Axions and other very light axion-like particles appear in many extensions of the Standard Model, and are leading candidates to compose part or all of the missing matter of the Universe. They also appear in models of inflation, dark radiation, or even dark energy, and could solve some long-standing astrophysical anomalies. The physics case of these particles has been considerably developed in recent years, and there are now useful guidelines and powerful motivations to attempt experimental detection. Admittedly, the lack of positive signal of new physics at the high energy frontier, and in underground detectors searching for weakly interacting massive particles, is also contributing to the increase of the interest in axion searches. The experimental landscape is rapidly evolving, with many novel detection concepts and new experiments being proposed lately. An updated account of those initiatives is lacking in the literature. In this review we attempt to provide such a review. We will focus on the new experimental approaches and their complementarity, but will also review the most relevant recent results from the consolidated strategies and the prospects of new generation experiments under consideration in the field. We will also briefly review the latest developments of the theory, cosmology and astrophysics of axions and we will discuss the prospects to probe a large fraction of relevant parameter space in the coming decade.

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寻找类轴子粒子的新实验方法

轴子和其他非常轻的轴子状粒子出现在标准模型的许多扩展中，并且是构成宇宙中部分或全部缺失物质的主要候选者。它们还出现在暴胀、暗辐射甚至暗能量的模型中，并且可以解决一些长期存在的天体物理异常。近年来，这些粒子的物理案例得到了长足的发展，现在有了有用的指导方针和强大的动力来尝试进行实验检测。诚然，在高能前沿缺乏新物理学的积极信号，以及在寻找弱相互作用大质量粒子的地下探测器中，也有助于增加对轴子搜索的兴趣。实验环境正在迅速发展，最近提出了许多新的检测概念和新实验。文献中缺乏对这些举措的最新描述。在这篇评论中，我们试图提供这样的评论。我们将重点关注新的实验方法及其互补性，但也会回顾整合策略中最相关的最新结果以及该领域正在考虑的新一代实验的前景。我们还将简要回顾轴子的理论、宇宙学和天体物理学的最新发展，并讨论未来十年探测大部分相关参数空间的前景。我们将重点关注新的实验方法及其互补性，但也会回顾整合策略中最相关的最新结果以及该领域正在考虑的新一代实验的前景。我们还将简要回顾轴子的理论、宇宙学和天体物理学的最新发展，并讨论未来十年探测大部分相关参数空间的前景。我们将重点关注新的实验方法及其互补性，但也会回顾整合策略中最相关的最新结果以及该领域正在考虑的新一代实验的前景。我们还将简要回顾轴子的理论、宇宙学和天体物理学的最新发展，并讨论未来十年探测大部分相关参数空间的前景。