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Measurement of 𝐶𝑃 Violation in 𝐵0→𝜓(→ℓ+ℓ−)𝐾0𝑆(→𝜋+𝜋−) Decays
A measurement of time-dependent 𝐶𝑃 violation in the decays of 𝐵0 and ¯𝐵0 mesons to the final states 𝐽/𝜓(→𝜇+𝜇−)𝐾0𝑆, 𝜓(2𝑆)(→𝜇+𝜇−)𝐾0𝑆 and 𝐽/𝜓(→𝑒+𝑒−)𝐾0𝑆 with 𝐾0𝑆→𝜋+𝜋− is presented. The data correspond to an integrated luminosity of 6 fb−1 collected at a center-of-mass energy of √𝑠=13 TeV with the LHCb detector. The 𝐶𝑃-violation parameters are measured to be 𝑆𝜓𝐾0𝑆=0.717±0.013(stat)±0.008(syst) and 𝐶𝜓𝐾0𝑆=0.008±0.012(stat)±0.003(syst). This measurement of 𝑆𝜓𝐾0𝑆 represents the most precise single measurement of the CKM angle 𝛽 to date and is more precise than the current world average. In addition, measurements of the 𝐶𝑃-violation parameters of the individual channels are reported and a combination with the LHCb Run 1 measurements is performed.