AI 中文总结
该研究分析亚GeV暗物质的直接与间接探测互补性，发现DAMIC-M与间接探测在矢量门户模型中互补性最佳，间接探测还可约束直接探测无法触及的中微子本底以下参数空间。
AI 中文摘要
我们在两个现实模型（矢量门户（暗光子）和标量门户（希格斯门户）模型）的框架下，分析了亚GeV暗物质（DM）的直接探测（DD）与间接探测（ID）之间的互补性。对于直接探测，我们重点关注当前DAMIC-M实验对DM-电子散射的最新约束及其未来投影；对于间接探测，我们考虑了现有的多个X射线/伽马射线和宇宙线（e±）观测，以及即将到来的MeV望远镜COSI，以获得DM湮灭率的相应约束和投影，随后将其转换为DM-电子散射截面并与直接探测的约束/投影进行比较。我们适当考虑了天体物理和银河传播的不确定性。研究发现，DAMIC-M与间接探测的互补性在矢量门户模型中表现最佳，尤其是当矢量媒介子比DM粒子更重时：在这种情况下，对于3 MeV ≲ m_DM ≲ 20 MeV的范围，当前DAMIC-M的约束与间接探测的综合约束相当（在某些天体物理构型下甚至更优）。对于其他情况和质量范围，间接探测通常更具约束性，且在某些质量范围内还能约束直接探测实验无法触及的中微子本底以下的参数空间。
英文摘要
We analyze the complementarity between direct detection (DD) and indirect detection (ID) searches of sub-GeV dark matter (DM) in the context of two realistic models: the vector-portal (dark photon) and scalar-portal (higgs-portal) models. For DD we focus on the latest constraints on the DM-electron scattering from the present DAMIC-M experiment as well as its future projection. For ID we consider several existing X-rays/gamma-rays and cosmic-ray ($e^\pm$) observations as well as the upcoming MeV telescope COSI to obtain the corresponding bounds and projections on the DM annihilation rate, which are then translated in terms of the DM-electron scattering cross-section and compared with the DD bounds/projections. We properly take into account astrophysical and galactic propagation uncertainties. We find that the complementarity between DAMIC-M and ID works best for the vector-portal model, especially for the case where the vector mediator is heavier than the DM particle: in this case, the present DAMIC-M bound becomes comparable to (or better than, for some astrophysical configurations) the combined ID limit for $3\,{\rm MeV} \lesssim m_{\rm DM} \lesssim 20\,{\rm MeV}$. For other cases and mass ranges, the ID is in general more constraining and can also, for some mass ranges, constrain the parameter space below the neutrino floor, which is inaccessible to DD experiments.
Comments25 pages, 7 figures. v2: references added, along with a note on the supernova bound and the self-interaction bound (for very light scalar)
