Nuclear deformation and neutron excess as competing effects for dipole strength in the pygmy region.
Nuclear deformation and neutron excess as competing effects for dipole strength in the pygmy region.
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核变形和中子过剩作为侏儒区偶极子强度的竞争效应
DOI：
10.1103/physrevlett.112.072501
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发表时间：
2014
影响因子：
8.6
通讯作者：
M. Anders
中科院分区：
文献类型：
--
作者：
R. Massarczyk;R. Schwengner;F. Dönau;S. Frauendorf;M. Anders
本文利用德累斯顿-罗森多夫亥姆霍兹中心的韧致辐射装置和三角大学达勒姆核实验室的韧致辐射装置，对质量数为128、132和134的氙同位素在中子分离能以下的电磁偶极强度进行了核共振荧光实验研究。系统的研究获得了关于中子过剩以及核变形对俾格米偶极共振区域强度的影响的新信息。的结果进行了比较与链的钼同位素和预测的随机相位近似在变形的基础上。结果表明，与中子过剩引起的核形变效应相比，核形变效应的作用较小。一个全球参数化的中子和质子数的强度，使我们能够推导出一个公式，能够预测的summedstrengths在侏儒地区的广泛质量范围内的核素。
The electromagnetic dipole strength below the neutron-separation energy has been studied for the xenon isotopes with mass numbers, 128, 132, and 134 in nuclear resonance fluorescence experiments using thebremsstrahlung facility at Helmholtz-Zentrum Dresden-Rossendorf and thefacility at Triangle Universities Nuclear Laboratory Durham. The systematic study gained new information about the influence of the neutron excess as well as of nuclear deformation on the strength in the region of the pygmy dipole resonance. The results are compared with those obtained for the chain of molybdenum isotopes and with predictions of a random-phase approximation in a deformed basis. It turned out that the effect of nuclear deformation plays a minor role compared with the one caused by neutron excess. A global parametrization of the strength in terms of neutron and proton numbers allowed us to derive a formula capable of predicting the summedstrengths in the pygmy region for a wide mass range of nuclides.