来自增强暗物质的高能核反冲用于LZ 248-keV事件：超越晕依赖的高速尾部
High-Energy Nuclear Recoils from Boosted Dark Matter for the LZ 248-keV Event: Beyond the Halo-Dependent High-Velocity Tail
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中文总结 AI 辅助
针对LZ实验248-keV核反冲候选事件，提出轻增强暗物质弹性或非弹性散射的新解释，避开晕速度尾部不确定性，并给出基准谱与补充测试方案。
中文摘要 AI 辅助
LUX-ZEPLIN (LZ) 合作组报告了一个核反冲候选事件，其能量为 $E_R=248\pm23_{\rm stat}\pm23_{\rm sys}$ keV，最大局部显著性为 $3.4\sigma$，全局显著性为 $2.6\sigma$。一种突出的解释涉及接近非弹性阈值的重晕暗物质，因此敏感地依赖于银河系速度分布中约束较差的高速尾部。在本快报中，我们提出了一种基于轻增强暗物质（BDM）的定性不同的可能性，其入射能量主要由暗扇区质量谱决定。我们考虑多组分场景，其中增强态与氙核发生弹性或非弹性散射。对于弹性散射，赝标量介导的动量依赖性抑制了低能反冲。近阈吸热散射的近似单色BDM通量可以将信号限制在运动学确定的反冲端点之间，从而抑制低能和高能边带中的事件。此外，上散射态可能在暗扇区内不可见地衰变，从而保持单核反冲特征，而不需要它探测器稳定。我们展示了代表性的基准谱，并讨论了使用其他靶核和大体积液体闪烁体实验的补充测试。
英文摘要
The LUX-ZEPLIN (LZ) Collaboration has reported a nuclear-recoil candidate at $E_R=248\pm23_{\rm stat}\pm23_{\rm sys}$ keV, with a maximum local significance of $3.4σ$ and a global significance of $2.6σ$. A prominent interpretation invokes heavy halo dark matter near an inelastic threshold and therefore depends sensitively on the poorly constrained high-speed tail of the Galactic velocity distribution. In this Letter, we propose a qualitatively different possibility based on light boosted dark matter (BDM), whose incident energy is determined primarily by the dark-sector mass spectrum. We consider multi-component scenarios in which the boosted state scatters elastically or inelastically off xenon nuclei. For elastic scattering, pseudoscalar-mediated momentum dependence suppresses low-energy recoils. Near-threshold endothermic scattering of a nearly monochromatic BDM flux can instead confine the signal between kinematically determined recoil endpoints, suppressing events in both the low- and high-energy sidebands. The upscattered state may furthermore decay invisibly within the dark sector, preserving a single-nuclear-recoil signature without requiring it to be detector-stable. We present representative benchmark spectra and discuss complementary tests using other target nuclei and large-volume liquid-scintillator experiments.
发表机构
- Jazan University（扎赞大学）
- University of South Dakota（南达科他大学）
- University of Kansas（堪萨斯大学）
- Chungnam National University（忠南国立大学）
- Jeonbuk National University（全北国立大学）
- Korea Institute for Advanced Study（韩国高等研究院）
- Institute for Basic Science（基础科学研究院）
机构由 AI 辅助整理，请以论文原文为准。
