Measurement of the Spectral Function for the τ- →k-ksντ Decay

The decay τ⁻→ K⁻K_Sν_τ has been studied using 430×106e⁺e⁻ → τ⁺τ⁻ events produced at a center-of-mass energy around 10.6 GeV at the PEP-II collider and studied with the BABAR detector. The mass spectrum of the K⁻K_S system has been measured and the spectral function has been obtained. The measured branching fraction B(τ⁻ → K⁻K_Sν_τ)=(0.739±0.011(stat)±0.020(syst))×10⁻³ is found to be in agreement with earlier measurements.