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2000 Fiscal Year Final Research Report Summary

Quantum Fluctuation Effects on Fragment Formation Processes

Research Project

Project/Area Number 09640329
Research Category

Grant-in-Aid for Scientific Research (C)

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

Principal Investigator

OHNISHI Akira  Hokkaido Univ., Grad.School of Sci., Asso.Prof., 大学院・理学研究科, 助教授 (70250412)

Project Period (FY) 1997 – 2000
KeywordsQuantum Langevin / AMD / Multifragmentation / Liquid-gas transition / Atomic Cluster / Stopped Ξ^- / GeV Proton / Percolation
Research Abstract

One of the main goals of nuclear reaction study is to explore various phases of nuclear matter and achieve an understanding of the associated phase transitions. Since the the experimental exploration of nuclear phases must rely on nuclear collisions, it is necessary to have deep knowledges of nuclear collision dynamics, including the non-equilibrium character as well as the quantal statistical nature of the nuclear system.
In this research project, first we have developed a tractable method to describe the quantum statistical mechanics of wave-packets. Then we have constructed a dynamical model, the Quantum Langevin model, in which we implement a stochastic term having a quantum mechanical origin into wave-packet molecular dynamics. With this stochastic term, it is ensured that the system relaxes to proper quantum statistical equilibrium automatically, by the form of the equations of motion itself. We have successfully applied this model to various fragmentation processes : multifragmen … More tation in heavy-ion collisions, atomic cluster formation, and double, twin, and single-hyperfragment formation from Ξ^- absorption at rest. From these studies, we have clarified the following important roles of quantum fluctuations in fragment formation processes. (1) Inclusion of quantum fluctuation drastically improves the statistical properties of nuclear systems. (2) With quantum fluctuations, it becomes possible to describe dynamical formation of cold fragments, which are stable enough to survive later statistical decays. (3) This dynamical fragment formation is much faster than that in usual molecular dynamics without fluctuations. This fast fragmentation would be the origin of anomalous IMF angular distribution (side peaked) observed in high-energy proton induced reactions. We have verified this idea by using a combined framework of a intranuclear cascade model with a non-equilibrium percolation model.
Based on these achievements and other works on strangeness nuclear physics and relativistic heavy-ion collisions, we have published twelve original papers (incl.one submitted paper), and fifteeen conference proceedings during these four years. Less

  • Research Products

    (52 results)

All Other

All Publications (52 results)

  • [Publications] Y.Nara: "Study of (K^-,K^+) Reactions within the Quantum Molecular Dynamics Approach"Proc.of the 25th INS Int.Symp.on Nuclear and Particle Physics with High-Intensity Proton Accelerators (World Scientific). 324-329 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Naohiko Ohtsuka: "Thermodynamical Evolution of Hot and Dense Hadronic Matter from Intranuclear Cascade Simulation"Proc.of the 25th INS Int. Symp.on Nuclear and Particle Physics with High-Intensity Proton Accelerators (World Scientific). 415-416 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Inclusion of Quantum Fluctuations in Wave Packet Dynamics"Ann.Phys.(N.Y.). 253. 279-309 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Nara: "K^+ momentum spectrum from (K^-,K^+) reactions in intranuclear cascade model"Nuclear Physics. A614. 433-460 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Quantum Fluctuation Effects on Nuclear Fragment Formation"Physics Letters. B394. 260-268 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Quantum Fluctuations Affect the Critical Properties of Noble Gases"Physical Review A. 55. 3315R-3318R (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Branching ratio change in K^- absorption at rest and the nature of the Λ(1405)"Physical Review C. 56. 2767-2773 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Quantum Fluctuation Effects on Nuclear and Atomic Cluster Formation"Nuclear Physics. A630. 223c-230c (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Quantum Fluctuation Effects on Nuclear and Atomic Fragmentations"Proc.of Int.Symp.on Similarities and Differences between Atomic Nuclei and Clusters (American Institute of Physics). 455-458 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yasushi Nara: "What is the Role of Higher Baryonic Resonances in AA Collisions at AGS Energies?"Progress of Theoretical Physics Supplement. 129. 33-37 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yuichi Hirata: "Formation of twin and double hypernuclei from Ξ^- absorption at rest on ^<12>C"Nuclear Physics. A639. 389c-392c (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Quantum fluctuation effects on nuclear multifragmentation"Proc.of 3rd Japan-Italy Joint Symp.'97,Perspectives in Heavy Ion Physics (World Scientific). 162-171 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Molecular dynamics with quantum fluctuations and its application to heavyion collisions"Proc.of the XVII RCNP Int.Symp.on Innovative Computational Methods in Nuclear Many-Body Problems (World Scientific). 470-474 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yuichi Hirata: "Effects of Quantum Fluctuations in Antisymmetrized Molecular Dynamics"Proc.of the XVII RCNP Int.Symp.on Innovative Computational Methods in Nuclear Many-Body Problems (World Scientific). 475-477 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] N.Otuka: "The Role of Higher Excited Baryonic Resonances in Heavy Ion Collisions at AGS Energies"Proc.of the XVII RCNP Int.Symp.on Innovative Computational Methods in Nuclear Many-Body Problems (World Scientific). 495-497 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Takayuki Myo: "Resonance and Continuum Components of the Strength Function"Progress of Theoretical Physics. 99. 801-817 (1998)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "Can We Extract Lambda-Lambda Interaction from Two-Particle Momentum Correlation?"Nuclear Physics. A670. 297c-300c (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 大西明: "重イオン反応と核物質の相"数理科学. 430. 46-52 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Yuichi Hirata: "Quantum fluctuation effects on hyperfragment formation from Ξ^- absorption at rest on ^<12>C"Progress of Theoretical Physics. 102. 89-119 (1999)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Akira Ohnishi: "ΛΛ INTERFEROMETRY IN (K^-,K^+) AND AA REACTIONS"Proc.of APCTP Workshop on Strangeness Nuclear Physics (World Scientific). 175-182 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A.Ohnishi: "ΛΛ Interferometry in (K^-,K^+) Reactions at P(K^-)=1.8 GeV/c"Few-Body Systems Supplement. 12. 367-371 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Nara: "Study of relativistic nuclear collisions at AGS energies from p+Be to Au+Au with hadronic cascade model"Physical Review C. 61. 024901,1-19 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] P.K.Sahu: "Baryon flow from SIS to AGS energies"Nuclear Physics. A672. 376-386 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Pradip Kumar Sahu: "SU(2) Chiral sigma model and the properties of neutron stars"Progress of Theoretical Physics. 104. 1163-1171 (2000)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A.Ohnishi: "Hyperon Distribution and Correlation in (K^-,K^+) Reactions"Nuclear Physics. A684. 595-597 (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] A.Ohnishi: "Lambda-Lambda correlation in (K^-,K^+) reaction-Is there a virtual pole?"Nuclear Physics. A(印刷中). (2001)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Y.Nara et al.: "Study of (K^-, K^+) Reactions within the Quantum Molecular Dynamics Approach"Proc.of the 25th INS Int.Symp.on Nuclear and Particle Physics with High-Intensity Proton Accelerators (World Scientific). 324-329 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Naohiko Ohtsuka et al.: "Thermodynamical Evolution of Hot and Dense Hadronic Matter from Intranuclear Cascade Simulation"Proc.of the 25th INS Int.Symp.on Nuclear and Particle Physics with High-Intensity Proton Accelerators (World Scientific). 415-416 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Inclusion of Quantum Fluctuations in Wave Packet Dynamics"Ann.Phys.(N.Y.). 253. 279-309 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Nara et al.: "K^+ momentum spectrum from (K^-, K^+) reactions in intranuclear cascade model"Nucl.Phys.. A614. 433-460 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Quantum Fluctuation Effects on Nuclear Fragment Formation"Phys.Lett.. B394. 260-268 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Quantum Fluctuations Affect the Critical Properties of Noble Gases"Phys.Rev.. A55. 3315R-3318R (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Branching ratio change in K^- absorption at rest and the nature of the Λ(1405)"Phys.Rev.. C56. 2767-2773 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Quantum Fluctuation Effects on Nuclear and Atomic Cluster Formation"Nucl.Phys.. A630. 223c-230c (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Quantum Fluctuation Effects out Nuclear and Atomic Fragmentations"Proc.of Int.Symp.on Similarities and Differences between Atomic Nuclei and Clusters (American Inst.of Phys.). 455-458 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yasushi Nara et al.: "What is the Role of Higher Baryonic Resonances in AA Collisions at AGS Energies ?"Prog.Theor.Phys.Suppl.. 129. 33-37 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yuichi Hirata et al.: "Formation of twin and double hypernuclei from Ξ^- absorption at rest on ^<12>C"Nucl.Phys.. A639. 389c-392c (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Quantum fluctuation effects on nuclear multifragmentation"Proc.of 3rd Japan-Italy Joint Symp. '97, Perspectives in Heavy Ion Physics (World Scientific). 162-171 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Molecular dynamics with quantum fluctuations and its application to heavy ion collisions"Proc.of the XVII RCNP Int.Symp.on Innovative Computational Methods in Nuclear Many-Body Problems (World Scientific). 470-474 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yuichi Hirata et al.: "Effects of Quantum Fluctuations in Antisymmetrized Molecular Dynamics"Proc.of the XVII RCNP Int.Symp.on Innovative Computational Methods in Nuclear Many-Body Problems (World Scientific). 475-477 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] N.Otuka et al.: "The Role of Higher Excited Baryonic Resonances in Heavy Ion Collisions at AGS Energies"Proc.of the XVII RCNP Int.Symp.on Innovative Computational Methods in Nuclear Many-Body Problems (World Scientific). 495-497 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Takayuki Myo et al.: "Resonance and Continuum Components of the Strength Function"Prog.Theor.Phys.. 99. 801-817 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "Can We Extract Lambda-Lambda Interaction from Two-Particle Momentum Correlation ?"Nucl.Phys.. A670. 297c-300c (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi: "Heavy-Ion Collision and Phases of Nuclear Matter (in Japanese)"Suri-Kagaku. 430. 46-52 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Yuichi Hirata et al.: "Quantum fluctuation effects on hyperfragment formation from Ξ^- absorption at rest on ^<12>C"Prog.Theor.Phys.. 102. 89-119 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Akira Ohnishi et al.: "ΛΛ INTERFEROMETRY IN (K^-, K^+) AND AA REACTIONS"Proc.of APCTP Workshop on Strangeness Nuclear Physics (World Scientific). 175-182 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Ohnishi et al.: "ΛΛ Interferometry in (K^-, K^+) Reactions at P(K^-)=1.8 GeV/c"Few-Body Syst.Suppl.. 12. 367-371 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Y.Nara et al.: "Study of relativistic nuclear collisions at AGS energies from p+Be to Au+Au with hadronic cascade model"Phys.Rev.C. 61. 024901,1-19 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] P.K.Sahu et al.: "Baryon flow from SIS to AGS energies"Nucl.Phys.. A672. 376-386 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Pradip Kumar Sahu et al.: "SU(2) Chiral sigma model and the properties of neutron stars"Prog.Theor.Phys.. 104. 1163-1171 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Ohnishi et al.: "Hyperon Distribution and Correlation in (K^-, K^+) Reactions"Nucl.Phys.. A684. 595-597 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] A.Ohnishi et al.: "Lambda-Lambda correlation in (K^-, K^+) reaction-Is there a virtual pole ?"Nucl.Phys.. A,(in press). (2001)

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

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Published: 2002-03-26  

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