论文标题
在费米子暗物质模型中早期动力学脱钩的效果
The effect of the early kinetic decoupling in a fermionic dark matter model
论文作者
论文摘要
我们研究了早期动力学去耦的效果，该模型仅通过交换希格斯玻色子而与标准模型粒子相互作用，该模型与标准模型粒子相互作用。有两个DM-HIGGS耦合，分别是CP支持和CP侵入耦合。如果DM的质量略低于希格斯玻色子质量的一半，则抑制耦合以通过冷冻机制获得DM能量密度的测量值。另外，如果CP侵入DM-HIGGS耦合大于CP支持的偶数，则少量动量转移会抑制DM OFF颗粒的散射过程。由于抑制作用，DM的温度可能与热浴的温度不同。通过求解DM的数量密度和温度的耦合方程，我们计算了DM-HIGGS耦合，以重现适量的DM Relic丰度。我们发现，不考虑温度差异的情况，耦合必须大于获得的耦合。 DM-HIGGS耦合增强的结果是增强了Higgs隐形衰减分支比率。在当前和未来的对撞机实验中，可以测试增强。
We study the effect of the early kinetic decoupling in a model of fermionic dark matter (DM) that interacts with the standard model particles only by exchanging the Higgs boson. There are two DM-Higgs couplings, namely CP-conserving and CP-violating couplings. If the mass of the DM is slightly below half of the Higgs boson mass, then the couplings are suppressed to obtain the measured value of the DM energy density by the freeze-out mechanism. In addition, the scattering processes of DM off particles in the thermal bath are suppressed by the small momentum transfer if the CP-violating DM-Higgs coupling is larger than the CP-conserving one. Due to the suppression, the temperature of the DM can differ from the temperature of the thermal bath. By solving coupled equations for the number density and temperature of the DM, we calculate the DM-Higgs couplings that reproduce the right amount of the DM relic abundance. We find that the couplings have to be larger than the one obtained without taking into account the difference in the temperatures. A consequence of the enhancement of the DM-Higgs couplings is the enhancement of the Higgs invisible decay branching ratio. The enhancement is testable at current and future collider experiments.
