A Model of Weak Interactions and Application to the π- andK-Meson Decays

Abstract

A possible model of weak interactions, which is capable of describing both of the semi-leptonic and non-leptonic decays consistently, is proposed and is applied to the π- and K-meson decays. Modified hadronic currents are introduced, each of which is the sum of a vector current and an axial vector current having their respective phase factors. It is suggested that the weak interactions are universal in the sense that the pure-leptonic, semi-leptonic and non-leptonic processes are describable with a common effective coupling constant. The origin of the fact that a significant violation of the ΔI = 1/2 rule is observed in the K →2π mode but not in the K →3π mode is shown to be related to the fact that Δθ≡θA-θV ≠0, where θV and θA are two Cabibbo angles characteristic of the vector and axial vector currents respectively. By generalizing the non-leptonic interaction so as to allow the CP violation, the amplitude ratio of the KL0 →ππ mode to the KS0 →ππ mode is also discussed.