Pure Neutron and Pure Proton Transitions in Inelastic Scattering of Pions byC13

Differential cross sections ${\sigma }_{{\pi }^{\pm }}\left(\theta \right)$ for elastic and inelastic scattering of 162-MeV pions from ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ were measured at momentum transfers between 0.6 and 2.1 ħ · ${\mathrm{fm}}^{-1\mathrm{}}$. For two inelastic transitions, enhancement of ${\sigma }_{{\pi }^{-}}$ over ${\sigma }_{{\pi }^{+}}$ and of ${\sigma }_{{\pi }^{+}}$ over ${\sigma }_{{\pi }^{-}}$ were observed which are consistent with the values for pion scattering from free nucleons. The results are discussed qualitatively in terms of simple shell-model and weak-coupling-model configurations.