Pion elastic and inelastic scattering on s-d shell nuclei in the Delta 33-resonance region. Coupled-channel analysis.

Abstract

Equations of the coupled-channel method are solved in momentum space for pion scattering on /sup 24,26/Mg and /sup 28/Si in the ..delta../sub 33/-resonance region. The elastic and inelastic differential cross sections are calculated by using the nuclear ground-state and transition densities which correctly describe the (e,e') data for the same nuclear states. Also calculated are the double-analog double-charge-exchange reactions /sup 26/Mg(..pi../sup +/,..pi../sup -/) /sup 26/ Si and /sup 18/O(..pi../sup +/,..pi../sup -/) /sup 18/ Ne, and the results obtained are in surprisingly good agreement with the experimental data. From the comparison of our coupled-channel and distorted-wave impulse approximation results we conclude that the multistep mechanisms play a minor role in the reactions considered.