Dynamical Dark Matter from Thermal Freeze-Out
Dynamical Dark Matter from Thermal Freeze-Out
复制标题
热冻结产生的动态暗物质
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
B. Thomas
中科院分区：
文献类型：
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作者：
K. Dienes;Jacob R. Fennick;J. Kumar;B. Thomas
在动力学暗物质（DDM）框架中，暗扇区由大量的暗粒子组成，它们的质量、寿命和宇宙学丰度彼此之间遵循特定的标度关系。特别是，这个框架的最自然的版本往往需要一个宇宙学丰度谱，它与质量成反比，因此质量较大的暗扇区状态具有较小的丰度。到目前为止，DDM模型的建立主要依赖于非热机制的丰度生成，如错位生产，因为这些机制产生的丰度，具有这种属性。相比之下，最简单的热冻结倾向于产生丰度，随着暗物质成分的质量增加而不是减少。在本文中，我们证明了传统的热冻结机制存在相对简单的修改，“翻转”所产生的丰度谱，产生丰度与质量成反比。此外，我们证明了更广泛的各种寿命，丰度和质量之间的缩放关系可以出现通过热冻结比通过非热机制先前考虑的DDM合奏。因此，本文的结果扩展到热域的DDM框架，并基本上允许我们“设计”我们的DDM合奏随意，以实现丰富的阵列所产生的暗物质现象。
In the Dynamical Dark Matter (DDM) framework, the dark sector comprises a large number of constituent dark particles whose individual masses, lifetimes, and cosmological abundances obey specific scaling relations with respect to each other. In particular, the most natural versions of this framework tend to require a spectrum of cosmological abundances which scale inversely with mass, so that dark-sector states with larger masses have smaller abundances. Thus far, DDM model-building has primarily relied on non-thermal mechanisms for abundance generation such as misalignment production, since these mechanisms give rise to abundances that have this property. By contrast, the simplest versions of thermal freeze-out tend to produce abundances that increase, rather than decrease, with the mass of the dark-matter component. In this paper, we demonstrate that there exist relatively simple modifications of the traditional thermal freeze-out mechanism which "flip" the resulting abundance spectrum, producing abundances that scale inversely with mass. Moreover, we demonstrate that a far broader variety of scaling relations between lifetimes, abundances, and masses can emerge through thermal freeze-out than through the non-thermal mechanisms previously considered for DDM ensembles. The results of this paper thus extend the DDM framework into the thermal domain and essentially allow us to "design" our resulting DDM ensembles at will in order to realize a rich array of resulting dark-matter phenomenologies.