Theory of Partially Conserved Axial-Vector Current and Mesonic Exchange Effects in Nuclear Beta Decay

Abstract

By assuming that the axial-vector current is partially conserved, a relationship is obtained between the phenomenological meson-exchange operator in beta decay and the two-body pion-production operator. An analysis of the experimental results for the process $p+p\ensuremath{\rightarrow}d+{\ensuremath{\pi}}^{+}$ in terms of this operator is made, and the strength of the meson-exchange operator is then deduced from the relationship. It is found that the strength does not agree with that necessary to account for the $\mathrm{ft}$ value of the beta-decay process ${\mathrm{H}}^{3}\ensuremath{\rightarrow}{\mathrm{He}}^{3}+{e}^{\ensuremath{-}}+\overline{\ensuremath{\nu}}$. Possible reasons for the disagreement are discussed.