Interference between Coulomb and Nuclear Excitation in Inelastic Scattering ofO16Ions

Abstract

The excitation function for the process ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$(${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$′)${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$* (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 $B\left(E2\mathrm{}\right)\mathrm{}$ value of $(0.066\mathrm{}\pm 0.004)e^2$ ${\mathrm{b}}^2$. 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).