Yukawa sector in nonsupersymmetric renormalizable SO(10)

Abstract

We discuss the ordinary, nonsupersymmetric SO(10) as a theory of fermion masses and mixings. We construct two minimal versions of the Yukawa sector based on ${\overline{\mathbf{126}}}_{\mathbf{H}}$ and either ${\mathbf{10}}_{\mathbf{H}}$ or ${\mathbf{120}}_{\mathbf{H}}$. The latter case is of particular interest since it connects the absolute neutrino mass scale with the size of the atmospheric mixing angle ${\ensuremath{\theta}}_{A}$. It also relates the smallness of ${V}_{cb}$ with the largeness of ${\ensuremath{\theta}}_{A}$. These results are based on the analytic study of the second and third generations. Furthermore, we discuss the structure of the light Higgs and the role of the Peccei-Quinn symmetry for dark matter and the predictivity of the theory.