Nuclear-structure dependence of heavy-ion-fusion partial-wave distributions

Abstract
Partial-wave cross sections for fusion of Zr64 and Zr64 at energies of 5% and 7% above the Bass-model fusion barrier have been measured with the Darmstadt-Heidelberg Crystal Ball. The distribution for fusion with the more neutron-deficient target Zr92 exhausts the unitarity limit for lower angular momenta. In contrast, fusion with the slightly more neutron-rich target Zr96 yields a broad angular momentum distribution with cross sections well below unitarity even for small partial waves.