Determination of the e(+)e(-)->gamma gamma(gamma) cross-section at centre-of-mass energies ranging from 189 GeV to 202 GeV

Journal article

A test of the QED process e+e- → γγ(γ) is reported. The data analysed were collected with the DELPHI detector in 1998 and 1999 at the highest energies achieved at LEP, reaching 202 GeV in the centre-of-mass. The total integrated luminosity amounts to 375.7 pb-1. The differential and total cross-sections for the process e+e- → γγ were measured, and found to be in agreement with the QED prediction. 95% confidence level (C.L.) lower limits on the QED cut-off parameters of Λ+ > 330 GeV and λ- > 320 GeV were derived. A 95% C.L. lower bound on the mass of an excited electron of 311 GeV/c2 (for λγ = 1) was obtained, s-channel virtual graviton exchange was searched for, resulting in 95% C.L. lower limits on the string mass scale, M(S): M(S) > 713 GeV/c2 (λ = 1) and M(S) > 691 GeV/c2 (γ = -1). (C) 2000 Published by Elsevier Science B.V.

Authors: Abreu, P; Adam, W; Adye, T; Adzic, P; Albrecht, Z

• Publication status: Published
• Journal: Physics Letters B
• Volume: 491
• Issue: 1-2
• Pages: 67-80
• Publication date: 2000-10-12
• DOI: 10.1016/S0370-2693(00)01013-3
• ISSN: 0370-2693
• Language: English