Speaker
Description
The NMSSM has the attractive features of being able to provide at least a partial solution to the little hierarchy problem through the introduction of a guage singlet. Its usefulness in electroweak baryogenesis is more pronounced - with the singlet being useful to catalyze a boost in the strength of the EWPT without conflicting with collider constraints. Furthermore, interactions between the singlino-higgsino and the space time varying vacuum provide a source of CP violation not present in the MSSM and virtually unconstrained by negative searches for permanent EDMs. We present an in depth analysis of the prospects of electroweak baryogenesis within the NMSSM.
Summary
We calculate the baryon asymmetry in the Z3-invariant NMSSM where Singlino interactions with the space time varying vacuum provide the source of CP violation necessary for the production of baryon asymmetry. We derive and solve transport equations using the closed time path formalism for the cases where the singlet acquires a vacuum expectation value before and during the electroweak phase transition. The thermal width of the singlino is relatively small which affects how near a resonance one needs to be in order to produce a sufficiently large baryon asymmetry. We examine whether this is possible under the constraint of a Higgs mass of 125 GeV. We also investigate whether it helps to have the singlet acquire a VEV before or during the EWPT as well as examining the dependence of the baryon assymetry on the three body interactions involving gauge singlets.