A transfer-reaction experiment of ~9Be(~9Be,^(10)Be)~8Be was performed at a beam energy of 45 Me V.Excited states in ^(10)Be up to 18.80 Me V are produced using missing mass and invariant mass methods.Most of the observed high-lying resonant states,reconstructed from theα+~6He and t+~7Li decay channels,agree with the previously reported results.In addition,two new resonances at 15.6 and 18.8 Me V are identified from the present measurement.The 18.55 Me V state is found to decay into both the t + ~7Lig:s: and t + ~7Li?(0.478 MeV) channels, with a relative branching ratio of 0:93 ± 0:33. Further theoretical investigations are encouraged to interpret this new information on cluster structure in neutron-rich light nuclei.
Continuum discretised coupled-channels(CDCC) method with a ^(10)Be(0^+) + n two-body cluster model is applied to systematically analyze the elastic scattering of the halo nucleus ^(11)Be from the proton target at various incident energies below 100 MeV/nucleon.Using the renormalized ^(10)Be- p potential deduced from the ^(10)Be+ p elastic scattering data, the differential cross sections of ^(11)Be + p scattering are well reproduced by the CDCC calculations without any further adjustment parameters, demonstrating the applicability of this approach for describing the scattering of exotic nuclei based on the scattering of the less exotic core nuclei.
β-decay properties of N=18-22,Z=10-14 nuclei are analyzed with a new shell-model Hamiltonian using the Gogny densitydependent interaction.The Gogny force which has been widely and successfully used in mean-field theory can provide reasonable two-body matrix elements for cross-shell calculations.The log f t values andβ-decay level schemes are systematically studied using the D1S-Gogny interaction and compared with the SDPF-M results and experimental data.It is shown that the new Hamiltonian provides reliable results forβ-decay along with subtle level schemes for this region.Shell-model calculations with Gogny interaction can lead to a successful description of nuclei in and around the N=20 island of inversion and supplements experiment where sufficient data are not available.
Pairing-deformation-frequency self-consistent crankingWoods-Saxon model is employed to investigate the triaxiality in the ground states of the neutron-rich even-even Mo, Ru isotopes. Deformation evolutions and transition probabilities have been studied, giving the triaxial shapes in their ground states. The kinematic moments of inertia have been calculated to illustrate the gradually rigid deformation. To understand the origin of the asymmetry shape in this region, we analyze the evolution of single-particle orbits with changing γ deformation. The present calculations reveal the importance of the triaxial deformation in describing not only static property, but also rotational behaviors in this mass region, providing significant probes into the shell structure around.
The influence of short-range correlations in nuclei was investigated with realistic nuclear force. The nucleon-nucleon interaction was renormalized with Vlowk technique and applied to the Green's function calculations. The Dyson equation was reformulated with algebraic diagrammatic constructions. We also analyzed the binding energy of 4He, calculated with chiral potential and CD-Bonn potential. The properties of Green's function with realistic nuclear forces are also discussed.
近年来,越来越多的实验表明,很多轻奇特核结构中都有核心激发成分。本研究以丰中子晕核^(11)Be为例,介绍核心激发成分的实验和理论研究进展,重点阐述核心激发成分对直接核反应微分截面的影响。实验上,1n移除反应及^(11)Be(p,d)和^(10)Be(d,p)转移反应是测量^(11)Be核心激发成分比例的典型实验类型。理论上,发展了能够包括^(11)Be核心激发成分的Faddeev AGS方法,XDWBA方法以及XCDCC方法。加入核心激发成分后,这些模型的计算结果可以更加合理地描述^(11)Be在各种靶上的弹性散射和碎裂微分截面。通过对比是否包含核心激发成分的计算结果,发现其影响主要体现在弹散微分截面的大质心系角度,以及(p,d)转移反应角分布的小质心系角度。另外,对Ex=0.5～3 Me V的激发能区的碎裂反应,核心激发的影响不可忽略;对Ex=3～5.5 Me V的碎裂反应,核心激发的贡献非常重要。
