SU(4)⊗ SU(2) L⊗ SU(2) R as a surrogate SUSY GUT

Abstract

We consider a supersymmetric SU(4)⊗ SU(2) L ⊗ SU(2) R model broken at 10 16 GeV, and propose natural solutions to the problems of Planck-scale unification and light fermion masses in this model. The resulting model shares many of the successes of conventional SUSY GUTs such as the successful prediction of sin 2 θ w and Yukawa unification for the third family, without suffering from the potential problems of Higgs doublet-triplet splitting, the μ-problem, and the incorporation of adjoint representations into a fully unified string model.