A measurement of electron-tau universality from decays of intermediate vector bosons at the CERN\(\bar pp\) collider

The ratio of branching fractions of theW decaying to τ ande leptons is measured using\(\bar pp\) collisions at\(\sqrt s = 630\) GeV. The ratio of the electroweak charged current couplings to theW is then determined to begτW/geW=0.997±0.056 (stat.)±0.042 (syst.). The decay modeZ→τ+→τ+ is observed and also found to be consistent withe-τ universality.