Is the weak axial-vector current renormalized in nuclei?

Abstract

The measured Gamow-Teller strength in $^{37}\mathrm{Ca}$ ${\mathrm{\ensuremath{\beta}}}^{+}$ decay, which has an unusually high energy release, differs significantly from shell-model predictions and also from the analogous strength inferred from the $^{37}\mathrm{Cl}$(p,n) reaction. This calls into question the claim, based primarily on shell-model analyses of low-energy-release \ensuremath{\beta}-decay rates and (p,n) cross sections, that ${\mathit{g}}_{\mathit{A}}$ is significantly renormalized in complex nuclei.