Nuclear Structure in Chiral Quark Models Nuclear Force and Many-Body Problem
| Project/Area Number |
04640284
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
核・宇宙線・素粒子
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| Research Institution | The University of Tokyo |
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Principal Investigator |
BENTZ Wolfgang The University of Tokyo, Graduate School of Science Research Associate, 大学院・理学系研究科, 助手 (20168769)
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| Co-Investigator(Kenkyū-buntansha) |
YAZAKI Koichi The University of Tokyo, Graduate School of Science Professor, 大学院・理学系研究科, 教授 (60012382)
田中 和廣 理化学研究所, 基礎科学特別研究員
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1993: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1992: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | Chiral Quark Model / Nuclear Structure / Faddeev Equation / Mean Field Approximation / Many Body Problem |
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| Research Abstract |
The research was carried out along the following three lines : First, we used effective quark theories based on QCD to investigate the internal quark structure of baryons in the mean field approximation. We found that in the simplest Nambu-Jona-Lasinio (NJL) model there exist no stable soliton solutions. If we extend the model to flavor SU(3), the instanton induced 6-Fermi interaction plays the dominant role to stabilize the soliton against collapse. In this way we could describe both meons and baryons within the same model. We also investigated the chiral sigma model, and developed a method to eliminate the Landau-ghost from the soliton.
Second, we solved the relativistic 3-quark Faddeev equation in the NJL model exactly, including the J=0 and J=2 two body channels. This is the most important achievement of the present research. We have shown that with the original NJL Lagrangian one cannot obtain a bound state, and we have given the form of the Lagrangian by which one can describe the pion in the Bethe-Salpeter framework, and nucleon and delta in the Faddeev framework. We used the solution of the Faddeev equation to describe static properties of the nucleon, and found that the results of the naive quark-diquark model are close to the exact ones provided that the quark-diquark binding energy is small.
Third, we investigated the equation of state of nuclear and neutron matter in the framework of relativistic meson-nucleon theory. Using the 1/N expansion, we have shown the importance of the higher order correlation terms to soften the equation of state. We have found that the softening of the relativistic equation of state holds over a wide range of temperatures and densities.
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Report
(3 results)
Research Products
(20 results)
