Pauli-Principle Effects in Pion-Nucleus Scattering

Abstract

In lectures from the LAMPF summer school. A quantitative estimate is made of the changes in pi -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 Schroedinger 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 although the approximately 15% changes in total cross sections can signiftcantly improve the agreement with data. To reach these conclusions it is necessary to use a realistic model for nuclear scattering such as the optical model. Describing the nucleus by an unmodified Fermi gas model is not acceptable; some of its unphysical properties are removed when performing the calculation. (auth)