发表机构
Brown University; Harvard University（布朗大学; 哈佛大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对LZ合作组报告的单原子核反冲事件，分析了1.1 TeV热希格斯微子暗物质模型的参数空间，探讨了其超对称紫外完备性及非热宇宙学情景，为相关实验提供了方向。
AI 中文摘要
希格斯微子暗物质是一种经典但仍可行的弱相互作用大质量粒子（WIMP）模型，该模型可能指向超对称（一种新的时空对称性），它是“非弹性暗物质”机制的简单实现，其与原子核的散射发生在两个近简并态之间。有趣的是，LZ合作组近期报告了一个高反冲能下的单原子核反冲事件。假设该事件是暗物质候选者，它可由希格斯微子暗物质解释，例如1.1 TeV的热希格斯微子，其质量分裂约为350 keV（采用标准晕模型；需更深入理解暗物质速度分布的高速尾端以实现更精确的测定）。我们绘制了希格斯微子质量-分裂平面中可解释该LZ单事件的参数空间。所需的质量分裂意味着超对称中的电弱gauginos（规范微子）和重希格斯标量必须处于约10³至10⁴ TeV的更高能标。我们讨论了可能的紫外完备理论，以生成一种超对称谱，其中所有超对称粒子都处于共同能标，仅希格斯微子质量μ要轻得多。除热基准情形外，我们还探讨了希格斯微子暗物质与引力微子、模衰变相关的非热宇宙学情景。希格斯微子暗物质场景也可通过其他互补探测手段寻找，例如间接探测和未来对撞机。这一引人注目的LZ单事件可能预示着未来进一步实验发展的光明前景。
英文摘要
Higgsino dark matter is a classic, but still viable, weakly-interacting massive particle (WIMP) scenario that could point to supersymmetry, a new spacetime symmetry of nature. It is a simple realization of the "inelastic dark matter" mechanism, where its scattering off a nucleus occurs between two nearly degenerate states. Intriguingly, very recently the LZ collaboration reported a single nuclear recoil event at a high recoil energy. Assuming that this event is a dark matter candidate, it could be explained by higgsino dark matter, e.g., a 1.1 TeV thermal higgsino with a mass splitting of order hundreds of keV. The mass splitting required is very sensitive to the extreme high speed tail of the local dark matter velocity distribution, and thus susceptible to astrophysical uncertainties: the standard halo model prefers ~350 keV, while a model incorporating Large Magellanic Cloud effects prefers ~500 keV (a rough estimate based on partial information about a particular simulation). A much better understanding of the high speed tail is needed to evaluate whether the parameter space is consistent with an IceCube constraint on the annihilation of dark matter captured by the Sun. In any case, the mass splitting of several hundred keV implies that the electroweak gauginos and heavy Higgs scalars in supersymmetry have to be at a much higher scale ~10^{3-4} TeV. We discuss possible UV completions to generate a SUSY spectrum in which all superpartners are at a common scale, except for a much lighter higgsino mass $μ$. Besides the thermal benchmark, we comment on possible non-thermal cosmological scenarios of higgsino dark matter with gravitino and modulus decays. The higgsino dark matter scenario could also be searched for at other complementary probes such as indirect detection and future colliders. One striking LZ event may herald an exciting future of further experimental developments.
Commentsv3: references added. v2: further emphasized the large astrophysical uncertainty in extracting the mass splitting, in light of the recent solar capture and Icecube bound; typos corrected and references added. 35 pages, 10 figures, human work
