Kaehler Potentials for Hilltop F-term Hybrid Inflation

We consider the basic supersymmetric (SUSY) models of F-term hybrid inflation (FHI). We show that a simple class of Kaehler potentials ensures a resolution to the \eta problem and allows for inflation of hilltop type. As a consequence, observationally acceptable values for the spectral index, ns, can be achieved constraining the coefficient c4k of the quartic supergravity correction to the inflationary potential. For about the central value of ns, in the case of standard FHI, the grand unification (GUT) scale turns out to be well below its SUSY value with the relevant coupling constant \kappa in the range (0.0006-0.15) and c4k=-(1100-0.05). In the case of shifted [smooth] FHI, the GUT scale can be identified with its SUSY value for c4k=-16 [c4k=-1/16].