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arXiv 2006.02698nucl-th
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ρ介子和夸克子结构对核自旋轨道势的贡献

Contribution of the rho meson and quark sub-structure to the nuclear spin-orbit potential

Guy Chanfray, Jérôme Margueron

摘要:

探讨了亚重子自由度自旋轨道势的微观起源,并讨论了其在核和超核中的应用。因此,我们开发了一个手征相对论的方法,耦合到标量和矢量介子场的夸克子结构控制。这种方法表明,SO势的等密度和等矢量密度依赖性可以用来测试在相对论框架中实现的微观成分:基态核子的夸克子结构及其与富介子扇区的耦合,其中$ρ$介子起着至关重要的作用。这也符合矢量优势模型(VDM)现象学和已知的核子磁性。我们探索的预测Hartree和Hartree-Fock平均场的基础上,以及各种情况下的$ρ$ -核子耦合,排名为弱,中等和强,这会影响SO潜在的isoscope和isovector密度依赖。我们发现,一个中等到强的$ρ$耦合是必不可少的再现Skyrme现象在$N=Z$核以及其isovector依赖。在SU(6)价夸克模型的假设下,我们的方法推广到超子,并对超核中$NΛ$自旋轨道势的猝灭有了一个微观的理解。它也适用于其他超子,如$Σ$,$Ξ$和$Ω$。

英文摘要:

The microscopic origin of the spin-orbit (SO) potential in terms of sub-baryonic degrees of freedom is explored and discussed for application to nuclei and hyper-nuclei. We thus develop a chiral relativistic approach where the coupling to the scalar- and vector-meson fields are controlled by the quark substructure. This approach suggests that the isoscalar and isovector density dependence of the SO potential can be used to test the microscopic ingredients which are implemented in the relativistic framework: the quark substructure of the nucleon in its ground-state and its coupling to the rich meson sector where the $ρ$ meson plays a crucial role. This is also in line with the Vector Dominance Model (VDM) phenomenology and the known magnetic properties of the nucleons. We explore predictions based on Hartree and Hartree-Fock mean field, as well as various scenarios for the $ρ$-nucleon coupling, ranked as weak, medium and strong, which impacts the isoscalar and isovector density dependence of the SO potential. We show that a medium to strong $ρ$ coupling is essential to reproduce Skyrme phenomenology in $N=Z$ nuclei as well as its isovector dependence. Assuming an SU(6) valence quark model our approach is extended to hyperons and furnishes a microscopic understanding of the quenching of the $NΛ$ spin-orbit potential in hyper-nuclei. It is also applied to other hyperons, such as $Σ$, $Ξ$ and $Ω$.

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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