Conveners
EWPT
- Mayumi Aoki (Kanazawa University)
EWPT
- Kin-ya Oda (Tokyo Woman's Christian University)
To realize first-order electroweak phase transition, it is necessary to generate a barrier in the thermal Higgs potential, which is usually triggered by scalar degree of freedom. We instead investigate phase transition patterns in pure fermion extensions of the standard model, and find that additional fermions with mass hierarchy and mixing could develop such barrier and realize strongly...
In this talk, we discuss whether a multi-step electroweak phase transition (EWPT) occurs in two Higgs doublet models (2HDMs). The EWPT is related to interesting phenomena such as baryogenesis and a gravitational wave from it. We examine parameter regions in CP-conserving 2HDMs and find certain areas where the multi-step EWPTs occur. In addition, we compute the Higgs trilinear coupling in the...
We numerically investigate the B + L violation process by performing three-dimensional lattice simulations of a unified scenario of first-order phase transitions and the sphaleron generation. The simulation results indicate that the Chern-Simons number changes along with the helical magnetic field production when the sphaleron decay occurs. Based on these numerical results, we then propose a...
The Georgi-Machacek model extends the standard model Higgs sector with one complex and one real isospin triplet scalar fields and preserves the custodial symmetry. Using the HEPfit, a Bayesian MCMC analysis package for particle physics, we scan for allowed parameter space under the constraints of Higgs productions and direct searches from LHC data, as well as various theory bounds. From the...
We study the feasibility of strong first-order electroweak phase transition in a degenerate-scalar scenario of a complex singlet extension of the Standard Model, in which a mass of an additional scalar is nearly degenerate with that of the Higgs boson, 125 GeV. This scenario is known to be free from strong constraints from dark matter direct detection experiments due to cancellations between...
