Electron and photon energy measurement calibration with the ATLAS detector

An accurate calibration of the energy measurement of electron and photon is needed for many ATLAS physics analyses, such as the Higgs boson mass measurement. The calibration of the energy measurement is performed in-situ using a large statistics of Z->ee events. A prerequisite of this calibration is a good understanding of the material in front of the calorimeter and of the inter-calibration of the different calorimeter layers. The Z->ee sample is also used to measure the energy resolution. High-precision calibration of the whole Run 2 dataset corresponding to an integrated luminosity of 140 fb-1 of pp collisions at sqrt(s)=13 TeV is presented for the first time, including several methodological improvements.