One-prong tau decays with kaons

One-prong tau decays into final states involving kaons are studied with about 161000 tau(+) tau(-) events collected by the ALEPH detector from 1991 to 1995. Charged kaons are identified by dE/dx measurement, while K(L)(0)'s are detected through their interaction in calorimeters. Branching ratios are measured for the inclusive mode, B (tau(-) --> K(-)X nu(tau)) = (1.52 +/- 0.04 +/- 0 04)%, where X can be any system of neutral particles, and for the exclusive modes B(tau(-) --> K(-)nu(tau)) = (6.96 +/- 0.25 +/- 0.14) x 10(-3), B(tau(-) --> K(-)pi(0)nu(tau)) =(4.44 +/- 0.26 +/- 0.24) x 10(-3), B(tau(-) --> K(-)pi(0)pi(0)nu(tau)) = (0.56 +/- 0.20 +/- 0.15) x 10(-3), B(tau(-) --> K(-)pi(0)pi(0)pi(0)nu(tau)) = (0.37 +/- 0.21 +/- 0.11) x 10(-3), B(tau(-) --> K(-)K(0)nu(tau)) = (1.62 +/- 0.21 +/- 0.11) x 10(-3), B(tau(-) --> K-K(0)pi(0)nu(tau)) = 1.43 +/- 0.25 +/- 0.15) x 10(-3), B(tau(-) --> <(K(0))over bar>pi(-)nu tau) = (9.28 +/- 0.45 +/- 0.34) x 10(-3), B(tau(-) --> <(K(0))over bar>pi(-)nu(tau)) = (3..47 +/- 0.53 +/- 0.37) x 10(-3), where the first error is statistical and the second is systematical. Upper limits for B(tau(-) --> K(0)pi(-)pi(0)pi(0)nu(tau)) and B(tau(-) --> K(-)K(0)pi(0)pi(0)nu(tau)) are also obtained. Mass spectra in the final states are investigated in order to study the relevant dynamics.