A Model of Weak Interaction Based on the Three-Triplet Model of Hadrons

Possible roles which the internal degrees of freedom in the three-triplet model of hadrons play in weak interactions are investigated. It is pointed out that, if we introduce a charged current!lp,a(x) (p=index of Lorentz vector, a=1, ···,4) of the so-called 'double V-A ' type which is a certain kind of charged current so extended as to carry the internal degrees of freedom contained in the three-triplet model, and assume that the weak interaction is.5Cw=(Go/2y''l:)!lp,a·!l~,a • then the ldii=1/2 rule is derived for nonleptonic decays of ordinary hadrons (assumed to belong to the SU(3)"'-singlet). The purely leptonic interaction obtained from.5Cw contains 'pseudo-diagonal ' terms, (eJI")(llpe) and (iiJie)Cllef.l), but not the so-called diagonal ones. From the semi-leptonic interaction one obtains four kinds of hadronic currents which couple to the electron-, muon-, (iiJie)- and (eJI")-currents, i.e., Wp(e; x), Wp(/.l; x), Wp(Jief.l; x) and Wp(JI"e; x). These are different from each other, but, as far as one treats matrix elements between SU(3)'•-singlet states, the former two of them give the same values and the latter two have no contributions under the assumption that the symmetry-breaking of strong interaction preserves the SU(3)"'-symmetry. In this sense, the f.l-e universality holds. Various observable effects expected from our.5C w are investigated, in which are included properties of charm-nonconserving interaction, magnitude of the structure functions of deep inelastic neutrino reactions and so on