GeV-scale thermal WIMPs: Not even slightly ruled out
GeV-scale thermal WIMPs: Not even slightly ruled out
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DOI：
10.1103/physrevd.98.023016
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发表时间：
2018-05
影响因子：
5
通讯作者：
R. K. Leane;T. Slatyer;J. Beacom;K. Ng
中科院分区：
文献类型：
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作者：
R. K. Leane;T. Slatyer;J. Beacom;K. Ng
弱相互作用大质量粒子（WIMP）长期以来一直是暗物质候选者的主要类别之一。观测到的暗物质丰度可以通过早期宇宙中弱尺度暗物质湮灭的冻结而自然获得。这种“热弱相互作用”的情况下作出的总湮灭截面，可以在当今的实验测试的直接预测。虽然暗物质的质量约束可以高达$m_\chi\gtrsim100$ GeV的特定湮灭通道，总截面的约束尚未确定。我们构建的第一个模型独立的限制WIMP总湮灭截面，显示允许的组合的湮灭通道分支比大大削弱的灵敏度。对于具有s波湮灭到可见终态的热WIMP，我们发现暗物质的质量仅为m_\chi\gtrsim20 $ GeV。这是热遗迹WIMP质量的最强的基本上与模型无关的下限，以及幺正性界的质量上限（$m_\chi\lesssim 100$ TeV），它定义了我们所说的“WIMP窗口”。为了探索剩余的质量范围，我们概述了前进的道路。
Weakly Interacting Massive Particles (WIMPs) have long reigned as one of the leading classes of dark matter candidates. The observed dark matter abundance can be naturally obtained by freezeout of weak-scale dark matter annihilations in the early universe. This "thermal WIMP" scenario makes direct predictions for the total annihilation cross section that can be tested in present-day experiments. While the dark matter mass constraint can be as high as $m_\chi\gtrsim100$ GeV for particular annihilation channels, the constraint on the total cross section has not been determined. We construct the first model-independent limit on the WIMP total annihilation cross section, showing that allowed combinations of the annihilation-channel branching ratios considerably weaken the sensitivity. For thermal WIMPs with $s$-wave $2\rightarrow2$ annihilation to visible final states, we find the dark matter mass is only known to be $m_\chi\gtrsim20$ GeV. This is the strongest largely model-independent lower limit on the mass of thermal-relic WIMPs, together with the upper limit on the mass from the unitarity bound ($m_\chi\lesssim 100$ TeV), it defines what we call the "WIMP window". To probe the remaining mass range, we outline ways forward.