Collaborative Research: Axion Resonant InterAction DetectioN Experiment (ARIADNE)

多次天文观测已经证实，宇宙中大约85%的物质不是由已知粒子构成的。破译这种所谓的暗物质的本质对宇宙学、天体物理学和高能粒子物理学至关重要。粒子物理学中最令人兴奋的任务之一是寻找超越粒子物理学标准模型的新粒子。标准模型的扩展不仅预测了具有大质量的新粒子，而且还预测了一些质量非常小的粒子。这样的候选者就是轴子，它被引入来解释量子色动力学中电荷宇称（CP）破坏的小性，而且它也被证明是宇宙中暗物质组成的主要候选者。该奖项将为研发提供资金，以开发一种新的实验，以寻找亚毫米范围内原子核之间的轴子样相互作用。在参与这项研究的同时，一个由博士后、研究生和本科生组成的团队将在实验原子物理的各种技术方面接受广泛的培训，如低温物理、磁屏蔽、真空系统和建模。实验采用旋转的非磁性物质作为轴子场的源，用密集的激光极化氦-3核系综通过核磁共振探测轴子场。在核自旋进动频率处适当调节轴子势，可以使轴子场的信号共振增强。该方法有可能将以前的轴子实验和天体物理界限提高几个数量级，并深入探索理论上有趣的Peccei-Quinn （PQ）轴子体系。这个实验对更奇异的类轴子粒子也很敏感。据估计，这种方法最终可以超过目前实验室对自旋依赖的短程力的限制，最高可达8个数量级，并且可以在10^9和10^12之间的f_a主要轴子范围内将实验室/天体物理的综合限制提高10^4倍，深入探索理论上有趣的PQ轴子制度。与宇宙轴子搜索不同的是，该装置对轴子很敏感，即使它不构成暗物质的大部分。

Multiple astronomical observations have established that about 85% of the matter in the universe is not made of known particles. Deciphering the nature of this so-called Dark Matter is of fundamental importance to cosmology, astrophysics, and high-energy particle physics. One of the most exciting quests in particle physics is the search for new particles beyond the Standard Model of particle physics. Extensions of the Standard Model predict not only new particles with large masses but also some with very small masses. Such a candidate is the axion, which has been introduced to explain the smallness of Charge-Parity (CP) violation in Quantum Chromodynamics and which turns out to also be a prime candidate for a constituent of the dark matter in the universe. This award will provide funds for R&D towards developing a new experiment to search for axion-like interactions between nuclei at sub-millimeter ranges. While participating in this research, a team of postdocs, graduate students and undergraduate researchers will be broadly trained in the various techniques of experimental atomic physics such as low-temperature physics, magnetic shielding, vacuum systems and modeling. The experiment involves a rotating non-magnetic mass to source the axion field, and a dense ensemble of laser-polarized He-3 nuclei to detect the axion field by NMR. The signal from an axion field can be resonantly enhanced by properly modulating the axion potential at the nuclear spin precession frequency. The method has the potential to improve previous experimental and astrophysical bounds on axions by several orders of magnitude and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. The experiment is also sensitive to more exotic axion-like particles. It is estimated that this method can ultimately exceed present laboratory constraints on spin-dependent short-range forces by up to eight orders of magnitude and can improve on the combined laboratory/astrophysical limits by a factor of 10^4 in the prime axion range of f_a between 10^9 and 10^12, probing deep into the theoretically interesting regime for the PQ axion. In contrast to cosmic axion searches, the setup is sensitive to the axion even if it does not make up most of the dark matter.