Pion single charge exchange on 14C from 35 to 295 MeV.

Abstract

The $^{14}\mathrm{C}$(${\ensuremath{\pi}}^{+}$,${\ensuremath{\pi}}^{0}$${)\mathrm{}}^{14}$N reaction to the isobaric analog state has been studied at pion energies between 35 and 100 MeV as an extension of earlier measurements at 100 to 295 MeV. Absolute differential cross sections were measured over the 0\ifmmode^\circ\else\textdegree\fi{}--25\ifmmode^\circ\else\textdegree\fi{} angular range, except at 49.3 MeV, where the range was extended to 75\ifmmode^\circ\else\textdegree\fi{}. A deep minimum was found in the 0\ifmmode^\circ\else\textdegree\fi{} excitation function near 50 MeV, similar to that in the ${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$p\ensuremath{\rightarrow}${\ensuremath{\pi}}^{0}$n excitation function due to the near cancellation of the S- and P-wave contributions. A comparison of the data with several theoretical models is presented.