发表机构
University of Wisconsin, Madison; Fermi National Accelerator Laboratory; University of Chicago（威斯康星大学麦迪逊分校; 费米国家加速器实验室; 芝加哥大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一个赝狄拉克费米子暗物质模型，通过强子型媒介子解释LZ事件和银河系中心伽马射线超出，并指出特定质量劈裂下同一参数空间可同时解释两者。
AI 中文摘要
我们提出暗物质（DM）是一种质量约为$20-100$ GeV的赝狄拉克费米子，它通过一个强子型自旋1媒介子$V$（自发破缺重子数的规范玻色子）与标准模型发生非弹性耦合。两个DM本征态$\chi_{1}$和$\chi_2$在热冻结后获得近似相等的丰度，并通过过程$\chi_1 \chi_1 \to VV$和$\chi_2 \chi_2 \to VV$被消耗。尽管较重的态不稳定，但对于低于电子-正电子阈值的质量劈裂以及足够小的与$Z$玻色子的质量混合，其寿命可以超过宇宙年龄，使得两个态在银河系晕中保持近似相等的丰度。对于热遗迹湮灭截面，该模型可以产生与长期存在的银河系中心伽马射线超出（GCE）的观测特征一致的信号。如果$\delta \sim 1000$ keV，解释GCE的同一参数空间也可以通过氙核上的放热$\chi_2 \to \chi_1$下散射来解释LZ事件。
英文摘要
We propose that the dark matter (DM) is a pseudo-Dirac fermion with a mass of approximately $20-100$ GeV that couples inelastically to the Standard Model through a hadrophilic spin-1 mediator, $V$, the gauge boson of spontaneously broken baryon number. The two DM eigenstates, $χ_{1}$ and $χ_2$, acquire approximately equal abundances after thermal freeze-out and are depleted through the processes $χ_1 χ_1 \to VV$ and $χ_2 χ_2 \to VV$. Although the heavier state is unstable, for a mass splitting below the electron-positron threshold and sufficiently small mass mixing with the $Z$ boson, its lifetime can exceed the age of the universe, allowing both states to remain approximately equally abundant in the Galactic halo. For a thermal-relic annihilation cross section, this model can produce a signal that is consistent with the observed features of the longstanding Galactic Center Gamma-Ray Excess (GCE). If $δ\sim 1000$ keV, the same parameter space that explains the GCE can also explain the LZ event through exothermic $χ_2 \to χ_1$ downscattering off xenon nuclei.
Comments7 pages, 6 figures, comments welcome!
