Ge74(p, α)Ga71reaction at 36.25 MeV.

The ${}_{}{}^{74}{}_{}{}^{}\mathrm{Ge}(p, \alpha ){}_{}{}^{71}{}_{}{}^{}\mathrm{Ga}$ reaction has been studied at 36.25 MeV bombarding energy. Angular distributions of alpha particles were recorded and analyzed with distorted-wave Born approximation theory and a totally microscopic form factor for the three-particle transfers. Theoretical calculations in a restricted shell-model space using a modified surface $\delta$ interaction reproduce fairly well the ${}_{}{}^{71}{}_{}{}^{}\mathrm{Ga}$ excitation energies and the observed strengths in ($d$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) and ($p, \alpha$) spectra, with the exception of the ($p, \alpha$) ground state transition. This disagreement confirms the anomalies observed by ($d$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) reactions, in the occupation numbers $Z=32\mathrm{}$ and between $N=40\mathrm{} \mathrm{and} 42$, which can be related to changes in the nuclear shape.