Radiative proton capture reactions into nuclei with closed subshells and into the neighboring nuclei with one additional proton produce gamma-ray spectra with remarkably similar major features. Detailed measurements of ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}(\mathrm{p},\gamma ){}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(\mathrm{p},\gamma ){}_{}{}^{13}{}_{}{}^{}\mathrm{N}$, described here, reveal additional striking similarities. A generalized direct-semidirect picture of the reaction is presented, from which quantitative relationships between such capture reaction pairs may be derived, including comparisons of angular distributions, analyzing powers, and cross-section ratios over a wide range of bombarding energies. The data are in good agreement with the theoretical predictions.

• Received 30 March 1984

DOI:https://doi.org/10.1103/PhysRevC.30.423