Angularly integrated cross sections for the reaction ${}_{}{}^7{}_{}{}^{}\mathrm{Li}({\pi }^{+}, {\pi }^0){}_{}{}^7{}_{}{}^{}\mathrm{Be}_{}^{*}{}_{}{}^{}$ (429 keV) were measured over the energy range of 90 to 210 MeV by a selective "prompt-$\gamma$" detection method. These results, combined with the summed cross sections to the ground state and excited state, yield the cross section for the ground state alone. The excitation function for the excited state is flat with cross sections of about 0.3 mb. For the ground-state transition the cross sections are between 1.2 and 1.9 mb. The data are compared with theoretical calculations.

• Received 2 August 1977

DOI:https://doi.org/10.1103/PhysRevLett.39.864