Bi-large neutrino mixing and CP violation in an SO(10) SUSY GUT for fermion masses

We construct a simple SO(10) SUSY GUT with D3 family symmetry and low energy R-parity. The model describes fermion mass matrices with 14 parameters and gives excellent fits to 20 observable masses and mixing angles in both quark and lepton sectors, giving 6 predictions. Bi-large neutrino mixing is obtained with hierarchical quark and lepton Yukawa matrices; thus avoiding the possibility of large lepton flavor violation. The model naturally predicts small 1-3 neutrino mixing, sinθ13≃0.05, and a CP violating phase δ close to π/2. Among other interesting predictions is a tiny effective Majorana mass for neutrinoless double-beta decay. Leptogenesis is also possible with the decay of the lightest right-handed neutrino giving an acceptable CP violating asymmetry ε1 of order 10−6, and with the correct sign for the resultant baryon asymmetry. Note, similar models with the non-Abelian symmetry groups SU(2) or D4, instead of D3, can be constructed.