Processes with tau-leptons in the final state are important for Standard Model measurements and searches for physics beyond the Standard Model. The ATLAS experiment at the Large Hadron Collider observes tau-leptons produced in proton–proton collisions only through their decay products. Data analyses involving hadronically decaying tau-leptons face challenges due to backgrounds from jets misidentified as tau-leptons that are not modelled reliably by Monte Carlo simulations. Data-driven methods such as the fake-factor method allow such misidentified backgrounds to be predicted by measuring transfer factors, known as fake factors, in data from dedicated regions. This paper describes a refined technique for determining the fake factors, the Universal Fake Factor method. It evaluates the fake factors for a signal region by using fake factors from samples enriched in different sources of jets misidentified as tau-leptons (light-quark, gluon, b-quark, and pile-up jets). Each fake factor is calculated as a linear combination of fake factors measured in these different enriched samples. For the full Run 2 data set, the systematic uncertainty of the calculated fake factors, evaluated using W(mu nu) enriched event sample, ranges from 15 to 35% depending on the tau-lepton’s transverse momentum and charged-particle decay multiplicity.

Null, N., Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., et al. (2025). Estimation of backgrounds from jets misidentified as tau-leptons using the Universal Fake Factor method with the ATLAS detector. EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 85(12) [10.1140/epjc/s10052-025-14916-1].

Estimation of backgrounds from jets misidentified as tau-leptons using the Universal Fake Factor method with the ATLAS detector

Aielli, G.;Camarri, P.;Cerrito, L.;De Sanctis, U.;Di Ciaccio, A.;Giuli, F.;
2025-01-01

Abstract

Processes with tau-leptons in the final state are important for Standard Model measurements and searches for physics beyond the Standard Model. The ATLAS experiment at the Large Hadron Collider observes tau-leptons produced in proton–proton collisions only through their decay products. Data analyses involving hadronically decaying tau-leptons face challenges due to backgrounds from jets misidentified as tau-leptons that are not modelled reliably by Monte Carlo simulations. Data-driven methods such as the fake-factor method allow such misidentified backgrounds to be predicted by measuring transfer factors, known as fake factors, in data from dedicated regions. This paper describes a refined technique for determining the fake factors, the Universal Fake Factor method. It evaluates the fake factors for a signal region by using fake factors from samples enriched in different sources of jets misidentified as tau-leptons (light-quark, gluon, b-quark, and pile-up jets). Each fake factor is calculated as a linear combination of fake factors measured in these different enriched samples. For the full Run 2 data set, the systematic uncertainty of the calculated fake factors, evaluated using W(mu nu) enriched event sample, ranges from 15 to 35% depending on the tau-lepton’s transverse momentum and charged-particle decay multiplicity.
2025
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore PHYS-01/A - Fisica sperimentale delle interazioni fondamentali e applicazioni
English
Con Impact Factor ISI
Null, N., Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., et al. (2025). Estimation of backgrounds from jets misidentified as tau-leptons using the Universal Fake Factor method with the ATLAS detector. EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 85(12) [10.1140/epjc/s10052-025-14916-1].
Null, N; Aad, G; Aakvaag, E; Abbott, B; Abdelhameed, S; Abeling, K; Abicht, Nj; Abidi, Sh; Aboelela, M; Aboulhorma, A; Abramowicz, H; Abulaiti, Y; Ach...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/447763
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