Effect of beam polarization on two-photon processes

Abstract

A general treatment of the effect of (transverse or longitudinal) beam polarization on two-photon processes, ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}X$, is given. It is found that the change in the cross section is negligible for most processes including the processes $X={\ensuremath{\pi}}^{0}, {\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}, \mathrm{and} {\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$.