Three-dimensional lattice studies of the electroweak phase transition at MHiggs · 70 GeV

Abstract

We study the electroweak phase transition by lattice simulations of an effective 3-dimensional theory, for a Higgs mass of about 70 GeV. Exploiting, among others, a variant of the equal weight criterion of phase equilibrium, we obtain transition temperature, latent heat and surface tension, and compare with MH ≈ 35 GeV. In the broken phase masses and Higgs condensates are compared to perturbation theory. For the symmetric phase, bound state masses and the static force are determined. *

Measuring the interface tension when the electroweak phase transition becomes weak

“…It is even more difficult to measure the interface tension for weak transitions. This we have observed in our recent work [5] where we have estimated the interface tension for a Higgs mass near to its critical value.…”

“…The relations between 3-dimensional and 4-dimensional quantities have been obtained as in [5] using (in the same notations as there) table 3 which is recalculated here for M * H = 57 GeV. Though the top contribution apparently changes the interface tension only insignificantly (∆ g is small) some of the fermionic one-loop corrections to the 4d couplings are already too large and the other Our present result for the case of M * H = 70 GeV is larger by a factor 3.3 than the previous rough estimate [5]. The latter was obtained as a result of our equal weight histogram method, finally based on a global infinite volume extrapolation of the mixed phase thermodynamical weight for lattices of various aspect ratios.…”

“…The majority of results for the interface tension has been obtained with the second method based on the two-state signal in the histogram of an order parameter like quantity o [10,13,5,3]. Here the whole system is simulated at the pseudocritical point.…”

“…In contrast to measurements of the temperature dependent Higgs mass on both sides of the transition [5] (which requires to separate pure phase samples) the emphasis is here on correlations due to different phases in coexistence. The tunneling correlation length is measured in a very elongated volume L 2 × L z , stretched along the z-direction.…”

Electroweak bubble nucleation, nonperturbatively

“…the free energy/area carried by the phase interface -with the histogram method [45]. This has become the standard and well-understood method for computing the surface tension in a variety of lattice theories, including work closely related to ours, SU(2) gauge + Higgs theories [3,46,9] and effective theories for the MSSM [34].…”