Single and multi-photon events with missing energy in e+e- collisions at √s = 189 GeV

Single and multi-photon events with missing energy are analysed using data collected with the L3 detector at LEP at a centre-of-mass energy of 189 GeV, for a total of 176 pb<sup>-1</sup> of integrated luminosity. The cross section of the process e+e- → <math><mtext>ν</mtex...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Dova, María Teresa, L3 Collaboration
Formato: Articulo
Lenguaje:Inglés
Publicado: 1999
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/80542
Aporte de:
Descripción
Sumario:Single and multi-photon events with missing energy are analysed using data collected with the L3 detector at LEP at a centre-of-mass energy of 189 GeV, for a total of 176 pb<sup>-1</sup> of integrated luminosity. The cross section of the process e+e- → <math><mtext>ν</mtext><mtext>ν</mtext><mtext>̄</mtext></math>γ(γ) is measured and the number of light neutrino flavours is determined to be N<sub>v</sub> = 3.011±0.077 including lower energy data. Upper limits on cross sections of supersymmetric processes are set and interpretations in supersymmetric models provide improved limits on the masses of the lightest neutralino and the gravitino. Graviton-photon production in low scale gravity models with extra dimensions is searched for and limits on the energy scale of the model are set exceeding 1 TeV for two extra dimensions.