One- and two-proton transfer reactions in ³²S+⁶⁴Ni and ²⁸Si+⁶⁸Zn at near-barrier energies

Abstract

One- and two-proton transfer reactions were studied at bombarding energies around the barrier in ³²S+⁶⁴Ni and ²⁸Si+⁶⁸Zn systems. The decrease of one- and two-proton stripping probabilities with the distance of closest approach was observed to be slower than that expected from semiclassical considerations, at above barrier energies, especially for two-proton stripping. The effect of these transfer channels on the sub-barrier fusion enhancement was investigated on the basis of semiclassical theories. It was found that the couplings to the inelastic channels and the one- and two-proton transfer channels cannot explain the observed enhancement, indicating the importance of the one- and two-neutron transfer channels in explaining the fusion data.