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arXiv 2107.14545nucl-thastro-ph.HEhep-ph
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强子-夸克交叉中子星的手征凝聚:从宇称二重态核子模型到NJL夸克模型

Chiral condensates for neutron stars in hadron-quark crossover: from a parity doublet nucleon model to an NJL quark model

Takuya Minamikawa, Toru Kojo, Masayasu Harada

摘要:

我们从核到夸克物质的范围研究了中子星物质中的手征凝聚。我们用宇称偶重态模型(PDM)描述核物质,用Nambu-Jona-Lasino(NJL)模型描述夸克物质,用插值核物质和夸克物质状态方程描述中等密度物质.模型参数受核物理和中子星观测的约束。内插域中的各种冷凝物估计从冷凝物的化学势依赖于在插值的边界。使用具有大量手征不变质量($m_0 \gtrsim 500$ MeV,这是中子星观测所青睐的)的PDM预测温和的手征恢复,和显着的手征凝聚体仍然重子密度$n_B \sim 2-3n_0$($n_0\simeq 0.16\,{\rm fm}^{-3}$:核饱和密度),顺利接近NJL预测的色味锁定相位在$n_B \gtrsim 5n_0$。同样的方法也可以用来估计双夸克凝聚、上夸克、下夸克和奇夸克的数密度以及轻子分数。在我们的描述中,手征恢复的内插域进行两个概念上不同的手征恢复效果;第一个是与核子中的正标量密度,相关的稀释制度,和其他主要来自修改的夸克狄拉克海,这是由夸克费米海的增长所引发的。本文讨论了几种在核物质和夸克物质中进行微观物理插值的定性方法。

英文摘要:

We study the chiral condensates in neutron star matter from nuclear to quark matter domain. We describe nuclear matter with a parity doublet model (PDM), quark matter with the Nambu--Jona-Lasino (NJL) model, and a matter at the intermediate density by interpolating nuclear and quark matter equations of state. The model parameters are constrained by nuclear physics and neutron star observations. Various condensates in the interpolated domain are estimated from the chemical potential dependence of the condensates at the boundaries of the interpolation. The use of the PDM with substantial chiral invariant mass ($m_0 \gtrsim 500$ MeV, which is favored by the neutron star observations) predicts the mild chiral restoration, and the significant chiral condensate remains to baryon density $n_B \sim 2-3n_0$ ($n_0\simeq 0.16\,{\rm fm}^{-3}$: nuclear saturation density), smoothly approaching the NJL predictions for the color-flavor-locked phase at $n_B \gtrsim 5n_0$. The same method is applied to estimate diquark condensates, number densities of up-, down- and strange-quarks, and the lepton fraction. In our descriptions the chiral restoration in the interpolated domain proceeds with two conceptually distinct chiral restoration effects; the first is associated with the positive scalar density in a nucleon, relevant in dilute regime, and the other primarily arises from the modification of the quark Dirac sea, which is triggered by the growth of the quark Fermi sea. We discuss several qualitative conjectures to interpolate the microphysics in nuclear and quark matter.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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