• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

STUDY OF MEDIUM EFFECT IN HADRON MANY-BODY SYSTEM AT DEEP INSIDE OF NUCLEI

Research Project

Project/Area Number 11694080
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 InstitutionKYUSHU UNIVERSITY (2000-2001)
Osaka University (1999)

Principal Investigator

NORO Tetsuo  Faculty of Science, Kyushu University Prof., 大学院・理学研究院, 教授 (30164750)

Co-Investigator(Kenkyū-buntansha) WAKASA Tomotsugu  Res. C. for Nucl. Phys, Osaka Univ., Res. Ass., 核物理研究センター, 助手 (10311771)
SAKAGUCHI Harutaka  Graduate School of Science, Kyoto Univ. Ass. Prof., 大学院・理学研究科, 助教授 (30025465)
HATANAKA Kichiji  Res. C. for Nucl. Phys, Osaka Univ., Prof., 核物理研究センター, 教授 (50144530)
Project Period (FY) 1999 – 2000
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
KeywordsQUASI-FREE SCATTERING / MEDIUM EFFECT / CHIRAL SYSMMETRY / RELATTVISTIC EFFECT / NUCLEAR REACTION / HADRON / INTERNATIONAL COLLABORATION / RUSSIA / 偏極 / 磁気スペクトロメータ / 核子準弾性散乱 / 核内ハドロン / 偏極分解能 / 誘起偏極 / 核相関 / (p,2p)反応
Research Abstract

It is predicted theoretically in the framework of QCD and QHD (quantum hadrodynamics) that hadron masses in nuclear field is modified as a result of partial restoration of chiral symmetry or as a representation of the lower-component enhancement of the nucleon Dirac spinor in a strong scalar field. At several hundred MeV of incident energies, the interactions between nucleons are well described by theoretical models based on the meson exchange forces. Thus it is expected that those mass modifications cause modification of NN interactions which is detectable in some nuclear reactions. And the nucleon quasifree scattering is expectable one of such reactions, since this reaction can be regarded as a NN scattering in nuclear field and suited for studying the NN interaction in nuclear field. It is first found by TRIUMP people that the analyzing power for a (p,2p) reaction leading to a 1s1/2-hole state shows distinct reduction from the free p-p scattering values. At RCNP, this reduction is s … More hown to be monotonically density-dependent, which suggests the existence of some medium effect. Such reduction has also been observed at 1 GeV for a 7Li target.
In the present study, we have measured polarization for the (p,2p) reactions at 1 GeV at PNPI. The two-arm magnetic spectrometer system is employed for the measurement and a focal plane polarimeter which consists of a carbon analyzer and MWPC's is used on each spectrometer in order to measure the polarization of outgoing protons. We found that the data show strong density-dependent reductions from calculated values using the free NN interaction. This result is consistent with the 392 MeV result. From the fact that the consistent results are obtained at different incident energies and from several evidences found at 392 MeV, it is concluded that the most part of the reductions are not nuclear reaction originated, such as by a multi-step effect. We have estimated the effect of nucleon-mass modification in a Schodenger-equivalent form of the relativistic DWIA and found that about a half of the reduction is explained by this model, which is again consistent with previous 392 MeV result. It is already known that a nonrelativistic calculation with the Pauli blocking effect does not reproduce the observed reduction and the present result, in conjunction with the 392 MeV results, supports the idea that the reduction is a manifestation of a medium effect in the hadron level. Less

Report

(3 results)
  • 2001 Final Research Report Summary
  • 2000 Annual Research Report
  • 1999 Annual Research Report
  • Research Products

    (11 results)

All Other

All Publications (11 results)

  • [Publications] T.Noro: "Nuclear Medium Effect Studied by Nucleon Quasifree Scattering ---A trial for study of nucleon and meson mass in nuclei---"Proceedings of 14th International Spin Physics Symposium (AIP Proceedings). 570. 228-237 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T.Noro, et al.: "Spin Observables in Quasifree Scattering --Study of Medium Effects on the NN interactions and Hadrons in Nuclei--"Proceedings of the RCNP-TMU Sympo. on Spins in Nuclear and Hadron Reactions (World Scientific). 23-28 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T.Noro, et al.: "In-medium NN Interaction and Nucleon and Meson Masses Studied with Nucleon Knockout Reactions"Nuclear Physics. A663&664. 517c-520c (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T.Noro, et al.: "Study of Nuclear Medium Effect on Hadrons in Nuclei by Nucleon Quasifree Scattering"Proceedings of International Nuclear Physics Conference (AIP Proceedings). (in press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T. Noro et al.: "Nuclear Medium Effect Studied by Nucleon Quasifree Scattering --- A trial for study of nucleon and meson mass in nuclei ---"AIP Proceedings. 570. 228-237 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T. Noro et al.: "Spin Observables in Quasifree Scattering -- Study of Medium Effects on the NN interactions and Hadrons in Nuclei --"Proceedings of the RCNP-TMU Sympo. on Spins in Nuclear and Hadron Reactions (World Scientific). 23-28 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T. Noro et al.: "In-medium NN Interaction and Nucleon and Meson Masses Studied with Nucleon Knockout Reactions"Nuclear Physics. A663&664. 517c-520c (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T. Noro et al.: "Study of Nuclear Medium Effect on Hadrons in Nuclei by Nucleon Quasifree Scattering"Proceedings of International Nuclear Physics Conference. (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] T.Noro: "Nuclear Medium Effect Studied by Nucleon Quasifree Scattering-A trial for study of nucleon and meson mass in unclei-"Proceedings of 14th International Spin Symposium . (AIP Proceedings in press).

    • Related Report
      2000 Annual Research Report
  • [Publications] T.Noro et al.: "NN Interaction and Nucleon and Meson Masses Studied with Nucleon Knockout Reactions"Proc.of PANIC99(1999,Uppsala). (to be published in Nucl.Phys.).

    • Related Report
      1999 Annual Research Report
  • [Publications] T.Noro et al.: "Spin Observables in Quasifree scattering"Proc.of RCNP-TMU Sympo.on Spins in Nucleear and Hadron Reactions(1999,Tokyo).

    • Related Report
      1999 Annual Research Report

URL: 

Published: 1999-04-01   Modified: 2016-04-21  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi