A dark matter model that reconciles tensions between the cosmic-ray e(+/-) excess and the gamma-ray and CMB constraints
A dark matter model that reconciles tensions between the cosmic-ray e(+/-) excess and the gamma-ray and CMB constraints
复制标题
暗物质模型，可协调宇宙射线 e(/-) 过剩与伽马射线和 CMB 约束之间的紧张关系
DOI：
10.1016/j.physletb.2017.09.003
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发表时间：
2017
影响因子：
4.4
通讯作者：
Yin Peng Fei
中科院分区：
文献类型：
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作者：
Xiang Qian Fei;Bi Xiao Jun;Lin Su Jie;Yin Peng Fei
AMS-02观测到的宇宙线（CR）e±过剩可以用暗物质（DM）湮灭来解释。然而，DM解释需要一个大的湮灭截面，这是强烈不赞成其他观测，如费米-LAT的矮星系的伽玛射线观测和宇宙微波背景（CMB）的普朗克观测。此外，CR e±过剩所需的DM湮灭截面也太大，无法用热生产产生正确的DM残余密度。在这项工作中，我们使用Breit-Wigner机制与速度依赖DM湮灭截面来调和这些紧张局势。如果占CR e±的DM粒子与v <$O（10− 3）的过量非常接近物理极点情况下的共振，它们在银河系中的湮灭截面达到最大值。另一方面，相对速度较小的DM粒子在矮星系中和重组时的湮灭截面会受到抑制，这可能会分别影响伽玛射线和CMB观测。我们找到了一个能同时解释AMS-02结果和热遗迹密度的合适的参数区域，同时满足Fermi-LAT和Planck约束。
The cosmic-ray (CR) e±excess observed by AMS-02 can be explained by dark matter (DM) annihilation. However, the DM explanation requires a large annihilation cross section which is strongly disfavored by other observations, such as the Fermi-LAT gamma-ray observation of dwarf galaxies and the Planck observation of the cosmic microwave background (CMB). Moreover, the DM annihilation cross section required by the CR e±excess is also too large to generate the correct DM relic density with thermal production. In this work we use the Breit–Wigner mechanism with a velocity dependent DM annihilation cross section to reconcile these tensions. If DM particles accounting for the CR e±excess with v∼ O (10− 3) are very close to a resonance in the physical pole case, their annihilation cross section in the Galaxy reaches a maximal value. On the other hand, the annihilation cross section would be suppressed for DM particles with smaller relative velocities in dwarf galaxies and at recombination, which may affect the gamma-ray and CMB observations, respectively. We find a proper parameter region that can simultaneously explain the AMS-02 results and the thermal relic density, while satisfying the Fermi-LAT and Planck constraints.