Update on minimal supersymmetric hybrid inflation in light of PLANCK

The minimal supersymmetric (or F-term) hybrid inflation is defined by a unique renormalizable superpotential, fixed by a U(1) R-symmetry, and it employs a canonical Kähler potential. The inflationary potential takes into account both radiative and supergravity corrections, as well as an important soft supersymmetry breaking term, with a mass coefficient in the range (0.1-10) TeV. The latter term assists in obtaining a scalar spectral index ns close to 0.96, as strongly suggested by the PLANCK and WMAP 9 yr measurements. The minimal model predicts that the tensor-to-scalar r is extremely tiny, of order 10−12, while the spectral index running, |dns/dlnk|∼10−4. If inflation is associated with the breaking of a local U(1)B−L symmetry, the corresponding symmetry breaking scale M is (0.7-1.6)⋅1015 GeV with ns≃0.96. This scenario is compatible with the bounds on M from cosmic strings, formed at the end of inflation from B−L symmetry breaking. We briefly discuss non-thermal leptogenesis which is readily implemented in this class of models.