Probing EWPT in 2HDM with future lepton colliders

The electroweak phase transition can be made first order by extending the Standard Model (SM) Higgs sector with extra scalars. Here, we focus on the strong first-order electroweak phase transition (SFOEWPT) in the Type-II two Higgs doublet models (2HDMs). Through a parameter space scan, we find that SFOEWPT suggests upper limits on the masses of the heavy Higgs m(A/H/H +/-), which is less than 1TeV. High-temperature expansion and Higgs vacuum uplifting are used for analytical understanding of our results. We find that sizeable loop corrections require m(A)asymptotic to m(H +/-)> m(H) to meet the SFOEWPT condition in the Type-II 2HDM. We also study the possibility of probing SFOEWPT at the one-loop level from Higgs and Z-pole precision measurements at future Higgs and Z factories.

Automated summary

By extending the Higgs sector in the Standard Model with extra scalars, the electroweak phase transition can be made first order. In this study, we focus on the strong first-order electroweak phase transition in the Type-II two Higgs doublet models. Through a parameter space scan, we find upper limits on the masses of the heavy Higgs, which are less than 1TeV. High-temperature expansion and Higgs vacuum uplifting are used for analytical understanding of the results. We also investigate the possibility of probing the strong first-order electroweak phase transition at the one-loop level through precision measurements at future Higgs and Z factories.