Speaker
Description
Excellent electron and photon identification capabilities are crucial for many aspects of the ATLAS
physics program, from standard model measurements (including Higgs boson) to new physics searches.
The identification of prompt photons and the rejection of backgrounds, mostly coming from photons
from hadron decays, relies on the high granularity of the ATLAS calorimeter. Electron identification is
based on a likelihood discrimination to separate isolated electron candidates from candidates originating
from photon conversions, hadron misidentification and heavy flavor decays. Isolation variables are used
as further handles to extract the signal. The measurement of the efficiencies of the identification and
isolation cuts are performed using several high-statistics data samples, including Z->ee and J/psi->ee
decays, radiative Z decays, and inclusive high energy photon samples. The results of these
measurements, performed with pp collision data recorded at sqrt(s)=13 TeV during 2015-2017 and
corresponding to an integrated luminosity of 80 fb-1, are presented. The impact of the pile-up, especially
large in the second part of 2017 data taking, is discussed.
