Speaker
Fernando Monticelli
(Universidad Nacional de La Plata (AR))
Description
Electron and photon triggers covering transverse energies from 5 GeV
to several TeV are essential for signal selection in a wide variety
of ATLAS physics analyses to study Standard Model processes and to
search for new phenomena. Final states including leptons and photons
had, for example, an important role in the discovery and measurement
of the Higgs particle. Dedicated triggers are also used to collect
data for calibration, efficiency and fake rate measurements. The
ATLAS trigger system is divided in a hardware-based Level 1 and a
software based high level trigger, both of which were upgraded
during the long shutdown of the LHC in preparation for data taking
in 2015. The increasing luminosity and more challenging pile-up
conditions as well as the planned higher center-of-mass energy
demanded the optimisation of the trigger selections at each level,
to control the rates and keep efficiencies high. To improve the
performance multivariate analysis techniques are introduced.
The evolution of the ATLAS electron and photon triggers and
their performance will be presented, including new results from the
2015 LHC Run 2 operation.
