Supersymmetric inflation and baryogenesis via extra-flat directions of the minimal supersymmetric standard model

One interpretation of proton stability is that it implies the existence of extra-flat directions of the minimal supersymmetric standard model, in particular u(c)u(c)d(c)e(c) and QQQL, where the operators lifting the potential are suppressed by a mass scale. which is much larger than the Planck mass,Lambda greater than or similar to 10(26) GeV. Using D-term hybrid inflation as an example, we show that such. at directions can serve as the inflaton in supersymmetric inflation models. The resulting model is a minimal version of D-term inflation which requires the smallest number of additional fields. In the case where Q-balls form from the extra-flat direction condensate after inflation, successful Affleck-Dine baryogenesis is possible if the suppression mass scale is greater than or similar to 10(31)-10(35) GeV. In this case the reheating temperature from Q-ball decay is in the range 3-100 GeV, while observable baryon isocurvature perturbations and non-thermal dark matter are possible. In the case of extra-flat directions with a large t squark component, there is no Q-ball formation and reheating is via conventional condensate decay. In this case the reheating temperature is in the range 1-100 TeV, naturally evading thermal gravitino overproduction while allowing sphaleron erasure of any large B-L asymmetry.