论文标题
$^{29} $ f揭幕了两种中子光环
A two-neutron halo is unveiled in $^{29}$F
论文作者
论文摘要
我们报告了$^{27,29} $ f的反应横截面（$σ_r^{\ rm ex} $）的测量值，其中riken的碳靶。出乎意料的大$σ_r^{\ rm ex} $和派生的物质半径标识$^{29} $ f是迄今为止最重的两种中子borromean halo。光环归因于中子占据$ 2p_ {3/2} $ orbital，从而消失了与中子数$ n = 20 $相关的外壳闭合。结果通过最新的壳模型计算来解释。基于强核力量的有效场理论的耦合群集计算描述了$^{27} $ f的物质半径，但对$^{29} $ f受到挑战。
We report the measurement of reaction cross sections ($σ_R^{\rm ex}$) of $^{27,29}$F with a carbon target at RIKEN. The unexpectedly large $σ_R^{\rm ex}$ and derived matter radius identify $^{29}$F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the $2p_{3/2}$ orbital, thereby vanishing the shell closure associated with the neutron number $N = 20$. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of $^{27}$F but are challenged for $^{29}$F.
