Data for near-barrier ${}^{16}\mathrm{O}+{}^{208}\mathrm{Pb}$ inelastic scattering to the 2.60-MeV $3_1^{-}$ level of ${}^{208}\mathrm{Pb}$ have proved difficult to fit within the distorted-wave Born approximation (DWBA) or coupled-channel (CC) formalisms employing collective model form factors. In particular, the data for incident energies in the vicinity of the so-called threshold anomaly proved impossible to describe without introducing an unphysically large quadrupole reorientation term into CC calculations, even when allowing the nuclear deformation lengths to vary with the incident energy. In this work a satisfactory description of the elastic and inelastic scattering for a range of energies close to the Coulomb barrier was obtained with fixed coupling strengths derived from the results of a recent Coulomb excitation measurement. The description of the data was insensitive to the inclusion of the small quadrupole reorientation term for the $3_1^{-}$ level consistent with the strength derived from the Coulomb excitation measurement. Coupled-channel calculations employing the same coupling scheme and coupling strengths were able to describe well near-barrier $\alpha +{}^{208}\mathrm{Pb}$ elastic and inelastic scattering data. Simultaneous minimization of ${\chi }^2$ for elastic and inelastic scattering was crucial to obtaining a good description of the ${}^{16}\mathrm{O}+{}^{208}\mathrm{Pb}$ data with either DWBA or CC calculations.

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• Direct reactions
• Elastic scattering reactions
• Inelastic scattering reactions
• Low & intermediate energy heavy-ion reactions
• Nuclear reactions