Precision measurements of electron reconstruction, identifcation, and isolation efciencies and photon identifcation efciencies 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 identifcation efciencies 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 efciencies that are more independent of the amount of pile-up activity. Updated photon identifcation efciencies 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 identifcation efciencies, thanks to the increased amount of available data.

Null, N., Aad, G., Abbott, B., Abeling, K., Abicht, N.J., Abidi, S.H., et al. (2024). Electron and photon efficiencies in LHC Run 2 with the ATLAS experiment. JOURNAL OF HIGH ENERGY PHYSICS, 2024(5), 162-1-162-65 [10.1007/jhep05(2024)162].

Electron and photon efficiencies in LHC Run 2 with the ATLAS experiment

Alberghi, G. L.;Alfonsi, F.;Ballabene, E.;Bellagamba, L.;Bianco, G.;Boscherini, D.;Bruni, A.;Carratta, G.;Cremonini, D.;De Castro, S.;Fabbri, F.;Fabbri, L.;Franchini, M.;Gabrielli, A.;Giacobbe, B.;Lasagni Manghi, F.;Massa, L.;Monzani, S.;