A search for charged-lepton-flavor violating 𝜇⁢𝜏⁢𝑞⁢𝑡 (𝑞=𝑢, 𝑐) interactions is presented, considering both top-quark production and decay. The data analyzed correspond to 140  fb−1 of proton-proton collisions at a center-of-mass energy of √𝑠 =13  TeV recorded with the ATLAS detector at the Large Hadron Collider. The analysis targets events containing two muons with the same electric charge, a hadronically decaying 𝜏-lepton and at least one jet, with exactly one 𝑏-tagged jet, produced by a 𝜇⁢𝜏⁢𝑞⁢𝑡 interaction. Agreement with the Standard Model expectation within 1.6 standard deviations is observed, and limits are set at the 95% confidence level (CL) on the charged-lepton-flavor violation branching ratio of ℬ⁡(𝑡 →𝜇⁢𝜏⁢𝑞) <8.7 ×10−7. An effective field theory interpretation is performed yielding 95% CL limits on Wilson coefficients, dependent on the flavor of the associated light quark and the Lorentz structure of the coupling. These range from |𝑐3⁢(2313) 𝗅𝖾𝗊𝗎|/Λ2 <0.10  TeV−2 for 𝜇⁢𝜏⁢𝑢⁢𝑡 to |𝑐1⁢(2323) 𝗅𝖾𝗊𝗎|/Λ2 <1.8  TeV−2 for 𝜇⁢𝜏⁢𝑐⁢𝑡. An additional interpretation is performed for scalar leptoquark production inducing charged-lepton-flavor violation, with fixed intergenerational couplings. Upper limits on leptoquark coupling strengths are set at the 95% CL, ranging from 𝜆LQ =1.3 to 𝜆LQ =3.7 for leptoquark masses between 0.5 and 2.0 TeV.

Aad, G., Aakvaag, E., Abbott, B., Abeling, K., Abicht, N. J., Abidi, S. H., et al. (2024). Search for charged-lepton-flavor violating 𝜇⁢𝜏⁢𝑞⁢𝑡 interactions in top-quark production and decay in 𝑝⁢𝑝 collisions at √𝑠 =13  TeV with the ATLAS detector at the LHC. PHYSICAL REVIEW D, 110(1), 012014-1-012014-34 [10.1103/physrevd.110.012014].

Search for charged-lepton-flavor violating 𝜇⁢𝜏⁢𝑞⁢𝑡 interactions in top-quark production and decay in 𝑝⁢𝑝 collisions at √𝑠 =13  TeV with the ATLAS detector at the LHC

Alfonsi, F.;Ballabene, E.;Bellagamba, L.;Bianco, G.;Boscherini, D.;Bruni, A.;Carratta, G.;Corchia, F.  A.;Cremonini, D.;De Castro, S.;Fabbri, F.;Fabbri, L.;Franchini, M.;Gabrielli, A.;Giacobbe, B.;Lasagni Manghi, F.;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.;
2024

Abstract

A search for charged-lepton-flavor violating 𝜇⁢𝜏⁢𝑞⁢𝑡 (𝑞=𝑢, 𝑐) interactions is presented, considering both top-quark production and decay. The data analyzed correspond to 140  fb−1 of proton-proton collisions at a center-of-mass energy of √𝑠 =13  TeV recorded with the ATLAS detector at the Large Hadron Collider. The analysis targets events containing two muons with the same electric charge, a hadronically decaying 𝜏-lepton and at least one jet, with exactly one 𝑏-tagged jet, produced by a 𝜇⁢𝜏⁢𝑞⁢𝑡 interaction. Agreement with the Standard Model expectation within 1.6 standard deviations is observed, and limits are set at the 95% confidence level (CL) on the charged-lepton-flavor violation branching ratio of ℬ⁡(𝑡 →𝜇⁢𝜏⁢𝑞) <8.7 ×10−7. An effective field theory interpretation is performed yielding 95% CL limits on Wilson coefficients, dependent on the flavor of the associated light quark and the Lorentz structure of the coupling. These range from |𝑐3⁢(2313) 𝗅𝖾𝗊𝗎|/Λ2 <0.10  TeV−2 for 𝜇⁢𝜏⁢𝑢⁢𝑡 to |𝑐1⁢(2323) 𝗅𝖾𝗊𝗎|/Λ2 <1.8  TeV−2 for 𝜇⁢𝜏⁢𝑐⁢𝑡. An additional interpretation is performed for scalar leptoquark production inducing charged-lepton-flavor violation, with fixed intergenerational couplings. Upper limits on leptoquark coupling strengths are set at the 95% CL, ranging from 𝜆LQ =1.3 to 𝜆LQ =3.7 for leptoquark masses between 0.5 and 2.0 TeV.
2024
Aad, G., Aakvaag, E., Abbott, B., Abeling, K., Abicht, N. J., Abidi, S. H., et al. (2024). Search for charged-lepton-flavor violating ��⁢��⁢��⁢�� interactions in top-quark production and decay in ��⁢�� collisions at √�� =13  TeV with the ATLAS detector at the LHC. PHYSICAL REVIEW D, 110(1), 012014-1-012014-34 [10.1103/physrevd.110.012014].
Aad, G.; Aakvaag, E.; Abbott, B.; Abeling, K.; Abicht, N.  J.; Abidi, S.  H.; Aboelela, M.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; A...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/1008744
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