Minimal supersymmetric hybrid inflation, flipped SU(5) and proton decay

Minimal supersymmetric hybrid inflation utilizes a canonical Kahler potential and a renormalizable superpotential which is uniquely determined by imposing a U(1) R-symmetry. In computing the scalar spectral index n(s) we take into account modifications of the tree level potential caused by radiative and supergravity corrections, as well as contributions from the soft supersymmetry breaking terms with a negative soft mass-squared term allowed for the inflaton. All of these contributions play a role in realizing n(s) values in the range 0.96-0.97 preferred by WMAP. The U(1) R-symmetry plays an important role in flipped SU(5) by eliminating the troublesome dimension five proton decay. The proton decays into e(+)pi(0) via dimension six operators arising from the exchange of superheavy gauge bosons with a lifetime of order 10(34)-10(36) years. (C) 2010 Elsevier B.V. All rights reserved.