Charged-πPhotoproduction at 180° in the Energy Range between 300 and 1200 MeV

Abstract

The differential cross sections at 180° for the reactions $\gamma +p\to {\pi }^{+}+n$ and $\gamma +n\to {\pi }^{-}+p$ were measured using a magnetic spectrometer to detect ${\pi }^{\pm }$ mesons. In order to reduce the spread of energy resolution due to the nucleon motion inside the deuteron, a photon difference method was employed with a 50-MeV step for the reaction $\gamma +n\to {\pi }^{-}+p$. The data show structures at the second- and the third-resonance regions for both reactions. A simple phenomenological analysis was made for fitting the data, and the results are compared with those of previous analyses.