A theoretical Study of Structure of Superhigh-density Stars based on Realistic Interactions between Baryons
| Project/Area Number |
15540264
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
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| Research Institution | Gifu University |
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Principal Investigator |
SHINMURA Shoji Gifu University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (50187572)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | neutron star / baryon-baryon interaction / hyperon mixing / high-density baryonic matter / three-body force / 高密度核物質 / バリオン間三体力 |
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| Research Abstract |
In this research, main achievements are summarized in the following three points. [A] We constructed a potential model for realistic baryon-baryon interactions. Using recent data of double hypernuclei, we improved the interaction model and proposed a new potential model referred to as GSOBEP. We determined the properties of few-body double hypernuclei based on the full coupled-channel baryon-baryon (S=-2) interaction (ΛΛ-ΞN-ΣΣ interaction). [B] We developed a computer code to calculate the equation of state (EOS) of high-densitybaryonic matter. This is an extended version of the C-matrix code for ordinary nuclear matter. This code can treat baryonic matter with arbitrary baryon compsitions, and also can determine EOS of β-stable, charge-neutral baryonic matter including leptons, which is believed to be realized in core region of neutron stars. [C] Using the code mentioned above, we determined EOS of high-density baryonic matter with realistic baryon-baryon interactions and found that by the effect of hyperon mixing, EOS become too soft to reproduce the properties (masses and radii) of neutron stars. In addition, we proposed generalized three-baryon force (ππ3BF), which is a generalization of two-pion-exchange Δ-mechanism of three nucleon force (ππ3NF) and apply ππ3BF to neutron-star matter. As a result, ππ3BF is found to provide attractive contribution and soften the EOS further. Then we intreoduced a phenomenological short-range three baryon force (short-3BF), which are extended from short-range three-nucleon force introduced to reproduce the symmetric energy of nuclear matter. We found that short-3BF makes EOS stiff and the EOS is reasonable to reproduce observed masses ans radii of neutron stars.
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Report
(3 results)
Research Products
(14 results)
