No abstract

The electroweak phase transition and the sphaleron decoupling condition in the minimal supersymmetric standard model are revisited taking the latest experimental data into account. The light Higgs boson scenario and the ordinary decoupling limit which are classified by the relative size between the CP -odd Higgs boson mass and Z boson mass are considered within the context of electroweak baryogenesis. We investigate v/T at not only the critical temperature at which the effective potential has two degenerate minima but also the nucleation temperature of the critical bubbles, where v is a vacuum expectation value of the Higgs boson and T denotes a temperature.It is found that v/T at the nucleation temperature can be enhanced by about 10% compared to that at the critical temperature.We also evaluate the sphaleron decoupling condition including the zero mode factors of the fluctuations around sphaleron. It is observed that the sphaleron decoupling condition at the nucleation temperature is given by v/T > ∼ 1.38 for the typical parameter sets. In any phenomenologically allowed region, v/T at both the critical and nucleation temperatures cannot be large enough to satisfy such a sphaleron decoupling condition.

We study phase transitions in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) with the weak scale vacuum expectation values of the singlet scalar, constrained by Higgs spectrum and vacuum stability. We find four different types of phase transitions, three of which have two-stage nature. In particular, one of the two-stage transitions admits strongly first order electroweak phase transition, even with heavy squarks. We introduce a tree-level explicit CP violation in the Higgs sector, which does not affect the neutron electric dipole moment. In contrast to the MSSM with the CP violation in the squark sector, a strongly first order phase transition is not so weakened by this CP violation.Comment: 21 pages, 8 figure

No abstract

A general prescription to solve the Dirac equation in the presence of a CP-violating electroweak bubble wall is presented. The profile of the bubble wall is not specified except that the wall height is m o and zero deep in the broken-and the symmetric-phase regions, respectively, where m o is a fermion mass given by the Higgs vacuum, expectation value and the Yukawa coupling. The CP-violating effects are