Search for charged-lepton-flavour violating eμtq interactions at √s=13 TeV with the ATLAS detector
Abstract
A search for charged-lepton-flavour violation (cLFV) in top-quark production and decay is presented. The data analysed correspond to 140 fb−1 of proton-proton collisions recorded at a centre-of-mass energy of √s= 13 TeV by the ATLAS detector at the Large Hadron Collider. The possible cLFV contribution is studied via two mechanisms. The first is via the production of a leptonically-decaying single-top quark in association with a pair of oppositely-charged different-flavour leptons. The second is the production of top-quark pairs, where one top quark decays into a pair of oppositely-charged different-flavour leptons and a u- or c-quark, while the other decays into a leptonically-decaying W boson and a b-quark, according to the Standard Model. The signal processes contain three charged leptons, taken to be electrons or muons. No significant deviation from the Standard Model prediction is observed, and these results are interpreted within an Effective Field Theory framework. Upper limits are placed at 95% confidence level on six Wilson coefficients, ranging from |Ctensoreμtu|/Λ2 < 0.018 TeV−2 to |Cscalareμtc|/Λ2 < 0.32 TeV−2 for the tensor u-quark and scalar c-quark couplings, respectively. These Wilson coefficient limits are translated into 95% confidence level upper limits on cLFV top-quark decay branching ratios, ranging from B(t → eμu) < 6 · 10−9 to B(t → eμc) < 2.7 · 10−7 for the scalar u-quark and tensor c-quark couplings, respectively.
Related
- Search for the charged lepton flavor violating decay η→ e±μ∓
- Search for charginos and neutralinos with B−L R-parity violating decays in √s=13 TeV and $13.6$ TeV pp collisions with the ATLAS detector
- First double-differential cross-section measurements in proton multiplicity and kinematics for mesonless νμ charged-current interactions on argon using the MicroBooNE detector
- Flavour current correlators and the non-Abelian hydrodynamic approximation: the charged sector
- Charged lepton flavor violating decays and (g−2)ea in an extended standard model with singlet and triplet leptoquarks
BibTeX
@misc{aad2026search,
title = {{Search for charged-lepton-flavour violating $eμtq$ interactions at $\sqrts=13$ TeV with the ATLAS detector}},
author = {Georges Aad and Erlend Aakvaag and Braden Keim Abbott and Sara Abdelhameed and Kira Abeling and Nils Julius Abicht and Haider Abidi and Mohammed Aboelela and Asmaa Aboulhorma and Halina Abramowicz and Bobby Samir Acharya and Anke Ackermann and Jona Ackerschott and Claire Adam Bourdarios and Leszek Adamczyk and Sagar Addepalli and Jahred Adelman and Habeeb Adenle and Aytul Adiguzel and Tim Adye and Tony Affolder and Yoav Afik and Merve Nazlim Agaras and Anamika Aggarwal and Catalin Agheorghiesei and Ammara Ahmad and Faig Ahmadov and Sonakshi Ahuja and Xiaocong Ai and Giulio Aielli and Arya Aikot and Malak Ait Tamlihat and Torsten Akesson and Daiya Akiyama and Sina Aktas and Gian Luigi Alberghi and Justin Albert and Una Helena Alberti and Pietro Albicocco and Sara Alderweireldt and Zackary Lee Alegria and Martin Aleksa and Igor Alexandrov and Calin Alexa and Theodoros Alexopoulos and Fabrizio Alfonsi and Malte Algren and Muhammad Alhroob and Babar Ali and Hanadi Ali and Shahzad Ali and Samuel William Alibocus and Malik Aliev and Gianluca Alimonti and Corentin Allaire and Benedict Allbrooke and Derrick Allen and Jonny Allen and Camron Stephen Alley and Earl Russel Tang Almazan},
howpublished = {HAL},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.01308},
eprint = {2610.01308},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05820874v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Search for charged-lepton-flavour violating eμtq interactions at √s=13 TeV with the ATLAS detector
AU - Georges Aad
AU - Erlend Aakvaag
AU - Braden Keim Abbott
AU - Sara Abdelhameed
AU - Kira Abeling
AU - Nils Julius Abicht
AU - Haider Abidi
AU - Mohammed Aboelela
AU - Asmaa Aboulhorma
AU - Halina Abramowicz
AU - Bobby Samir Acharya
AU - Anke Ackermann
AU - Jona Ackerschott
AU - Claire Adam Bourdarios
AU - Leszek Adamczyk
AU - Sagar Addepalli
AU - Jahred Adelman
AU - Habeeb Adenle
AU - Aytul Adiguzel
AU - Tim Adye
AU - Tony Affolder
AU - Yoav Afik
AU - Merve Nazlim Agaras
AU - Anamika Aggarwal
AU - Catalin Agheorghiesei
AU - Ammara Ahmad
AU - Faig Ahmadov
AU - Sonakshi Ahuja
AU - Xiaocong Ai
AU - Giulio Aielli
AU - Arya Aikot
AU - Malak Ait Tamlihat
AU - Torsten Akesson
AU - Daiya Akiyama
AU - Sina Aktas
AU - Gian Luigi Alberghi
AU - Justin Albert
AU - Una Helena Alberti
AU - Pietro Albicocco
AU - Sara Alderweireldt
AU - Zackary Lee Alegria
AU - Martin Aleksa
AU - Igor Alexandrov
AU - Calin Alexa
AU - Theodoros Alexopoulos
AU - Fabrizio Alfonsi
AU - Malte Algren
AU - Muhammad Alhroob
AU - Babar Ali
AU - Hanadi Ali
AU - Shahzad Ali
AU - Samuel William Alibocus
AU - Malik Aliev
AU - Gianluca Alimonti
AU - Corentin Allaire
AU - Benedict Allbrooke
AU - Derrick Allen
AU - Jonny Allen
AU - Camron Stephen Alley
AU - Earl Russel Tang Almazan
PY - 2026
DA - 2026/10/01
PB - HAL
DO - 10.48550/arxiv.2610.01308
UR - https://hal.science/hal-05820874v1
AB - A search for charged-lepton-flavour violation (cLFV) in top-quark production and decay is presented. The data analysed correspond to 140 fb^−1 of proton-proton collisions recorded at a centre-of-mass energy of √s= 13 TeV by the ATLAS detector at the Large Hadron Collider. The possible cLFV contribution is studied via two mechanisms. The first is via the production of a leptonically-decaying single-top quark in association with a pair of oppositely-charged different-flavour leptons. The second is the production of top-quark pairs, where one top quark decays into a pair of oppositely-charged different-flavour leptons and a u- or c-quark, while the other decays into a leptonically-decaying W boson and a b-quark, according to the Standard Model. The signal processes contain three charged leptons, taken to be electrons or muons. No significant deviation from the Standard Model prediction is observed, and these results are interpreted within an Effective Field Theory framework. Upper limits are placed at 95% confidence level on six Wilson coefficients, ranging from |C^tensor_eμtu|/Λ^2 < 0.018 TeV^−2 to |C^scalar_eμtc|/Λ^2 < 0.32 TeV^−2 for the tensor u-quark and scalar c-quark couplings, respectively. These Wilson coefficient limits are translated into 95% confidence level upper limits on cLFV top-quark decay branching ratios, ranging from B(t → eμu) < 6 · 10^−9 to B(t → eμc) < 2.7 · 10^−7 for the scalar u-quark and tensor c-quark couplings, respectively.
ER -