Isotopic effects in elastic and inelastic 12C + 16, 18O scattering.

Complete angular distributions of the ¹²C + ¹⁸O elastic and inelastic scattering were measured at the energy E_lab(¹⁸O) = 105 MeV ( E_c.m. = 42 MeV) . Comparison of these elastic-scattering data with those from previously measured ¹²C + ¹⁶O data show their large-angle cross-sections to differ by as much as a factor of 100 with the ¹⁶O data being the largest. These and the ¹²C + ¹⁸O scattering data taken from the literature at the energies E_c.m. = 12.9-56 MeV were analysed within the optical model and coupled-reaction-channels methods. Sets of Woods-Saxon ¹²C + ¹⁸O optical potential parameters were obtained and their energy dependence was deduced. A similar analysis was carried out for ¹²C + ¹⁶O where it was shown that over a wide energy range, the primary difference in the ¹⁶O and ¹⁸O scattering potentials is in their imaginary parts. The large-angle enhancement for the ¹²C + ¹⁸O elastic-scattering was shown to arise from the transfer of nucleons. The inelastic-scattering data were well described over the entire angular range as arising from collective excitations of the states in the target and projectile nuclei. [ABSTRACT FROM AUTHOR]