Analysis of the sub-barrier fusion ofO16+Sm148,150,152,154

Abstract

Recent measurements of the sub-barrier fusion of ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ with isotopes of Sm, which span the transition region from spherical to deformed equilibrium shapes, are analyzed in terms of static and dynamic reaction models. The classical equivalent-spheres method of incorporating the effect of nuclear deformation on heavy-ion fusion is shown to overpredict the experimentally observed differences in the fusion cross sections. An approximate, classical estimate of dynamic effects connected with the rotation of the target before fusion removes part, but not all, of this discrepancy. Coupled-channels calculations, which treat dynamic effects through the excitation of the $2^{+}$ and $4^{+}$ levels, are also presented. An estimate is given of the effects one may expect to observe for fusion with a polarized deformed target.