Interference between coulomb and nuclear excitation in inelastic scattering of O16 ions

The excitation function for the process Ni58(O16, O16′)Ni58* (1.45 MeV) has been measured at 60°, 75°, and 90° lab over the energy range 34-58 MeV. At low energy the cross section rises as expected from Coulomb excitation of an electric quadrupole with a B(E2) value of (0.066±0.004)e2 b2. As the energy is increased further, the 2+ excitation function exhibits a deep valley, due to an interference between Coulomb and nuclear excitations, which is localized over a distance of ∼1 F and appears to be correlated with a rise in elastic scattering (relative to Rutherford scattering).