Search for CP Violation in the Decay τ−→π−KS0(≥0π0)ντ at BaBar

Abstract

We report a search for CP violation in the decay ${\tau }^{-}\to {\pi }^{-}{K}_S^0(\ge 0{\pi }^0){\nu }_{\tau }$ using a dataset of 437 million τ lepton pairs, corresponding to an integrated luminosity of 476 fb⁻¹, collected with the BaBar detector at the PEP-II asymmetric energy $e^{+}{e}^{-}$ storage rings. The CP-violating decay-rate asymmetry is determined to be (−0.36 ± 0.23 ± 0.11)% approximately 2.8 standard deviations from the Standard Model prediction of (0.36 ± 0.01)%.