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Study of eta and omega meson mass shift in nuclei using recoil-less reactions

Research Project

Project/Area Number 11440073
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 InstitutionThe University of Tokyo

Principal Investigator

HAYANO Ryugo  Graduate School of Science, The University of Tokyo, Professor, 大学院・理学系研究科, 教授 (30126148)

Co-Investigator(Kenkyū-buntansha) HIRENZAKI Satoru  Nara women's University, Department of Physics, Associate Professor, 理学部, 助教授 (60283925)
Project Period (FY) 1999 – 2001
Project Status Completed (Fiscal Year 2001)
Budget Amount *help
¥12,100,000 (Direct Cost: ¥12,100,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2000: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥7,200,000 (Direct Cost: ¥7,200,000)
KeywordsQuantum Chromo Dynamics / pi meson / eta meson / omega meson / effective mass / GSI / Cherenkov detector / Chiral symmetry / 中間子
Research Abstract

Whether or not the masses of hadrons are modified in nuclear matter is one of the central problems of modern nuclear physics. In order to study this problem, there are many on-going efforts world wide to produce mesons in nuclei via high-energy heavy ion collisions, and to reconstruct the meson masses from the dilepton decays. The present study is based on an entirely different approach of "recoilless" production of mesons in nuclei, and of determination of their masses from the analyzes of Q-value spectra.
We analyzed the deeply-bound pionic atom data (π^- meson bound in the 1s level of pionic ^<205>Pb atom), and unambiguously showed that the pi^- mass in lead nucleus is heavier by about 26 MeV as compared with its vacuum value. This result has been published in Physical Review Letters. In order to further study the contribution of the neutron/proton distribution difference on the meson mass, we performed another experiment using a series of Sn isotopes (different neutron numbers). The data are being analyzed, but preliminary results already show that the expected isotope effects are clearly seen.
Our proposal to study eta (η) and omega (ω) meson mass shift in nuclei had already been approved at GSI laboratory in Darmstadt, Germany, but the beam time was deferred due to the fact that we chose to run the Sn experiment first. Meanwhile, we constructed a special focal-plane detector, sensitive to ^3He (our signal) but insensitive to protons (our background) based on the Cherenkov detection. The detector was tested at KEK, and was shown to perform as expected.

Report

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

    (19 results)

All Other

All Publications (19 results)

  • [Publications] S.Hirenzaki, E.Oset: "Deeply bound pionic atoms from the (γ,p) reaction in nuclei"Physics Letters B. 527. 69-72 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] A.Ramos, S.Hirenzaki, et al.: "Antikaons in nuclei and dense nuclear matter"Nuclear Physics A. 691. 258-267 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Y.Umemoto, S.Hirenzaki, K.Kume, H.Toki, I.Tahihata: "Deeply bound pionic atoms on -unstable nuclei"Nuclear Physics A. 679. 549-562 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] H.Geissel, H.Gilg, A.Gillitzer, R.S.Hayano et al.: "Deeply Bound 1s and 2p Pionic States in ^<205>Pb and Determination of the s-Wave Part of the Pion-Nucleus Interaction"Physical Review Lettersに掲載決定済み(受理番号LD8637). 1-4 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] S. Hirenzaki and E. Oset: "Deeply bound pionic atoms from the (γ,p) reaction in nuclei"Physics Letters B. 527. 69-72 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] A. Ramos, S. Hirenzaki, et al.: "Antikaons in nuclei and dense nuclear matter"Nuclear Physics A. 691. 258-267 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] Y. Umemoto, S. Hirenzaki, K. Kume, H. Toki and I. Tahihata: "Deeply bound pionic atoms on -unstaoie nuclei"Nuclear Physics A. 679. 549-562 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] H. Geissel, H. Gilg, A. Gillitzer, R.S. Hayano et al.: "Deeply Bound 1s and 2p Pionic States in ^<205>Pb and Determination of the s-Wave Part of the Pion-Nucleus Interaction"Physical Review Letters. (in press). (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2001 Final Research Report Summary
  • [Publications] S.Hirenzaki, E.Osct: "Deeply bound pionic atoms from the(γ,p)reaction in nuclei"Physics Letters B. 527. 69-72 (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] A.Ramos, S.Hirenzaki, et al.: "Antikaons in nuclei and dense nuclear matter"Nuclear Physics A. 691. 258-267 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] Y.Umemoto, S.Hirenzaki, K.Kume, H.Toki, I.Tahihata: "Deeply Bound pionic atoms on-unstable nuclei"Nuclear Physics A. 679. 549-562 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] H.Geissel, H.Gilg, A.Gillitzer, R.S.Hayano, et al.: "Deeply Bound 1s and 2p Pionic States in ^<205>Pb and Determination of the s-Wave Part of the Pion-Nucleus Interaction"Physical Review Letters. (掲載決定済み(受理番号LD8637)). 1-4 (2002)

    • Related Report
      2001 Annual Research Report
  • [Publications] Gilg G,Hayano RS et al.: "Deeply bound pi-states in Pb-207 formed in the Pb-208(d.He-3) reaction.I.Experimental method and results"Physical Review C. C62. 25201-11 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Itahashi K,Hayano RS et al: "Deeply bound pi(-)states in Pb-207 formed in the Pb-208(d,He-3) reaction.II.Deduced binding energies and widths and the pion-nucleus interaction"Physical Review C. C62. 25202-12 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Oset E,Hirenzaki S et al.: "Chiral unitary approach to the (K)over-bar nucleus interaction and kaonic atoms"ACTA PHYS POL. B31. 2285-2294 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Umemoto Y,Hirezak S et al: "Isotope dependence of deeply bound pionic states in Sn and Pb"Physical Review C. C62. 24606-12 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Hirenzaki S et al: "Chiral unitary model for the kaonic atom"Physical Review C. C61. 5205-15 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Hirenzaki S,Toki H: "Structure and formation of deeply bound pionic atoms"Nuclear Physics. A670. 194-197 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] R. S. Hayano, S. Hirenzaki, and A. Gillitzer: "Formation of η/ω-mesic Nuclei Using the Recoilless (d,3 He) Reaction"European Physical Journal A. A6. 99-105 (1999)

    • Related Report
      1999 Annual Research Report

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

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