(π,πN) reactions in 48Ca

Excitation functions for the formation of 47Ca and 47K from 48Ca with 100-, 180-, and 300-MeV π+- have been determined by activation methods. The contributions of both quasifree and nonquasifree processes are observed in the excitation functions. Unlike (π,πN) reactions on 12C, final-state nucleon charge exchange is found to play only a minor role in 48Ca. This decreasing importance of nucleon charge exchange with increasing nuclear mass is explained by a newly-developed (π,πN) theory. In order to establish the magnitude of nucleon charge exchange in medium-mass nuclei, we have measured the cross section for the reaction 45Sc(π-,πN)44K at 180 MeV. An upper limit of 0.25 mb has been determined