Quark and Lepton Mass Matrices in the SO(10) Grand Unified Theory with Generation Flipping

TL;DR

This paper explores an SO(10) grand unified model with generation flipping, successfully reproducing quark and lepton masses and mixings, and explaining neutrino oscillation phenomena.

Contribution

It introduces a novel SO(10) GUT model with an extra matter multiplet and analyzes its parameter space for realistic fermion masses and mixings.

Findings

Model reproduces observed quark masses and mixings.

Large mixing between second and third generations in leptons.

Can explain solar neutrino oscillation solutions.

Abstract

We investigate the SO(10) grand unified model with generation flipping. The model contains one extra matter multiplet $\psi(10)$ and it mixes with the usual matter multiplets $\psi_i(16)$ when the SO(10) is broken down to SU(5). We find the parameter region of the model in which the observed quark masses and mixings are well reproduced. The resulting parameter region is consistent with the observation that only $\psi_i(16)$ have a source of hierarchies and indicates that the mixing between second and third generations tends to be large in the lepton sector, which is consistent with the observed maximal mixing of the atmospheric neutrino oscillation. We also show that the model can accommodate MSW and vacuum oscillation solutions to the solar neutrino deficit depending on the form of the Majorana mass matrix for the right-handed neutrinos.