Ústav technické a experimentální fyziky Institute of Experimental and Applied Physics

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

NázevTitle
Precise test of lepton flavour universality in W-boson decays into muons and electrons in pp collisions at √s=13 TeV with the ATLAS detectorPrecise test of lepton flavour universality in W-boson decays into muons and electrons in pp collisions at √s=13 TeV with the ATLAS detector
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
G. Aad, E. Aakvaag, B. Abbott, S. Abdelhameed, B. Ali, K. Augsten, B. Bergmann, H. Day-Hall, P. Fiedler, Z. Hubáček, S. Mondal, M. Myška, L. Novotný, V. Petousis, S. Pospíšil, K. Smolek, A. Sopczak, V. Vacek, P. Vokáč, O. Zaplatílek
DOIDOI
10.1140/epjc/s10052-024-13070-4
Časopis / citaceJournal / citation
European Physical Journal C. 2024, 84(10), ISSN 1434-6052.
RokYear
2024
JazykLanguage
eng
WoSWoS
001394631200001
ScopusScopus
2-s2.0-85206098232
RIVRIV
RIV/68407700:21220/24:00380666!RIV25-MSM-21220___
ProjektProject
CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026)CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026); Výzkum základních stavebních kamenů hmoty s využitím špičkových technologiíFundamental constituents of matter through frontier technologies

AbstraktAbstract

The ratio of branching ratios of the W boson to muons and electrons, R-W(mu/e) = B(W -> mu nu)/B(W -> e nu), has been measured using 140 fb(-1) of pp collision data at root s = 13TeV collected with the ATLAS detector at the LHC, probing the universality of lepton couplings. The ratio is obtained from measurements of the t (t) over bar production cross-section in the ee, e mu and mu mu dilepton final states. To reduce systematic uncertainties, it is normalised by the square root of the corresponding ratio R-Z(mu mu/ee) for the Z boson measured in inclusive Z -> ee and Z -> mu mu events. By using the precise value of R-Z(mu mu/ee) determined from e(+)e(-) colliders, the ratio R-W(mu/e) is determined to be R-W(mu/e) = 0.9995 +/- 0.0022 (stat) +/- 0.0036 (syst) +/- 0.0014 (ext). The three uncertainties correspond to data statistics, experimental systematics and the external measurement of R-Z(mu mu/ee), giving a total uncertainty of 0.0045, and confirming the Standard Model assumption of lepton flavour universality in W-boson decays at the 0.5% level.

The ratio of branching ratios of the W boson to muons and electrons, R-W(mu/e) = B(W -> mu nu)/B(W -> e nu), has been measured using 140 fb(-1) of pp collision data at root s = 13TeV collected with the ATLAS detector at the LHC, probing the universality of lepton couplings. The ratio is obtained from measurements of the t (t) over bar production cross-section in the ee, e mu and mu mu dilepton final states. To reduce systematic uncertainties, it is normalised by the square root of the corresponding ratio R-Z(mu mu/ee) for the Z boson measured in inclusive Z -> ee and Z -> mu mu events. By using the precise value of R-Z(mu mu/ee) determined from e(+)e(-) colliders, the ratio R-W(mu/e) is determined to be R-W(mu/e) = 0.9995 +/- 0.0022 (stat) +/- 0.0036 (syst) +/- 0.0014 (ext). The three uncertainties correspond to data statistics, experimental systematics and the external measurement of R-Z(mu mu/ee), giving a total uncertainty of 0.0045, and confirming the Standard Model assumption of lepton flavour universality in W-boson decays at the 0.5% level.