发表机构
University of Alberta; University of Illinois Chicago（阿尔伯塔大学; 伊利诺伊大学芝加哥分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究探讨LZ实验高能事件是否源于类氢原子暗物质的超精细激发，通过TeV尺度暗原子和约340 keV分裂解释观测，并预测靶材层次及年调制，同时考虑大麦哲伦云的影响。
AI 中文摘要
LUX--ZEPLIN（LZ）合作组在扩展的高能搜索窗口中报告了一个核反冲候选事件，能量为$248\pm23~({\rm stat})\pm23~({\rm sys})~{\rm keV}$。我们研究该事件是否可能源于类氢原子暗物质的超精细激发。对于TeV尺度的暗原子，接近$340~{\rm keV}$的超精细分裂通过自然选择银河系晕的高速尾部，同时抑制主要的低能弹性响应，使氙散射接近观测值。由此产生的吸热运动学预测了显著的目标层次：基准跃迁在Ar和Ge上不可达，在Xe上接近阈值，而在W等更重的靶上保持开放，这特定于我们的模型参数。由于氙探测极端高速尾部，信号表现出大的年调制和对假定晕分布的强烈依赖。我们还研究了麦哲伦云（Large Magellanic Cloud）的落入如何增强银河系本地暗物质分布的高速尾部，将运动学范围扩展到更大的超精细分裂。
英文摘要
The LUX-ZEPLIN (LZ) Collaboration has reported a nuclear-recoil candidate at $248\pm23~({\rm stat})\pm23~({\rm sys})~{\rm keV}$ in an extended high energy search window. We investigate whether this event can arise from the hyperfine excitation of hydrogen-like atomic dark matter. For a TeV-scale dark atom, a hyperfine splitting near $340~{\rm keV}$ places xenon scattering close to the observed value by naturally selecting the high-velocity tail of the Galactic halo while suppressing the leading low-energy elastic response. The resulting endothermic kinematics predict a pronounced target hierarchy: the benchmark transition is inaccessible on Ar and Ge, lies close to threshold on Xe, and remains open on heavier targets such as W, which is specific to our model parameters. Because xenon probes the extreme high-speed tail, the signal exhibits a large annual modulation and a strong dependence on the assumed halo distribution. We also examine how the infall of the Large Magellanic Cloud enhances the high-speed tail of the Milky Way's local dark matter distribution, extending the kinematic reach to larger hyperfine splittings.
Comments16 pages, 7 figures
