The branching ratio for the decay tau(-) --> e(-) <(nu)over bar>(e)nu(tau)
has been measured using Z(0) decay data collected by the OPAL experiment at
LEP. In total 33 073 tau(-) --> e(-) <(nu)over bar>(e)nu(tau) candidates w
ere identified from a sample of 186 197 selected tau. decays, giving a bran
ching ratio of B(tau(-) --> e(-) <(nu)over bar>(e)nu(tau)) = (17.81 +/- 0.0
9 (stat) +/- 0.06 (syst))%. This result is combined with other measurements
to test e - mu and mu - tau universality in charged-current weak interacti
ons. Additionally, the strong coupling constant alpha(s)(m(tau)(2)) has bee
n extracted from B(tau(-) --> e(-) <(nu)over bar>(e)nu(tau)) and evolved to
the Z(0) mass scale, giving alpha(s)(m(Z)(2)) = 0.1204 +/- 0.0011 (exp) +/
- 0.0019 (theory). (C) 1999 Published by Elsevier Science B.V. All rights r
eserved.