A Non - Minimal SO ( 10 ) × U ( 1 ) F SUSY - GUT Model Obtained from a Bottom - Up Approach

A non-minimal supersymmetric SO(10) × U (1) F grand unified model is developed based on the Yukawa structure of a model previously constructed in collaboration with S. Nandi to explain the quark and lepton masses and mixings in a particular neutrino scenario. The U (1) F family symmetry can be made anomaly-free with the introduction of one conjugate pair of SO(10)-singlet neutrinos with the same U (1) F charge. Due to a plethora of conjugate pairs of supermultiplets, the model develops a Landau singularity within a factor of 1.5 above the GUT scale. With the imposition of a Z 2 discrete symmetry, all higgsino triplets can be made superheavy while just one pair of higgsino doublets remains light and results in mass matrix textures previously obtained from the bottom-up approach. Diametrically opposite splitting of the first and third family scalar quark and lepton masses away from the second family ones results from the nonuniversal D-term contributions. –2– FERMILAB–Pub–96/234–T