Yukawa sector in non-supersymmetric renormalizable SO(10)

Abstract

We discuss the ordinary, non-supersymmetric SO(10) as a theory of fermion masses and mixings. We construct two minimal versions of the Yukawa sector based on ${\overline{126}}_H$ and either $10_H$ or $120_H$. The latter case is of particular interest since it connects the absolute neutrino mass scale with the size of the atmospheric mixing angle ${\theta }_A$. It also relates the smallness of $V_{cb}$ with the largeness of ${\theta }_A$. 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.

8 pages. Reference added, one formula corrected