TY - JOUR

T1 - Search for Lepton-Flavor Violation in Z -Boson Decays with τ Leptons with the ATLAS Detector

AU - The ATLAS collaboration

AU - Aad, G.

AU - Abbott, B.

AU - Abbott, D. C.

AU - Abed Abud, A.

AU - Abeling, K.

AU - Abhayasinghe, D. K.

AU - Abidi, S. H.

AU - Abramowicz, H.

AU - Abreu, H.

AU - Abulaiti, Y.

AU - Abusleme Hoffman, A. C.

AU - Acharya, B. S.

AU - Achkar, B.

AU - Adam, L.

AU - Adam Bourdarios, C.

AU - Adamczyk, L.

AU - Adamek, L.

AU - Adelman, J.

AU - Adiguzel, A.

AU - Adorni, S.

AU - Adye, T.

AU - Affolder, A. A.

AU - Afik, Y.

AU - Agapopoulou, C.

AU - Agaras, M. N.

AU - Agarwala, J.

AU - Aggarwal, A.

AU - Agheorghiesei, C.

AU - Aguilar-Saavedra, J. A.

AU - Ahmad, A.

AU - Ahmadov, F.

AU - Ahmed, W. S.

AU - Ai, X.

AU - Anisenkov, A. V.

AU - Baldin, E. M.

AU - Beloborodov, K.

AU - Bobrovnikov, V. S.

AU - Buzykaev, A. R.

AU - Kazanin, V. F.

AU - Kharlamov, A. G.

AU - Kharlamova, T.

AU - Maslennikov, A. L.

AU - Maximov, D. A.

AU - Peleganchuk, S. V.

AU - Podberezko, P.

AU - Rezanova, O. L.

AU - Soukharev, A. M.

AU - Talyshev, A. A.

AU - Tikhonov, Yu A.

AU - Zhulanov, V.

N1 - Funding Information: We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; ANID, Chile; CAS, MOST and NSFC, China; Minciencias, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF and Danish Natural Science Research Council, Denmark; IN2P3-CNRS and CEA-DRF/IRFU, France; Shota Rustaveli National Science Foundation of Georgia, Georgia; BMBF, HGF and MPG, Germany; General Secretariat for Research and Innovation, Greece; RGC and Hong Kong SAR, China; ISF and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; NWO, Netherlands; Research Council of Norway, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; JINR; Ministry of Education and Science of the Russian Federation and NRC KI, Russian Federation; Ministry of Education, Science and Technological Development, Serbia; Ministry of Education, Science, Research and Sport, Slovakia; ARRS and Ministry of Education, Science and Sport, Slovenia; DSI/NRF, South Africa; MICINN, Spain; Swedish Research Council and Wallenberg Foundation, Sweden; Secretariat for Education and Research, Switzerland, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, USA In addition, individual groups and members have received support from BCKDF, CANARIE, Compute Canada and CRC, Canada; COST, ERC, ERDF, Horizon 2020 and Marie Skłodowska-Curie Actions, European Union; Investissements d’Avenir Labex, Investissements d’Avenir Idex and ANR, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF, Greece; BSF-NSF and GIF, Israel; Norwegian Financial Mechanism 2014-2021, Norway; La Caixa Banking Foundation, CERCA Programme Generalitat de Catalunya and PROMETEO and GenT Programmes Generalitat Valenciana, Spain; Göran Gustafssons Stiftelse, Sweden; The Royal Society and Leverhulme Trust, United Kingdom. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN, the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in Ref. . Publisher Copyright: © 2021 CERN.

PY - 2021/12/31

Y1 - 2021/12/31

N2 - A search for lepton-flavor-violating Z→eτ and Z→μτ decays with pp collision data recorded by the ATLAS detector at the LHC is presented. This analysis uses 139 fb-1 of Run 2 pp collisions at s=13 TeV and is combined with the results of a similar ATLAS search in the final state in which the τ lepton decays hadronically, using the same data set as well as Run 1 data. The addition of leptonically decaying τ leptons significantly improves the sensitivity reach for Z→ℓτ decays. The Z→ℓτ branching fractions are constrained in this analysis to B(Z→eτ)<7.0×10-6 and B(Z→μτ)<7.2×10-6 at 95% confidence level. The combination with the previously published analyses sets the strongest constraints to date: B(Z→eτ)<5.0×10-6 and B(Z→μτ)<6.5×10-6 at 95% confidence level.

AB - A search for lepton-flavor-violating Z→eτ and Z→μτ decays with pp collision data recorded by the ATLAS detector at the LHC is presented. This analysis uses 139 fb-1 of Run 2 pp collisions at s=13 TeV and is combined with the results of a similar ATLAS search in the final state in which the τ lepton decays hadronically, using the same data set as well as Run 1 data. The addition of leptonically decaying τ leptons significantly improves the sensitivity reach for Z→ℓτ decays. The Z→ℓτ branching fractions are constrained in this analysis to B(Z→eτ)<7.0×10-6 and B(Z→μτ)<7.2×10-6 at 95% confidence level. The combination with the previously published analyses sets the strongest constraints to date: B(Z→eτ)<5.0×10-6 and B(Z→μτ)<6.5×10-6 at 95% confidence level.

UR - http://www.scopus.com/inward/record.url?scp=85123457439&partnerID=8YFLogxK

U2 - 10.1103/PhysRevLett.127.271801

DO - 10.1103/PhysRevLett.127.271801

M3 - Article

C2 - 35061407

AN - SCOPUS:85123457439

VL - 127

JO - Physical Review Letters

JF - Physical Review Letters

SN - 0031-9007

IS - 27

M1 - 271801

ER -