Isospin Effects In Pion Single-Charge-Exchange Reactions

The (${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}, {\ensuremath{\pi}}^{0}$) reactions were studied on targets of $^{12}\mathrm{C}$, $^{14}\mathrm{C}$, $^{16}\mathrm{O}$, and $^{18}\mathrm{O}$ at 160 MeV by measuring the energy spectra of the neutral pions at several laboratory angles between 6\ifmmode^\circ\else\textdegree\fi{} and 160\ifmmode^\circ\else\textdegree\fi{}. The shapes of the energy spectra, the angular distributions, and the ratios of cross sections for isotopic pairs are used to infer the isospin dependence of the $\ensuremath{\Delta}$-nucleus interaction.