The authors report on analyses of tau lepton decays?− →?K−?{sub?} and?− →??−?{sub?}, with? →??−?°, using 470 fb−1 of data from the BABAR experiment at PEP-II, collected at center-of-mass energies at and near the?(4S) resonance. They measure the branching fraction for the?− →?K−?{sub?} decay mode,?({tau}− →?K−?{sub {tau}}) = (1.42 ± 0.11(stat) ± 0.07(syst)) x 10−4, and report a 95% confidence level upper limit for the second-class current process {tau}− →??−?{sub {tau}},?({tau}− →??−?{sub {tau}})

We report an analysis of?− decaying into??−?{sub?} with? →??−?° using a data sample containing nearly 320 million {tau} pairs collected with the BABAR detector at the PEP-II B-Factory. We find no evidence for second-class currents and we set an upper limit of 0.69% at 90% confidence level for the fraction of second-class currents in this decay mode.