DOI 10.1007/s100520000434
Photon events with missing energy at
183 to 189 GeV
The DELPHI Collaboration
P.Abreu22 - et al.
22 LIP, IST, FCUL - Av. Elias Garcia, 14-1o,
1000 Lisboa Codex, Portugal
Received: 28 January 2000 / Revised version: 27 April 2000
/
Published online: 26 July 2000 - © Springer-Verlag 2000
Abstract
The production of single photons has been studied
in the reaction
at
centre-of-mass energies of 183 GeV and 189 GeV.
A previously published analysis of events with multi-photon
final states accompanied by missing energy has been updated with 189 GeV data.
The data were collected with the DELPHI detector and correspond to
integrated
luminosities of about 51 pb-1 and 158 pb-1 at the two
energies. The number of light neutrino families is measured to be
.
The absence of
an excess of events beyond that expected from Standard Model
processes is used to set limits on new physics
as described by supersymmetric and composite models.
A limit on the gravitational scale is also determined.
Copyright Società Italiana di Fisica, Springer-Verlag 2000
