Energy-Level Structure of ${\mathrm{Ca}}^{40}$ as Observed with the ${\mathrm{K}}^{39}({\mathrm{He}}^3, d){\mathrm{Ca}}^{40}$ Reaction

The ${\mathrm{K}}^{39}({\mathrm{He}}^3, d){\mathrm{Ca}}^{40}$ reaction was studied at a bombarding energy of 12 MeV with a broad-range magnetic spectrograph. Angular-distribution data were obtained for 15 levels which were observed in ${\mathrm{Ca}}^{40}$ between 3.5- and 8.6-MeV excitation. Spectroscopic factors were extracted with a distorted-wave Born approximation analysis of the data. The major components of the ${\left({d_{\frac{3}{2}}}^{-1\mathrm{}}{f}_{\frac{7}{2}}\right)}_{T=0\mathrm{}}$, ${\left({d_{\frac{3}{2}}}^{-1\mathrm{}}{p}_{\frac{3}{2}}\right)}_{T=0\mathrm{}}$, and ${\left({d_{\frac{3}{2}}}^{-1\mathrm{}}{f}_{\frac{7}{2}}\right)}_{T=1\mathrm{}}$ configurations in ${\mathrm{Ca}}^{40}$ were identified. The remarkably close agreement of the spacings and spectroscopic factors of the $T=1\mathrm{}$ states with their analogs in ${\mathrm{K}}^{40}$ is hard to reconcile with the large Coulomb-mixing effects in the hole-particle calculations of Gillet and Sanderson.