Elastic $\alpha$ scattering on the target nuclei ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, and ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$ has been studied microscopically using the framework of the generator coordinate method. Combined with the results of previous microscopic investigations of elastic $\alpha$ scattering on the oxygen and calcium isotopes the present studies allow to set up some systematics which may lead to useful predictions concerning the general behavior of elastic $\alpha$ scattering on target nuclei in the mass range $A\simeq 14-48$. It is pointed out that the pure elastic phase shifts (correspondingly, the real part of the optical potential) cannot serve as an explanation for the different cross section behavior at backangles observed for elastic $\alpha$ scattering in this mass region. It is qualitatively shown that these differences are due to absorptive effects.

[NUCLEAR REACTIONS Generator coordinate method, study of $\alpha -{}_{}{}^{14}{}_{}{}^{}\mathrm{C}$, $\alpha -{}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, and $\alpha -{}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, comparison of elastic $\alpha$ scattering on target nuclei in the mass region $A=14-48\mathrm{}$ at low energies, backangle anomaly, molecular resonances.]

• Received 17 January 1983

DOI:https://doi.org/10.1103/PhysRevC.29.40