Test of effective cluster interactions by pion scattering

Abstract

The superposition of effective interactions is studied by a cluster approach to the pion-nucleus potential with particular emphasis on the treatment of the Pauli principle between the clusters. The model is based on the formalism of Kerman, McManus, and Thaler and constructs the pion-nucleus interaction by a superposition procedure of pion-cluster interactions in the framework of the fish-bone model. The second-order contribution due to excitations of the relative motion between the clusters has been taken into account as well as true absorption. A test calculation ofΠ +_20 scattering with the cluster approach reproduces the gross structure of the differential elastic cross section and the total non-elastic cross section of conventional calculations quite well. Furthermore, it is confirmed that the three-body Pauli interaction is negligible also in the case of a realistic and rather complicated pion-nucleus interaction thus justifying the usual folding approach. The rotational bands contribute about 10% to the cross sections.