Physics of CP Violation at the Tevatron

Tevatron 的 CP 破坏物理学

• 批准号: 11440072
• 负责人: KIM Shinhong
• 金额: $ 9.09万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440072/
• 关键词: Proton-antiproton collisions; CP violation; B hadrons; TOF counter; Kobayashi-Maskawa theory; Photomultiplier tubes; International collaboration; Bシステム

The CDF collaboration has studied proton-antiproton collisions at a center-of-mass energy of 1.8 TeV, using the Tevatron collider at Fermi National Accelerator Laboratory (Fermilab) in Batavia, USA, since its first collisions observed in 1985. CDF finished its last physics run (Run I) in 1996, and the next run (Run II) is scheduled to begin spring 2001 with an upgraded detector along with a higher luminosity provided by the also upgraded accelerator complex.One of the most important physics topics in Run II will be a detailed study of CP violation phoenomena in the B hadron system. It would provide a test of the Standard Model of elementary particles, including the validity of the Kobayashi-Maskawa theory as the origin of CP violation.The CDF TOF counter will play a crucial role in the study of B hadrons. We have developed and mass-produced the photomultiplier tubes for the TOF counter together with Hamamatsu Photonics. The construction of the TOF counter as a whole has been performed with a close collaboration with researchers from other institutes, including Fermilab and the University of Pennsylbania, USA.The prototype photomultiplier tubes was tested in July 1999 for performance in a 1.4 T magnetic field at the High Energy Accelerator Research Organization, KEK.The mass production started in July 1999, and all of them have been tested in a similar fashion. They have been shipped to Fermilab and installed in the CDF detector. At this moment, the TOF counter is complete except for readout electronics, which will be installed in the coming months.Along with the TOF detector construction, we have been employed in development of event reconstruction programs and physics analyses.

自 1985 年观察到第一次碰撞以来，CDF 合作一直使用美国巴达维亚费米国家加速器实验室 (Fermilab) 的 Tevatron 对撞机研究质心能量为 1.8 TeV 的质子-反质子碰撞。CDF 完成了最后一次碰撞物理运行（运行 I）于 1996 年进行，下一次运行（运行 II）计划于 2001 年春季开始，配备升级的探测器以及更高的Run II 中最重要的物理主题之一将是对 B 强子系统中 CP 破坏现象的详细研究。它将提供对基本粒子标准模型的测试，包括小林-益川理论作为CP破坏起源的有效性。CDF TOF计数器将在B强子的研究中发挥至关重要的作用。我们与Hamamatsu Photonics共同开发并量产了TOF计数器用光电倍增管。 TOF 计数器的整体构建是与费米实验室和美国宾夕法尼亚大学等其他研究所的研究人员密切合作完成的。原型光电倍增管于 1999 年 7 月在 1.4 T 磁场中进行了性能测试。高能加速器研究组织KEK。1999年7月开始批量生产，所有这些都经过了类似的测试。它们已被运送到费米实验室并安装在 CDF 探测器中。目前，除了读出电子设备外，TOF 计数器已完成，读出电子设备将在未来几个月内安装。随着 TOF 探测器的构建，我们还致力于事件重建程序和物理分析的开发。

项目成果

F.Abe et al.: "A Search for B^0_s-B^^-^0_s Oscillations Using the Semileptonic Decay B^0_s→φl^+ Xν"Phys.Rev.Lett.. 82. 3576-3580 (1999)

F.Abe 等人：“使用半轻衰变 B^0_s→φl^+ Xν 搜索 B^0_s-B^^-^0_s 振荡”Phys.Rev.Lett.. 82. 3576-3580 (1999)

F.Abe et al.: "Measurement of the B^0_d-B^^-^0_d Oscillation Frequency and Study of Same Side Tagging of B Mesons in pp^^- Collisions"Phys.Rev.D. 59. 032001 (1999)

F.Abe 等人：“B^0_d-B^^-^0_d 振荡频率的测量和 pp^^- 碰撞中 B 介子同侧标记的研究”Phys.Rev.D。

F.Abe et al.: "A Search for B^0_s-B^^-^0_s Oscillations Using the Semileptonic Decay B^0_s→φl^+Xv"Phys.Rev.Lett.. 82. 3576-3580 (1999)

F.Abe 等人：“使用半轻衰变 B^0_s→φl^+Xv 搜索 B^0_s-B^^-^0_s 振荡”Phys.Rev.Lett.. 82. 3576-3580 (1999)

F.Abe et al.,: "Measurement of B^0B^0 oscillation frequency using l^-D^<*+> pairs and lepton flavor tags"Phys. Rev. D60,. 112004 (1999)

F.Abe 等人：“使用 l^-D^<* > 对和轻子风味标签测量 B^0B^0 振荡频率”Phys。

F.Abe et al.: "Measurement of the B^0-B^^-^0 Oscillation Frequency Using Jet-Charge and Lepton Flavor Tagging in pp^^- Collisions at √<s>=1.8 TeV"Phys.Rev.D. 60. 072003 (1999)

F.Abe 等人：“在 √<s>=1.8 TeV 的 pp^^- 碰撞中使用喷射电荷和轻子风味标记测量 B^0-B^^-^0 振荡频率”Phys.Rev。 D.60.072003 (1999)