Study of Core Coupling inRb87Through Isobaric-Analog Resonances. II

The level structure of the ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$-${}_{}{}^{87}{}_{}{}^{}\mathrm{Kr}$ system has been investigated by means of the inelastic scattering of protons through isobaric-analog resonances (IAR's). 24 levels in ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ between 1.55 and 5.07 MeV have been identified in the spectra. Excitation-function data indicate that coupling of the $d_{\frac{5}{2}}$ single particle to excited states of ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ provides important contributions to the wave function of the IAR's. The coefficients describing the coupling of single-particle states to the excited core states in ${}_{}{}^{86}{}_{}{}^{}\mathrm{Kr}$ were extracted from the angular-distribution measurements of the inelastic proton decay of the 5.348-, 6.826-, and 8.374-MeV IAR's. The inclusion of these coefficents together with previously deduced elastic spectroscopic factors allows a rather full description of the wave functions for the parent analog states of these IAR's. A calculation of the wave functions and binding energies in terms of a simple core-coupling model has been performed for the $d$ and $s$ states in ${}_{}{}^{87}{}_{}{}^{}\mathrm{Kr}$. The calculation shows good agreement with the results of the analysis of the proton decay of the IAR for the low-lying states.