Limiting Angular Momenta for Light Heavy-Ion Fusion at High Energy

Abstract

The shapes of angular distributions in reactions $^{12}\mathrm{C}$($^{16}\mathrm{O}$, $\ensuremath{\alpha}$) to the ${J}^{\ensuremath{\pi}}={0}^{+}$ $^{24}\mathrm{Mg}$ ground state are studied from $E(^{16}\mathrm{O})=28.5 \mathrm{to} 100$ MeV. The position of the first minimum (and maximum) of these oscillatory angular distributions is expected to be sensitive to the presence of a low-angular-momentum cutoff in the compound-nucleus formation cross section. No evidence for a low-$L$ cutoff is found even at energies well beyond the predicted threshold.