Speaker
Description
This poster presents the techniques to measure the photon identification efficiencies in the ATLAS experiment, on the proton-proton collisions collected at √s = 13 TeV, with an integrated luminosity of 3.2 fb−1 and 33.3fb-1 corresponding to 2015 and 2016. Three independent analyses have been exploited. One uses photons from radiative Z→llγ decays. The second extracts the shower shape properties of electrons from Z→ee decays and extrapolates them to photons. The third directly measures the efficiency on samples of reconstructed photons, after determining and subtracting the hadronic background with a technique based on track isolation. The results from all analyses are then compared with each other and with the prediction from the simulation.
