Study of high-multiplicity three-prong and five-prong τ decays at BABAR

We present measurements of the branching fractions of three-prong and five-prong τ decay modes using a sample of 430 million τ lepton pairs, corresponding to an integrated luminosity of 468  fb^(-1), collected with the BABAR detector at the PEP-II asymmetric-energy e^+e^- storage rings at SLAC National Accelerator Laboratory. The τ^- → (3π)^-ην_τ, τ^- → (3π)^-ων_τ, and τ^- → π^-f_1(1285)ν_τ branching fractions are presented, as well as a new limit on the branching fraction of the second-class current decay τ^- → π^-η^′(958)ν_τ. We search for the decay mode τ^- → K^-η^′(958)ν_τ and for five-prong decay modes with kaons, and place the first upper limits on their branching fractions.