  We implement the mechanism of non-thermal leptogenesis in the framework of an
inflationary model based on a supersymmetric (SUSY) Pati-Salam Grand Unified
Theory (GUT). In particular, we show that inflation is driven by a quartic
potential associated with the Higgs fields involved in the spontaneous GUT
symmetry breaking, in the presence of a non-minimal coupling of the inflaton
field to gravity. The inflationary model relies on renormalizable
superpotential terms and does not lead to overproduction of magnetic monopoles.
It is largely independent of one-loop radiative corrections, and it can be
consistent with current observational data on the inflationary observables,
with the GUT symmetry breaking scale assuming its SUSY value. Non-thermal
leptogenesis is realized by the out-of-equilibrium decay of the two lightest
right-handed (RH) neutrinos, which are produced by the inflaton decay.
Confronting our scenario with the current observational data on light
neutrinos, the GUT prediction for the heaviest Dirac neutrino mass, the baryon
asymmetry of the universe and the gravitino limit on the reheating temperature,
we constrain the masses of the RH neutrinos in the range (10^10-10^15) GeV and
the Dirac neutrino masses of the two first generations to values between 0.1
and 20 GeV.
