Pion Production in Electron-Positron Collisions

The properties due to the presence of symmetries in pion production processes in electron-positron collisions are discussed. Cross sections are calculated for the production reactions $e^{+}+e^{-}\to {\pi }^0+\gamma$, $e^{+}+e^{-}\to e^{+}+e^{-}+{\pi }^0$, and $e^{+}+e^{-}\to {\pi }^{+}+{\pi }^{-}$. The photon spectrum for the reaction $e^{+}+e^{-}\to {\pi }^{+}+{\pi }^{-}+\gamma$ is also calculated. The role of form factors and some of the possible effects of resonant strong interactions are discussed.