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 beg /g =0.997±0.056 (stat.)±0.042 (syst.). The decay modeZ→τ+→τ+ is observed and also found to be consistent withe-τ universality.