Non-minimal Higgs inflation and non-thermal leptogenesis in a supersymmetric Pati-Salam model

Abstract

We consider a supersymmetric (SUSY) Grand Unified Theory (GUT)based on the gauge group GPS = SU(4)C × SU(2)L × SU(2)R, which incorporates non-minimalchaotic inflation, driven by a quartic potential associated withthe Higgs fields involved in the spontaneous breaking of GPS.The inflationary model relies on renormalizable superpotentialterms and does not lead to overproduction of magnetic monopoles.It is largely independent of the one-loop radiative correctionsand can become consistent with the current observational data onthe inflationary observables, with the symmetry breaking scale ofGPS assuming its SUSY value. Within our model, the strongCP and the μ problems of the minimal SUSY standard model canbe resolved via a Peccei-Quinn symmetry. Moreover baryogenesisoccurs via non-thermal leptogenesis realized by theout-of-equilibrium decay of the right-handed neutrinos, which areproduced by the inflaton's decay. We consider two versions of sucha scenario, assuming that the inflaton decays to the lightest orto the next-to-lightest right-handed neutrino. Both scenaria canbecome compatible with the constraints arising from the baryonasymmetry of the universe, the gravitino limit on the reheatingtemperature and the upper bound on the light neutrino masses,provided that the gravitino is somehow heavy. In the secondscenario, extra restrictions from the SU(4)C GUT symmetryon the heaviest Dirac neutrino mass and the data on theatmospheric neutrino oscillations can be also met.