ELECTROWEAK BARYOGENESIS IN THE MINIMAL SUPERSYMMETRIC STANDARD MODEL

I describe work done in collaboration with M. Joyce and K. Kainulainen on (1) the strength of the electroweak phase transition in the MSSM and (2) the mechanism for producing the baryon asymmetry during the phase transition. In the former we compare the effective potential and dimensional reduction methods for describing the phase transition and search the parameter space of the MSSM for those values where it is strong enough. In the latter we give a systematic computation of the baryon asymmetry due the CP-violating force acting on charginos in the vicinity of the bubble wall. We find that a light right-handed stop, a light Higgs boson, and a large phase in the µ parameter, are the main necessary ingredients for producing the baryon asymmetry. 1 Experimentally testable baryogenesis? A major triumph of astroparticle physics is our understanding of the light element abundances through big bang nucleosynthesis. Equally exciting is the prospect of putting the measured baryon asymmetry of the universe, η = nB/nγ ∼ = 3 ×10 −10, on a similar footing. To do so we must have a theory that