6533b856fe1ef96bd12b2422
RESEARCH PRODUCT
Determination of the e(+)e(-)->gamma gamma(gamma) cross-section at centre-of-mass energies ranging from 189 GeV to 202 GeV
Delphi CollaborationReyes Alemany FernándezSusana Cabrera UrbánMaría Victoria Castillo GiménezEduardo Cortina GilMaría José Costa MezquitaAntonio Ferrer SoriaJuan A. Fuster VerdúCarmen García GarcíaInés Gil BotellaJuan José Hernández ReyEmilio Higón RodríguezFernando Martínez VidalSergio Navas ConchaArantza Oyanguren CamposJosé Salt CairolsPablo Tortosa Martínezsubject
Astrophysics::High Energy Astrophysical PhenomenaHigh Energy Physics::PhenomenologyHigh Energy Physics::ExperimentFísica nuclearPartícules (Física nuclear)description
A test of the QED process e+e- -> gamma gamma (gamma) 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- -> gamma gamma 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 Lambda+ > 330 GeV and Lambda- > 320 GeV were derived. A 95% C.L. lower bound on the mass of an excited electron of 311 GeV/c^2 (for lambda_gamma = 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/c^2 (lambda = 1) and M_S > 691 GeV/c^2 (lambda = -1).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2000-01-01 |