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arXiv · hep-ex/0608039

Observation of Time-Dependent CP Violation in B0 -> eta' K0 Decays and Improved Measurements of CP Asymmetries in B0 -> phiK0, KsKsKs and B0 -> J/psi K0 Decays

The Belle Collaboration·K. -F. Chen
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Abstract

We present improved measurements of CP-violation parameters in B0->phiK0, eta'K0, KsKsKs decays based on a sample of 535x10^6 BBbar pairs collected at the Y(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. We obtain sin2phi_1^eff=+0.64+-0.10(stat)+-0.04(syst) for B0->eta'K0, +0.50+-0.21(stat)+-0.06(syst) for B0->phiK0, and +0.30+-0.32(stat) +-0.08(syst) for B0->KsKsKs decays. We have observed CP violation in the B0->eta'K0 decay with a significance of 5.6 standard deviations. We also perform an improved measurement of CP asymmetries in B0->J/psiK0 decays and obtain sin2phi_1=+0.642+- 0.031(stat)+-0.017(syst).

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The Belle Collaboration, K. -F. Chen. 2007-01-17. Observation of Time-Dependent CP Violation in B0 -> eta' K0 Decays and Improved Measurements of CP Asymmetries in B0 -> phiK0, KsKsKs and B0 -> J/psi K0 Decays. https://doi.org/10.1103/physrevlett.98.031802

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