Alpha-transfer reactions in light nuclei. III. (7Li, t) stripping reaction

The 12C(7Li, t)16O and 16O(7Li, t)20Ne reactions have been studied at a beam energy of 38 MeV. At this energy these reactions exhibit a high selectivity for populating α-particle cluster states. The angular distributions for these states have been analyzed using an exact-finite-range coupled-channels Born-approximation code incorporating final-state cluster wave functions derived from an α-core folded potential. The resulting α-particle spectroscopic factors (S/sub alpha/) for the 0+, 2+, and 4+ members of the 20Ne ground state band are in good agreement with cluster model predictions. For the 7.12-MeV (1-) state in 16O, the spectroscopic factor (S/sub alpha/ approx. = 0.20) is consistent with other analyses but is uncertain by a factor of 2 due to the presence of significant compound-nuclear contributions to this transition. In general, for those states which are not selectively populated at forward angles the measured angular distributions are well described by a Hauser-Feshbach calculation. In particular it is shown that both the magnitude and shape of the angular distributions for the 11.10-MeV (4+) state populated in the 12C(6Li, d)16O and 12C(7Li, t)16O reactions can be well accounted for in terms of statistical compound-nuclear contributions. The elastic scattering of 7Li ions from several light targets has also been studied and optical-model potentials derived