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A measurement of the tau(-) -> mu(-)(nu)over-bar(mu)nu(tau) branching ratio

Research output: Contribution to journalJournal article

<mark>Journal publication date</mark>07/2003
<mark>Journal</mark>Nuclear Physics B - Proceedings Supplements
Number of pages10
Pages (from-to)30-39
<mark>Original language</mark>English


The tau(-) --> mu(-)(&nu;) over bar (mu)nu(tau), branching ratio has been measured using data collected from 1990 to 1995 by the OPAL detector at the LEP collider. The resulting value of B(tau- --> mu(-)(&nu;) over bar mu(nu)mu(tau)) = 0.1734 +/- 0.0009(stat) +/- 0.0005(syst) has been used in conjunction with other OPAL measurements to test lepton universality, yielding the coupling constant ratios g(mu)/g(e) = 1.0005 +/- 0.0043 and g(tau)/g(e) = 1.0031 +/- 0.0047, in good agreement with the Standard Model prediction of unity, and also to determine a value for the Michel parameter eta = 0.004 +/- 0.036. This is subsequently used to find a model-dependent limit of the mass for the charged Higgs boson, m(H)+/- > 1.30 tan beta, in the Minimal Supersymmetric Standard Model framework.