原子核中的量子相变与铑元素的起源
Quantum Phase Transitions in Nuclei and the Origin of Rhodium
- Michigan State University（密歇根州立大学）
- Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究揭示太阳系铑和钌同位素丰度增强源于r-过程中不稳定核的形状突变（量子相变），为轻r-过程元素起源提供新诊断，并指出早期银河系可能存在不同类型的r-过程。
AI中文摘要：
天体物理快速中子俘获过程（r-过程）是负责产生比铜更重元素的主要核合成过程。观测推断的r-过程丰度分布中的显著特征为天体物理条件和可能的r-过程场所提供了关键线索。对于比碲更轻的r-过程元素，缺乏清晰特征导致提出了广泛的可能性场景和可能产生这些元素的替代过程。在这里，我们表明太阳系中铑和钌同位素相对于邻近同位素的增强可以作为这样一个特征。这种增强可以追溯到轻元素r-过程路径中不稳定稀有同位素形状的突然变化。这种形状变化已被描述为量子相变。这一发现指向了具有相对高中子密度和温度的r-过程场景，以解释太阳系中铑和钌的起源。在r-过程增强恒星中观测到的铑和钌丰度现在可以用作诊断产生这些较轻r-过程元素的r-过程条件的工具。这些元素的观测数据表明，不同类型的r-过程可能在早期银河系中运行，且这些条件不一定与过去使用的弱r-过程和主r-过程分类相一致。
英文摘要：
The astrophysical rapid neutron capture process (r-process) is a major nucleosynthesis process responsible for the production of elements heavier than copper. Prominent features in the observationally inferred r-process abundance distributions provide critical clues for astrophysical conditions and possible r-process sites. The lack of clear features for the r-process elements lighter than tellurium has led to a broad range of proposed possible scenarios and alternative processes that may produce these elements. Here we show that the enhancement found in the solar system of rhodium and ruthenium isotopes compared to neighboring isotopes can serve as such a feature. The enhancement can be traced back to sudden changes in shape of unstable rare isotopes in the path of the light element r-process. Such shape changes have been described as quantum phase transitions. This finding points to r-process scenarios with relatively high neutron densities and temperatures for the origin of rhodium and ruthenium in the solar system. Rhodium and ruthenium abundances observed in r-process enhanced stars can now be used as diagnostics for the r-process conditions that produce these lighter r-process elements. Observational data for these elements indicate that different types of r-processes may have operated in the early Galaxy, and that the conditions do not necessarily align with the weak and main r-process classifications used in the past.
