Measurement of the ReactionO16(π+,π0p)

The first coincidence measurements of the (${\pi }^{+},{\pi }^{0}p$) reaction are reported. These were performed on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ at $T_{{\pi }^{+}}=245\mathrm{}$ MeV for ${\theta }_{{\pi }^0}=50\mathrm{}°-130°$. Events corresponding to removal of $p$-shell nucleons were identified by their ${\pi }^0$ and $p$ energies. The ${\pi }^0$ energy spectra for such events are compared to predictions of $\Delta$-hole model calculations; the calculations generally underestimate the (${\pi }^{+},{\pi }^{0}p$) cross sections. At forward $\pi$ angles experimental ratios of the (${\pi }^{+},{\pi }^{+}p$) and (${\pi }^{+},{\pi }^{0}p$) reactions are shown to differ significantly from estimates based on free $\pi -N$ cross sections.