2001/03/22 by D. Bourilkov, Bourilkov, D. · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #hep-ex #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ex/0103039
20 pages, 12 figures, 7 tables; Invited LEP2 review talk, Les Rencontres de Physique de la Vallee d'Aoste, La Thuile, Aosta Valley, Italy, 4-10 March 2001; v2 - minor typo corrected
openalex publication_date 2001/03/22 · arxiv created 2001/03/23 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair and photon-pair production in e+e- collisions on the full LEP2 data set. The details of the experimental measurements and results from their LEP-wide combination are presented. No statistically significant deviations from the Standard Model expectations are observed and lower limits, some obtained in dedicated analyses, for new physics phenomena at 95 % confidence level are derived. The scales of contact interactions are constrained to lie above 10-20 TeV, depending on the helicity structure. The Standard Model has thus been tested at LEP2 down to distances 10-19 - 10-20 m. This has many implications, one example being the interpretation of the new result on the anomalous magnetic moment of the muon as coming from muon substructure. For gamma-gamma final states the QED cut-offs are Lambda+ > 0.44 TeV and Lambda- > 0.37 TeV. In a combined analysis, using e+e- and gamma-gamma final states, the most stringent lower limits to date, Ms+ > 1.13 TeV (lambda = +1) and Ms- > 1.39 TeV (lambda = -1), on the low gravity effective Planck scale are set. Constrains on the scales of string models like TeV strings and D-branes are derived. In the last case the lower limit is 1.5 - 4 TeV, depending on the coupling strength.