Sneutrino Hybrid Inflation in Supergravity

Abstract

We propose a hybrid inflation scenario in which the singlet sneutrino, the superpartner of the right-handed neutrino, plays the role of the inflaton. We study a minimal model of sneutrino hybrid inflation in supergravity, where we find a spectral index $n_s\approx 1+2\gamma$ with $|\gamma |\lesssim 0.02$, and predict a running spectral index $|d{n}_s/d\ln k|\ll |\gamma |$ and a tensor-to-scalar ratio $r\ll {\gamma }^2$ for field values well below the Planck scale. In our scenario, the baryon asymmetry of our universe can be explained via non-thermal leptogenesis and a low reheat temperature $T_{RH}\approx 10^6$ GeV can be realized.

4 pages; minor corrections; version to appear in Phys. Rev. D