共查询到19条相似文献,搜索用时 156 毫秒
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回顾了相对论连续谱Hartree-Bogoliubov理论对奇特核结构的描述.包括对11Li晕核的微观描述,并发现了其形成机制是由于Cooper对从1p1/2轨道被散射到2s1/2轨道;预言了滴线核的新现象——由6个中子组成的巨晕,给出了形成晕现象的条件为弱束缚与低离心位垒;解释了实际核中的赝自旋对称性;自旋轨道分裂与势能位垒弥散的关系;经典禁区内粒子对晕的影响;超重元素的结构研究等. 相似文献
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在单粒子壳模型下, 研究了N=8及N=9同中子素的基态性质. 通过在伍兹--萨克逊势深中引入同位旋依赖项, 考虑了同位旋效应对核平均势的影响. 理论计算的均方根半径和自旋宇称值与实验结果整体上符合较好, 尤其是N=9同中子素中的2s1/2与1d5/2中子能级间的能级反转得到了较好的解释. 计算结果还显示在14B和15C基态中存在单中子晕. 相似文献
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丁怀博 朱胜江 J.H.Hamilton A.V.Ramayya J.K.Hwang Y.X.Luo J.O.Rasmussen I.Y.Lee 车兴来 陈永静 李明亮 《中国物理 C》2006,30(Z2):172-174
通过对重核252Cf自发裂变产生的瞬发γ谱的测量, 对丰中子核105Mo的能级结构进行了研究. 除确认与扩展了基带转动带外, 新识别了3个转动带, 它们分别被指定为建立在Nilsson能级3/2+[411], 1/2+[411]和5/2+[413]轨道上的单中子激发带, 并对这些集体带的特性进行了讨论. 相似文献
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葛愉成 叶沿林 郑涛 王全进 李智焕 李湘庆 江栋兴 A.Ozawa Y.Yamaguchi C.Wu R.Kanungo D.Fang I.Tanihata 《中国物理 C》2004,28(3):262-267
报道了经仔细设计的150MeV 6He+9Be实验,并在质心系大角度处测量10Be和11Be同位素产物的实验数据.鉴别得到相应于单中子转移的371个10Be事件,同时观测到了相应于双中子转移的5个11Be事件.由此得到相应微分截面分别为(0.11±0.02)mb/sr(θcm≈137.4°)和(1.0±0.7)μb/sr(θcm≈133.4°),结果表明在所研究的反应体系中,单中子转移截面要比双中子转移截面约大100倍.在6He由5He-n和α-2n组成的集团模型下,利用零力程扭曲波玻恩近似(DWBA)的计算程序,在数量级上重现了单、双中子转移反应的实验数据 相似文献
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在三体模型的基础上,采用汤川作用势,进行变分计算,进一步研究了晕核11Li,14Be和17B的基态性质,给出了晕中子密度分布的一个解析表达式.理论计算结果与最新的实验数据一致. 相似文献
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张玉虎柳敏良 G.de Angelis Zs.Podolyak 郭文涛 A.Gadea C.Ur N.Marginean C.Rusu R.Schwengner D.R.Napoli R.Menegazzo S.Lunardi D.Bazzacco< 《中国物理 C》2004,28(9):941-946
通过重离子融合蒸发反应16O(82Se+4n)94Mo布局了94Mo核的高自旋态.利用多探头探测器阵列GASP进行了在束γ测量,从而重新研究了94Mo核的高自旋态能级结构.基于新发现的一些重要的连接跃迁,对94Mo核的高自旋态能级纲图做了重要修改.将新的能级结构与壳模型计算进行了比较和讨论.结果表明要正确的描述94?Mo核的高自旋态(自旋值大于14)能级结构,应考虑价中子在d5/2,g7/2和h11/2轨道上的激发. 相似文献
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The properties of neutron-rich boron isotopes are studied in the relativistic continuum Hartree-Bogoliubov theory in coordinate space with NL-SH, PK1 and TM2 effective interactions. Pairing corrections are taken into account by a density dependent force of zero range. The binding energies calculated for these nuclei agree with the experimental data quite well. The neutron-rich nucleus 17B has been predicted to have a two-neutron halo structure in its ground state. The halo structure of 17B is reproduced in a self-consistent way, and this halo is shown to be formed by the valence neutron level 2s1/2. 相似文献
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Isao Tanihata 《Acta Physica Hungarica A》1997,6(1-4):127-142
The use of radioactive nuclear beams (RNB) has provided an opportunity to study nuclei far from the stability line. Reaction studies using intermediate and high-energy (30–1000 AMeV) radioactive beams have revealed new structures of nuclei that are not seen in nuclei near to the stability line [1]. One such new structure is the neutron halo, a long low-density tail of the neutron distribution [2]. It has been observed in neutron drip-line nuclei, such as6He,11Li and11Be. The neutron halo has put light on many new structure problems. Among those, recent studies of a softE1 mode, a low-frequency oscillation of halo neutrons against the core, are discussed in the following section in connection with a recent (p, p′) reaction measurement [3]. Also, the effect of changes in single-particle orbitals on halo formation is discussed [4]. Another new finding is the formation of neutron skins in neutron-rich unstable nuclei [5]. The relation between the equation-of-state (EOS) of asymmetric nuclear matter and the neutron-skin thickness as well as the density distribution of nuclei far from the stability line is discussed in the last section. 相似文献
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在三体模型的基础上,采用汤川作用势,进行变分计算,进一步研究了晕核11Li,14Be和17B的基态性质,给出了晕中子密度分布的一个解析表达式.理论计算结果与最新的实验数据一致. 相似文献
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The Be chain of isotopes is investigated within the Sernimicroscopic Algebraic Cluster Model (SACM). For that the SACM is extended to odd-mass p-shell nuclei. We show that the main features of the Be isotopes can be well explained. Though for the neutron halo nucleus 11Be some problems remain, the shell model still can describe the rough structures of these nuclei. In 11Be a shell inversion takesplace reflecting the high deformation of the system. The quadrupole—quadrupole interaction plays a dominant role in p-shell nuclei. 相似文献
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We have extracted the nuclear asymptotic normalization coefficients (ANC) for the virtual transitions B→A+N via some transfer reactions and the radioactive nuclear beam experiments. With these coefficients, root-mean-square (rms) radii for the valence particle in some possible halo nuclei have been calculated. The values of rms radii extracted with ANC approach are nearly model-independent, hence are a good quantity for the investigation of nuclear halo. In addition, we have also calculated the rms radii for the two valence neutrons in some three-body systems in terms of the relationship between the radii of valence particle, core nucleus and nuclear matter. With two conditions for nuclear halo formation, we have examined these extracted rms radii. The results show that 11Be(1/2+, g.s), 12B(1-, 2.621 MeV), 13C(1/2+, 3.089 MeV), 14C(0-, 6.903 MeV), 14C(1-, 6.094 MeV), 15C(1/2+, g.s) and 19C(1/2+, g.s) with the valence particle in the 2s ground or excited state are the neutron halo nuclei, whereas 17F(1/2+, 0.495 MeV) and 21Na(1/2+, 2.423 MeV) are the proton halo nuclei in the excited state. For three-body systems, except the well-established two-neutron halo nuclei 6He and 11Li, 14Be and 17B might be the two-neutron halo nuclei as well. 相似文献
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In Order to extend the conventional shell model(SM) calculation with harmonic oscillator bases to halo nuclei, a self-similar, structure shell model(SSM) is proposed. The SSM is achieved by a rescaling of both the Kinetic and potential energy term of the harmonic oscillator and a mean field imitation, so that the single particle orbit in SSM has state (orbit) -dependent frequency. The large r. m. s. radius and the thick neutron skin for halo nuclei as well as the bound state properties of Borromean nuclei such as 6He, 11Li and 14Be can be reproduced. 相似文献