Supersymmetric hybrid inflation with a light scalar

Light scalar fields present during inflation can lead to interesting observable signatures, especially in models with nonequilibrium reheating dynamics. We study a supersymmetric hybrid inflation model with a third scalar whose lightness is protected by symmetry, using analytical and numerical techniques, and demonstrate that the amplitude, the spectral index and the non-Gaussianity parameter f(NL) of the primordial curvature perturbation are within the Planck observational bounds for suitable parameter values.