Proton scattering onA=92−116nuclei with extended optical models and the interacting boson approximation

Differential cross sections for proton elastic and inelastic scattering have been measured at $E_p=22.3\mathrm{}$ MeV for 14 nuclei with $92\le A\le 116$. The energy dependence has been studied between 10 and 35 MeV, considering also reaction cross sections at lower incident energies. The long standing sub-Coulomb optical model anomalies are thereby eliminated. Nuclear structure effects found in the analysis of elastic scattering are identified with strong couplings between ground and one-phonon states. These couplings are satisfactorily described by traditional collective models, using deformation parameters in agreement with those deduced from electromagnetic data. The transitions to weakly excited states require a more accurate spectroscopic description. Spectroscopic amplitudes taken from the interacting boson model are used. The radial dependence of transition densities is derived from optical model potentials.