Proton decay in the semi-simple unification

Semi-simple unification is one of models which naturally solve two difficulties in the supersymmetric grand unification theory: doublet-triplet splitting problem and suppression of dimension 5 proton decay, We analyzed the dimension 6 proton decay of this model using perturbative analysis at the next-to-leading order. The life time of proton is 3 x 10(34)-10(35) years for wide range of SUSY breaking parameters, and there is an intriguing possibility of observing proton decay signals in the next-generation water Cerenkov detectors such as Hyper-Kamiokande and TITAND. Several uncertainties in this prediction are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.