OPAL Collaboration (1998) Multi-photon production in e+ e- collisions at √s=183 GeV. Physics Letters B, 438 (3-4). pp. 379-390. ISSN 0370-2693
Full text not available from this repository.Abstract
The process e e q y™gg gŽ . is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pby1 taken at a centre-of-mass energy of 183 GeV. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits at 95% CL on the QED cut-off parameters: Lq y ) 233 GeV and L ) 265 GeV as well as a mass limit for an excited electron, Me)) 227 GeV assuming equal e)eg and eeg couplings. No evidence for resonance production is found in the invariant mass spectrum of photon pairs. Limits are obtained for the cross-section times branching ratio for a resonance decaying into two photons.