Radiative corrections to γ γ processes in e⁺e⁻ ,e⁻ e⁺e⁺collision rings

Abstract

Computation of the correction rate has shown that:

• -- in double tagging experiments, the radiative corrections are rather small. The inelastic corrections are limited by the resolution of the tagging system and, thus,we have a very small contribution of the hard photons. Moreover, the use of the double equivalent photon approximation is completely justified in that case.

• -- in no tagging experiments, the radiative corrections are extremely small and even negligible. They cannot practically affect the cross section.

However, there are other types of γγ experiments, namely single-tagging experiments and measurements at finite angle, and the next work is to compute the corresponding radiative corrections to obtain their order of magnitude.