Influence of the ground state spin of target nuclei on the anomalous behavior of fission fragment anisotropies.

The angular distributions of fission fragments have been measured over a range of near- and sub-barrier energies for reactions involving {sup 12}C projectiles on {sup 235,236,238}U targets. For the reactions involving the zero spin targets, the discrepancies between the experimental fission anisotropies and the transition state model increase dramatically as the beam energy decreases through the region of the fusion barriers. However, the {sup 12}C+(I=7/2){sup 235}U fission anisotropies exhibit a much less dramatic departure from the transition state model. {copyright} {ital 1997} {ital The American Physical Society}