旋转中子星质量半径关系的研究

发布时间：2018-04-12 13:38

本文选题：中子星 + 质量半径关系　；参考：《华中师范大学》2013年硕士论文

【摘要】：极值条件下的核物质理论是在高能核物理的重要课题之一。它在了解重离子碰撞以及致密星的演化起着至关重要的作用。结合致密星内部物质的状态方程(EOS)和流体静力平衡条件下的TOV方程,就可以得到致密星的质量半径关系。中子星有非常丰富的结构。中子星的内部物质可能是高密度的核物质、夸克物质、奇异夸克物质、混合的核夸克物质,甚至还有可能是色超导。因为中子星是宇宙中仅次于黑洞的致密物体,在足够高的密度下,夸克可以从强子物质中解禁闭出来。因为库伯不稳定性,在高密度下夸克甚至可以像电子一样形成配对,由于两个夸克之间的吸引而形成色超导。不同组成和结构的中子星其EOS都不同。在不同模型和不同EOS的前提下,我们讨论了中子星的质量半径关系,同时也考虑了旋转。本文首先讨论了裸夸克星,并求解了单味色超导状态方程(CSL、polar、planar和A),同时也使用了CFL和2SC的状态方程。首先我们固定能隙△,得到不同色超导相下星体旋转频率对质量半径关系的影响。其次,考虑能隙△对化学势的依赖,对质量半径关系重新做了对比。我们发现状态方程对质量半径关系有一定影响,同时随着旋转频率增大,星体的质量也会变大。论文的第二个工作就是考虑混合星的质量半径关系。首先采用了BPAL模型来描述强子物质,并求解强子物质的状态方程。同时我们假定强子-夸克相变为一个等压相变过程。因此,可以通过强子-夸克物质的化学势-压强图(U-P图)来寻找相变点。当强子物质与三种不同色超导的相变点确定后,再依据TOV方程和TOV方程旋转微扰修正,我们就可以得到混合星的质量半径关系图。论文最后对全文所做的研究工作进行了一个小结,同时也对以后的工作方向做了大致的描述。
[Abstract]:Nuclear matter theory under extreme condition is one of the important subjects in high energy nuclear physics.It plays a vital role in understanding heavy ion collisions and the evolution of dense stars.The relation of mass radius of dense star can be obtained by combining the equation of state of matter in dense star and the TOV equation under hydrostatic equilibrium condition.Neutron stars have very rich structures.The inner matter of the neutron star may be high density nuclear matter, quark matter, strange quark matter, mixed nuclear quark matter, or even color superconducting.Because neutron stars are the only dense objects in the universe after black holes, quarks can be released from Hadron matter at a sufficiently high density.Because of the Cooper instability, quarks can even be paired like electrons at high density, and color superconductors are formed by the attraction between two quarks.The EOS of neutron stars with different composition and structure is different.On the premise of different models and different EOS, we discuss the relation of mass radius of neutron star and the rotation.In this paper, we first discuss the bare quark stars, and solve the equations of state of the single color superconducting superconducting, CFL and 2SC.First, we fixed the energy gap and obtained the influence of star rotation frequency on the mass radius under different color superconducting phases.Secondly, considering the dependence of energy gap on chemical potential, the relation of mass radius is recompared.It is found that the equation of state has a certain influence on the relation of mass radius, and the mass of stars increases with the increase of rotation frequency.The second work of this paper is to consider the mass radius relation of mixed stars.First, the BPAL model is used to describe the Hadron matter, and the equation of state of the Hadron matter is solved.We also assume that the Hadron-quark phase transition is an isobaric phase transition process.Therefore, the phase transition point can be found by the chemical potential-pressure diagram of Hadron quark matter (U-P diagram).When the phase transition points of Hadron matter and three different color superconductors are determined, and then the perturbation correction is made according to the TOV equation and TOV equation, the mass radius relation diagram of the mixed star can be obtained.At the end of the paper, a summary of the research work is given, and the future work direction is described.
【学位授予单位】：华中师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P145.6

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