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


Aad G., Aakvaag E., Abbott B., Abdelhameed S., Abeling K., Abicht N., ...Daha Fazla

European Physical Journal C, cilt.84, sa.10, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 84 Sayı: 10
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1140/epjc/s10052-024-13070-4
  • Dergi Adı: European Physical Journal C
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, zbMATH, Directory of Open Access Journals
  • İstanbul Üniversitesi Adresli: Evet

Özet

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 (Formula presented.) 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.