Astrophysical Studies of Quark Deconfinement

这个项目涉及在超高密度(比原子核密度高10到20倍)和温度(几千亿度)下强相互作用物质的性质的理论探索。科学界普遍认为，宇宙在大爆炸后不久就充满了超稠密物质。在灾难性恒星事件的最后阶段，如核心塌缩超新星和伽马射线爆发，超稠密物质继续被创造出来，它可能存在于坍塌恒星的核心深处，即众所周知的中子星。中子星通常直径约20公里，自转速度很快，通常每秒旋转数百圈。一个装满中子星物质的顶针将有10亿吨的质量！在如此特殊的条件下，原子本身崩塌，原子核被挤压得如此紧密，以至于产生了新的基本粒子，创造了新的物质状态。这使得中子星和创造它们的灾难性恒星事件成为优秀的天体物理实验室，用于广泛的物理研究，这在这个项目中得到了解决。关于这些极端条件下物质状态方程的理论预测可以用来与轨道和地面天文台快速积累的观测数据进行比较，这些观测数据跨越了从X射线到射电波长的辐射光谱。本项目重点研究(原)中子星和核坍塌超新星事件中夸克去禁闭的作用，使用最先进的(非局部三味Polyakov-Nambu-Jona-Lasinio，n3PNJL)模型来描述夸克物质。N3PNJL模型解释了手征对称性的动力学破缺，并通过Polyakov环势模拟了夸克禁闭。近年来，Nambu-Jona-Lasinio模型已经成为理论核物理中各种研究的主力，因为它为强相互作用理论(量子色动力学，QCD)提供了一种非常通用的和可数值处理的方法。这项研究将包括五个相互交织的活动：(1)冷夸克杂化物质的状态方程；(2)在n3PNJL模型框架下处理的彩色超导；(3)(原)中子星中的夸克解禁；(4)可能存在于中子星核心中的夸克-强子库仑晶格的性质；以及(5)夸克解禁对核坍塌超新星的作用。来自重离子碰撞和中子星观测的最佳可用数据将被用来对将在本研究项目框架内开发的状态方程施加尽可能最强的约束。状态方程将提供给更广泛的核和天体物理界，以探索(原)中子星的诞生、结构和演化以及产生它们的事件。

This project concerns the theoretical exploration of the properties of strongly interacting matter at ultra-high densities (10 to 20 times denser than atomic nuclei) and temperatures (several hundred billion degrees). It is generally accepted by the scientific community that the universe was filled with super-dense matter shortly after the Big Bang. Super-dense matter continues to be created in the final stages of catastrophic stellar events, such as core-collapse supernovae and gamma-ray bursts, and it may be present deep inside the cores of collapsed stars, known as neutron stars. Neutron stars are typically about 20 kilometers across and spin rapidly, often making many hundred of rotations per second. A thimble full of neutron star matter would have a mass of one billion tons! At such extraordinary conditions atoms themselves collapse, and atomic nuclei are squeezed so tightly together that new fundamental particles are generated and novel states of matter are created. This makes neutron stars, and the catastrophic stellar events creating them, into excellent astrophysical laboratories for a wide range of physical studies, which are addressed in this project. Theoretical predictions concerning the equation of state of matter under these extreme conditions can be used to compare the results of simulations with observational data accumulating rapidly from both orbiting and ground based observatories spanning the radiation spectrum from X-rays to radio wavelengths.This project focuses on the role of quark deconfinement for (proto) neutron stars and core-collapse supernova events, using a state-of-the-art (non-local 3-flavor Polyakov-Nambu-Jona-Lasinio, n3PNJL) model for the description of quark matter. The n3PNJL model accounts for the dynamical breaking of chiral symmetry and mimics quark confinement via the Polyakov loop potential. In recent years, the Nambu-Jona-Lasinio model has become the workhorse for various studies in theoretical nuclear physics, as it provides a very versatile and numerically treatable approach to the theory of the strong interaction (quantum chromodynamics, QCD). This research will consists of five intertwined activities concerning (1) the equation of state of cold quark-hybrid matter; (2) color superconductivity treated in the framework of the n3PNJL model; (3) quark deconfinement in (proto) neutron stars; (4) the properties of a quark-hadron Coulomb lattice that may exist in the cores of neutron stars; and (5) the role of quark deconfinement for core-collapse supernovae. The best available data from heavy ion collisions and neutron star observations will be used to impose the strongest possible constraints on the equation of state that will be developed in the framework of this research project. The equations of state will be made available to the wider nuclear and astrophysics community to explore the birth, structure and evolution of (proto) neutron stars and the events which create them.