Creating the Matter Antimatter Asymmetry of the Universe out of Higgs Bubble Collisions
Explaining the matter antimatter asymmetry of the universe requires a source of baryon number violation.
Baryon number is efficiently violated in the Standard Model of particle physics at high temperature through electroweak vacuum transitions, the so-called sphaleron processes, which play a key role in essentially all models of baryogenesis, whether at the electroweak scale or well beyond, as in leptogenesis.
I will show that these transitions can also be induced at zero temperature for large departure from equilibrium of the Higgs field.
In particular, we compute the rate of baryon number violation at T=0 arising from Higgs bubble collisions during a strong first-order electroweak phase transition. This opens up the possibility for a new mechanism of electroweak baryogenesis in the supercooled limit.