Distortion effects in (π, πp) quasifree knockout reactions

Distorted wave impulse approximation calculations for the ($\pi , \pi p$) quasifree knockout reaction on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ have been carried out for a variety of bombarding energies and angle pairs. In general, the distortion effects arising from the interaction of the pions and protons with the target core are strong and vary with bombarding energy. The results emphasize the need to include these interactions properly in any analysis of experimental data.