Fusion of Ca-48+Sm-154 near the Coulomb barrier: enhancement vs. suppression

Fusion-evaporation and fusion-fission cross sections have been measured in the reaction48Ca+154Sm from well below to well above the Coulomb barrier. The comparison of fusion cross sections for this reaction with previous data corresponding to16O+186W, leading to the same compound nucleus202Pb*, puts in evidence an interesting competition between sub-barrier enhancement, due to the strong couplings related to the154Sm deformation, and above barrier suppression for the48Ca induced reaction. The fusion hindrance mechanism has been attributed to the strong quasi-fission component observed in the mass-energy distributions of fission fragments