Experimental study of vanishing of N=20 magicity in neutron rich nuclei
| Project/Area Number |
15540271
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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 | Osaka University |
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Principal Investigator |
IZUMI Hideaki Osaka University, Graduate School of Science, Research Associate, 理学研究科, 助手 (50294153)
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| Co-Investigator(Kenkyū-buntansha) |
SHIMODA Tadashi Osaka University, Graduate School of Science, Professor, 理学研究科, 教授 (70135656)
MIYATAKE Hiroari High energy Accelerator Research Organization, Institute of Particle and Nucear Studies, Associate Professor, 素粒子原子核研究所, 助教授 (50190799)
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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 |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2003: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | nuclear structure / unstable nuclei / neutron-rich nuclei / beta decay / spin polarization / parit / excited state / beta asymmetry / 殻模型 / 中性子 / γ線 / 核分光 |
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| Research Abstract |
The excited states in the light neutron-rich nucleus ^<11>Be have been studied through the β-delayed neutron- and γ -decays from spin-polarized ^<11>Li_<g.s>.. The experiment is based on the new method in the β-delayed decay spectroscopy from a spin polarized nucleus, ^<11>Li_<g.e.>(β)→11Be(n)→^<10>Be^* (γ)→^<10>Be_<g.e.>, to unambiguously assign the spins and parities of the states populated in β-decay., by taking advantage of the fact that the allowed B-decay from a polarized nucleus shows an angular distribution of W(θ) 〜1 + AP cosθ, which depends on the spin value of the daughter state. Here, θ, A and P are the emission angle with respect to the polarization axis, the asymmetry parameter of β-transition and the polarization of the parent nucleus, respectively.
The level scheme and decay scheme of ^<11>Be^* were established from the β-γ, β-n and β-n-γcoincidences, and the spins and parities for 7 levels in ^<11>Be were firmly assigned from the βdecay asymmetries measured in coincidence with the delayed radiations. The neutron-spectroscopic factors of the levels in ^<11>Be were also determined. Some of the levels show good accord with predictions by the anti-symmetrized molecular dynamics (AMD) theory, which predicts various types of 2α-cluster states in the rotational bands and a single α-cluster state.
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Report
(3 results)
Research Products
(6 results)
