SUPERSYMMETRIC MODEL FOR FERMION MASS HIERARCHY

A scheme for radiative mass hierarchy among fermions is realised within a supersymmetric SU(2)L⊗SU(2)R⊗SU(4)C model. In this model, the masses of top and bottom quarks arise at the tree-level. At the one loop level, the charm quark and the tau lepton pick up mass whereas the strange, down and up quarks as well as the muon and the electron become massive at the two-loop level with a natural hierarchy between the first- and second-generation masses. Furthermore, mu<md and ms≈mμ follow from the model without any further assumptions. © 1990.