Particle dark matter in the solar system
Particle dark matter in the solar system
复制标题
太阳系中的粒子暗物质
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
A. Peter
中科院分区：
文献类型：
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作者：
A. Peter
银河晕中的粒子暗物质可能通过与太阳中核子的弱相互作用而发生弹性散射(弱散射)，或者通过与行星(主要是木星)的引力相互作用(引力俘获)而绑定到太阳系。在这篇论文中，我模拟了弱散射，引力俘获，以及随后束缚轨道的演化，以确定束缚暗物质在地球位置的分布。以前关于这一主题的工作表明，在暗物质探测实验中，束缚粒子造成的事故率可能是直接探测实验中晕粒子的事故率的数量级，而由地球暗物质湮灭产生的中微子的事故率要高出几个数量级。我在一个由太阳和木星组成的简化太阳系中使用轨道的直接积分。我跟随束缚轨道，直到粒子在太阳中重新散射到不再与地球相交的轨道上，从太阳系抛出，或者达到太阳系TSS=4.5Gyr的寿命。由于粒子轨道的许多方面对传统的轨道积分方法提出了严重的问题，我针对这个问题提出了一种新的积分方案，即使在很长时间内对高度偏心的轨道也只有很小的振荡能量误差。使用我从模拟中产生的束缚暗物质分布函数，我证明了束缚暗物质对直接探测事件率的影响很小，使用新一代千米级中微子望远镜几乎不可能探测到地球上暗物质湮灭的中微子。我还展示了分布函数和由此产生的直接探测和中微子望远镜事件率如何按比例调整到其他粒子质量和弹性散射截面。
Particle dark matter in the Galactic halo may be bound to the solar system either by elastic scattering through weak interactions with nucleons in the Sun (weak scattering) or by gravitational interactions with the planets, mainly Jupiter (gravitational capture). In this thesis, I simulate weak scattering, gravitational capture, and the subsequent evolution of the bound orbits to determine the distribution of bound dark matter at the position of the Earth. Previous work on this subject suggested that the event rate in dark matter detection experiments due to bound particles could be of order the event rate of halo particles in direct detection experiments, and several orders of magnitude higher for neutrinos arising from dark matter annihilation in the Earth. I use direct integration of orbits in a simplified solar system consisting of the Sun and Jupiter. I follow bound orbits until the particles are either rescattered in the Sun onto orbits that no longer intersect the Earth, ejected from the solar system, or reach the lifetime of the solar system tSS = 4.5 Gyr. Since many aspects of the particle orbits pose severe problems for traditional orbit integration methods, I develop a novel integration scheme for this problem, which has only small and oscillatory energy errors even for highly eccentric orbits over very long times. Using the bound dark matter distribution functions I generate from the simulations, I show that bound dark matter has a small effect on direct detection event rates, and that it will be almost impossible to detect neutrinos from dark matter annihilation in the Earth with the new generation of km3scale neutrino telescopes. I also show how the distribution functions and resulting direct detection and neutrino telescope event rates can be scaled to other particle masses and elastic scattering cross sections.