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

Abstract

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, $h_1$. The microwave background temperature anisotropy determines this coupling to be $h_1\simeq 10^{-7}$, 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 $\simeq 10^{12}$GeV when the universe cools to a temperature $T\lesssim 10^3$GeV. This leads to an invisible axion, a weak scale $\mu$-term and an electron Majorana neutrino mass $M_{N_1}\simeq 10^5$GeV. A second inflationary period can also occur via a flat-direction field. In this case the universe can be reheated to a temperature $T_{RH}\simeq 10^6$GeV, without restoring PQ symmetry. Baryogenesis will then occur via out-of-equilibrium neutrino decay.