A large signal for CP violation in B-meson decays has been observed by the Belle collaboration. This mixing-induced CP violation is measured by reconstructing one B meson in a CP eigenstate (J/ψK_S, ψ(2S)K_S, X_(c1)K_S, η_cK_S, J/ψK_L, and J/ψK~(*0)(K_Sπ_0)) while tagging the flavor of the partner B meson. From a fit to the time-dependent asymmetry we find sin 2Φ~1 = 0.99 +- 0.14 +- 0.06, where the first error is statistical and the second systematical.
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