par Abreu, Pedro;Van Lysebetten, Ann;Van Remortel, Nick;Verbeure, F;Wickens, John H. 
;Alderweireld, Thomas;Bertrand, Daniel ;D'Hondt, Jorgen;De Clercq, Catherine;Herquet, P. ;Hoorelbeke, S.;Lemonne, Jacques ;Van den Boeck, W.; [et al.]
Référence Physics letters. Section B, 491, 1-2, page (67-80)
Publication Publié, 2000-10
;Alderweireld, Thomas;Bertrand, Daniel ;D'Hondt, Jorgen;De Clercq, Catherine;Herquet, P. ;Hoorelbeke, S.;Lemonne, Jacques ;Van den Boeck, W.; [et al.]Référence Physics letters. Section B, 491, 1-2, page (67-80)
Publication Publié, 2000-10
Article révisé par les pairs
| Résumé : | 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. |
