Publicação
Search for charged-lepton-flavor violating μτqt interactions in top-quark production and decay in pp collisions at √s=13 TeV with the ATLAS detector at the LHC
| Resumo: | A search for charged-lepton-flavor violating \( \mu \tau q t \) (\( q = u, c \)) 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 \( \sqrt{s} = 13 \) 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 \( \tau \)-lepton and at least one jet, with exactly one \( b \)-tagged jet, produced by a \( \mu \tau q t \) 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 \( \mathcal{B}(t \rightarrow \mu \tau q) < 8.7 \times 10^{-7} \). 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 \( |c_3(2313)_{leq u}|/\Lambda^2 < 0.10\,\text{TeV}^{-2} \) for \( \mu \tau u t \) to \( |c_1(2323)_{leq u}|/\Lambda^2 < 1.8\,\text{TeV}^{-2} \) for \( \mu \tau c t \). 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 \( \lambda_{LQ} = 1.3 \) to \( \lambda_{LQ} = 3.7 \) for leptoquark masses between 0.5 and 2.0 TeV. |
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| Autores principais: | Castro, Nuno Filipe |
| Outros Autores: | Onofre, A.; ATLAS Collaboration |
| Assunto: | Ciências Naturais::Ciências Físicas |
| Ano: | 2024 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | A search for charged-lepton-flavor violating \( \mu \tau q t \) (\( q = u, c \)) 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 \( \sqrt{s} = 13 \) 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 \( \tau \)-lepton and at least one jet, with exactly one \( b \)-tagged jet, produced by a \( \mu \tau q t \) 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 \( \mathcal{B}(t \rightarrow \mu \tau q) < 8.7 \times 10^{-7} \). 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 \( |c_3(2313)_{leq u}|/\Lambda^2 < 0.10\,\text{TeV}^{-2} \) for \( \mu \tau u t \) to \( |c_1(2323)_{leq u}|/\Lambda^2 < 1.8\,\text{TeV}^{-2} \) for \( \mu \tau c t \). 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 \( \lambda_{LQ} = 1.3 \) to \( \lambda_{LQ} = 3.7 \) for leptoquark masses between 0.5 and 2.0 TeV. |
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