Time : 2021/2/22 (Mon.) 12:30
Place : R517, New Physics Building, NTU

Abstract:
We construct a supersymmetric flipped SU(5) grand unified model that possesses an R symmetry. This R symmetry forbids dangerous non-renormalizable operators suppressed by a cut-off scale up to sufficiently large mass dimensions so that the SU(5)-breaking Higgs field develops a vacuum expectation value of the order of the unification scale along the F- and D-flat directions by the supersymmetry-breaking effect. The mass terms of the Higgs fields are forbidden by the R symmetry, with which the doublet-triplet splitting problem is solved with the missing partner mechanism. The masses of right-handed neutrinos are generated by non-renormalizable operators, which then yield light neutrino masses through the seesaw mechanism. This model predicts one of the color-triplet Higgs multiplets to lie at an intermediate scale, and its mass is constrained by proton decay experiments. Future proton decay experiments at Hyper-Kamiokande p → π 0µ + and p → K0µ + decay modes can distinguish our model from other scenarios.