The Strongly Interacting Electroweak Phase Transition

TL;DR

This work investigates the high-temperature electroweak phase transition by nonperturbatively solving a renormalization-group flow for the three-dimensional effective potential $U_k(\rho)$, including the running three-dimensional gauge coupling $\bar{g}_3^2(k)$ and the scalar anomalous dimension. The RG-improved potential reveals substantial differences from perturbative results, notably in the barrier between phases and the critical temperature, suggesting that nonperturbative effects can strongly influence the transition and possibly enable baryogenesis for realistic Higgs masses. The study emphasizes that a reliable description requires nonperturbative methods beyond standard loop expansion, and it highlights the role of W-boson condensation and strong-coupling dynamics in shaping the phase structure, with lattice results providing important cross-checks. Together, these insights indicate that the electroweak transition may be weakened or even cross over at large Higgs masses, while remaining strongly first-order for smaller masses, contingent on nonperturbative condensates and dynamics.

Abstract

A quantitative discussion of nonperturbative effects for the high temperature electroweak phase transition is presented. We propose a method for the computation of the temperature dependent effective scalar potential that takes into account the running of the effective gauge coupling. Compared to perturbation theory we find a moderate decrease of the critical temperature and an important change in the strength of the first order transition. We conclude that perturbation theory gives a misleading picture of the dynamics of the transition.