Abstract
This paper reports measurements of the differential cross sections for the reactions → (Bhabha scattering) and →γγ (γ-pair production). The reactions are studied at a center-of-mass energy of 29 GeV and in the polar-angular region ‖costheta‖<0.55. A direct cross-section comparison between these two reactions provides a sensitive test of the predictions of quantum electrodynamics (QED) to order . When the ratio of γ-pair to Bhabha experimental cross sections, integrated over ‖costheta‖<0.55, is divided by the same ratio predicted from QED theory, the result is 1.007±0.009±0.008. The 95%-confidence limits on the QED-cutoff parameters are >154 GeV and >220 GeV for Bhabha scattering, and >59 GeV and >59 GeV for γ-pair production.
- Received 12 May 1986
DOI:https://doi.org/10.1103/PhysRevD.34.3286
©1986 American Physical Society