Pauli-principle effects in pion--nucleus scattering

A quantitative estimate is made of the changes in pion-nucleus scattering caused by incorporating the Pauli principle in a realistic optical potential. A modification is hypothesized in which the theoretical momentum-space potential is simply multiplied by a Pauli suppression factor. Several forms for this factor are derived, combined with the optical potential, and the Schr\"odinger equation including these potentials is solved in momentum space. It is found that including the Pauli principle in a realistic optical potential can have significant albeit not drastic effects on calculated low- and intermediate-energy elastic scattering. The effects on differential cross sections are not readily noticeable, except at large angles, whereas the approximately 15% changes in total cross sections can significantly improve the agreement with data.