arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1406.3445nucl-th
收藏

旋转奇$A$核中$γ$振动的单声子和多声子激发

Single-phonon and multi-phonon excitations of the $γ$ vibration in rotating odd-$A$ nuclei

Masayuki Matsuzaki

摘要:

尽管量子多体系统中的集体运动被描述为玻色子激发,但原子核中的多声子激发很少被观察到。特别是,第一个双声子$γ$振动($2γ$)激发奇- $A$核在2006年报道,只有少数已被知道。最近,在$^{105}$ Nb中观察到显著增强的$B(E2)$ s喂养$2γ$态,并证实它们的母态是$3γ$态的候选者。在目前的工作中,模型空间是扩大从本作者以前的计算$^{103}$ Nb。目的有两个:一是研究如何改进$2γ$态的描述,二是研究集体$3γ$态的存在性,当集体$3γ$态存在时,通过计算带间$B(E2)$ s研究其集体性.基于推转模型和无规相位近似的粒子-振动耦合模型被用来计算旋转奇$A$核的振动态。采用广义强度关系方法计算了带间$B(E2)$。计算结果很好地再现了$0γ$ - $2γ$态的光谱,给出了$^{103}$ Nb和$^{105}$ Nb中$2γ$态与$B(E2)$ s增强的集体$3γ$态.最集体的$3γ$状态与最高的$K$在零旋转被认为是观察到的带的主要组成部分。

英文摘要:

Multi-phonon excitations in atomic nuclei were observed very rarely although collective motions in quantum many-body systems are described as bosonic excitations. In particular, the first two-phonon $γ$ vibrational ($2γ$) excitation in odd-$A$ nuclei was reported in 2006 and only a few have been known. Quite recently, conspicuously enhanced $B(E2)$s feeding $2γ$ states were observed in $^{105}$Nb and conjectured that their parent states are candidates of $3γ$ states. In the present work, the model space is enlarged from the present author's previous calculation for $^{103}$Nb. The purpose is twofold: One is to see how the description of $2γ$ states is improved, and the other is to examine the existence of collective $3γ$ states, and when they exist, study their collectivity through calculating interband $B(E2)$s. The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. Interband $B(E2)$s are calculated by adopting the method of the generalized intensity relation. The present calculation reproduces the observed spectra of $0γ$ - $2γ$ states well and gives collective $3γ$ states with enhanced $B(E2)$s to $2γ$ states in $^{103}$Nb and $^{105}$Nb. The most collective $3γ$ state with the highest $K$ at zero rotation is thought to be the main component of the observed band.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑