Effect of density distribution and ray bending on resonant pion-nucleus scattering

Abstract

The dependence of the pion-nucleus total scattering cross section on the realistic density distribution is studied for the nuclei ¹²C, ³²S, ¹²⁰Sn and ²⁰⁸Pb. The model used is based on the use of a pion propagator to calculate the potential and includes many-body effects. The potential is used in the Glauber formalism to calculate the cross sections. Realistic density distributions based on electron scattering data improve the fit to the experimental data and are insensitive to details of the parametrisation. The corrections due to ray bending are calculated and seem in general to be negligible. The resonance position as indicated by the vanishing of the real part of the amplitude is found not to shift down with mass number, though the maxima of the cross section curves are well fitted.