Measurement of the branching fractions and mass spectra for τ lepton decays including KS0 at Belle

Abstract

We report a study of τ lepton decays involving $K_S^0$ with a 669 fb⁻¹ data sample accumulated with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The branching fractions have been measured for the ${\tau }^{-}\to {\pi }^{-}{K}_S^0{\nu }_{\tau }$, $K^{-}{K}_S^0{\nu }_{\tau }$, ${\pi }^{-}{K}_S^0{\pi }^0{\nu }_{\tau }$, $K^{-}{K}_S^0{\pi }^0{\nu }_{\tau }$, ${\pi }^{-}{K}_S^0{K}_S^0{\nu }_{\tau }$ and ${\pi }^{-}{K}_S^0{K}_S^0{\pi }^0{\nu }_{\tau }$ decays. We also provide the unfolded mass spectra for ${\tau }^{-}\to {\pi }^{-}{K}_S^0{\pi }^0{\nu }_{\tau }$ and ${\tau }^{-}\to K^{-}{K}_S^0{\pi }^0{\nu }_{\tau }$.