DOI: 10.1140/epjc/s2002-01129-7
Single- and multi-photon production
in e
+e
- collisions at
up to 209 GeV
The ALEPH Collaboration (Received: 27 May 2002 / Published online: 14 March 2003 )
Abstract
Events containing only energetic photons
are analysed in a sample of
of data recorded from
collisions
at centre-of-mass energies
between 189 and 209 GeV by the ALEPH detector at LEP. The
and
cross sections are measured and found
to be
in agreement with the standard model predictions.
The number of light neutrino generations is determined to be
. Upper limits are derived on the cross
sections for
photon production in the context of several supersymmetric models.
Limits are also set on the parameters of models with extra spatial
dimensions,
with contact interactions and with excited electrons.
© Società Italiana di Fisica, Springer-Verlag 2003