β+decays ofCa37: Implications for the efficiency of theCl37solar ν detector

We studied ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ca}$ ${\mathrm{\beta }}^{+}$ decays using a mass separated ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ca}$ beam and a proton telescope with 16-keV resolution. Delayed p’s were detected in coincidence with γ’s to identify p decays of ${}_{}{}^{37}{}_{}{}^{}\mathrm{K}$ daughter levels to excited states of ${}_{}{}^{36}{}_{}{}^{}\mathrm{Ar}$. We observed 43 previously undetected proton groups, yielding an integrated B(GT) twice as large as that observed previously. Although our result increases the efficiency of the ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$ detector for counting solar ν’s by 6%, its main effect is to reduce uncertainties in this efficiency arising from discrepancies between previous ${}_{}{}^{37}{}_{}{}^{}\mathrm{Ca}$ β decay and ${}_{}{}^{37}{}_{}{}^{}\mathrm{Cl}$(p,n) results.