Pion-induced single-nucleon removal to discrete final states

$\ensuremath{\gamma}$ radiation from targets of $^{7}\mathrm{Li}$, $^{9}\mathrm{Be}$, $^{12}\mathrm{C}$, $^{13}\mathrm{C}$, and $^{16}\mathrm{O}$ bombarded by ${\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\pi}}^{+}$ at energies between 60 and 300 MeV was uniquely associated with states formed by removing a single nucleon by the ($\ensuremath{\pi},\ensuremath{\pi}N$) reaction. All yields were found to reflect the well-known 3-3 resonance near 180 MeV in the pion-nucleon system. Ratios of yields for ${\ensuremath{\pi}}^{\ensuremath{-}}$ and ${\ensuremath{\pi}}^{+}$ beams were measured for $^{7}\mathrm{Li}$, $^{9}\mathrm{Be}$, and $^{13}\mathrm{C}$. These ratios were very similar to one another and to previous results on $^{12}\mathrm{C}$, $^{14}\mathrm{N}$, and $^{16}\mathrm{O}$ for neutron removal. Several reaction mechanisms based on quasifree processes are tested by comparison to the data, and all are rejected.[NUCLEAR REACTIONS $^{7}\mathrm{Li}$, $^{9}\mathrm{Be}$, $^{12}\mathrm{C}$, $^{13}\mathrm{C}$, $^{16}\mathrm{O}$. (${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}},\ensuremath{\pi}N$), detect $\ensuremath{\gamma}$ decay of residual nucleus, measure $\ensuremath{\sigma}({E}_{\ensuremath{\pi}})$.]