Supersymmetric inflation and baryogenesis via Extra-Flat directions of the MSSM

TL;DR

This paper explores how extra-flat directions in the MSSM can serve as inflatons in SUSY inflation models, enabling baryogenesis and dark matter production with distinctive reheating temperatures and observational signatures.

Contribution

It demonstrates that MSSM flat directions can act as inflatons in minimal D-term inflation models and discusses conditions for successful baryogenesis and dark matter production.

Findings

Extra-flat directions can drive inflation with minimal additional fields.

Q-ball formation enables Affleck-Dine baryogenesis at high suppression scales.

Reheating temperatures vary from GeV to TeV range, affecting dark matter and baryon asymmetry.

Abstract

One interpretation of proton stability is the existence of extra-flat directions of the MSSM, in particular $u^{c}u^{c}d^{c}e^{c}$ and $QQQL$, where the operators lifting the potential are suppressed by a mass scale $\Lambda$ which is much larger than the Planck mass, $ \Lambda \gae 10^{26} \GeV$. Using D-term hybrid inflation as an example, we show that such flat directions can serve as the inflaton in SUSY 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 $\gae 10^{31}-10^{35} \GeV$. 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 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.