标题： 搜索B0_s与反B0_s振荡以及利用包含重建顶点的事件测量B0_d与反B0_d振荡 显示英文标题

标题： Search for B0_s - anti-B0_s oscillations and a measurement of B0_d - anti-B0_d oscillations using events with an inclusively reconstructed vertex

摘要： 中性B介子在B0_s - 反-B0_s和B0_d - 反-B0_d系统中的振荡通过DELPHI探测器在1992年至2000年间记录的约400万个强子Z衰变样本进行了研究。 移除了具有高横向动量轻子的事件，并选择了一个包含77万事件的样本，这些事件具有包容性重建的顶点。 在B0_d - 反-B0_d系统中两个物理状态之间的质量差被测量为： \Delta m_d = (0.531 +/- 0.025 (统计) +/- 0.007 (系统)) ps^{-1}。 还获得了这些状态宽度差的以下限制： |\Delta \Gamma _{B_d}| / \Gamma _{B_d} < 0.18 在95%置信度下。 由于未发现B0_s - anti-B0_s振荡的证据，给出了两个物理态质量差的限制： \Delta m_s > 5.0 ps^{-1} 在95%置信度下。 此分析的相应灵敏度等于6.6 ps^{-1}。 显示英文摘要

摘要： Neutral B meson oscillations in the B0_s - anti-B0_s and B0_d - anti-B0_d systems were studied using a sample of about 4.0 million hadronic Z decays recorded by the DELPHI detector between 1992 and 2000. Events with a high transverse momentum lepton were removed and a sample of 770 k events with an inclusively reconstructed vertex was selected. The mass difference between the two physical states in the B0_d - anti-B0_d system was measured to be: \Delta m_d = (0.531 +/- 0.025 (stat.) +/- 0.007 (syst.)) ps^{-1}. The following limit on the width difference of these states was also obtained: |\Delta\Gamma_{B_d}| / \Gamma_{B_d} < 0.18 at 95% CL. As no evidence for B0_s - anti-B0_s oscillations was found, a limit on the mass difference of the two physical states was given: \Delta m_s > 5.0 ps^{-1} at 95% CL. The corresponding sensitivity of this analysis is equal to 6.6 ps^{-1}.