Electron efficiency in LHC Run-2 with the ATLAS experiment

TL;DR

This paper evaluates the electron reconstruction, identification, and isolation performance in the ATLAS experiment during LHC Run-2, demonstrating high efficiency and close data-MC agreement across various conditions and working points.

Contribution

It provides a comprehensive overview of electron performance metrics in ATLAS at 13 TeV, including efficiency, correction factors, and isolation strategies, with detailed dependency analyses.

Findings

Electron reconstruction efficiency exceeds 97%.

Data-to-MC efficiency ratio is close to unity with uncertainties below 0.1%.

Multiple isolation working points effectively reject fake electrons.

Abstract

The document presents a general overview of the electron reconstruction, identification and isolation performance in the ATLAS experiment. The results are obtained using 13 TeV proton-proton collision data collected during the LHC Run-2. The electron reconstruction efficiency is higher than 97%, and the ratio of data to Monte Carlo simulation efficiency is close to unity, with associated uncertainties generally smaller than 0.1%. The electron identification is shown for three working points, and depending on the electron $E_T$, it can be as low as 60%, increasing to more than 80% above 50 GeV. The correction factors are close to one, generally within 5%. Five isolation working points are recommended in the ATLAS experiment, to successfully reject fake/non-prompt electrons. Their dependency on the electron identification working points is shown and discussed, as well as their pile-up dependency, and their performance versus electron $E_T$ and $\eta$. Document based on a presentation at the XI International Conference on New Frontiers in Physics (ICNFP 2022). keywords; prompt electrons, reconstruction, identification, isolation, fake/non-prompt electrons