phase Transition at M_H <= 70 GeV in a 3-dimensional SU(2)-Higgs Model

Physical parameters of the electroweak phase transition in a 3d effective lattice SU(2)-Higgs model are presented. The phase transition temperatures, latent heats and continuum condensate discontinuities are measured at Higgs masses of about 70 and 35 GeV. Masses and Higgs condensates are compared to perturbation theory in the broken phase. In the symmetric phase bound states and the static force are determined.Comment: Talk presented at LATTICE96(electroweak), 4 pages, 5 figure

33--Dimensional Approach to Hot Electroweak Matter for MHiggs≤70M_{Higgs} \leq 70 GeV

We study the electroweak phase transition by lattice simulations of an effective 3-dimensional theory, for a Higgs mass of about $70$ GeV. Exploiting a variant of the equal weight criterion of phase equilibrium, we obtain transition temperature, latent heat and surface tension and compare with $M_H \approx 35$ GeV. For the symmetric phase, bound state masses and the static force are determined and compared with results for pure $SU(2)$ theory.Comment: 6 pages with 4 figures, latex,postscript figures and uuencode

One-Loop Quantum Energy Densities of Domain Wall Field Configurations

We discuss a simple procedure for computing one-loop quantum energies of any static field configuration that depends non-trivially on only a single spatial coordinate. We specifically focus on domain wall-type field configurations that connect two distinct minima of the effective potential, and may or may not be the solutions of classical field equations. We avoid the conventional summation of zero-point energies, and instead exploit the relation between functional determinants and solutions of associated differential equations. This approach allows ultraviolet divergences to be easily isolated and extracted using any convenient regularization scheme. Two examples are considered: two-dimensional $\phi^4$ theory, and three-dimensional scalar electrodynamics with spontaneous symmetry breaking at the one-loop level.Comment: RevTex, 29 pages, 1 figure, minor corrections, references adde

Detailed Phase Transition Study at M_H <= 70 GeV in a 3-dimensional SU(2)SU(2)--Higgs Model

We study the electroweak phase transition in an effective 3-dimensional theory for a Higgs mass of about 70 GeV by Monte Carlo simulations. The transition temperature and jumps of order parameters are obtained and extrapolated to the continuum using multi-histogram techniques and finite size analysis.Comment: Talk presented at LATTICE96(electroweak), 4 pages, 5 figure

Derivative expansion of quadratic operators in a general 't Hooft gauge

A derivative expansion technique is developed to compute functional determinants of quadratic operators, non diagonal in spacetime indices. This kind of operators arise in general 't Hooft gauge fixed Lagrangians. Elaborate applications of the developed derivative expansion are presented.Comment: 40 pages, to appear in Phys. Rev.

Derivative expansion and gauge independence of the false vacuum decay rate in various gauges

In theories with radiative symmetry breaking, the calculation of the false vacuum decay rate requires the inclusion of higher-order terms in the derivative expansion of the effective action. I show here that, in the case of covariant gauges, the presence of infrared singularities forbids the consistent calculation by keeping the lowest-order terms. The situation is remedied, however, in the case of $R_{\xi}$ gauges. Using the Nielsen identities I show that the final result is gauge independent for generic values of the gauge parameter $v$ that are not anomalously small.Comment: Some comments and references adde