Early kinetic decoupling and a pseudo-Nambu-Goldstone dark matter model
Early kinetic decoupling and a pseudo-Nambu-Goldstone dark matter model
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DOI：
10.1103/physrevd.104.035025
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发表时间：
2021-06
期刊：
影响因子：
--
通讯作者：
T. Abe
中科院分区：
文献类型：
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作者：
T. Abe
本文研究了伪南武-戈德斯通暗物质模型中的早期动力学解耦效应。在早期宇宙中，粒子与热浴中粒子的pNG DM散射过程被小动量转移所抑制。结果，不能保持动力学平衡，并且DM的温度不同于冻出时期的热浴的温度。这种温差影响DM的热遗迹丰度。我们调查的早期动力学去耦在希格斯共振区，50 GeV。m X。mh/2，其中mx是DM的质量，并且mh/2 '62.5GeV。我们发现文献中为了得到DM能量密度的测量值而确定的DM-Higgs耦合被低估了。耦合的增强导致了希格斯粒子不可见衰变率的增大。它扩大了在对撞机实验中发现希格斯玻色子衰变的DM信号的能力。
We study the early kinetic decoupling effect in a pseudo-Nambu-Goldstone (pNG) dark matter (DM) model. The pNG DM scattering processes with particles in the thermal bath in the early Universe are suppressed by the small momentum transfer. As a result, kinetic equilibrium is not maintained, and the temperature of DM is different from the temperature of the thermal bath at the freeze-out era. This temperature difference affects the thermal relic abundance of DM. We investigate the early kinetic decoupling in the Higgs resonance region, 50 GeV . mχ . mh/2, where mχ is the mass of the DM, and mh/2 ' 62.5 GeV. We find that the DM-Higgs coupling determined to obtain the measured value of the DM energy density is underestimated in the literature. The enhancement in the coupling leads larger value of the Higgs invisible decay rate. It enlarges the capability to discover the DM signals from the decay of the Higgs bosons at collider experiments.