Isobaric Analog States in Heavy Nuclei. V. Resonances inZr90from Proton Inelastic Scattering

Abstract

Isobaric-spin analog resonances have been observed as compound-nucleus resonances in ${\mathrm{Zr}}^{90}$ through the reaction ${\mathrm{Y}}^{89}(p, {p}^{\ensuremath{'}}){\mathrm{Y}}^{89*}$. These resonances are compared with the predictions of a proposed weak-coupling model which explains the analog resonances in terms of the coupling of a single proton to excited states of the target nucleus. A tentative analysis of the results is performed in terms of a general expression for the cross section which contains an undefined scattering matrix. This equation is put in a form which shows the interference between the resonant and nonresonant cross sections. The weak-coupling model is not explicitly verified, but support is given for its validity. Also included are the measurements of the excitation energies of the first four excited states of ${\mathrm{Y}}^{89}$.