Study of the decay of B →ωKS at Belle I

The study of CP violation in the decays of the B meson is important for constraining the CKM unitarity triangle in the Standard Model (SM). Second order b →s loop (also called ''penguin'') decays such as B0 →ωKS0 are sensitive to the unitarity weak phase φ1 and provide a consistency check for the CP violation found in first order weak b →c anti cs transitions (e.g. B0 →J/ψKS0). Penguin decays are particularly sensitive to new physics particles in the loop which may shift the measured CP asymmetries from our expectations. Considering corrections from other SM contributions, CP violation in b →s modes are predicted to be larger than that found in b →c. However, the experimental tendency is for the measurements to be smaller. We plan to update the measurement of CP asymmetries in B0 →ωKS0 with the final Belle data set which will enhance our understanding of CP violation in penguin dominated decays.