2001 Fiscal Year Final Research Report Summary
Three- and four-body study of light hypernuclei and YN interaction
| Project/Area Number |
11640283
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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 |
素粒子・核・宇宙線
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KAMIMURA Masayasu Kyushu University, Department of Physics, Professor, 理学研究院, 教授 (10037210)
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| Co-Investigator(Kenkyū-buntansha) |
HIYAMA Emiko High Energy Accelerator Research Organization, Institute of Particle and nuclear Study, Research Assistant, 高エネルギー加速器研究機構・素粒子原子核研究所, 助手 (10311359)
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| Project Period (FY) |
1999 – 2001
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| Keywords | hypemuclei / hypenon / strangeness / 3-body problem / 4-body problem / Λ particle |
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| Research Abstract |
[1] Theoretical prediction of B(E2) in hypemuclei.
We calculated B(E2: 5/2^+_1 → 1/^+_1) in ^7_λLi and B(E2: 3^+_1→1^+_1) of the core nucleus ^6_λLi. From their comparison, we predicted that size of ^7_λLi is shrunk by 21% from the core nucleus. KEK-E419 experiment verified this prediction.
[2] YN spin-orbit force and the level structure of ^9_λBe and ^13_λ3C.
With the use of the two kinds of YN interactions we calculated energy splitting in the spin orbit doublet in ^9_λBe and ^13_λ3C. The quark-model-based interaction gave very small splitting, where as the meson-theory- based interaction gave substantially large splitting. Experiments at BNL reported a small splitting which agrees with the former case of our prediction.
[3] Four-body study of ^4_λH and ^4_λHe.
We performed, for the first time, four-body calculation of ^4_λH and ^4_λHe with the explicit use of the (3Ν+Λ) and (3Ν+Σ) channel. The ΛΝ-Σ coupling is treated accurately. We were able to explain the level structure of the hypemuclei and estimated the probability of the (3Ν+Σ) channel. It is 2% in the 0^+ state and 1% in the 1^+ state, but plays important role in making the states bound.
[4] Spectroscopy of the double-Λ hypemuclei.
We predicted the energy levels of the A=7-10 double-Λ hypemuclei with the use of the α+χ+Λ+Λ four-body model with χ= n,p,t,^3He,α. Our prediction for 2^+ state of ^<10>_<ΛΛ>Be was recently verified by the DEMACHI-YANAGI event in the KEK-E373 experiment.
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