Pion single charge exchange onC14

Abstract

Forward-angle differential cross sections for the isobaric-analog state in the $^{14}\mathrm{C}({\ensuremath{\pi}}^{+}, {\ensuremath{\pi}}^{0})^{14}\mathrm{N}$ reaction were measured at 100, 165, 230, and 295 MeV. The extracted excitation function is found to have a maximum near 200 MeV and its shape resembles that of the free $\ensuremath{\pi}\mathrm{N}$ cross sections. Impulse-approximation calculations with optical potentials linear in the nuclear density do not reproduce the trends of the data. Systematics of 0\ifmmode^\circ\else\textdegree\fi{} cross sections with $N$ and $Z$ are presented.