Testing the Lorentz structure of the charged weak current in $\tau$ -decays

Abstract

We review the current experimental situation on the determination of the Lorentz structure of the charged weak current in τ decays. We propose a method to extent these studies to decays of τ leptons to righthanded daughter leptons which are forbidden in the standard model. We reanalyse the available data in the framework of specific models and derive limits on the mass of charged Higgs bosons of m(H±) > 1.5 tan β GeV at 90 % c.l. and on righthanded W-bosons of m(W2) > 230 GeV at 90 % c.l., valid if the righthanded neutrinos associated with it are light compared to the τ.