发表机构
Lawrence Berkeley National Laboratory; University of California, Berkeley; Massachusetts Institute of Technology; Stanford University; SLAC National Accelerator Laboratory（劳伦斯伯克利国家实验室; 加州大学伯克利分校; 麻省理工学院; 斯坦福大学; SLAC国家加速器实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究针对LZ实验报告的单248 keV核反冲事件的希格斯微子解释，利用高能边带发现可能存在张力，还指出非热500 GeV希格斯微子或可规避该约束，未来重靶实验可检验相关解释。
AI 中文摘要
LZ实验在其2.84吨·年曝光量的氙靶中报告了一个248 keV的核反冲事件，低能核反冲事件的缺失可由非弹性散射暗物质（DM）自然解释，此类暗物质的核反冲能谱从零位向上偏移。令人兴奋的是，观测到的事例率和能谱与热产生的1.1 TeV希格斯微子（该粒子可解释全部暗物质，两个最低马约拉纳态间的质量分裂δ约为370-490 keV，范围取决于潜在的暗物质速度分布）一致。然而，本研究表明，具有这些性质的希格斯微子暗物质通常会在LZ实验S1c能轴上的高能边带产生更多高能反冲事件，但LZ实验在该能区未报告任何事例，这暗示了可能存在的张力，且该能区的接受度尚未公开，可由LZ合作组进一步探索。我们还表明，非热产生的约500 GeV希格斯微子可能规避该边带约束，未来使用重靶的实验或可从正反两方面检验该事件的希格斯微子解释。
英文摘要
The LZ experiment has reported a single 248 keV nuclear recoil event in their $2.84$ ton-yr exposure on a xenon target. The absence of lower nuclear recoil events is naturally explained by inelastically scattering dark matter (DM), for which the nuclear recoil energy spectra are shifted upwards from zero. Excitingly, the observed rate and spectra are consistent with a thermal $1.1$ TeV higgsino that explains all of DM with a mass splitting $δ\sim 370 - 490$ keV between the two lowest-lying Majorana states, with the range depending on the underlying DM velocity distribution. In this work, however, we show that higgsino DM with these properties would generically produce more higher-energy recoil events in a high-energy sideband along the LZ $S1c$ energy axis, while the LZ experiment reports no events in that bin. This suggests a possible tension which could be further explored by the LZ Collaboration, as the acceptance in that bin is not public. We further show that a non-thermal $\sim$500 GeV higgsino may evade the sideband constraint and that future experiments using heavy targets can potentially test the higgsino interpretation of the event either way.
Comments9 pages, 1 figure
