Interference between Coulomb and nuclear excitation in the inelastic scattering ofNe22fromSr88

Abstract

We have measured the excitation function at ${\theta }_{\mathrm{lab}}=175\mathrm{}°$ for the excitation of the first $2^{+}$ state in ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}_{}^{*}{}_{}{}^{}$ by inelastic scattering of ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}$. At the same time we obtained similar data for the excitation of the first $2^{+}$ state of the beam particle itself. The measurements span the energy range 49-65 MeV containing the region of the Coulomb-nuclear interference. In terms of Rutherford trajectories, the ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}_{}^{*}{}_{}{}^{}$ interference minimum is located at a separation ∼ 0.2 fm greater than for ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}_{}^{*}{}_{}{}^{}$. An optical potential was obtained by a fit to elastic scattering data consisting of an excitation function at ${\theta }_{\mathrm{lab}}=175\mathrm{}°$ and an angular distribution at 65.4 MeV lab. A collective model distorted-wave Born-approximation calculation with this potential can account for the ${}_{}{}^{88}{}_{}{}^{}\mathrm{Sr}_{}^{*}{}_{}{}^{}$ data but fails to describe the shape of the ${}_{}{}^{22}{}_{}{}^{}\mathrm{Ne}_{}^{*}{}_{}{}^{}$ excitation function.