Baryogenesis Constraints on the Electroweak Phase Transition in Two-Higgs-Doublet Models

[摘要] The preservation of the baryon asymmetry of the universe (BAU) after the electroweak phase transition (EW PT) is endangered by baryon-number violating sphaleron transitions. Limits on the sphaleron transition rate in order to protect the BAU require a strongly first order EW PT and lead to an upper mass limit on the Standard Model Higgs scalar mass of around 60GeV. This is in direct disagreement with the experimental lower limit on the SM Higgs mass, which is now greater than 60GeV.I consider the problem of avoiding this disagreement by extending the scalar sector of the SM to include a second complex scalar Higgs doublet. My primary aim is to locate a region of the parameter space which can sustain the first order EW PT required for baryogenesis and satisfy the experimental bounds on Higgs masses.

[发布机构] University:University of Glasgow

[关键词] Theoretical physics