We report on our calculation of the energy and angular dependence of the cross sections for the production of various particles by two-photon annihilation processes in $e^{+}{e}^{-}$ and $e^{-}{e}^{-}$ colliding beams. For beam energy $E$ of more than 1 GeV, these cross sections [$\sigma \propto {\alpha }^4{\left(\ln E\right)}^3$] become increasingly more important than the usual one-photon cross sections [$\sigma \propto {\alpha }^2{\mathrm{}\left(E\right)\mathrm{}}^{-2\mathrm{}}$] for hadron production.

• Received 11 August 1970

DOI:https://doi.org/10.1103/PhysRevLett.25.972