A self-calibrating, double-ratio method to test tau lepton universality in W boson decays at the LHC

S. Dysch, T. R. Wyatt

Measurements in $W^{+}{W}^{-}$ events at LEP2 and in $B$ hadron semileptonic decays at B factories and LHCb provide intriguing hints of a violation of lepton universality in the charged…