Fusion cross-sections around the barrier in11,9Be +209Bi

The11,9Be +209Bi subbarrier fusion cross-sections were measured. The good quality of the9Be data allowed also to extract the fusion barrier distribution. The data are in good agreement with the theoretical predictions above the barrier but not below, where the cross-sections are similar, in contradiction with present theories. The barrier distribution for9Be does not evidence fusion processes originating from breakup.