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 Gρ,α(x) (ρ= index of Lorentz vector, α=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 HW=(G0/2√2)Gρ,α·G*ρ,α, then the |ΔI|=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 HW contains `pseudo-diagonal' terms, (eνµ)(νµe) and (µνe)(νeµ), 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-, (µνe)- and (eνµ)-currents, i.e., Wρ(e;x), Wρ(µ;x), Wρ(νeµ;x) and Wρ(νµe;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 µ-e universality holds. Various observable effects expected from our HW are investigated, in which are included properties of charm-nonconserving interaction, magnitude of the structure functions of deep inelastic neutrino reactions and so on.