发表机构
Pusan National University; Korea Institute for Advanced Study; Tohoku University; University of Tokyo（釜山国立大学; 韩国高等研究院; 东北大学; 东京大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究探讨了环境依赖的轴子耦合Higgsino暗物质湮灭，发现其在太阳和银河系中增强，可解释少量暗物质并满足中微子约束，同时产生可探测的伽马射线信号。
AI 中文摘要
我们研究了与质量略低于Higgsino对阈值的类轴子粒子耦合的准狄拉克Higgsino暗物质的环境依赖湮灭。在太阳和银河系晕中，相对于电弱湮灭，轴子介导的湮灭变得比晚期非热产生后的宇宙学再湮灭更为重要。这种分离源于亚阈值传播子的低速增强以及从共湮灭Higgsino多重态到最轻中性态的变化。在太阳俘获-湮灭平衡中，占主导地位的湮灭通道为无质量暗光子，抑制了高能中微子信号，同时保持俘获效率。因此，Higgsino可以占总暗物质丰度的百分之几，同时满足太阳中微子约束并保持可观的地面非弹性散射率，这对LZ高反冲候选事件具有意义。在银河系晕中，增强的截面反而产生相关的连续谱和线状伽马射线信号，对于尖点银河暗物质分布，这些谱线可能接近当前灵敏度。我们讨论了基于广义幻影调解和隐藏强动力学的超对称实现，以及扩展希格斯扇区替代方案。暗光子还对暗辐射有贡献，提供了互补的宇宙学探测手段。
英文摘要
We study environment-dependent annihilation of quasi-Dirac Higgsino dark matter coupled to an axion-like particle with a mass slightly below the Higgsino-pair threshold. Axion-mediated annihilation becomes more important relative to electroweak annihilation in the Sun and Galactic halo than during cosmological reannihilation following late nonthermal production. This separation arises from both the low-velocity enhancement of the subthreshold propagator and the change from a coannihilating Higgsino multiplet to the lightest neutral state. In solar capture-annihilation equilibrium, a dominant annihilation channel into massless dark photons suppresses the high-energy neutrino signal while leaving capture efficient. Higgsinos can consequently account for a few percent of the total dark matter abundance while satisfying solar-neutrino constraints and retaining an appreciable terrestrial inelastic-scattering rate, with implications for the LZ high-recoil candidate. In the Galactic halo, the enhanced cross section instead produces correlated continuum and line gamma-ray signals, with the lines potentially close to the present sensitivity for a cuspy Galactic dark-matter profile. We discuss supersymmetric realizations based on generalized mirage mediation and hidden strong dynamics, as well as an extended Higgs-sector alternative. The dark photons also contribute to dark radiation, providing a complementary cosmological probe.
Comments52 pages, 1 figure
