SO(3) family symmetry and axions

Understand

Motivated by the idea of comprehensive unification, we study a gauged SO(3) flavor extension of the extended Standard Model, including right-handed neutrinos and a Peccei-Quinn symmetry with simple charge assignments.

• The model accommodates the observed fermion masses and mixings and yields a characteristic, successful relation among them.
• The Peccei-Quinn symmetry is an essential ingredient.