A recent treatment of first-forbidden ${\mathrm{\beta }}^{\mathrm{-}}$ decay in the lead region is extended to ${\mathrm{\beta }}^{+}$ decay and electron capture. The modified Kuo-Herling shell-model interaction recently described by Warburton and Brown is used to calculate wave functions and observables for ${}_{}{}^{211}{}_{}{}^{}\mathrm{Po}$. The log${\mathit{f}}_0$t values for the ${}_{}{}^{211}{}_{}{}^{}\mathrm{Bi}$(9/$2^{\mathrm{-}}$)${\to }^{211}$Po(9/$2^{+}$) ${\mathrm{\beta }}^{\mathrm{-}}$ transition and the electron capture of ${}_{}{}^{211}{}_{}{}^{}\mathrm{At}$(9/$2^{\mathrm{-}}$) into the 9/2 ${}_1{}^{+}{}_{}{}^{}$ and 11/2 ${}_1{}^{+}{}_{}{}^{}$ states of ${}_{}{}^{211}{}_{}{}^{}\mathrm{Po}$ are predicted to be 6.008, 5.891, and 5.850 as compared to the experimental values of 6.026±0.017, 5.960±0.008, and 5.831±0.090, respectively. The wave functions and spectrum of ${}_{}{}^{211}{}_{}{}^{}\mathrm{Po}$ are calculated in the Kuo-Herling model space. The yrast spectrum is presented for comparison to anticipated results from fusion-evaporation reaction studies. The experimental ${}_{}{}^{210}{}_{}{}^{}\mathrm{Po}$(d,p${)}^{211}$Po spectroscopic factors are quite accurately reproduced.

• Received 1 May 1991

DOI:https://doi.org/10.1103/PhysRevC.44.1500