Theoretical Analysis of the Frascati Data on the Single-Bremsstrahlung Processe+e−→e+e−γ

The angular distributions of the process $e^{+}{e}^{-}\to e^{+}{e}^{-}$ measured by the Bologna-CERN-Frascati group at the electron-positron colliding-beam facility Adone are analyzed in terms of standard quantum electrodynamics (QED) to order ${\alpha }^3$ including soft- and hard-photon emission. An analytical expression is given for the cross section of the process $e^{+}{e}^{-}\to e^{+}{e}^{-}\gamma$ for hard photons. Detailed numerical results for that specific experimental setup are obtained by a Monte Carlo program. It is found that this bremsstrahlung process is responsible for the noncollinear and noncoplanar events observed at Frascati. Therefore, these data, together with the present calculation, provide a test of QED for this particular physical situation involving high energies and large momentum transfers.