arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1607.04007nucl-thastro-ph.HEastro-ph.SR
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密度相关相对论Hartree-Fock理论和中子星中的$Δ$(1232)效应

$Δ$ (1232) effects in density-dependent relativistic Hartree-Fock theory and neutron stars

Zhen-Yu Zhu, Ang Li, Jin-Niu Hu, Hiroyuki Sagawa

摘要:

将密度相关的相对论Hartree-Fock(DDRHF)理论推广到$Δ$等压线,用于研究致密核物质和中子星。为此,我们求解了自旋为3/2粒子的Rarita-Schwinger方程。详细计算了$Δ$ -同量异位素自能的直接项和交换项。与相对论平均场论(Hartree近似)相比,DDRHF的参数依赖性较弱。在$ρ_B\sim0.27$ fm $^{-3}$处发现了早期出现的$Δ$ -同量异位素,与超子相当.另外,我们发现$Δ$ -等压线对物态方程的软化主要是由于等夸克介子耦合的约化Fock贡献,而π介子的贡献很小,可以忽略不计.我们最终得出结论,在典型的参数集,中子星与$Δ$ -等压星在其内部可能是一样重的两个大质量的质量被精确测量,半径比正常的中子星略小。

英文摘要:

The density-dependent relativistic Hartree-Fock (DDRHF) theory is extended to include $Δ$-isobars for the study of dense nuclear matter and neutron stars. To this end, we solve the Rarita-Schwinger equation for spin-3/2 particle. Both the direct and exchange terms of the $Δ$-isobars' self-energies are evaluated in details. In comparison with the relativistic mean field theory (Hartree approximation), a weaker parameter dependence is found for DDRHF. An early appearance of $Δ$-isobars is recognized at $ρ_B\sim0.27$fm$^{-3}$, comparable with that of hyperons. Also, we find that the $Δ$-isobars' softening of the equation of state is found to be mainly due to the reduced Fock contributions from the coupling of the isoscalar mesons, while the pion contributions are found negligibly small. We finally conclude that with typical parameter sets, neutron stars with $Δ$-isobars in their interiors could be as heavy as the two massive pulsars whose masses are precisely measured, with slightly smaller radii than normal neutron stars.

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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