Dramatic nuclear structure effects in (π,πN) reactions

Ratios of pion-induced nucleon knockout cross sections are discussed utilizing a modified nucleon charge exchange model which takes into account nuclear structure effects on the effective number of nucleons and on the various probabilities for charge exchange. The availability of particle-stable analog states in the charge exchange transitions can give factor of 2 differences in the neutron knockout ratio between isotopes for a given Z. On the other hand, proton knockout ratios are largely independent of nuclear structure. Predictions of the model are in reasonable semiquantitative agreement with all experimental data