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Study of Asymmetric Weak decay of Polarized Hypernuclei Produced by(K^-, pi^0)

Research Project

Project/Area Number 04452027
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 核・宇宙線・素粒子
Research InstitutionOsaka University

Principal Investigator

KISHIMOTO Tadafumi  Dept.of Physics Osaka Univ.Assoc.Prof., 理学部, 助教授 (90134808)

Co-Investigator(Kenkyū-buntansha) NAKANO Takashi  , 助手 (80212091)
NOUMI Hiroyuki  Nat.Lab.for High Energy Phys.Research Assoc., 助手 (10222192)
OHSUMI Hideaki  Dept.of Physics Osaka Univ.Research Assoc., 理学部, 助手 (70176882)
EJIRI Hiroyasu  Dept.of Physics Osaka Univ.Prof., 理学部, 教授 (80013374)
Project Period (FY) 1991 – 1993
Project Status Completed (Fiscal Year 1993)
Budget Amount *help
¥7,300,000 (Direct Cost: ¥7,300,000)
Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1992: ¥6,600,000 (Direct Cost: ¥6,600,000)
KeywordsWeak Decay / Asymmetry / Polarization / Hypernuclei / Nonmesonic Decay / (K^-, pi) Reaction / (pi^+, K^+) Reaction
Research Abstract

The purpose of this research project is to study strangeness changing weak hyperon nucleon interaction by observing asymmetric angular distibution of the nonmesonic weak decay of polarized hypernuclei. There are(pi^+, K^+)and n(K^-, pi)reactions to produce polarized hypernuclei. We showed that the n(K^-, pi)reaction introduces larger polarization to hypernuclei^1 and we planned to use it in the beginning of this project.
Meanwhile new beam line and superconducting spectrometer are constructed at KEK.They made the study of hypernuclei by using the(pi^+, K^+)reaction quite effective in practice, although the use of n(K^-, pi)reaction is still good in principle. We proposed an experiment "Study of asymmetric nonmesonic weak decay of polarized LAMBDA^^5He hypernuclei" to the KEK proton synchrotron which uses(pi^+, K^+)reaction. It was approved(PS-E278)in 1992 and successfully completed at the end of 1993.
The experiment is expected to give new information on the strangeness changing weak hyperon nucleon interaction. Futhermore since quality of data exceeds far the previous study, we should be able to gives new information on production, structure and weak decay of LAMBDA^^5He hypernuclei. We will spend another year to extract results out of them. Meanwhile we were carring out study of related physics and following results were obtained.
1) Polarization of LAMBDA hyperons in the quasifree process (ref.3,5)
2) Separation of quasifree LAMBDA production and production of hypernuclei (ref.6)
3) Polarization of hypernuclei produced by the (pi^+, K^+) reaction and asymmetry nonmesonic decay (ref.2,4,7)
4) Hyperon and nucleon weak interaction and weak nonmesonic decay (ref.8,9)
5) Strong and weak hyperon nucleon interaction in nuclei (ref.8)

Report

(3 results)
  • 1993 Annual Research Report   Final Research Report Summary
  • 1992 Annual Research Report
  • Research Products

    (27 results)

All Other

All Publications (27 results)

  • [Publications] T.Kishimoto S.Ajimura: "Polarization of Λ Produced by the Quasifree(π^+K^+)Reaction" Prog.Theo.Phys. 1021-1026 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] L.Lee,D.R.Gill et al: "An Active Segmented Target for Studying Hypernuclear Productions" Nucl.Inst.Meth.A327. 287-295 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] A.Higashi,S.Ajimura et al: "Polarization and Decays of Λ hypernuclei Produced by(π^+K^+)reaction" Proc.of the Japan-China Joint Nuclear Physics Symp.“Receyt Topics on Nuclear Physics"Nov.30-Dec.3. 163-168 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] T.Kishimoto: "Polarization and Weak Decays ΛN Hypernuclei" Proc.of Int.Nat.Workshop on“future Directions in Particle and Nuclear Physics at Multi-Gev Hadron Facilities"March.4-6. 368-373 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] T.Kishimoto: "Weak Decay and Strong ΛN Interaction in a Nucleus" Proc.of XIII PANIC Conference Jul.3. (in press). (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] H.Noumi,S.Ajimura et al: "Polarization and Weak Decay of Polarized Λ Hypernuclei Produced by the(π^+,K^+)Reaction an ^<12>C" SOCIETA ITALIANA DIFISICA,“Flavour and Spin in Hadronic and Electromagnetic Interactions"Torino,21-23 Sept.Conf.Proc 39. 123-141 (1993)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] T.Kishimoto, H.Ejiri, and H.Bando: "Production of Polarized Hypernuclei in the (K^-, p^i) Reaction in GeV Region" Phys.Lett.B 232. 24 (1989)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] S.Ajimura, H.Ejiri, T.Fukuda, D.R.Gill, A.Higashi, O.Hashimoto, G.Inoue, Y.Iseki, K.Kimura, T.Kishimoto, L.Lee, K.Maeda, F.Nakamura, H.Noumi, H.Nomachi, A.Ohkusu, H.Ohsumi, A.Olin, T.Shibata, and S.Yen: "Polarization and Weak Decay of LAMBDA Hypernuclei Produced by the (pi^+, K^+) Reaction on C^<12>N" Phys.Lett.B 282. 293 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] S.Ajimura, H.Ejiri, A.Higashi, G.Inoue, Y.Iseki, T.Kishimoto, F.Nakamura, H.Noumi, H.Ohsumi, H.Sano, D.R.Gill, L.Lee, A.Olin, S.Yen, T.Fukuda, O.Hashimoto, T.Shibata, M.Nomachi, K.Maeda and K.Kimura: "Polarization of LAMBDA Hyperons Produced by the quasifree (pi^+, K^+) Reaction on C^<12>N" Phys.Rev.Lett.Vol.68. 2137 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] S.Ajimura, H.Ejiri, A.Higashi, G.Inoue, Y.Iseki, T.Kishimoto, F.Nakamura, H.Noumi, H.Ohsumi, H.Sano, D.R.Gill, L.Lee, A.Olin, S.Yen, T.Fukuda, O.Hashimoto, T.Shibata, M.Nomachi, K.Maeda and K.kimura: "Polarization and Weak Decay of LAMBDA hypernuclei Produced by the C^<12>N(pi^+, K^+) reaction." Nucl.Phys.A547(1992)47cProc.Int.Conf.on "Hypernuclear and Strange Particle Physics" Shimoda. (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] T.Kishimoto, and S.Ajimura: "Polarization of LAMBDA Produced by the Quasifree (pi^+, K^+) Reaction" Prog.Theo.Phys.1021 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] L.Lee, D.R.Gill, A.Olin, S.Yen, S.Ajimura, H.Ejiri, A.Higashi, G.Inoue, T.Kishimoto, F.Nakamura, H.Noumi, T.Fukuda, O.Hashimoto, and T.Shibata: "An Active Segmented Target for Studing Hypernuclear Production" Nucl.Inst.Meth.A327. 287 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] A.Higashi, S.Ajimura, H.Ejiri, T.Fukuda, D.R.Gill, O.Hashimoto, G.Inoue, Y.Iseki, K.Kimura, T.Kishimoto, L.Lee, K.Maeda, F.Nakamura, M.Nomachi, H.Noumi, H.Ohsumi, A.Okusu, A.Olin, H.Sano, T.Shibata, and S.Yen: "Polarization and Decays of LAMBDA hypernuclei Produced by (pi^+, K^+) reaction" Proc.of the Japan-China Joint Nuclear Physics Symposium "Recent Topics on Nuclear Physics". 163 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] T.Kishimoto: "Polarization and Weak Decay LAMBDAN Hypernuclei" Proc.of Int.Nat.Workshop on "Future Directions in Particle and Nuclear Physics at Multi-Gev Hadron Facilities" BNL NY. 360 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] H.Noumi, S.Ajimura, H.Ejiri, T.Fukuda, D.R.Gill, O.Hashimoto, A.Higashi, G.Inoue, Y.Iseki, K.Kimura, T.Kishimoto, L.Lee, K.Maeda, F.Nakamura, M.Nomachi, H.Ohsumi, A.Olin, H.Sano, T.Shibata, and S.Yen: "Polarization and Weak Decay of Polarized LAMBDA Hypernuclei Produced by the (pi^+, K^+) Reaction on C^<12>N" SOCIETA ITALIANA DI FISICA, Conference Proceding Vol.39 "Flavor and Spin in Hadronic and Electromagnetic Interactions" Torino. 123 (1993)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1993 Final Research Report Summary
  • [Publications] T.Kishimoto S.Ajimura: "Polarization of Λ Produced by the Quasifree(π^+,K^+)Reaction" Prog.Theo.Phys.1021 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] L.Lee,D.R.Gill et al: "An Active Segmented Target for Studying Hypernuclear Production" Nucl.Inst.Meth.A327. 287 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] A.Higashi,S.Ajimura et al: "Polarization and Decays of Λ hypernuclei Produced by(π^+,K^+)reaction" Proc.of the Japan-China Joint Nuclear Physics Symp.“Recent Topics on Nuclear Physics"Nov.30-Dec.3. 163 (1992)

    • Related Report
      1993 Annual Research Report
  • [Publications] T.Kishimoto: "Polarization and Weak Decays ΛN Hypernucleicilities"March4-6" Proc.of Int.Nat.Workshop on“Future Directions in Particle and Nuclear Physics at Multi-Gev Hadron Fa. (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] T.Kishimoto: "Weak Decay and Strong ΛN Interaction in a Nucleus" Proc.of XIII PANIC Conference Jul.3. in Press. (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] H.Noumi,S.Ajimura et al: "Polarization and Weak Decay of Polarized Λ Hypernuclei Produced by the (π^+,K^+)Reaction on ^<12>C3 Sept." SOCIETA ITALIANA DIFISICA,“Flavour and Spin in Hadronic and Electromagnetic Interactions"Torino,21-2. Conf.Proc.39. 123 (1993)

    • Related Report
      1993 Annual Research Report
  • [Publications] S.Ajimura et al.,: "Polarization of Λ Hyperons Produced by the Quasifree (π^+,K^+)Reaction on ^<12>C" Physical Review Letters. 68. 2137-2140 (1992)

    • Related Report
      1992 Annual Research Report
  • [Publications] T.Kishimoto and S.Ajimura: "Polarization of Λ Produced by the Quasifree (π^+,K^+)Reaction" Progress Theretical Physics.

    • Related Report
      1992 Annual Research Report
  • [Publications] S.Ajimura et al.,: "Polarization and Weak Decay of Λ Hypernuclei Produced by the (π^+,K^+)Reaction on ^<12>C" Physics Letters. B282. 293-298 (1992)

    • Related Report
      1992 Annual Research Report
  • [Publications] T.Motoba et al.,: "Spin Excitation in (K^-,π^<°->)Reactions" XIII International Conference on Particle and Nuclei (PANIC) Contributed Papers.

    • Related Report
      1992 Annual Research Report
  • [Publications] T.Kishimoto et al.,: "Study of Parity Violating Weak Λ Huclear Interation in ^5_^He" XIII International Conference on Particle and Nuclei (PANIC) Contributed Papers.

    • Related Report
      1992 Annual Research Report
  • [Publications] T.Kishimoto et al.,: "Asymmetry Parameter of Mesonic decay of ^5_^He" XIII International Conference on Particle and Nuclei (PANIC) Contributed Papers.

    • Related Report
      1992 Annual Research Report

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Published: 1992-04-01   Modified: 2016-04-21  

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