Current theoretical models for the pion-nucleus interaction in the (3,3)-resonance region are discussed. We conclude that nonlocal potentials of the Kisslinger type are inadequate. The most promising potential is local and closely related to the Glauber model. Some properties of the Glauber model are also studied. Thus we show that the multiple-scattering series can be summed and charge-exchange effects can easily be accounted for.

• Received 11 May 1971

DOI:https://doi.org/10.1103/PhysRevC.5.400