K-leptonic decay and partially conserved currents

Abstract

An operational definition for the partial conservation of the strangeness-changing vector current is given and applied to leptonic K+ and K20 decay. The K* resonance is explicitly included in the calculation and quantitative agreement with experiment is obtained. A detailed comparison with the K+ data of Brown et al. and Dobbs et al. is given. Because of rapid variations of a form factor, it is found that the data of these two groups are not in contradiction. From the K20 experiment of Luers et al., I=1/2 and 3/2 currents are seen to exist. Λβ decay is briefly considered. It is found that an explanation for the slowness of K leptonic decay and the vector part of Λβ decay may be connected with the partial conservation of the strangeness-changing vector current.