致密物质中的pasta物相
Pasta Phases in Dense Matter
申虹 1胡金牛 1纪凡 2武旭浩 3琚敏4
作者信息
- 1. 南开大学物理科学学院,天津 300071
- 2. 粒子输运与富集技术全国重点实验室,天津 300180
- 3. 燕山大学理学院,河北秦皇岛 066004
- 4. 中国石油大学(华东)理学院,山东青岛 266580
- 折叠
摘要
Pasta物相有可能出现在热的超新星物质和冷中子星中.在超新星物质中,具有一系列几何形状的pasta物相可以采用可压缩液滴(CLD)模型研究,其中核物质被划分为核子的致密液相和核子的稀薄气相.通过最小化包括表面能和库仑能贡献的总自由能,可以推导出两相共存的平衡条件.与仅考虑球形核的结果相比,包括pasta物相可以延迟向均匀物质的相变并扩大相图中的非均匀物质区域.研究发现,各种pasta形状的密度范围依赖于温度和质子分支比.采用CLD模型描述pasta物相所得到的热力学量与采用Thomas-Fermi近似得到的用于天体物理数值模拟的现实状态方程表中的热力学量基本一致.另一方面,采用能量最小化(EM)方法研究了可能发生在大质量中子星内部的强子-夸克pasta物相,该方法类似于CLD方法用于研究核的pasta物相.研究发现,采用的模型参数对于强子-夸克pasta物相有显著影响.
Abstract
The pasta phases are expected to appear in hot supernova matter and cold neutron stars.In supernova matter,the pasta phases with a series of geometric shapes are studied using the compressible liquid-drop(CLD)mod-el,where nuclear matter separates into a dense liquid phase of nucleons and a dilute gas phase of nucleons and a particles.The equilibrium conditions for two coexisting phases are derived by minimization of the total free energy including the surface and Coulomb contributions.Compared to the results considering only spherical nuclei,the in-clusion of pasta phases can delay the transition to uniform matter and enlarge the region of nonuniform matter in the phase diagram.It is found that the density ranges of various pasta shapes depend on both the temperature and the proton fraction.The thermodynamic quantities obtained with the pasta phases using the CLD model are consistent with those in the realistic equation of state table for astrophysical simulations using the Thomas-Fermi approxima-tion.The hadron-quark pasta phases occurring in the interior of massive neutron stars are studied using the energy minimization(EM)method,which is analogous to the CLD method for nuclear pasta.It was found that the hadron-quark pasta phases could be significantly affected by the model parameters used.
关键词
pasta物相/超新星物质/中子星Key words
pasta phase/supernova matter/neutron star引用本文复制引用
出版年
2024
NETL
NSTL
万方数据