Title: Sphaleron in the Higgs Triplet Model
Speaker: Bingrong Yu (Cornell University & Korea University)
Abstract: The Higgs triplet model (HTM) extends the Standard Model (SM) by one complex triplet scalar (also known as the type II seesaw model), offering a simple and viable way to account for nonzero neutrino masses. On the other hand, the nontrivial couplings of the triplet to the gauge fields and to the SM Higgs field are expected to influence the topological vacuum structure of the SM and, consequently, the energy and field configuration of the electroweak sphaleron. The sphaleron process plays a crucial role in dynamically generating the baryon asymmetry of the universe. In this talk, I will introduce our recent work, which studied the vacuum structure of the gauge and Higgs fields and calculated the saddle-point sphaleron configuration in the HTM. The coupled nonlinear equations of motion of the sphaleron were solved using the spectral method. We found that the inclusion of the triplet scalar could, in principle, significantly change the sphaleron energy compared with the SM. Nevertheless, at zero temperature, the current stringent experimental constraint on the vacuum expectation value of the triplet suppresses the difference. Interestingly, we found that there still exists some narrow parameter space where the sphaleron energy can be enhanced up to 30% compared with the SM case. I will also briefly discuss the electroweak phase transition and electroweak baryogenesis in this model.
This talk is based on arXiv: 2307.04713.
Meeting ID: 880 7640 4883