On Generation Labels and Mass Matrices of Composite Quarks and Leptons

Abstract

Recently, very interesting scenarios1l) have been presented for the understanding of the generation labels and of the mass matrices of quarks and leptons, on the basis of the subquark models in which quarks and leptons are approximately massless composites of massless subquarks which are confined by a subcolour dynamics with a scale parameter Asc > Te V. These scenarios can be summarized as follows. A) Quarks and leptons having different generation labels correspond!),4).S) to the composites having different quantum numbers of X'S6) where X's are generators of some remaining unbroken discrete subgroups of U(l)A symmetries which are broken by subcolour instantons. As for the composites having different X's-numbers, the following possibilities can be considered: A_l)!)-3l.S) 3 fermion composites having different X's-numbers. A-2)4) 3 fermion composite, which is labeled as 1st generation, and composites of the 3 fermion and some fermion pairs having only X's-numbers, which are labeled as 2nd and 3rd generations. B) Technicoloured subquarks!),7) are assumed to be included in the subquark model and the technicolour condensation ) of the composite techniquarks 1),7) is postulated. Then, the effective 4-fermi interactions among composite fermions generate!),7) small masses of quarks and leptons. The masses of quarks and leptons, mQOrl, thus generated, are of the order of!),7)