CERN Accelerating science

Article
Title The number of neutrinos and the Z line shape
Author(s) Blondel, A (Faculte des Sci)
In: C. R. Acad. Sci., 4 3, 9 (2002) pp.1155-64
Subject category Particle Physics - Experiment
Accelerator/Facility, Experiment CERN LEP ; ALEPH
CERN LEP ; DELPHI
CERN LEP ; L3
CERN LEP ; OPAL
Abstract Thanks to a precise calibration and monitoring of the LEP beam energy the Z resonance line shape has been precisely measured, hence permitting accurate determinations of the Z mass and width. A large effort was spent on experiments for the measurement of the LEP luminosity, enabling the number of neutrino types to be precisely determined. The result, N/sub nu /=2.9841+or-0.0083, demonstrates the existence of only 3 neutrino species. (16 refs).



 Záznam vytvorený 2003-06-18, zmenený 2014-07-22