Exact results one+e−→e+e−+2γat energies reached at the SLAC Linear Collider and CERNe+e−collider LEP

Abstract
We use the spinor methods of the CALKUL Collaboration, as realized by Xu, Zhang, and Chang, to calculate the differential cross section for e+e−→e+e−+2γ for c.m. system energies in the regime of the SLAC Linear Collider (SLC) and CERN e+e− collider LEP. An explicit complete formula for the respective cross section is obtained. The leading-logarithmic approximation is used to check the formula. Applications of the formula to high-precision luminosity calculations at the SLAC and/or LEP are discussed.