Ali, Hanadi and Alsolami, Zainab and Barton, A.E. and Borissov, G. and Bouhova-Thacker, E.V. and Ferguson, Ruby and Ferrando, James and Fox, H. and Hagan, Alina and Henderson, R.C.W. and Jones, R.W.L. and Kartvelishvili, V. and Love, P.A. and Marshall, Emma J. and McElhinney, Luke and Meng, L. and Muenstermann, D. and Sampson, Elliot and Smizanska, M. and Wharton, A.M. (2025) Test of lepton flavour universality in W-boson decays into electrons and τ-leptons using pp collisions at = 13 TeV with the ATLAS detector. Journal of High Energy Physics, 2025 (5): 38. ISSN 1029-8479
Full text not available from this repository.Abstract
A measurement of the ratio of the branching fractions, Rτ/e = B(W → τν)/B(W → eν), is performed using a sample of W bosons originating from top-quark decays to final states containing τ-leptons or electrons. This measurement uses pp collisions at s = 13 TeV, collected by the ATLAS experiment at the Large Hadron Collider during Run 2, corresponding to an integrated luminosity of 140 fb−1. The W → τντ (with τ → eνeντ) and W → eνe decays are distinguished using the differences in the impact parameter distributions and transverse momentum spectra of the electrons. The measured ratio of branching fractions Rτ/e = 0.975 ± 0.012 (stat.) ± 0.020 (syst.), is consistent with the Standard Model assumption of lepton flavour universality in W-boson decays.