The effects of intercluster antisymmetrization in ${}_{}{}^3{}_{}{}^{}\mathrm{He}$+$\alpha$ and $\alpha$+${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ systems are examined. The result indicates that the characteristic quantities of the Born-equivalent local potentials can be reliably employed to predict the relative importance of the various nucleon-exchange terms. Based on these quantities and by studying the cross section or phase-shift behavior, it is noted that many exchange terms are of only minor significance when the energy is high or when the absorption is strong. Furthermore, one finds that, at an energy higher than about 25 MeV/nucleon, the features of the cross-section angular-distribution curve, which has a distinct V shape, can be simply explained. Here our investigation shows that the contribution to the cross section in the decreasing part of the V-shaped curve comes essentially from the direct term and the one-exchange terms (mainly the knockon exchange term), while the contribution to the cross section in the increasing part of this curve comes essentially from the core-exchange terms.

NUCLEAR REACTIONS ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ ($\alpha , \alpha$) ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}(\alpha , \alpha )$. Effects of antisymmetrization with resonating-group method.

• Received 7 May 1982

DOI:https://doi.org/10.1103/PhysRevC.26.1847