Bi-maximal neutrino mixings and proton decay in SO(10) with anomalous flavor U(1)

By supplementing supersymmetric SO(10) with an anomalous U(1) flavor symmetry and additional `matterʹ superfields carrying suitable U(1) charges, we explain the charged fermion mass hierarchies, the magnitudes of the CKM matrix elements, as well as the solar and atmospheric neutrino data. We stress bi-maximal vacuum neutrino mixings, and indicate how the small or large mixing angle MSW solution can be incorporated. The U(1) symmetry also implies that τp→Kν[SO(10)]∼(10–100)·τp→Kν[minimal SU(5)].