Speaker
Description
Jet energy scale (JES) and jet energy resolution (JER) uncertainties are among the dominant systematic uncertainties in many ATLAS measurements. After the applica- tion of simulation-based calibrations, residual differences between data and simulation are corrected using data-driven in situ techniques. In this contribution, a new in situ calibration approach exploiting tt̄ events in the single-lepton decay channel is presented. The method uses events in which one of the W bosons from top-quark decay decays hadronically into two jets, allowing the reconstruction of the W -boson invariant mass from the measured jet four-momenta. A forward-folding procedure is employed to generate template distributions of the reconstructed W -boson mass under different assumptions of the JES or JER. The mean (width) of these templates is then compared to the mean (width) of the mass distribution observed in data to extract optimal JES (JER) correction. Results obtained with this technique using the full Run 2 dataset and Run 3 data collected in 2022 and 2023 are presented. The method will be combined with other in situ calibration techniques to further improve the JES and JER precision in ATLAS.
| Speaker confirmation | Yes |
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