Calculation of the (π−, π0) Reaction on Complex Nuclei

The excitation function for the reaction ${}_Z{}^{}{}_{}{}^{}A({\pi }^{-}, {\pi }^0){}_{Z-1\mathrm{}}{}^{}{}_{}{}^{}A$ has been calculated using the Fermi-gas model of the nucleus and the impulse approximation. Experimental data on the differential cross section of the free-particle reaction ${\pi }^{-}+p\to {\pi }^0+n$ was used, and the effect of the momentum distribution of the nucleons on the kinematics was included. The predicted cross section shows a minimum near 200 MeV and maxima near 100 and 350 MeV. This structure, if confirmed experimentally, would lend support to this simple model, which is frequently used to interpret high-energy nuclear reactions.