Test of lepton flavour universality in W-boson decays into electrons and τ-leptons using pp collisions at s = 13 TeV with the ATLAS detector

The ATLAS collaboration

doi:10.1007/JHEP05(2025)038

Test of lepton flavour universality in W-boson decays into electrons and τ-leptons using pp collisions at s = 13 TeV with the ATLAS detector

The ATLAS collaboration

iThemba Labs
Department of Physics
University of South Africa
University of Zululand
Cadi Ayyad University
Departamento de Física Teórica y del Cosmos
University of Granada
CERN
Aix-Marseille Université
University of Bergen
University of Oklahoma
New York University Abu Dhabi
University of Göttingen
TU Dortmund University
United States Department of Energy
Southern Methodist University
Mohammed V University in Rabat
Tel Aviv University
New York University
National Institute for Nuclear Physics
Abdus Salam International Centre for Theoretical Physics
King's College London
Heidelberg University
Université Savoie Mont Blanc
AGH University of Krakow
SLAC National Accelerator Laboratory
University of Manchester
Northern Illinois University
Istanbul University
Rutherford Appleton Laboratory
University of California at Santa Cruz
The University of Chicago
Institute for High Energy Physics
Johannes Gutenberg University Mainz
Alexandru Ioan Cuza University of Iaşi
Azerbaijan National Academy of Sciences
Royal Holloway University of London
Zhengzhou University
University of Rome Tor Vergata
University of Valencia
University of Hassan II Casablanca
Lund University
Stony Brook University
Waseda University
University of Bonn
Bogazici University
Columbia University
University of Victoria BC
Université Grenoble Alpes
University of Edinburgh

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

Abstract

A measurement of the ratio of the branching fractions, R_τ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at s = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb⁻¹. The W → τν_τ (with τ → eν_eν_τ) and W → eν_e decays are distinguished using the differences in the impact parameter distributions and transverse momentum spectra of the electrons. The measured ratio of branching fractions R_τ/e = 0.975 ± 0.012 (stat.) ± 0.020 (syst.), is consistent with the Standard Model assumption of lepton flavour universality in W-boson decays.

Original language	English
Article number	38
Journal	Journal of High Energy Physics
Volume	2025
Issue number	5
DOIs	https://doi.org/10.1007/JHEP05(2025)038
State	Published - May 2025

Keywords

Flavour Physics
Hadron-Hadron Scattering
Tau Physics

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10.1007/JHEP05(2025)038

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@article{f67b0b66fa6b482ab83bed65e3cd7a70,

title = "Test of lepton flavour universality in W-boson decays into electrons and τ-leptons using pp collisions at s = 13 TeV with the ATLAS detector",

abstract = "A measurement of the ratio of the branching fractions, Rτ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at s = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb−1. The W → τντ (with τ → eνeντ) and W → eνe decays are distinguished using the differences in the impact parameter distributions and transverse momentum spectra of the electrons. The measured ratio of branching fractions Rτ/e = 0.975 ± 0.012 (stat.) ± 0.020 (syst.), is consistent with the Standard Model assumption of lepton flavour universality in W-boson decays.",

keywords = "Flavour Physics, Hadron-Hadron Scattering, Tau Physics",

author = "\{The ATLAS collaboration\} and G. Aad and E. Aakvaag and B. Abbott and S. Abdelhameed and K. Abeling and Abicht, \{N. J.\} and Abidi, \{S. H.\} and M. Aboelela and A. Aboulhorma and H. Abramowicz and Y. Abulaiti and Acharya, \{B. S.\} and A. Ackermann and \{Adam Bourdarios\}, C. and L. Adamczyk and Addepalli, \{S. V.\} and Addison, \{M. J.\} and J. Adelman and A. Adiguzel and T. Adye and Affolder, \{A. A.\} and Y. Afik and Agaras, \{M. N.\} and A. Aggarwal and C. Agheorghiesei and F. Ahmadov and S. Ahuja and X. Ai and G. Aielli and A. Aikot and \{Ait Tamlihat\}, M. and B. Aitbenchikh and M. Akbiyik and {\AA}kesson, \{T. P.A.\} and Akimov, \{A. V.\} and D. Akiyama and Akolkar, \{N. N.\} and S. Aktas and \{Al Khoury\}, K. and Alberghi, \{G. L.\} and J. Albert and P. Albicocco and Albouy, \{G. L.\} and S. Alderweireldt and H. Arnold and V. Dao and J. Hobbs and J. Jia and G. Piacquadio and D. Tsybychev",

note = "Publisher Copyright: {\textcopyright} The Author(s) 2025.",

year = "2025",

month = may,

doi = "10.1007/JHEP05(2025)038",

language = "English",

volume = "2025",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

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T1 - Test of lepton flavour universality in W-boson decays into electrons and τ-leptons using pp collisions at s = 13 TeV with the ATLAS detector

AU - The ATLAS collaboration

AU - Aad, G.

AU - Aakvaag, E.

AU - Abbott, B.

AU - Abdelhameed, S.

AU - Abeling, K.

AU - Abicht, N. J.

AU - Abidi, S. H.

AU - Aboelela, M.

AU - Aboulhorma, A.

AU - Abramowicz, H.

AU - Abulaiti, Y.

AU - Acharya, B. S.

AU - Ackermann, A.

AU - Adam Bourdarios, C.

AU - Adamczyk, L.

AU - Addepalli, S. V.

AU - Addison, M. J.

AU - Adelman, J.

AU - Adiguzel, A.

AU - Adye, T.

AU - Affolder, A. A.

AU - Afik, Y.

AU - Agaras, M. N.

AU - Aggarwal, A.

AU - Agheorghiesei, C.

AU - Ahmadov, F.

AU - Ahuja, S.

AU - Ai, X.

AU - Aielli, G.

AU - Aikot, A.

AU - Ait Tamlihat, M.

AU - Aitbenchikh, B.

AU - Akbiyik, M.

AU - Åkesson, T. P.A.

AU - Akimov, A. V.

AU - Akiyama, D.

AU - Akolkar, N. N.

AU - Aktas, S.

AU - Al Khoury, K.

AU - Alberghi, G. L.

AU - Albert, J.

AU - Albicocco, P.

AU - Albouy, G. L.

AU - Alderweireldt, S.

AU - Arnold, H.

AU - Dao, V.

AU - Hobbs, J.

AU - Jia, J.

AU - Piacquadio, G.

AU - Tsybychev, D.

PY - 2025/5

Y1 - 2025/5

N2 - A measurement of the ratio of the branching fractions, Rτ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at s = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb−1. The W → τντ (with τ → eνeντ) and W → eνe decays are distinguished using the differences in the impact parameter distributions and transverse momentum spectra of the electrons. The measured ratio of branching fractions Rτ/e = 0.975 ± 0.012 (stat.) ± 0.020 (syst.), is consistent with the Standard Model assumption of lepton flavour universality in W-boson decays.

AB - A measurement of the ratio of the branching fractions, Rτ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at s = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb−1. The W → τντ (with τ → eνeντ) and W → eνe decays are distinguished using the differences in the impact parameter distributions and transverse momentum spectra of the electrons. The measured ratio of branching fractions Rτ/e = 0.975 ± 0.012 (stat.) ± 0.020 (syst.), is consistent with the Standard Model assumption of lepton flavour universality in W-boson decays.

KW - Flavour Physics

KW - Hadron-Hadron Scattering

KW - Tau Physics

UR - https://www.scopus.com/pages/publications/105012466849

U2 - 10.1007/JHEP05(2025)038

DO - 10.1007/JHEP05(2025)038

M3 - Article

AN - SCOPUS:105012466849

SN - 1126-6708

VL - 2025

JO - Journal of High Energy Physics

JF - Journal of High Energy Physics

IS - 5

M1 - 38

ER -

Test of lepton flavour universality in W-boson decays into electrons and τ-leptons using pp collisions at s = 13 TeV with the ATLAS detector

Abstract

Keywords

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