Seminarium "Teoria cząstek elementarnych i kosmologia"

Twin Higgs (TH) models elegantly solve the little hierarchy problem of the Standard Model (SM) by introducing a twin (or mirror) copy of the SM. In my talk, I will review the EW phase transition in TH, demonstrating that it could be first-order, with a suitable source of asymmetry between the SM and twin sectors. This main result will be illustrated with concrete mechanisms of twin symmetry breaking that lead to the natural first-order phase transition (FOPT). I will discuss how the FOPT in TH can be embedded in a broader framework that explains the observed baryon asymmetry. Additionally, I will comment on the potential emission of stochastic gravitational waves that often accompany cosmological FOPTs.