Pion elastic and charge-exchange scattering on p-shell nuclei by isobar-doorway state model

The purpose of the present paper is to extend the isobar-hole model (i.e., the conventional isobar-doorway state model for the pion-nucleus reaction, to open-shell nuclei) by reformulating the model, and also to study the elastic scattering of pions from p-shell nuclei, the analyzing power and the charge-exchange reaction. For this purpose, we use the projection operator formalism, and take into account the correct center-of-mass transformation and the off-shell behavior of the pion-nucleon scattering amplitude. We assume a realistic nuclear model, i.e. the p-shell nuclear model of Cohen and Kurath. By studying elastic scattering from 12,13C and 15N, and the analyzing power and the charge-exchange reaction with 13C and 15N, we confirm the existence of the Lane term in the spreading potential implied by Hirata et al. (author)