Department of Physics, Faculty of Science, University of Tabuk, Tabuk 71451, Kingdom of Saudi Arabia.
SOKENDAI (The Graduate University for Advanced Studies), Hayama 240-0193, Japan.
Phys Rev Lett. 2015 Sep 18;115(12):121604. doi: 10.1103/PhysRevLett.115.121604. Epub 2015 Sep 16.
We report a measurement of the time-dependent CP asymmetry of B[over ¯]^{0}→D_{CP}^{()}h^{0} decays, where the light neutral hadron h^{0} is a π^{0}, η, or ω meson, and the neutral D meson is reconstructed in the CP eigenstates K^{+}K^{-}, K_{S}^{0}π^{0}, or K_{S}^{0}ω. The measurement is performed combining the final data samples collected at the ϒ(4S) resonance by the BABAR and Belle experiments at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6} BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6} BB[over ¯] pairs recorded by the Belle detector. We measure the CP asymmetry parameters -η_{f}S=+0.66±0.10(stat)±0.06(syst) and C=-0.02±0.07(stat)±0.03(syst). These results correspond to the first observation of CP violation in B[over ¯]^{0}→D_{CP}^{()}h^{0} decays. The hypothesis of no mixing-induced CP violation is excluded in these decays at the level of 5.4 standard deviations.
我们报告了对 B[over ¯]^{0}→D_{CP}^{()}h^{0}衰变的时变 CP 不对称性的测量，其中轻中性强子 h^{0}是 π^{0}、η 或 ω 介子，而中性 D 介子在 CP 本征态 K^{+}K^{-}、K_{S}^{0}π^{0}或 K_{S}^{0}ω 中被重建。该测量是由 BABAR 和 Belle 实验在 SLAC 的 PEP-II 和 KEK 的 KEKB 两个不对称能量 B 工厂的 Υ(4S)共振处收集的最终数据样本联合完成的。数据样本包含由 BABAR 探测器记录的 (471±3)×10^{6} BB[over ¯]对和由 Belle 探测器记录的 (772±11)×10^{6} BB[over ¯]对。我们测量了 CP 不对称参数 -η_{f}S=+0.66±0.10(stat)±0.06(syst) 和 C=-0.02±0.07(stat)±0.03(syst)。这些结果对应于 B[over ¯]^{0}→D_{CP}^{()}h^{0}衰变中首次观察到的 CP 破坏。在这些衰变中，混合诱导的 CP 破坏假设被排除在 5.4 个标准差的水平之外。
