发表机构
Universidad Andrés Bello; University of Coimbra; Instituto Tecnológico de Aeronáutica（安第斯贝尔托大学; 科英布拉大学; 航空技术学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出改进的mPNJL模型，结合强子物态方程得到稳定大质量冷混杂星，揭示模型参数对相变及混杂星结构的影响，发现排斥性矢量相互作用是稳定夸克核的关键。
AI 中文摘要
我们提出了一种改进的Polyakov圈Nambu-Jona-Lasinio（mPNJL）模型，其中Polyakov势显式依赖于夸克化学势，使其在零温度下仍保持有限，从而可描述冷致密物质中的禁闭-解禁闭相变。将该改进的夸克部分与强子物态方程通过麦克斯韦构造相结合，我们发现，根据模型参数的不同，物态方程可呈现两种相变：从强子物质到禁闭的夸克物质（夸克核物质），随后到解禁闭夸克物质；或单一相变，直接从强子物质到解禁闭夸克物质，或从强子物质到夸克核物质。我们获得了仅含夸克核相和/或解禁闭夸克相的稳定大质量冷混杂星。系统研究了改进Polyakov势的参数及夸克矢量相互作用如何控制这些相变的位置，发现排斥性矢量相互作用是获得稳定夸克核的关键。若在低密度下使用足够刚硬的强子物态方程，具有夸克核和/或解禁闭核心的混杂星可达到2倍太阳质量以上的最大质量。在最大质量构型的核心中，夸克核核心星的声速超过共形极限，即c_s²=1/3。本研究明确了每个模型参数在塑造混杂星结构中的定性作用。
英文摘要
We propose a modified Polyakov-loop Nambu--Jona-Lasinio (mPNJL) model in which the Polyakov potential is given by an explicit dependence on the quark chemical potential, allowing it to remain finite at zero temperature and thus to describe the confinement-deconfinement transition in cold dense matter. Combining this modified quark sector with hadronic equations of state via a Maxwell construction, we find that, depending on the model parameters, the equation of state can exhibit either two phase transitions, from hadronic matter to confined quark matter and subsequently to deconfined quark matter, or a single transition directly from hadronic to deconfined quark matter or from hadronic to confined quark matter. Stable massive cold hybrid stars with only confined and/or deconfined quark phase are obtained. We systematically examine how the parameters of the modified Polyakov potential and the quark vector interactions control the location of these transitions, and find that repulsive vector interactions are essential to obtain a stable quark core. Hybrid stars with confined and/or a deconfined core can reach maximum masses above $2M_\odot$, provided a sufficiently stiff hadronic equation of state is used at low density. In the core of the maximum-mass configurations, the speed of sound shows variations at finite baryon densities, with c$_s^2(μ)$ departing from the asymptotic conformal value c$_s^2$ = 1/3 in confined core stars. These variations serve as a diagnostic of the equation-of-state stiffness while remaining fully consistent with causality and thermodynamic stability. This work establishes the qualitative role of each model parameter in shaping hybrid-star structure.
