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Study of CP-Violating Asymmetries in B0 -> pi+pi- Decays

The Belle Collaboration·K. Abe
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Abstract

We present a measurement of CP-violating asymmetries in B0 -> pi+pi- decays based on a 41.8 fb-1 data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We fully reconstruct one neutral B meson as a B0 -> pi+pi- CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we obtain the CP-violating asymmetry parameters Spipi = -1.21 +0.38/-0.27(stat) +0.16/-0.13(syst) and Apipi = +0.94 +0.25/-0.31(stat) +/- 0.09(syst).

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The Belle Collaboration, K. Abe. 2002-07-03. Study of CP-Violating Asymmetries in B0 -> pi+pi- Decays. https://doi.org/10.1103/physrevlett.89.071801

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