Measurements of Branching Fractions of Tau Decays Involving Kaons

One-prong T decays into final states involving kaons have been studied with about 72.000 z0 ---+ T+T- events collected by the DELPHI detector during the years 1993, 1994 and 1995. Charged kaons and pions are identified using the Cherenkov angle measured in the gas RICH detector combined with the dE/dX measurement in the TPC. Tracks which could not be identified by the RICH were identified using the dE/dX measurement only. Branching ratios for both inclusive and exclusive modes have been measured. The obtained value for the three years combined is BR(T----+ K-v7 ) = (0.639 ± 0.028stat ± 0.026sys)%.