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arXiv 1703.03039astro-ph.HE
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中子星并合中的中微子味演化

Neutrino Flavor Evolution in Neutron Star Mergers

James Y. Tian, Amol V. Patwardhan, George M. Fuller

摘要:

本文研究了双中子星(BNS)合并后的盘状残留物(以下简称\lq \lq \rq \rq)中中微子的味演化。我们专门跟踪从圆盘中心发出的中微子,沿着垂直于赤道平面的极轴。我们进行了两种口味的模拟使用各种不同的初始中微子光度和能量谱,并进行比较,在特定情况下,三味模拟。在所有的模拟中,使用了正常的中微子质量等级。发现味道演变高度依赖于初始中微子光度和能谱;特别是,我们发现两大类结果取决于初始净电子中微子轻子数的符号(即,中微子数减去反中微子数)。在反中微子占主导地位的情况下,我们发现,物质中微子共振(MNR)效应占主导地位,与以前的结果一致,而在中微子占主导地位的情况下,双极光谱交换的发展。后一个结果所需的中微子主导条件已经实现,例如,在BNS合并模拟中,采用\lq \lq DD 2 \rq \rq\中子星物质的状态方程[Phys. Rev. D 93,044019(2016)]。在这种情况下,除了在低能量下的交换,一个集体的米赫耶夫-斯米尔诺夫-沃尔芬斯坦(MSW)机制产生了一个高能量的电子中微子尾。在这种情况下,高能电子中微子数量的增加可能会对中微子盘平面外的物质中的$r$过程核合成的前景产生影响。

英文摘要:

We examine the flavor evolution of neutrinos emitted from the disk-like remnant (hereafter called \lq\lq neutrino disk\rq\rq) of a binary neutron star (BNS) merger. We specifically follow the neutrinos emitted from the center of the disk, along the polar axis perpendicular to the equatorial plane. We carried out two-flavor simulations using a variety of different possible initial neutrino luminosities and energy spectra, and for comparison, three-flavor simulations in specific cases. In all simulations, the normal neutrino mass hierarchy was used. The flavor evolution was found to be highly dependent on the initial neutrino luminosities and energy spectra; in particular, we found two broad classes of results depending on the sign of the initial net electron neutrino lepton number (i.e., the number of neutrinos minus the number of antineutrinos). In the antineutrino dominated case, we found that the Matter-Neutrino Resonance (MNR) effect dominates, consistent with previous results, whereas in the neutrino dominated case, a bipolar spectral swap develops. The neutrino dominated conditions required for this latter result have been realized, e.g, in a BNS merger simulation that employs the \lq\lq DD2\rq\rq\ equation of state for neutron star matter[Phys. Rev. D 93, 044019 (2016)]. For this case, in addition to the swap at low energies, a collective Mikheyev-Smirnov-Wolfenstein (MSW) mechanism generates a high-energy electron neutrino tail. The enhanced population of high-energy electron neutrinos in this scenario could have implications for the prospects of $r$-process nucleosynthesis in the material ejected outside the plane of the neutrino disk.

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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