A NONMINIMAL SO(10) X U(1)(F) SUSY-GUT MODEL OBTAINED FROM A BOTTOM-UP APPROACH

Many of the ingredients are explored which are needed to develop a sup ersymmetric SO(10) x U(1)(F) grand unified model based on the Yukawa s tructure of a model previously constructed in collaboration with S. Na ndi to explain the quark and lepton masses and mixings in a particular neutrino scenario. The U(1)(F) family symmetry can be made anomaly-fr ee with the introduction of one conjugate pair of SO(10)-singlet neutr inos with the same U(1)(F) charge. Due to a plethora of conjugate pair s 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) disc rete symmetry and under certain conditions, all higgsino triplets can be made superheavy while just one pair of higgsino doublets remains li ght and results in mass matrix textures previously obtained from the b ottom-up approach. Diametrically opposite splitting of the first and t hird family scalar quark and lepton masses away from the second family ones results from the nonuniversal D-term contributions.