The radiative capture reactions ${}_{}{}^3{}_{}{}^{}(\mathit{p}$,γ${)}^4$He and ${}_{}{}^3{}_{}{}^{}(\mathit{n}$,γ${)}^4$He are studied within the framework of a microscopic multichannel resonating group model. Employing a charge symmetric nuclear force we find different thresholds for the mirror channels due to the Coulomb force. These differences in term together with channel coupling effects lead to marked variations between observables of the two mirror reactions. We demonstrate that all types of experimental data can be reproduced by our calculation except for the controversial integrated (n,γ) cross section data.

• Received 11 May 1988

DOI:https://doi.org/10.1103/PhysRevC.38.1139