Precise test of lepton flavour universality in W -boson decays into muons and electrons in pp collisions at s = 13 Te V with the ATLAS detector

Precise test of lepton flavour universality in W -boson decays into muons and electrons in pp collisions at s = 13 Te V with the ATLAS detector

The ratio of branching ratios of the W boson to muons and electrons, RWμ/e=B(W→μν)/B(W→eν), has been measured using 140fb-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¯...

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Dades bibliogràfiques
Autors principals: Aad, G, Aakvaag, E, Abbott, B, Abdelhameed, S, Abeling, K, Abicht, NJ, Abidi, SH, Aboelela, M, Aboulhorma, A, Abramowicz, H, Abreu, H, Abulaiti, Y, Acharya, BS, Ackermann, A, Bourdarios, CA, Adamczyk, L, Addepalli, SV, Addison, MJ, Adelman, J, Adiguzel, A, Adye, T, Affolder, AA, Afik, Y, Agaras, MN, Barr, AJ, Bortoletto, D, Bruckler, TL, Celli, F, Chen, M, Conroy, EI, Cooper-Sarkar, AM, Draguet, MA, Eberwein, GH, Frost, JA, Gallas, EJ, Grundy, JC, Gwenlan, C, Harris, YT, Hays, CP, Hodkinson, BH, Huffman, TB, Iizawa, T, Karava, K, Koch, SF, Li, Z, Nagai, K, Nedic, L, Nickerson, RB, Pacey, HA, Rossi, E, Ruggiero, A, Schopf, E, Shipsey, IPJ, Smith, HA, Sultan, DMS, Viehhauser, GHA, Weidberg, AR, Yildirim, TP
Format: Journal article
Idioma:English
Publicat: SpringerOpen 2024
Descripció
Sumari:The ratio of branching ratios of the W boson to muons and electrons, RWμ/e=B(W→μν)/B(W→eν), has been measured using 140fb-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 RZμμ/ee for the Z boson measured in inclusive Z→ee and Z→μμ events. By using the precise value of RZμμ/ee determined from e+e- colliders, the ratio RWμ/e is determined to be RWμ/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 RZμμ/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.

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