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arXiv 2404.02007nucl-thnucl-ex
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揭示手性三体力在驱动自旋-轨道劈裂中的机制

Uncovering the mechanism of chiral three-nucleon force in driving spin-orbit splitting

Tokuro Fukui, Giovanni De Gregorio, Angela Gargano

AI总结:

本研究通过基于不可约张量秩的分解方案,揭示手性三体力中秩-1分量是驱动p壳核自旋-轨道劈裂增强的主要机制,且不依赖接触项低能常数,为微观理解三体力对核壳结构影响奠定基础。

摘要:

三体力(3NF)在塑造原子核壳层结构中至关重要,尤其影响自旋-轨道(SO)劈裂的增强,特别是在偏离稳定性显著的原子核中。尽管其重要性,驱动这种增强的具体机制仍不清楚。在本研究中,我们引入了一种基于构成3NF的不可约张量秩的分解方案,该方案源自手性有效场论在次次领头阶,以阐明它们对SO劈裂的影响。在壳模型框架内,我们的分析揭示,3NF的秩-1分量是扩大p壳核中$0p_{3/2}$和$0p_{1/2}$单粒子能级之间能隙的主要因素,而秩-2分量贡献次主导。由于秩-1分量完全源自$2π$交换3NF,我们的发现将不依赖于接触项低能常数的选择。我们还讨论了秩-1 3NF的反对称性,这可能影响自旋态的量子纠缠。这项研究为进一步探索该领域奠定了基础,以实现对3NF对核壳结构影响的微观理解。

英文摘要:

The three-nucleon force (3NF) is crucial in shaping the shell structure of atomic nuclei, particularly impacting the enhancement of spin-orbit (SO) splitting, especially in nuclei with significant deviations from stability. Despite its importance, the specific mechanisms driving this enhancement remain unclear. In this study, we introduce a decomposition scheme based on the rank of irreducible tensors forming the 3NF, derived from chiral effective field theory at next-to-next-to-leading order, to elucidate their influence on SO splitting. Within the shell-model framework, our analysis reveals that the rank-1 component of the 3NF is the primary factor enlarging the energy gap between the $0p_{3/2}$ and $0p_{1/2}$ single-particle levels in $p$-shell nuclei, while the rank-2 component makes a subdominant contribution. Since the rank-1 component originates exclusively from the $2π$-exchange 3NF, our finding will not depend on the choice of the low-energy constants of contact terms. We also remark on the antisymmetry of the rank-1 3NF, which can affect the quantum entanglement of spin states. This study lays the groundwork for further exploration into this field toward a microscopic understanding of the 3NF impact on the nuclear shell structure.

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。

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