发表机构
Yonsei University; Korea Institute for Advanced Study（延世大学; 韩国高等研究院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出一种衰变母粒子产生高能粒子在氙上散射的吸热暗物质模型，解释了LZ实验248 keV核反冲候选事件，并给出了通量、寿命及散射谱的定量预测。
AI 中文摘要
LUX-ZEPLIN实验报告了一个接近248 keV的核反冲候选事件。我们研究了一种吸热解释的衰变来源：一个长寿命的暗母粒子产生高能基态粒子，这些粒子在氙上发生上散射。母粒子的质量决定了注入能量，而其寿命则决定了通过银河系暗物质柱密度的绝对通量。我们考虑了母粒子和观测者运动引起的多普勒展宽，并使用天然氙同位素的精确散射运动学。对于标量接触相互作用，一个以10 MeV入射态和506 MeV母粒子为基准的模型给出了在248.5 keV处达到峰值的效率加权反冲谱。在指定的高能窗口中发生一个事件需要$\tau_X \simeq 4.4 \times 10^{20}$ 秒 $f_X [\sigma_{\text{ref}}/(10^{-36} \text{cm}^2)]$，其归一化对核响应敏感。我们量化了伴随的弹性散射要求和目标依赖的阈值。该计算确定了增强通量的衰变实现以及保持反冲信号所需的门户条件；探测器级别的拟合和紫外特定约束对于完整的实验评估仍然是必要的。
英文摘要
The LUX-ZEPLIN experiment has reported a nuclear-recoil candidate near 248 keV. We investigate a decay source for an endothermic interpretation: a long-lived dark parent produces energetic ground-state particles that upscatter on xenon. The parent mass fixes the injection energy, while its lifetime determines the absolute flux through the Galactic dark-matter column density. We include the Doppler broadening from parent and observer motion and use exact scattering kinematics with natural xenon isotopes. For a scalar contact interaction, a benchmark with a 10 MeV incident state and a 506 MeV parent gives an efficiency-weighted recoil spectrum peaked at 248.5 keV. One event in a specified high-energy window requires $τ_X \simeq 4.4 \times 10^{20}$ s $f_X [σ_{\text{ref}}/(10^{-36} \text{cm}^2)]$, with a normalization sensitive to the nuclear response. We quantify the accompanying elastic-scattering requirement and the target-dependent thresholds. The calculation identifies a decay realization of the boosted flux and the portal conditions needed to preserve the recoil signal; a detector-level fit and ultraviolet-specific constraints remain necessary for a complete experimental assessment.
Comments9 pages, 3 figures
