标题： 超越WIMP：夸克（反）核子暗物质 显示英文标题

标题： Beyond WIMPs: the Quark (Anti) Nugget Dark Matter

摘要： 我们回顾了一个可检验的暗物质(DM)模型，该模型位于标准WIMP范式之外。 这个模型的独特之处在于，它能够自然地解释可见物质和暗物质密度之比 $\Omega_{\rm dark} \simeq \Omega_{\rm visible}$，这一比值源于它们共同的QCD起源：当两种物质（暗物质和可见物质）在QCD相变期间形成时，两者都与系统的单一维度参数 $\Lambda_{\rm QCD}$成比例。 我们指出，在存在奇异数量为 $\cal{CP}$的轴子场 $a(x)$ 的情况下，同样的QCD相变过程中不可避免地会发生电荷分离效应。 这会导致在可见宇宙尺度上，当轴子场 $a(x)$ 是相干的情况下，一种块状物更倾向于形成。 这种优先演化的自然结果是，在块状物完成形成后，系统中只留下一种类型的可见重子（而非反重子）。 与传统的WIMP暗物质候选者不同，块状物和反块状物是强相互作用但宏观尺度上的大物体。 反块状物与可见物质湮灭的稀有事件会导致一系列可观测的影响。 我们认为，从星系中心测量到的多个发射过量的相对强度（覆盖超过11个数量级）由标准且已确立的物理定律决定。 同时，发射的绝对强度由理论中的单一新基本参数决定，即轴子质量 $10^{-6} {\rm eV} \lesssim m_a \lesssim 10^{-3}{\rm eV}$。 最后，我们讨论了这些研究对轴子探测实验（包括微波腔和Orpheus实验）的意义。 显示英文摘要

摘要： We review a testable dark matter (DM) model outside of the standard WIMP paradigm. The model is unique in a sense that the observed ratio $\Omega_{\rm dark} \simeq \Omega_{\rm visible}$ for visible and dark matter densities finds its natural explanation as a result of their common QCD origin when both types of matter (DM and visible) are formed during the QCD transition and both are proportional to single dimensional parameter of the system, $\Lambda_{\rm QCD}$. We argue that the charge separation effect also inevitably occurs during the same QCD transition in the presence of the $\cal{CP}$ odd axion field $a(x)$. It leads to preferential formation of one species of nuggets on the scales of the visible Universe where the axion field $a(x)$ is coherent. A natural outcome of this preferential evolution is that only one type of the visible baryons (not anti- baryons) remain in the system after the nuggets complete their formation. Unlike conventional WIMP dark matter candidates, the nuggets and anti-nuggets are strongly interacting but macroscopically large objects. The rare events of annihilation of the anti-nuggets with visible matter lead to a number of observable effects. We argue that the relative intensities for a number of measured excesses of emission from the centre of galaxy (covering more than 11 orders of magnitude) are determined by standard and well established physics. At the same time the absolute intensity of emission is determined by a single new fundamental parameter of the theory, the axion mass, $10^{-6} {\rm eV} \lesssim m_a \lesssim 10^{-3}{\rm eV}$. Finally, we comment on implications of these studies for the axion search experiments, including microwave cavity and the Orpheus experiments.