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Studies of matter in neutron stars by using lattice quantum chromodynamics

Research Project

Project/Area Number 26400279
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Particle/Nuclear/Cosmic ray/Astro physics
Research InstitutionSaga University

Principal Investigator

Kouno Hiroaki  佐賀大学, 工学(系)研究科(研究院), 教授 (80234706)

Co-Investigator(Renkei-kenkyūsha) Yahiro Masanobu  九州大学, 理学研究科, 教授 (40300537)
Nakamura Atsushi  大阪大学, 核物理研究センター, 協同研究員 (30130876)
Project Period (FY) 2014-04-01 – 2017-03-31
Project Status Completed (Fiscal Year 2016)
Budget Amount *help
¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Fiscal Year 2016: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2015: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Keywords格子量子色力学 / 中性子星 / バリオン数 / アイソスピン / 虚数化学ポテンシャル / 現象論模型
Outline of Final Research Achievements

Quark matter is expected to exist in neutron stars. Theoretically, quark matter is studied by using the lattice quantum chromodynamics on the 4-dimesional discrete lattice in computer. The method is called "lattice QCD (LQCD)". When there is no unbalance between particle and antiparticle, the method of LQCD is almost established. However, due to the so called "sign problem", LQCD is not feasible when the number of particle is much larger than that of antiparticles. In this research, we have done the LQCD simulations under the situation with the real isospin and imaginary quark (or baryon) number chemical potentials.
The LQCD under the situation does not correspond to the situation in real physical world, but is feasible, since the sign problem is absent. From the results of the simulations, we have tried to get information of the situation which is realized in neutron stars.

Report

(4 results)
  • 2016 Annual Research Report   Final Research Report ( PDF )
  • 2015 Research-status Report
  • 2014 Research-status Report
  • Research Products

    (16 results)

All 2017 2016 2015 2014

All Journal Article (8 results) (of which Peer Reviewed: 8 results,  Acknowledgement Compliant: 8 results,  Open Access: 4 results) Presentation (8 results) (of which Invited: 1 results)

  • [Journal Article] Interplay between sign problem and Z3 symmetry in three-dimensional Potts models2016

    • Author(s)
      Takehiro Hirakida, Hiroaki Kouno, Junichi Takahashi, Masanobu Yahiro
    • Journal Title

      Physical Review D

      Volume: 94 Issue: 1

    • DOI

      10.1103/physrevd.94.014011

    • Related Report
      2016 Annual Research Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Determination of hadron-quark phase transition line from lattice QCD and two-solar-mass neutron star observations2016

    • Author(s)
      Junpei Sugano, Hiroaki Kouno, Masanobu Yahiro
    • Journal Title

      Physical Review D

      Volume: 94 Issue: 1

    • DOI

      10.1103/physrevd.94.014024

    • Related Report
      2016 Annual Research Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Equation of state and transition temperatures in the quark-hadron hybrid model2016

    • Author(s)
      Akihisa Miyahara, Yuhei Torigoe, Hiroaki Kouno, Masanobu Yahiro
    • Journal Title

      Physical Review D

      Volume: 94 Issue: 1

    • DOI

      10.1103/physrevd.94.016003

    • Related Report
      2016 Annual Research Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Determination of U(1)A restoration from pion and a0-meson screening masses: Toward the chiral regime2016

    • Author(s)
      Masahiro Ishii, Koji Yonemura, Junichi Takahashi, Hiroaki Kouno, Masanobu Yahiro
    • Journal Title

      Phys.Rev. D

      Volume: 93 Issue: 1 Pages: 016002-016002

    • DOI

      10.1103/physrevd.93.016002

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Acknowledgement Compliant
  • [Journal Article] Phase structure of two-color QCD at real and imaginary chemical potentials; lattice simulations and model analyses2016

    • Author(s)
      Takahiro Makiyama (Saga U., Japan), Yuji Sakai (Wako, RIKEN), Takuya Saito (Kochi U.), Masahiro Ishii, Junichi Takahashi (Kyushu U.), Kouji Kashiwa (Kyoto U., Yukawa Inst., Kyoto), Hiroaki Kouno (Saga U., Japan), Atsushi Nakamura (Hiroshima U., RIISE), Masanobu Yahiro (Kyushu U.)
    • Journal Title

      Phys. Rev. D

      Volume: 93 Issue: 1 Pages: 014505-014505

    • DOI

      10.1103/physrevd.93.014505

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Journal Article] Understanding of QCD at high density from Z3-symmetric QCD-like theory2015

    • Author(s)
      Hiroaki Kouno, Kouji Kashiwa, Junichi Takahashi, Tatsuhiro Misumi, Masanobu Yahiro
    • Journal Title

      Phys.Rev.D

      Volume: 93 Issue: 5 Pages: 056009-056009

    • DOI

      10.1103/physrevd.93.056009

    • Related Report
      2015 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Journal Article] Quark number densities at imaginary chemical potential in Nf=2 lattice QCD with Wilson fermions and its model analyses2015

    • Author(s)
      Junichi Takahashi, Hiroaki Kouno, and Masanobu Yahiro
    • Journal Title

      Physical Review D

      Volume: 91 Issue: 1 Pages: 014501-014501

    • DOI

      10.1103/physrevd.91.014501

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Journal Article] Determination of the strength of the vector-type four-quark interaction in the entanglement Polyakov-loop extended Nambu―Jona-Lasinio model2014

    • Author(s)
      J. Sugano, J. Takahashi, M. Ishii, H. Kouno, and M. Yahiro
    • Journal Title

      Physical Review D

      Volume: 90 Issue: 3 Pages: 037901-037901

    • DOI

      10.1103/physrevd.90.037901

    • Related Report
      2014 Research-status Report
    • Peer Reviewed / Open Access / Acknowledgement Compliant
  • [Presentation] 格子量子色力学を使った高密度物質の研究2017

    • Author(s)
      河野宏明
    • Organizer
      平成28年度 公募型利用制度成果報告会
    • Place of Presentation
      大阪大学サイバーメディアセンター
    • Related Report
      2016 Annual Research Report
    • Invited
  • [Presentation] 虚数クォーク数化学ポテンシャルと実数アイソピン化学ポテンシャルが存在する場合の格子QCD計算2017

    • Author(s)
      河野宏明
    • Organizer
      平成28年度 SX-ACE@RCNP成果報告・進捗状況報告会
    • Place of Presentation
      大阪大学核物理研究センター
    • Related Report
      2016 Annual Research Report
  • [Presentation] 格子QCDを用いた非対称有限密度物質の研究III2016

    • Author(s)
      河野宏明,高橋純一,石井優大,管野淳平,宮原昌久,八尋正信,中村純
    • Organizer
      日本物理学会2016年秋季大会
    • Place of Presentation
      宮崎大学
    • Related Report
      2016 Annual Research Report
  • [Presentation] 格子QCDを使った中性子星内物質の探究II2016

    • Author(s)
      河野宏明,高橋純一,石井優大,管野淳平,宮原昌久,八尋正信,中村純
    • Organizer
      第122回日本物理学会九州支部例会
    • Place of Presentation
      福岡大学
    • Related Report
      2016 Annual Research Report
  • [Presentation] 格子QCDを用いた非対称有限密度物質の研究II2015

    • Author(s)
      河野宏明,高橋純一,石井優大,管野淳平,宮原昌久,八尋正信,中村純
    • Organizer
      日本物理学会2015年秋季大会
    • Place of Presentation
      大阪市立大学
    • Year and Date
      2015-09-26
    • Related Report
      2015 Research-status Report
  • [Presentation] 格子QCDを用いた非対称有限密度物質の研究2015

    • Author(s)
      河野宏明,高橋純一,石井優大,管野淳平,米村浩司,宮原昌久,八尋正信,中村純
    • Organizer
      日本物理学会第70回年次大会
    • Place of Presentation
      早稲田大学
    • Year and Date
      2015-03-24
    • Related Report
      2014 Research-status Report
  • [Presentation] 格子QCDを使った中性子星内物質の探究2014

    • Author(s)
      河野宏明,高橋純一,米村浩司,石井優大,管野淳平,八尋正信,中村純
    • Organizer
      第120回日本物理学会九州支部例会
    • Place of Presentation
      崇城大学
    • Year and Date
      2014-12-06
    • Related Report
      2014 Research-status Report
  • [Presentation] 実数アイソスピン数密度化学ポテンシャルかつ虚数バリオン数密度化学ポンテシャル領域における格子QCD計算2014

    • Author(s)
      河野宏明, 高橋純一,石井優大,管野淳平,米村浩司, 八尋正信,中村純
    • Organizer
      日本物理学会2014年秋季大会
    • Place of Presentation
      佐賀大学
    • Year and Date
      2014-09-20
    • Related Report
      2014 Research-status Report

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Published: 2014-04-04   Modified: 2018-03-22  

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