Chaotic inflation and a radiatively generated intermediate scale in the supersymmetric standard model

We consider a phenomenological extension of the minimal supersymmetric standard model which incorporates chaotic inflation and a radiatively generated intermediate mass scale. Initially a period of chaotic inflation is driven by a quartic potential associated with the right-handed electron sneutrino. Supersymmetry relates the quartic coupling of the inflationary potential to the electron Majorana neutrino Yukawa coupling, h1. The microwave background temperature anisotropy determines this coupling to be h1 ⋍ 10−7, which is similar in magnitude to the electron Dirac Yukawa coupling. A U(1) Peccei-Quinn (PQ) symmetry is broken by radiative corrections at an intermediate scale ⋍ 1012 GeV when the universe cools to a temperature T ≲ 103 GeV. This leads to an invisible axion, a weak scale μ-term and an electron Majorana neutrino mass MN1 ⋍ 105 GeV. A second inflationary period can also occur via a flat-direction field. In this case the universe can be reheated to a temperature TRH ⋍ 106GeV, without restoring PQ symmetry. Baryogenesis will then occur via out-of-equilibrium neutrino decay.