Speaker
Description
In this talk, I will inspire how the phenomenology of the Electroweak Phase Transition (EWPT) can guide the search for new physics related to the Higgs sector with the concrete example of Higgs exotic decays. EWPT is the transition from an electroweak symmetric phase to a broken phase in the early universe, and is a cross over in the Standard Model (SM). The EWPT being strongly first order is a necessary condition for electroweak baryogenesis, a mechanism that explains the baryon asymmetry of the universe. Thus, extending the Higgs sector to accommodate a strongly first order EWPT remains a motivated study for beyond the Standard Model physics. Importantly, the Higgs potential and properties are necessarily modified when new physics degrees of freedom are introduced to couple to the Higgs, leading to potential smoking-gun signals in Higgs searches. In the talk, I will present a concrete model example with a generic singlet extension to the Higgs sector, where there is a firm correlation between the prediction of a light scalar and a strongly first order EWPT. As the SM Higgs can decay into a pair of light scalars, the Higgs exotic decay is a unique channel to probe a broad class of EWPT models featuring light scalars.
