Explanation of the masses of quarks and leptons in a supersymmetric preon model

Abstract

We have studied whether the radiative effects including gauge and Yukawa interaction corrections can improve the phenomenological consequences on the masses of quarks and leptons in the supersymmetric preon model. Our study shows that pure renormalization effects in the region from the metacolour scale to the electroweak scale produce quark-lepton distinction within a given family. They cannot, however, produce the desired up-down distinction or the expected quark-lepton asymmetry in the effective hierarchy parameter of the up, down and lepton sectors. It also shows that the pure radiative corrections cannot explain the `fine structure' effects exhibited by . These lead us to conclude that the symmetry structure of the preon theory cannot strictly respect left-right, up-down and quark-lepton symmetries near and below the Planck scale. This subsequently implies the symmetry both as regards unification of couplings near the Planck scale in the model and as regards its possible origin from a superstring theory.