Electron and Photon Efficiencies in Lhc Run 2 With the Atlas Experiment

Abstract

Precision measurements of electron reconstruction, identification, and isolation efficiencies and photon identification efficiencies are presented. They use the full Run 2 data sample collected by the ATLAS experiment in pp collisions at a centre-of-mass energy of 13 TeV during the years 2015-2018, corresponding to an integrated luminosity of 139 fb(-1). The measured electron identification efficiencies have uncertainties that are around 30%-50% smaller than the previous Run 2 results due to an improved methodology and the inclusion of more data. A better pile-up subtraction method leads to electron isolation efficiencies that are more independent of the amount of pile-up activity. Updated photon identification efficiencies are also presented, using the full Run 2 data. When compared to the previous measurement, a 30%-40% smaller uncertainty is observed on the photon identification efficiencies, thanks to the increased amount of available data.