Speaker
Dr
Yann Coadou
(CPPM Marseille)
Description
Tau leptons will play an important role in the physics program at the
LHC. In particular, they provide a useful signature in searches for
new phenomena like charged Higgs bosons or Supersymmetry. In addition,
they are being used for standard model electroweak measurements and
for detector related studies such as the determination of the missing
transverse energy scale.
Due to the huge background from QCD processes, efficient tau
identification techniques with large fake rejection are essential. Tau
objects appear as collimated jets with low track multiplicity and
single variable criteria are not enough to efficiently separate them
from jets and electrons.
We report on the commissioning steps and performance of the tau
trigger, which is designed to efficiently reject low-energy jets while
keeping a high efficiency with respect to hadronic tau leptons
identified by the offline algorithms.
We present the current status of tau reconstruction and identification
at the LHC with the ATLAS detector. Reconstructed tau candidates in
dijet backgrounds and W->taunu signal events are studied in data and
compared with predictions from Monte Carlo simulation. The performance
of the fake tau rejection is estimated in a dijet data sample. We
discuss the plans for measuring tau identification efficiency using
Z->tautau signal events and the fake rate using photon+jet and Z+jets
background events. Both cut-based and more advanced multivariate
techniques which make optimal use of all the information available are
presented. These standard model measurements are instrumental in
validating tau identification for discovery physics.
Author
Dr
Yann Coadou
(CPPM Marseille)
