Measurement of the one-prong hadronic tau branching ratios at LEP
  The branching ratios of the \tau^- -> h^- \nu_\tau, \tau^- -> h^- \pi^0 \nu_\tau, \tau^- -> h^- >=2 \pi^0 \nu_\tau decays have been measured using the 1991-1995 data recorded with the OPAL detector at LEP. These branching ratios are measured simultaneously using three selection criteria and are found to be   BR(\tau^- -> h^- \nu_\tau) = (11.98 +/- 0.13 +/- 0.16)%   BR(\tau^- -> h^- \pi^0 \nu_\tau) = (25.89 +/- 0.17 +/- 0.29)%   BR(\tau^- -> h^- >=2 \pi^0 \nu_\tau) = ( 9.91 +/- 0.31 +/- 0.27)%   where the first error is statistical and the second is systematic. 
The OPAL Collaboration, K. Ackerstaff et al