Measurement of B(τ → K nπ0ν), n = 0, 1, 2, 3 and B(τ → π nπ0ν), n = 3, 4 by BABAR

We report preliminary measurements of the branching fractions of the decays τ− → K−nπ0 ντ (n = 0, 1, 2, 3) and τ− → π−nπ0 ντ (n = 3, 4), excluding the contributions that proceed through the decay of intermediate K0 and η mesons. The measurements are based on a data sample of 435 million τ pairs produced in e+ e− collisions at and near the ϒ (4S) peak and collected with the BABAR detector in 1999-2008. The measured branching fractions are B(τ− → K−ντ ) = (7.174 ±0.033 ±0.213) × 10−3, B(τ− → K−π0 ντ ) = (5.054 ±0.021 ±0.148) × 10−3, B(τ− → K−2π0 ντ ) = (6.151 ± 0.117 ± 0.338) × 10−4, B(τ− → K−3π0 ντ ) = (1.246 ± 0.164 ± 0.238) × 10−4, B(τ− → π−3π0 ντ ) = (1.168 ± 0.006 ± 0.038) × 10−2, B(τ− → π−4π0 ντ ) = (9.020 ± 0.400 ± 0.652) × 10−4, where the first uncertainty is statistical and the second one systematic.