Physical Basis for Enhanced Forward Cross Sections in Heavy-Ion Reactions

Calculations show that indirect transitions can explain the forward cross section observed in some experiments, in particular ${}_{}{}^{60}{}_{}{}^{}\mathrm{Ni}$(${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$). Normal optical potentials which fit elastic and inelastic data are used in the analysis. An earlier analysis in terms of a surface transparent potential is shown to depend sensitively on a scaling factor that was introduced to simulate recoil effects. However when recoil is properly taken into account it is found that the surface transparent potential does not reproduce the data.