ISSN:
1434-6052
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract The OPAL detector at LEP is used to measure the branching ratio of theZ 0 into invisible particles by measuring the cross section of single photon events ine + e − collisions at centre-of-mass energies near theZ 0 resonance. In a data sample of 5.3 pb−1, we observe 73 events with single photons depositing more than 1.5 GeV in the electromagnetic calorimeter, with an expected background of 8±2 events not associated with invisibleZ 0 decay. With this data we determine theZ 0 invisible width to be 0.50±0.07±0.03 GeV, where the first error is statistical and the second systematic. This corresponds to 3.0±0.4±0.2 light neutrino generations in the Standard Model.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01551449