A CASE-STUDY OF COLLECTIVITY, TRANSFER AND FUSION ENHANCEMENT

Precise fusion and quasi-elastic scattering excitation functions have been measured for the systems Ca-40 + Zr-90,Zr-96 at energies spanning the Coulomb barrier. From both the fusion and the quasi-elastic scatt ering data representations of the barrier distributions have been extr acted. The barrier distributions of the two reactions are qualitativel y very different. While the lighter system is well described by couple d-channels calculations including multi-phonon excitations, this coupl ing scheme fails completely for the heavier system, possibly due to mu lti-neutron transfer. (C) 1998 Elsevier Science B.V.