Electroweak phase transition with composite Higgs models: calculability, gravitational waves and collider searches

Abstract

We study the strong first order electroweak phase transition (SFOEWPT) with the $SO(6)/SO(5)$ composite Higgs model, whose scalar sector contains one Higgs doublet and one real singlet. Six benchmark models are built with fermion embeddings in $\text{1}$, $\text{6}$, and $\text{15}$ of $SO(6)$. We show that SFOEWPT cannot be triggered under the minimal Higgs potential hypothesis, which assumes the scalar potential is dominated by the form factors from the lightest composite resonances. To get a SFOEWPT, the contributions from local operators induced by physics above the cutoff scale are needed. We take the $\text{6}+\text{6}$ model as an example to investigate the gravitational waves prediction and the related collider phenomenology.

Comments: 36 pages, 5 figures. The version to be appear on JHEP