Coupling Constants in β-Decay and Nucleon Structure

Abstract

The difficulty concerning the renormalized axial vector coupling constant of β-decay with pionic corrections in analyzed from a simple model about the nucleon structure. In this proposed model, the nucleon is supposed to consist of the `nucleon core' of spin ½ and the pionic cloud, and the core is assumed to be composed of static bare N, N ensemble. An attempt is made to determine what restrictions are imposed on the wave functional of the nucleon core by the known values of β-decay coupling constants. In the case in which the states of the bare particle are restricted to s- and p-state, it is found that the three-body configurations (NNN) play the predominant role in order to yield the maximum value of GA/GV( \cong 1.38), the ratio of the axial vector- to the vector-coupling constant of the nucleon core. From this analysis, N-N configurations of iso-singlet and spin triplet are shown to be predominant.