ChiralSU(7)?SU(7) preon model as a hierarchical unification theory

A chiralSU(7) ?SU(7) gauge model is selected out of a wide class of preon models. It contains a pair of chiral preons as well as vectorial ones. Mass splittings of the latter cause rank-retaining breakings of the hyperflavor gauge symmetry in the preonic phase. Hypercolor confinement of preons and the feature of chiral ones among resulting postons (or hyperhadrons) are studied. Rank-decreasing breakings of the hyperflavor symmetry occur successively in the postonic phase as chiral postons acquire dynamical masses. Our coupled equations for quark masses are based on the assumption that electroweak symmetry breaking is due to the cooperation of short-range postonic forces with the infinite-range gluonic one. Updown asymmetry of quark masses are discussed in terms of the equations.