Speaker
Description
The origin of the observed baryon asymmetry of our universe remains a mystery. Electroweak baryogenesis (EWBG) scenarios remain viable candidates which can be constrained by ongoing particle physics and upcoming gravitational wave experiments. The Standard Model has baryon number violating processes, the sphalerons. However, EWBG models have to introduce beyond the Standard Model physics at the electroweak scale to address the lack of a first-order phase transition (and notable CP/P violation) in the electroweak sector. The viability of these models hinges on the sphaleron rate freezing out fast enough as one transitions from the confinement-like phase to the Higgs phase. The computation of this rate in the increasingly complex BSM landscape can become untractable. Luckily, most of BSM models at high temperatures can be mapped perturbatively into an effective dimensionally reduced 3D Higgs+SU(2) theory. We can thus constrain many BSM models by studying the sphaleron rate in the parameter space of the simpler EFT. In this talk I will present a non-perturbative lattice determination of the sphaleron rate in the full parameter space relevant for first-order phase transitions. With these results we can obtain a robust model independent constraint for the strength of the transition that lead to viable baryogenesis scenario.