Observation of the Reactionse+e−→e+e−,e+e−→γγ, ande+e−→μ+μ−at a Center-of-Mass Energy of 5.2 GeV

Abstract

We report measurements of $e^{+}{e}^{-}\to e^{+}{e}^{-}$, $e^{+}{e}^{-}\to \gamma \gamma$, and $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}$ at angles close to 90°, relative to Bhabha scattering at 3.7°, at a center-of-mass energy equal to 5.2 GeV. The results are found to be consistent with the predictions of quantum electro-dynamics.