Axions are highly motivated hypothetical particles beyond the standard model that can be dark matter candidates and address the strong 𝐶⁢𝑃 problem. Here we search for axion-mediated interactions generated between two separated 129Xe gas ensembles, monitoring and polarizing the 129Xe nuclear spins through spin-exchange interactions with Rb vapor. Our method exploits the magnetic amplification through effective fields from Rb-Xe collisions, increasing the sensitivity for axion-mediated interactions by up to 145-fold relative to conventional methods. Moreover, we employ template filtering to extract exotic interactions with a maximum signal-to-noise ratio. By combining two techniques, axion-mediated interactions are constrained to be less than 10−5 of normal magnetic interactions on a length scale of 60 mm. We establish new constraints on the neutron-neutron pseudoscalar couplings for a mass range that expands into the well-motivated “axion window” (10  μ⁢eV–1 meV), improving previous constraints by up to 50-fold within it and 118-fold outside it. We further discuss promising applications in searches for other axion-nucleon interactions, including axion dark matter and black hole axion bursts with sensitivity well beyond astrophysical limits by several orders of magnitude.

中文翻译：

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使用磁扩增对轴子介导的自旋相互作用的新约束


轴子是超出标准模型的高度激励的假设粒子，可以成为暗物质候选者并解决强 CP 问题。在这里，我们搜索两个分离的 129Xe 气体集合之间产生的轴子介导的相互作用，通过与 Rb 蒸气的自旋交换相互作用来监测和极化 129Xe 核自旋。我们的方法利用了 Rb-Xe 碰撞有效场的磁放大，相对于传统方法，将轴子介导的相互作用的灵敏度提高了 145 倍。此外，我们采用模板过滤来提取具有最大信噪比的奇异相互作用。通过结合两种技术，轴子介导的相互作用被限制在 60 mm 长度尺度上小于正常磁相互作用的 10−5。我们在中子-中子伪标量耦合上建立了新的约束，其质量范围扩展到良好的“轴子窗口”（10μeV–1meV），将之前的约束提高了 50 倍，将外部提高了 118 倍。我们进一步讨论了在搜索其他轴子-核子相互作用方面的有前途的应用，包括轴子暗物质和黑洞轴子爆发，其灵敏度远远超出了天体物理学的极限几个数量级。