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1996 Fiscal Year Final Research Report Summary

Study of CP Violation in the Neutral Kaon System

Research Project

Project/Area Number 07044088
Research Category

Grant-in-Aid for international Scientific Research

Allocation TypeSingle-year Grants
SectionJoint Research
Research InstitutionOsaka University

Principal Investigator

YAMANAKA Taku  Graduate School of Science, Osaka University, 大学院・理学研究科, 助教授 (20243157)

Co-Investigator(Kenkyū-buntansha) ARISAKA Katsushi  Department of Physics, University of California, Los Angeles, ロサンゼルス校・物理学科, 助教授
TSCHIRHART Bob  Department of Physics, Fermi National Accelerator Laboratory, 物理部, 研究員
WINSTEIN Bruce  Department of Physics, University of Chicago, 物理学科, 教授
SADAMOTO Masayoshi  Graduate School of Science, Osaka University, 大学院・理学研究科, 学振特別研究員
HANAGAKI Kazunori  Graduate School of Science, Osaka University, 大学院・理学研究科, 学振特別研究員
HARA Takanori  Graduate School of Science, Osaka University, 大学院・理学研究科, 助手 (70283827)
HAZUMI Masashi  Graduate School of Science, Osaka University, 大学院・理学研究科, 助手 (20263197)
TAKITA Masato  Graduate School of Science, Osaka University, 大学院・理学研究科, 助手 (20202161)
NAGASHIMA Yorikiyo  Graduate School of Science, Osaka University, 大学院・理学研究科, 教授 (90044768)
Project Period (FY) 1995 – 1996
Keywordsweak interaction / CP violation / symmetry breaking / neutral K meson / rare decay / CsI calorimeter / data acquisition system / silicon strip detector
Research Abstract

The purpose of this project is to study the CP violation in the neutral kaon system from two fronts. One is to measure the double ratio of branching ratios of K_L, K_S*pi^0pi^0, and pi^+pi^- with a high precision (KTeV E832). The deviation of this ratio from unity is a proof of CP violation in the weak decay itself (direct CP violation). The other is to search for rare K_L decays where the effect of direct CP violation is dominant (KTeV E799).
We have prepared the new experiments at Fermi National Accelerator Laboratory at U.S.A.. In particular, we were reponsible for the phototubes for the CsI electromagnetic calorimeter, fast data acquisition system, and a special photon veto counter.
The experiment received the first neutral beam at the end of August 1995, and it was confirmed that the beam was clean as designed.
We took data for E832 for 2 months in 1996, and started taking data for E799 from mid-January, 1997. With a couple of switchovers, we plan to take data till September, 1997. We expect to start having preliminary results sometime late 1997.
We have also developed new silicon strip detectors for the B-factory experiment. After optimization with computer simulation, development of test system, and testing various prototypes, we have decided the final design. The mass production will start soon.

  • Research Products

    (8 results)

All Other

All Publications (8 results)

  • [Publications] B.Schwingenheuer,et al.: "CPT Tests in the Neutral Kaon System" Phys.Rev.Lett.74. 4376-4379 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] M.B.Spencer,et al.: "Measurement of the Branching Ratio and Form-Factor of K_L→μ^+μ^-γ" Phys.Rev.Lett.74. 3323-3326 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] J.N.Matthews,et al.: "New Measurement of the CP-Violation Parameter η+-γ" Phys.Rev.Lett.75. 2803-2807 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] P.Gu,et al.: "First Evidence for the Decay K_L→eeμμ" Phys.Rev.Lett.76. 4312-4315 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] B.Schwingenheuer, et al.: "CPT Tests in the Neutral Kaon System" Phys.Rev.Lett.74. 4376-4379 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] M.B.Spencer, et al.: "Measurement of the Branching Ratio and Form Factor of K_L*mu^+mu^-gamma" Phys.Rev.Let.74. 3323-3326 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] J.N.Matthews, et al.: "New Measurement of the CP-Violation Parameter eta+-_<gamma>" Phys.Rev.Lett.75. 2803-2807 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] P.Gu, et al.: "First Evidence for the Decay K_L*eemumu" Phys.Rev.Lett.76. 4312-4315 (1996)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1999-03-09   Modified: 2017-10-10  

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