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A Test of QCD at Low Energy by measuring a Lifetime of Di-mesonic Atoms

Research Project

Project/Area Number 12440069
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field 素粒子・核・宇宙線
Research InstitutionKyoto Sangyo University

Principal Investigator

OKADA Kenji  OKADA,Kenji, 理学部, 教授 (90093385)

Co-Investigator(Kenkyū-buntansha) YOSHIMURA Yoshio  KEK, Institute of particle and nuclear studies, emeritus professor, 素粒子原子核研究所, 名誉教授 (50013397)
KOBAYASHI Masaaki  KEK, Institute of particle and nuclear studies, professor, 素粒子原子核研究所, 教授 (40013388)
TAKEUTCHI Fujio  TAKEUTCHI,Fujio, 理学部, 教授 (40121537)
CHIBA Masami  Tokyo Metropolitan University, Graduate school of Science, Research assistance, 大学院・理学研究科, 助手 (60128577)
牧 孝  産業医科大学, 環境管理学部, 教授 (40037198)
Project Period (FY) 2000 – 2003
Project Status Completed (Fiscal Year 2003)
Budget Amount *help
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 2003: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2002: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2000: ¥3,300,000 (Direct Cost: ¥3,300,000)
KeywordsQCD / Hadronic Atom / Scintillating fiber / Chiral Perturbation / Topological Trigger / ππ scattering length / Atom / PSPM / 中間子原子 / シンチレーティングファイバ / 位置検出型光電子増倍管 / ハイドロニック原子 / DIRAC / トポロジロルートリガー
Research Abstract

The DIRAC experiment (PS2 12) aims to measure the lifetime of π+π-atoms using 20GeV proton beam provided by the CERN PS. The precise measurement of the lifetime enables to determine a s-wave pion-pion scattering length in a model independent way. The ππ scattering length have been calculated by means of Chiral perturbation theory with a precision of 5% at the starting stage of the DIRAC experiment. Now the precision of the calculation is better than 2.5%. The results are based on the assumption of a spontaneous chiral symmetry breaking due to a strong quark condensation. Therefore, a precise comparison of the theoretical value with the experimental one provides an opportunity to verify the current understanding of chiral symmetry breaking in QCD and to check the magnitude of the quark condensation.
Japan group has developed a topological trigger device consisting of scifi-hodos, a peak sensing circuit and a trigger logic circuit. They can select out on line a real π+π-pair due to π+π-atom breaking-up from a huge amount of background events.
The expected statistical accuracy of |aO-a2| scattering length obtained in the DIRAC experiment will be about 6% at the present stage. Although this value was a goal at the beginning, now it is still 3 times larger than the corresponding theoretical accuracy. An extension of this experiment applied for the LOI of the J-PARC is adopted

Report

(5 results)
  • 2003 Annual Research Report   Final Research Report Summary
  • 2002 Annual Research Report
  • 2001 Annual Research Report
  • 2000 Annual Research Report
  • Research Products

    (18 results)

All Other

All Publications (18 results)

  • [Publications] The DIRAC collaboration: "DIRAC : A High Resolution Spectrometer for Pionium Detection."Nucl.Inst.Meth.in Physics Research A. A515. 467-496 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] A.Afanasyev: "The multilevel trigger system of the DIRAC experiment."Nucl.Inst.Meth.in Physics Research A. A491. 376-386 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] M.Kobayashi: "Silicon strip detectors as a real-time, fast, medium-segmented hodoscope."Nucl.Inst.Meth.in Physics Research A. A487. 353-364 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] F.Gomez: "DIRAC experiment."Nucl.Phys.Proc.Suppl.B. B96. 259-266 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] P.Gianotti: "Test of chiral perturbation theory with DIRAC at CERN"Acta Phys.Polon.B. B31. 2571-2579 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] A.Gorin: "Peak-sensing discriminator for multichannel detectors with cross-talk."Nucl.Inst.Meth.in Physics Research A. A452. 280-288 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] The DIRAC collaboration: "DIRAC : A High Resolution Spectrometer for Pionium Detection."Nucl.Inst.Meth.in Physics Research. A515. 467-496 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] A.Afanasyev et al.: "The multilevel trigger system of the DIRAC experiment."Nucl.Inst.Meth.in Physics Research. A491. 376-386 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] M.Kobayashi et al.: "Silicon strip detectors as a real-time, fast, medium-segmented hodoscope."Nucl.Inst.Meth.in Physics Research. A487. 353-364 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] F.Goinez et al.: "DIRAC experiment."Nocl.Phys.Proc.Suppl.. B96. 259-266 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] P.Gianotti et al.: "Test of chiral perturbation theory with DIRAC at CERN"Acta Phys.Polon.. B31. 2571-2579 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] A.Gorin et al.: "Peak-sensing discriminator for multichannel detectors with cross-talk."Nucl.Inst.Meth.in Physics Research. A452. 280-288 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2003 Final Research Report Summary
  • [Publications] DIRAC collaboration: "DIRAC : A High Resolution Spectrometer for Pionium Detection."Nuclear Instruments and Methods in Physics Research A. A515. 467-496 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] L.Afanasyev et al.: "The multilevel trigger system of the DIRAC experiment"Nucl. Inst. and Meth. in Phys. Res.. A491. 376-389 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] A.M.Rodriguez et al.: "The DIRAC experiment at CERN : current status and future perspectives"PiN Newslett. 16. 352-354 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Kobayashi et al.: "Silicon strip detector as a real-time, fast, medium-segmented hodoscope"Nucl. Inst. And Meth. in Phys. Res.. A487. 353-364 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Kobayashi et al.: "Silicon strip detectors as a real-time, fast, medium-segmented hodoscope"Nuclear Instrument and Method Phys. Res. A. (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] A,Gorin et al.: "Peak-sensing discriminator for multichannel detectors with cross-talk."Nucl,Inst,Methods in Phy,Res.A. 452. 280-288 (2000)

    • Related Report
      2000 Annual Research Report

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Published: 2000-04-01   Modified: 2016-04-21  

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