This paper describes an algorithm for reconstructing and identifying a highly collimated hadronically decaying τ -lepton pair with low transverse momentum. When two τ -leptons are highly collimated, their visible decay products might overlap, degrading the reconstruction performance for each of the τ -leptons. A dedicated treatment attempting to tag the τ -lepton pair as a single object is required. The reconstruction algorithm is based on a large radius jet and its associated two leading subjets, and the identification uses a boosted decision tree to discriminate between signatures from τ +τ − systems and those arising from QCD jets. The efficiency of the identification algorithm is measured in Zγ events using proton–proton collision data at √s = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018, corresponding to an integrated luminosity of 139 fb−1. The resulting data-to-simulation scale factors are close to unity with uncertainties ranging from 26 to 37%.

Null, N., Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., et al. (2025). Reconstruction and identification of pairs of collimated τ -leptons decaying hadronically using √s = 13 TeV pp collision data with the ATLAS detector. EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 85(5), 1-35 [10.1140/epjc/s10052-025-14075-3].

Reconstruction and identification of pairs of collimated τ -leptons decaying hadronically using √s = 13 TeV pp collision data with the ATLAS detector

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.;Levrini, G.;Nechaeva, S.;Polini, A.;Rinaldi, L.;Romano, M.;Sanzani, E.;Sbarra, C.;Sbrizzi, A.;Semprini-Cesari, N.;Sioli, M.;Todome, K.;Valentinetti, S.;Villa, M.;Vittori, C.;Vivarelli, I.;Zoccoli, A.;
2025

Abstract

This paper describes an algorithm for reconstructing and identifying a highly collimated hadronically decaying τ -lepton pair with low transverse momentum. When two τ -leptons are highly collimated, their visible decay products might overlap, degrading the reconstruction performance for each of the τ -leptons. A dedicated treatment attempting to tag the τ -lepton pair as a single object is required. The reconstruction algorithm is based on a large radius jet and its associated two leading subjets, and the identification uses a boosted decision tree to discriminate between signatures from τ +τ − systems and those arising from QCD jets. The efficiency of the identification algorithm is measured in Zγ events using proton–proton collision data at √s = 13 TeV collected by the ATLAS experiment at the Large Hadron Collider between 2015 and 2018, corresponding to an integrated luminosity of 139 fb−1. The resulting data-to-simulation scale factors are close to unity with uncertainties ranging from 26 to 37%.
2025
Null, N., Aad, G., Aakvaag, E., Abbott, B., Abdelhameed, S., Abeling, K., et al. (2025). Reconstruction and identification of pairs of collimated τ -leptons decaying hadronically using √s = 13 TeV pp collision data with the ATLAS detector. EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS, 85(5), 1-35 [10.1140/epjc/s10052-025-14075-3].
Null, Null; Aad, G.; Aakvaag, E.; Abbott, B.; Abdelhameed, S.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboelela, M.; Aboulhorma, A.; Abramowicz, H.;...espandi
File in questo prodotto:
File Dimensione Formato  
unpaywall-bitstream-1973127157.pdf

accesso aperto

Tipo: Versione (PDF) editoriale / Version Of Record
Licenza: Licenza per Accesso Aperto. Creative Commons Attribuzione (CCBY)
Dimensione 4.73 MB
Formato Adobe PDF
4.73 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1044041
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 0
  • ???jsp.display-item.citation.isi??? 4
  • OpenAlex ND
social impact