Anomaly observed in subbarrier fusion-fission reactions

The fusion-fission cross sections and fragment angular distributions for the systems of 16O + 232Th, 16O + 238U and 19F + 232Th at near-and sub-barrier energies have been measured. The enhancement of fusion-fission cross sections at subbarrier energies is well explained in the framework of coupled-channels theory in which the target static deformations are explicitly taken into account. However, the experimental fragment anisotropies obviously deviate from the predictions of the statistic fission model