τ- → K-η(′)ντ decays in Chiral Perturbation Theory with resonances

We have studied the tau(-) -> K-eta(()'())nu(tau) decays within Chiral Perturbation Theory including resonances as explicit degrees of freedom. We have considered three different form factors according to treatment of final-state interactions. In increasing degree of soundness: Breit-Wigner, exponential resummation and dispersive representation. We find that although the first one fails in accounting for the data on the K eta mode, the other two approaches provide good fits to them which are sensitive to the K-star(1410) pole parameters, that are determined to be M-K star' = (1330(-41)(+27)) MeV and Gamma(K star') = 217(-122)(+68)) MeV. These values are competitive with the standard determination from tau(-) -> (K pi)(-)nu(tau) decays. The corresponding predictions for the tau(-) -> K-eta'nu(tau) channel respect the current upper bound and hint to the discovery of this decay mode in the near future.