Rules for Spin and Parity Assignments Based onLogftValues

Abstract

A survey was made of $log\mathrm{ft}$ values for forbidden $\beta$ transitions. Three cases, ${}_{}{}^{90m}{}_{}{}^{}\mathrm{Y}$, ${}_{}{}^{65}{}_{}{}^{}\mathrm{Ni}$, and ${}_{}{}^{144}{}_{}{}^{}\mathrm{Pm}$ decays, were examined experimentally. A number of low $log\mathrm{ft}$ values reported in the literature are superseded by more recent larger values. Empirical rules for making spin and parity assignments from $log\mathrm{ft}$ values are proposed.