The Electroweak Phase Transition in Ultra Minimal Technicolor

TL;DR

This paper investigates the electroweak phase transition in models with strongly coupled, nearly-conformal dynamics, revealing a complex phase diagram with multiple transitions using effective field theory and one-loop calculations.

Contribution

It introduces a detailed analysis of the electroweak phase transition in Ultra Minimal Walking Technicolor, highlighting the existence of multiple transitions and their interplay.

Findings

Identification of parameter regions with strong first order transition

Discovery of a second phase transition in the electroweak-singlet sector

Rich phase diagram with multiple interconnected transitions

Abstract

We unveil the temperature-dependent electroweak phase transition in new extensions of the Standard Model in which the electroweak symmetry is spontaneously broken via strongly coupled, nearly-conformal dynamics achieved by the means of multiple matter representations. In particular, we focus on the low energy effective theory introduced to describe Ultra Minimal Walking Technicolor at the phase transition. Using the one-loop effective potential with ring improvement, we identify regions of parameter space which yield a strong first order transition. A striking feature of the model is the existence of a second phase transition associated to the electroweak-singlet sector. The interplay between these two transitions leads to an extremely rich phase diagram.