Renormalizable SO(10) grand unified theory with suppressed dimension-5 proton decays

We study a renormalizable supersymmetric (SUSY) SO(10) grand unified theory model where the Yukawa couplings of single 10, single (126) over bar, and single 120 fields (Y-10, Y-126, and Y-120) account for the quark and lepton Yukawa couplings and the neutrino mass. We pursue the possibility that Y-10, Y-126, and Y-120 reproduce the correct quark and lepton masses, Cabibbo-Kobayashi-Maskawa and Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrices and neutrino mass differences, and at the same time suppress dimension-5 proton decays (proton decays via colored Higgsino exchange) through their texture, so that the soft SUSY-breaking scale can be reduced as much as possible without conflicting the current experimental bound on proton decays. We perform a numerical search for such a texture, and investigate implications of that texture on unknown neutrino parameters, the Dirac CP phase of the PMNS matrix, the lightest neutrino mass, and the (1, 1)-component of the neutrino mass matrix in the charged lepton basis. Here we concentrate on the case when the active neutrino mass is generated mostly by the Type-2 seesaw mechanism, in which case we can obtain predictions for the neutrino parameters from the condition that dimension-5 proton decays be suppressed as much as possible.