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Study of Mixiing-induced CP Violation in the Neutral B Meson System

Research Project

Project/Area Number 09246102
Research Category

Grant-in-Aid for Scientific Research on Priority Areas (A)

Allocation TypeSingle-year Grants
Research InstitutionThe University of Tokyo

Principal Investigator

AIHARA Hiroaki  the University of Tokyo, Graduate School of Science Professor, 大学院・理学系研究科, 教授 (60167773)

Co-Investigator(Kenkyū-buntansha) HARA Takanori  Osaka University, Graduate School of Science Reserch Associate, 大学院・理学研究科, 助手 (70283827)
HAZUMI Masashi  High Energy Accelerator Reserch Organization, Associate Professor, 助教授 (20263197)
TAJIMA Hiroyasu  the University of Tokyo, International Center for Elementary particle Physics, Reserche Associate, 助手 (80222107)
WATANABE Yasushi  Tokyo Institute of Technology, Faculty of Science Professor, 大学院・理工学研究科, 教授 (40126199)
長島 順清  大阪大学, 大学院・理学研究科, 教授 (90044768)
金行 健治  東京工業大学, 大学院・理工学研究科, 助手 (30224629)
Project Period (FY) 1997 – 2000
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥192,600,000 (Direct Cost: ¥192,600,000)
Fiscal Year 2000: ¥35,000,000 (Direct Cost: ¥35,000,000)
Fiscal Year 1999: ¥43,000,000 (Direct Cost: ¥43,000,000)
Fiscal Year 1998: ¥57,000,000 (Direct Cost: ¥57,000,000)
Fiscal Year 1997: ¥57,600,000 (Direct Cost: ¥57,600,000)
KeywordsB Meson / CP violation / B factory / Solid-state detector / 素粒子 / 対称性 / ピクセル検出器 / 小林・益川理論 / 集積回路 / 超対称標準理論 / 位置検出器
Research Abstract

1. Observation of CP violatin in the neutral B meson system : Based on a 29.1 fb^<-1> data sample which contains 31.3 million B-anti B pairs, we have observed CP violation in the neutral B meson system. One neutral B meson is fully reconstructed and the flavor of the accompanying B meson is determined from its decay products. From the symmetry in the distribution of the time intervals between the two B meson decay points, we measure the Standard Model CP violation parameter sin2φ_1=0.99±0.14±0.06. This measurement is made possible by the use of the high-precision silicon vertex detector, which our group constructed and operated. We have also made full use of multi-CPU server constructed with the grant. This observation of CP violation marks the achievement of the first goal.
2. Completion of R&D of the next-generation silicon vertex detector : The second goal of the project was to develop sensors and read-out Ics for the next-generation vertex detector. We have successfully developed both a new-type of silicon strip sensors and a radiation-hard Ics for readout. Taking advantage of our R&D results, we have finished the design of the detector and started construction of the final device.

Report

(5 results)
  • 2001 Final Research Report Summary
  • 2000 Annual Research Report
  • 1999 Annual Research Report
  • 1998 Annual Research Report
  • 1997 Annual Research Report
  • Research Products

    (16 results)

All Other

All Publications (16 results)

  • [Publications] K.Abe et all.: "Observation of Large CP Violation in the Neutral B Meson System"Physical Review Letters. 87. 091802 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] M.Yokoyama et al.: "Radiation Hardness of VA1 Fabricated with Submicron Process Technology"IEEE Trans.Nucl.Sci.. 48. 440 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] R.Abe et al.: "Performance of the Belle Silicon Vertex Detector"IEEE Trans.Nucl.Sci.. 48. 997 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] H.Aihara: "The BELLE silicon vertex detector"Nucl.Instr.Meth.. A46. 268 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] K. Abe et al.: "Obervation of Large CP Violation in the Neutral B Meson System"Physical Review Letters. 87. 091802 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] M. Yokoyama et al.: "Radiation Hardness of VA1 fabricated with Submicron Process Technology"IEEE Trans. Nucl. Sci.. 48. 440 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] R. Abe et al.: "Performance of the Belle Silicon Vertex Detector"IEEE Trans. Nucl. Sci.. 48. 997 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] H. Aihara: "The BELLE Silicon vertex detector"Nucl. Instr. Meth.. A 46. 268 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] H.Aihara 他: "The BELLE Silicon Vertex Detector"Nucl.Instrum.Methods. A453. 71-77 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] H.Aihara: "Measurment of CP Violation in BD Meson Decays with Belle"Proceedings of 30th International Conference on High Energy Physics. 1. 50-61 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] H.Aihara 他: "Measurment of the W boson mass"Physical Review Letters. D58. 1-37 (1998)

    • Related Report
      2000 Annual Research Report
  • [Publications] H. Aihara: "Prospects with the BELLE Detector"Proceeding of the XI Symposium on Hadron Collider Physics. 1. 130-136 (1997)

    • Related Report
      1999 Annual Research Report
  • [Publications] T.E.Browder et al.: "Pixel Detectors For B-Factories" Proceedings of International Pixel Detector Workshop. 1. 42-48 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] H.Aihara et al.: "Performance of a Double Sided Silicon Microstrip Detector with a Wide Pitch N Side Readout Using a Field Plate and a Multip-Stop Structure" IEEE Trans.Nucl.Sci.44. 622-628 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] J.Tanaka: "KEK BELLE NOTE No.193 Kfitter Usage ver 2.0" High Energy Accelerator Research Organization, 20 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] M.Yokoyama: "KEK BELLE NOTE No.196 Measurement of Radiation Effects on VA1 Chip" High Energy Accelerator Research Organization, 4 (1997)

    • Related Report
      1997 Annual Research Report

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Published: 1997-04-01   Modified: 2016-04-21  

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