A Measurement of the tau- ---> e- anti-neutrino(e) neutrino(tau) branching ratio

The branching ratio for the decay tau->e nue nutau has been measured using Z0 decay data collected by the OPAL experiment at LEP. In total 33073 tau->e nue nutau candidates were identified from a sample of 186197 selected tau decays, giving a branching ratio of 17.81 +- 0.09(stat) +_ 0.06(sys)%. This result is combined with other measurements to test e-mu and mu-tau universality in charged-current weak interactions. Additionally, the strong coupling constant alpha_s has been extracted and evolved to the Z0 mass scale, giving alpha_s = 0.1204 +- 0.0011(exp) +- 0.0019(theory).

Note:

16 pages, LaTeX, 5 eps figs included, submitted to Physics Letters B Report-no: CERN-EP/98-175

electron positron: colliding beams
electron positron: annihilation
Z0: electroproduction
Z0: leptonic decay
tau: pair production
tau-: leptonic decay
tau-: branching ratio
tau: lifetime
lepton: universality
electron: energy spectrum

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Figures(0)

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