Two Novel Approaches to the Hadron-Quark Mixed Phase in Compact Stars
Two Novel Approaches to the Hadron-Quark Mixed Phase in Compact Stars
复制标题
致密恒星中强子-夸克混合相的两种新方法
DOI：
10.3390/universe4090094
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发表时间：
2018
期刊：
影响因子：
2.9
通讯作者：
H. Grigorian
中科院分区：
文献类型：
--
作者：
V. Abgaryan;D. Alvarez;A. Ayriyan;D. Blaschke;H. Grigorian
一阶相变，如液气转变，是通过气泡和液滴等结构的形成进行的。在强相互作用的致密恒星物质中，在壳核转变以及核心中的强子-夸克转变中，这些结构形成了不同的形状，被称为“面食相”。我们描述了两种方法来获得单参数混合状态方程（EoS）族，取代麦克斯韦结构，模拟低密度强子和高密度夸克物质相之间面食相的热力学行为，而无需明确计算几何结构。这两种方法都将麦克斯韦构造作为一种极限情况再现。第一种方法用多项式插值法代替麦克斯韦构造临界压力附近有限区域内压力对化学势的变化。第二种方法使用麦克斯韦点以外的强子和夸克物质的外推来定义两者的混合，并且在麦克斯韦点周围有有限极限的权函数。我们将这两种方法应用于具有强一阶跃迁的混合EoS的情况，该跃迁需要形成第三族致密恒星和相应的质量双生现象。对于这两个模型，我们研究了这种现象对单一参数变化的稳健性：临界化学势处的压力增量，量化了与麦克斯韦构造的偏差。我们还展示了致密恒星除了质量和半径之外的一系列观测结果，即转动惯量和重子质量。
First-order phase transitions, such as the liquid-gas transition, proceed via formation of structures, such as bubbles and droplets. In strongly interacting compact star matter, at the crust-core transition but also the hadron-quark transition in the core, these structures form different shapes dubbed “pasta phases”. We describe two methods to obtain one-parameter families of hybrid equations of state (EoS) substituting the Maxwell construction that mimic the thermodynamic behaviour of pasta phase in between a low-density hadron and a high-density quark matter phase without explicitly computing geometrical structures. Both methods reproduce the Maxwell construction as a limiting case. The first method replaces the behaviour of pressure against chemical potential in a finite region around the critical pressure of the Maxwell construction by a polynomial interpolation. The second method uses extrapolations of the hadronic and quark matter EoS beyond the Maxwell point to define a mixing of both with weight functions bounded by finite limits around the Maxwell point. We apply both methods to the case of a hybrid EoS with a strong first order transition that entails the formation of a third family of compact stars and the corresponding mass twin phenomenon. For both models, we investigate the robustness of this phenomenon against variation of the single parameter: the pressure increment at the critical chemical potential that quantifies the deviation from the Maxwell construction. We also show sets of results for compact star observables other than mass and radius, namely the moment of inertia and the baryon mass.
影响因子：
8.7
作者：
Arzoumanian, Zaven;Brazier, Adam;Zhu, Weiwei
通讯作者：
Zhu, Weiwei
影响因子：
7.9
作者：
Bauswein, Andreas;Just, Oliver;Stergioulas, Nikolaos
通讯作者：
Stergioulas, Nikolaos