包含超子的中子星物质：核子模型与SU(6)/SU(3)超子模型的贝叶斯比较
Neutron star matter with hyperons: Bayesian comparison of nucleonic and SU(6)/SU(3) hyperonic models
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中文总结 AI 辅助
该研究采用贝叶斯推断对比纯核子、SU(6)和SU(3)超子三种中子星物质模型，发现SU(3)模型的物态方程更硬，当前约束无法区分纯核子与SU(3)模型，对SU(6)模型的证据则不够决定性。
中文摘要 AI 辅助
我们在密度依赖的相对论平均场框架内，采用贝叶斯推断方法研究包含超子的中子星物质，考虑三种组成场景：纯核子物质、SU(6)味对称性下的超子物质，以及具有自由矢量 sector 参数的SU(3)对称性下的超子物质。分析纳入了核物质经验性质的约束、低密度下的理论输入，以及中子星的多信使观测结果。我们发现，基于夸克模型和同位旋计数规则的SU(6)方案会导致物态方程显著更软；相比之下，SU(3)框架的额外灵活性增强了矢量排斥作用，产生的物态方程相对更硬，且在探索的参数空间内与观测约束一致，特别是后验分布支持矢量耦合比α_v低于SU(6)的极限值α_v=1。这些差异体现在中子星的可观测量中，包括质量-半径关系、潮汐形变率、直接Urca阈值和振荡性质，在SU(3)场景下所有这些量均与当前约束兼容。我们进一步通过质量-半径关系的曲率研究结构特征，发现尽管富含超子的构型会引发明显变化，但此类特征对物态方程的硬度敏感，因此并非普遍可靠的指示器。贝叶斯模型比较还表明，当前约束无法有效区分纯核子场景与SU(3)超子场景，同时提供了反对更具限制性的SU(6)框架的积极但非决定性的证据。
英文摘要
We investigate neutron star matter with hyperons within a density-dependent relativistic mean-field framework using Bayesian inference, considering three composition scenarios: purely nucleonic matter, hyperonic matter under SU(6) flavor symmetry, and hyperonic matter under SU(3) symmetry with free vector-sector parameters. The analysis incorporates constraints from empirical nuclear matter properties, theoretical inputs at low densities, and multimessenger observations of neutron stars. We find that the SU(6) scheme, grounded in the quark model and isospin counting rule, leads to a significantly softer equation of state. In contrast, the additional flexibility of the SU(3) framework enhances vector repulsion and yields a comparatively stiffer equation of state consistent with observational bounds across the explored parameter space; in particular, the posterior distributions favor values of the vector coupling ratio $α_v$ lower than the SU(6) limit $α_v = 1$. These differences are reflected in neutron star observables, including mass--radius relations, tidal deformabilities, direct Urca thresholds, and oscillation properties, all of which remain compatible with current constraints within the SU(3) scenario. We further examine structural signatures through the curvature of the mass--radius relation and find that, although hyperon-rich configurations can induce noticeable variations, such features depend sensitively on the stiffness of the equation of state and are therefore not universally robust indicators. Bayesian model comparison further shows that present constraints do not meaningfully discriminate between the purely nucleonic and SU(3) hyperonic scenarios, while providing positive, but not decisive, evidence against the more restrictive SU(6) framework.
