Torsion-Balance Searches for Ultra-Light Dark Matter

扭平衡搜索超轻暗物质

• 批准号: 2012350
• 负责人: Jens Gundlach
• 金额: $ 42.45万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2012350&HistoricalAwards=false
• 关键词: Torsion; Balance; Searches; Ultra; Light

Astrophysical observations and cosmological data give strong evidence that nearly a quarter of the Universe consists of dark matter. There are strong reasons to believe that it cannot consist of known particles. It is likely that the dark matter consists of new particles that have not yet revealed themselves in any other context. There are two well-motivated possibilities for the dark-matter particles: heavy fermionic particles called WIMPs and bosonic ultra-light dark matter (ULDM), of which axions are a subset. Searches at large-scale facilities for WIMPs have not yet found dark matter. Recent theoretical suggestions have inspired searches for ULDM particles with masses as low as 10^(-23) eV/c2. These particles are not detected individually, but rather by the coherent fields they produce, which are most-readily detected in small-scale precision experiments. The torsion balance technology developed by the Eöt-Wash Gravity Group is ideally suited to search for the effects expected from these bosonic fields. The group has a long tradition of teaching research to undergraduate students, graduate students, and postdocs. With formal and informal instruction this project will provide broad STEM education at all levels. This project offers unique training opportunities in fundamental physics, realization of precision mechanical instruments, and the execution of precision measurements. The technology developed is finding application in gravitational wave detection as well as in applied areas such as seismology.Torsion balances have become sensitive enough to be significant tools in the search for ULDM. Recently, such measurements have set some of the most stringent limits on axion-like and equivalence-principle-violating ULDM. Enabled by technological advances, this torsion balance search will encompass upgrades to existing instruments that make these dark matter searches substantially more sensitive. In addition, data analysis will be performed to look for the signature of equivalence-principle-violating bosonic ULDM in the data stream of concurrent torsion-balance tests of gravity. This award will fund searches for this bosonic ULDM using rotating and stationary torsion balances, using beryllium and polyethylene test materials to increase ULDM sensitivity; searches for spin-coupled axion-like ULDM using an existing unique spin-polarized torsion pendulum in an upgraded stationary torsion balance; and increase experimental sensitivity to ULDM signals by refining fused-silica fibers, adding auxiliary sensors, upgrading readout, and improving instrumental shielding.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

天体物理学观察结果和宇宙学数据提供了有力的证据，表明宇宙的几乎四分之一由暗物质组成。有充分的理由相信它不能由已知粒子组成。暗物质很可能由尚未在任何其他情况下尚未揭示自己的新粒子组成。黑暗粒子有两个动机的可能性：称为Wimps和Bosonic Ultraight Tark Matter（ULDM）的重型费米子颗粒（ULDM），其中轴为子集。在大规模设施中搜索WIMPS尚未发现暗物质。最近的理论建议激发了对质量低至10^（-23）eV/c2的ULDM颗粒的搜索。这些颗粒不是单独检测到的，而是通过它们产生的相干场来检测到的，这些粒子在小规模的精度实验中最明显地检测到。 Eöt-wash Gravity组开发的扭转平衡技术非常适合搜索这些骨磁场的预期。该小组有悠久的传统教授研究生，研究生和博士后。通过正式和非正式指示，该项目将在各个层面提供广泛的STEM教育。该项目在基本物理学，精确机械仪器的实现以及精确测量的执行方面提供了独特的培训机会。开发的技术正在发现引力波检测以及在地震学等应用领域中的应用。TORSION平衡已经变得足够敏感，可以成为搜索ULDM的重要工具。最近，此类测量已在类似于轴突的和等效侵入的ULDM上设定了一些最严格的限制。通过技术进步启用，这种扭转平衡搜索将涵盖使这些暗物质搜索更加敏感的现有工具的升级。此外，将进行数据分析以查找同时重力测试的数据流中等效性略大竞争性玻色子ULDM的签名。该奖项将利用腹膜和聚乙烯测试材料提高ULDM敏感性，利用旋转和固定扭转平衡来资助该玻色子ULDM的搜索；在升级的固定扭转平衡中，使用现有的独特的自旋旋转扭转摆来搜索旋转耦合的轴状ULDM；并通过精炼融合的二氧化硅纤维，增加辅助传感器，升级读数并改善工具性屏蔽来提高对ULDM信号的敏感性。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛影响的评估来审查审查的审查标准，这被认为是珍贵的支持。

项目成果

Torsion-balance search for ultralow-mass bosonic dark matter

• DOI: 10.1103/physrevd.105.042007
• 发表时间: 2021-09
• 期刊: Physical Review D
• 影响因子: 5
• 作者: E. Shaw;M. Ross;C. Hagedorn;E. Adelberger;J. Gundlach