Compton scattering of quasi-real virtual photons at LEP

Abstract

Compton scattering of quasi-real virtual photons, γe^±→γe^±, is studied with 0.6 fb^-1 of data collected by the L3 detector at the LEP e⁺e^- collider at centre-of-mass energies √s=189-209 GeV. About 4500 events produced by the interaction of virtual photons emitted by e^± of one beam with e∓ of the opposite beam are collected for effective centre-of-mass energies of the photon-electron and photon-positron systems in the range from √s'= 35 GeV up to √s'=175 GeV, the highest energy at which Compton scattering was ever probed. The cross sections of the γe^±→γe^± process as a function of √s' and of the rest-frame scattering angle are measured, combined with previous L3 measurements down to √s'≃20 GeV, and found to agree with the QED expectations.