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Kaon condensation and Neutron stars

Research Project

Project/Area Number 08640369
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 InstitutionKYOTO UNIVERSITY

Principal Investigator

TATSUMI Toshitaka  Kyoto U., Dept.of Phys., Research Associate, 大学院・理学研究科, 助手 (40155099)

Co-Investigator(Kenkyū-buntansha) TAKATSUKA Tatsuyuki  Iwate U., Fac.of Humanities and Social Sciences, Professor, 人文社会科学部, 教授 (50043427)
Project Period (FY) 1996 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥800,000 (Direct Cost: ¥800,000)
KeywordsNeutron stars / Equation of state / Protoneutron stars / Phase transition / Kaon condensation / Pion condensation / Hyperon superfluidity / Delayed collapse / カイラル対称性 / 核子超流動 / 超新星 / 高エネルギー重イオン反応
Research Abstract

1.Proper ties of hot neutron stars just born after supernova explosions by the use of a realistic nuclear force
We studied the properties of hot neutron stars and calculated the energy release and spin-up ratio during their evolution.
2.Kaon condensation at finite temperature and protoneutron stars
We proposed a framework to introduce quantum and thermal fluctuations in the kaon condensed phase on the basis of chiral symmetry, and derived the equation of state. Solving the TOV equation we obtained the equilibrium configuration of protoneutron stars and thereby discussed the possibility of the delayed collapse to black holes.
3.Appearance and growth of kaon condensation under nonequilibrium
We studied in detail the characteristic features of the dynamic phase transition under chemical nonequilibrium and pointed out that the reaction rates for creation and annihilation of thermal kaons are dominant over those of other processes before and after phase transition.
4.Nucleon superfluidity under pion condensation or large proton-mixing and hyperon superfluidity, and their implications on neutron-star cooling
Extending the privious theory to include the DELTA isobar degrees of freedom, we found that the critical temperature and the existing region are increased due to DELTA for pi^0 condensation ; while those are reduced for pi^C condensation. In the case of large proton mixing, where proton pairs condense as well, the net effect is not efficient for neutron star cooling. A hyperon superfluidity is also studied.
5.Recent experiment on Gamow-Teller resonance and pion condensation reexamined
We reexamined the possibility of pion condensation by using the recent information from giant Gamow-Teller resonance. Consequently we remarked that it should be seriously re-considered in the context of neutron stars and heavy-ion reactions.

Report

(4 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • 1996 Annual Research Report
  • Research Products

    (33 results)

All Other

All Publications (33 results)

  • [Publications] T.Tatsumi: "Thermal and quantum fluctuations in the kaon condensed phase" Nucl.Phys.A 印刷). (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Baryonic ^3P_2 Superfluidity under Charged-Pion Condensation with Δ Isobar" Prog.Theor.Phys.101 印刷中. (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Tatsumi: "Kaon condensation at finite temperature" Pliys.Lett.B441. 9-16 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Quasi-Neutron^3P_2-Dominant Superfluidity under π^0 Condensation with Δ isobar" Prog.Theor.Phys.98. 393-417 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Effects of charged-pion condensation on neutron ^3P_2 superfluidity" Prog.Theor.Phys.97. 263-281 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Nucleon superfluidity in neutron star core with direct URCA cooling" Prog.Theor.Phys.97. 345-350 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Hot neutron stars at birth and related problems" Prog.Theor.Phys.95. 901-912 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Tatsumi: "Restoration of chiral symmetry and dilepton production at finite temperature" Phys.Lett.B387. 132-138 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Tatsumi: "Thermal and quantum fluctuations in the kaon condensed phase" Nucl.Phys.A. (to be published). (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Baryonic ^3P_2 Superfluidity under Charged-Pion Condensation with DELTA Isobar" Prog.Theor.Phys.101 (in press). (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Tatsumi: "Kaon condensation at finite temperature" Phys.Lett.B441. 9-16 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Quasi-Neutron ^3P_2-Dominant Superfluidity under pi^0 Condensation with DELTA isobar" Prog.Theor.Phys.98. 393-417 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Effects of charged-pion condensation on neutron ^3P_2 superfluidity" Prog.Theor.Phys.97. 263-281 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Nucleon superfluidity in neutron star core with direct URCA cooling" Prog.Theor.Phys.97. 345-350 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Takatsuka: "Hot neutron stars at birth and related problems" Prog.Theor.Phys.95. 901-912 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Tatsumi: "Restoration of chiral symmetry and dilepton production at finite temperature" Phys.Lett.B387. 132-138 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] T.Tatsumi: "Kaon condensation at finite temperature" Phys.Lett.B441. 9-16 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Tatsumi: "Thermal and quantum fluctuations in the kaon condensed phase" Nucl.Phys.A(in press). (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] M.Yasuhira: "EOS for Kaou Condensed matter at Finite Temperature" Proc.of 1998 YITP-Workshop on QCD and Hadron Physics(World Scientific). in press. (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Tatsumi: "Protoneutron Stars with Kaon Condensate" Proc.of Int.Sympo.on “Physics of Hadrons and Nuclei"(Nucl.Phys.A). in press. (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Suzuki: "The Landau-Migdal Parameters,g'_<NN> and g'_<NΔ> and Pion Condensations" Proc.of RCNP Int.Mini Sympo.on “Nuclear Responses and medium effects"(Universal Academy Press). in press. (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Takatsuka: "A-Superfluidity in Neutron Star Cores" Proc.of Int.Sympo.on “Physics of Hadrons and Nuclei"(Nucl.Phys.A). in press. (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Tatsumi: "Thermal fluctuations in the Kaon Condensed Phase" Proc. of APCTP Workshop on “Properties of Hadrons in Matter" (World Scientific). (印刷中). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Tatsumi: "Thermal Properties of Kaon-Condensed Neutron Stars" Proc. of Int. Sympo. on “Pulsars and Neutron Stars" (Universal Academy Press). (印刷中). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Muto: "Nonequilibrium Processes in Kaon Condensation and Dynamical Evolution of Neutron Stars" Proc. of Int. Sympo. on “Pulsars and Neutron Stars" (Universal Academy Press). (印刷中). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Takatsuka: "Quasi-Neutron ^3P_2-Dominant Superfluidity under π^0 Condensation with Δ Isobar" Prog. Theor. Phys.98. 393-417 (1997)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Takatsuka: "Critical Mass of Neutron Stars Constrained by Evolution" Proc. of Int. Sympo. on “Pulsars and Neutron Stars" (Universal Academy Press). (印刷中). (1998)

    • Related Report
      1997 Annual Research Report
  • [Publications] T.Tatsumi: "Kaon in Medium and Dilepton Production from Strange Hardonic Matter" Australian J.of Physics. 50巻. 23-33 (1997)

    • Related Report
      1996 Annual Research Report
  • [Publications] T.Muto: "Nonequilibrium Processes in Kaon Condensation" Australian J.of Physics. 50巻. 13-22 (1997)

    • Related Report
      1996 Annual Research Report
  • [Publications] T.Tatsumi: "Restoration of chiral symmetry and dilepton production at finite temperature" Physics Letters B. 387巻. 132-138 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] T.Takatsuka: "Hot neutron stars at birth and related problems" Progress of Theoretical Physics. 95巻5号. 901-912 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] T.Takatsuka: "Nucleon superfluidity in neutron star core with direct URCA cooling" Progress of Theoretical Physics. 97巻2号. 345-350 (1997)

    • Related Report
      1996 Annual Research Report
  • [Publications] T.Takatsuka: "Effects of charged-pion condensation on neutron ^3P_2 superfluidity" Progress of Theoretical Physics. 97巻2号. 263-281 (1997)

    • Related Report
      1996 Annual Research Report

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Published: 1996-04-01   Modified: 2016-04-21  

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