Angular distributions from the ($p$,${\pi }^{+}$) and ($p$,${\pi }^{-}$) reactions on ${}_{}{}^9{}_{}{}^{}\mathrm{Be}$ leading to discrete isobaric analog states in ${}_{}{}^{10}{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^{10}{}_{}{}^{}\mathrm{C}$ have been measured at 800 MeV over the momentum-transfer interval 600-800 MeV/c. The ratio between the ($p$,${\pi }^{+}$) and ($p$,${\pi }^{-}$) production cross sections is found to be much larger at 800 MeV than at lower energy. The angular distributions from the ($p$,${\pi }^{-}$) reaction show a pronounced slope not observed in previous data.

• Received 22 May 1979

DOI:https://doi.org/10.1103/PhysRevLett.43.487