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arXiv 1102.3973nucl-thastro-ph.SRnucl-ex
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超致密非对称核物质中的非费米壳层核子

Off-Fermi Shell Nucleons in Superdense Asymmetric Nuclear Matter

Michael McGauley, Misak M. Sargsian

摘要:

最近的观测表明,质子-中子(pn)相互作用相对于pp和nn短程关联(SRC)在原子核中具有很强的优势,这表明非对称高密度核物质可能存在一种新的条件,即由于张量相互作用,pp和nn相互作用被抑制,而pn相互作用被增强.我们表明,足够的不对称的情况下,高密度的较小的p-分量的动量分布强烈变形与质子越来越多地填充超出费米表面的动量状态。这一结果是通过对包含高动量转移的电-核反应实验数据的分析,提取出双核子(2N)SRC的几率得到的。我们拟合提取的概率作为核密度和不对称性的函数,并使用拟合来估计与中子星相关的超致密核物质中的非费米壳层核子的分数。我们的结果表明,从三个核饱和密度开始,分数密度为1/9的质子将主要占据动量分布的高动量尾部,而只有2%的中子会这样做。我们讨论了这一条件的影响中子星,并强调它可能是任何非对称的两个组件费米系统的特征与抑制中心和增强的短程张量之间的相互作用。

英文摘要:

Recent observations of the strong dominance of proton-neutron (pn) relative to pp and nn short-range correlations (SRCs) in nuclei indicate on possibility of unique new condition for asymmetric high density nuclear matter, in which the pp and nn interactions are suppressed while the pn interactions are enhanced due to tensor interaction. We demonstrate that for sufficiently asymmetric case and high densities the momentum distribution of the smaller p-component is strongly deformed with protons increasingly populating the momentum states beyond the Fermi surface. This result is obtained by extracting the probabilities of two-nucleon (2N) SRCs from the analysis of the experimental data on high momentum transfer inclusive electro-nuclear reactions. We fitted the extracted probabilities as a function of nuclear density and asymmetry and used the fit to estimate the fractions of the off-Fermi shell nucleons in the superdense nuclear matter relevant to neutron stars. Our results indicate that starting at three nuclear saturation densities the protons with fractional densities 1/9 will populate mostly the high momentum tail of the momentum distribution while only 2% of the neutrons will do so. We discuss the implications of this condition for neutron stars and emphasize that it may be characteristic to any asymmetric two component Fermi system with suppressed central and enhanced short-range tensor interactions between the two components.

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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