Neutrino masses and mixings in SO(10)

Abstract

Assuming a Zee-like matrix for the right-handed neutrino Majorana masses in the see-saw mechanism, one gets maximal mixing for vacuum solar oscillations, a very small value for $U_{e3}$ and an approximate degeneracy for the two lower neutrino masses. The scale of right-handed neutrino Majorana masses is in good agreement with the value expected in a SO(10) model with Pati-Salam $SU(4)\text{ts}SU(2)\text{ts}SU(2)$ intermediate symmetry.

Comments: 11 pages, no figures. References added