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Статья

Aad, G.
Precise Test of Lepton Flavour Universality in W-Boson Decays into Muons and Electrons in pp Collisions at *%s=13 TeV with the ATLAS Detector / G.Aad, F.Ahmadov, I.N.Aleksandrov, V.A.Bednyakov, I.R.Boyko, G.A.Chelkov, A.Cheplakov, M.V.Chizhov, D.V.Dedovich, M.Demichev, M.I.Gostkin, S.N.Karpov, Z.M.Karpova, U.Kruchonak, V.Kukhtin, E.Ladygin, V.Lyubushkin, T.Lyubushkina, S.Malyukov, M.Mineev, E.Plotnikova, I.N.Potrap, N.A.Rusakovich, M.Shiyakova, A.Soloshenko, T.Turtuvshin, A.Vasyukov, I.Yeletskikh, A.Zhemchugov, N.I.Zimine, Y.Kulchitsky, [ATLAS Collab.] // The European Physical Journal C [Electronic resource]. – 2024. – Vol. 84, No. 10. – P. 993. – URL: https://doi.org/10.1140/epjc/s10052-024-13070-4. – Bibliogr.: 83.

The ratio of branching ratios of the W boson to muons and electrons, R&sup(μ/e)&sub(W) = B(W → μν)/B(W → eν), has been measured using 140 fb*−*1 of pp collision data at √s = 13 TeV collected with the ATLAS detector at the LHC, probing the universality of lepton couplings. The ratio is obtained from measurements of the tt^- production cross- section in the ee, eμ and μμ dilepton final states. To reduce systematic uncertainties, it is normalised by the square root of the corresponding ratio R μμ/ee Z for the Z boson measured in inclusive Z → ee and Z → μμ events. By using the pre- cise value of R μμ/ee Z determined from e+e− colliders, the ratio R μ/e W is determined to be R&sup(μ/e)&sub(W) = 0.9995 ± 0.0022 (stat) ± 0.0036 (syst)± 0.0014 (ext). The three uncertainties correspond to data statistics, experi- mental systematics and the external measurement of R&sup(μμ/ee)&sub(Z) , giving a total uncertainty of 0.0045, and confirming the Stan- dard Model assumption of lepton flavour universality in W - boson decays at the 0.5% level.



ОИЯИ = ОИЯИ (JINR)2024
Спец.(статьи,препринты) = С 346.2в - Взаимодействие протонов с протонами
Спец.(статьи,препринты) = С 346.6е2 - Промежуточные бозоны