A simple model for particle physics and cosmology

Abstract

We propose a simple extension of the minimal supersymmetric standard model by introducing a gauge singlet in addition to right-handed neutrinos. The model resolves the strong CP problem by Pecci-Quinn symmetry, explains the origin of left-handed neutrino masses as well as MSSM $\mu$-parameter. It also gives rise to thermal inflation, baryogenesis and dark matter in a remarkably consistent way. Interestingly, resolution of moduli problem by thermal inflation constrains tightly axion coupling constant and flaton decay temperature to be $f_a \sim 10^{12} \GeV$ and $T_\mathrm{d} \sim 100 \MeV$, respectively. Model parameters in this case are likely to give right amount of baryon asymmetry and dark matter at present. The main component of dark matter is expected to be the axino whose mass is nearly fixed to be about $1 \GeV$.