发表机构
Wuyi University; Nanjing University; National Taiwan University; Phenikaa University; University of Oslo; University of California, Los Angeles（五邑大学; 南京大学; 台湾大学; 菲尼亚卡大学; 奥斯陆大学; 加州大学洛杉矶分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出增强速度分布的轻磁偶极暗物质模型，可缓解LZ实验核反冲过剩与低能事件预测的矛盾，并支持GeV至TeV质量范围，为过剩提供可行解释。
AI 中文摘要
LZ合作组报告了在约248 keV处存在核反冲过剩现象，其全局显著性为$2.6\sigma$。尽管在LZ所考虑的相互作用中，具有磁偶极-偶极相互作用且质量在TeV量级的晕族暗物质对该过剩提供了最佳拟合，但它预测在较低反冲能量处会有大量事件，而那里并未观测到过剩。我们表明，增强的速度分布可以缓解这一矛盾，并为LZ反冲谱提供更好的拟合。此外，增强还开辟了用更轻的暗物质（质量可低至GeV量级）解释该过剩的可能性。我们首先在模型无关的分析中展示这些特征，然后在具体的暗物质模型中实现它们，在该模型中，晕族暗物质湮灭为在壳中介子，后者随后衰变为增强的暗扇区粒子。我们的结果表明，增强的暗扇区粒子为LZ过剩提供了一种可行的解释。
英文摘要
The LZ collaboration has reported a nuclear-recoil excess near 248 keV with a global significance of $2.6σ$. Although halo dark matter with a magnetic dipole-dipole interaction and a TeV-scale mass provides the best fit to the excess among the interactions considered by LZ, it predicts a considerable number of events at lower recoil energies, where no excess is observed. We show that a boosted velocity distribution can alleviate this tension and provide a better fit to the LZ recoil spectrum. Moreover, the boost opens up the possibility of explaining the excess with much lighter dark matter, with masses down to the GeV scale. We demonstrate these features first in a model-independent analysis and then realize them in a concrete dark matter model, in which halo dark matter annihilates into on-shell mediators that subsequently decay into boosted dark-sector particles. Our results demonstrate that boosted dark sector particles provide a viable interpretation of the LZ excess.
Comments6 pages, 3 figures
