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.

天体物理学观测和宇宙学数据提供了强有力的证据，表明宇宙中近四分之一是由暗物质组成的，有充分的理由相信它不可能由已知的粒子组成。暗物质很可能由尚未揭示的新粒子组成。暗物质粒子有两种有充分动机的可能性：称为 WIMP 的重费米子粒子和玻色子超轻暗物质（ULDM），其中轴子是大规模搜索的一个子集。 WIMP 设施尚未发现暗物质。最近的理论建议激发了对质量低至 10^(-23) eV/c2 的 ULDM 粒子的研究，这些粒子不是单独检测的，而是通过它们产生的相干场来检测的。 Eöt-Wash 重力小组开发的扭转平衡技术最容易在小规模精密实验中检测到，非常适合寻找这些玻色子场的预期效果。该小组拥有悠久的教学传统。通过正式和非正式的指导，该项目将为本科生、研究生和博士后提供广泛的 STEM 教育。该项目提供基础物理、精密机械仪器的实现和精密测量执行方面的独特培训机会。所开发的技术正在应用于引力波探测以及地震学等应用领域。扭转天平已经变得足够灵敏，成为寻找 ULDM 的重要工具。最近，此类测量对轴子设置了一些最严格的限制。 -像和在技​​术进步的推动下，这种扭转平衡搜索将包括对现有仪器的升级，使这些暗物质搜索变得更加敏感。此外，还将进行数据分析以寻找等效原理的签名。在重力同时扭转平衡测试的数据流中违反了玻色子 ULDM 该奖项将资助使用旋转和固定扭转天平来搜索这种玻色子 ULDM。铍和聚乙烯测试材料，以提高 ULDM 灵敏度；在升级的固定扭转天平中使用现有的独特自旋极化扭转摆来搜索自旋耦合类轴子 ULDM，并通过精制熔融石英纤维来提高对 ULDM 信号的实验灵敏度；辅助传感器、升级读数和改进仪器屏蔽。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力评估进行评估，认为值得支持优点和更广泛的影响审查标准。

项目成果

Torsion-balance search for ultralow-mass bosonic dark matter

扭转平衡寻找超低质量玻色子暗物质

• DOI: 10.1103/physrevd.105.042007
• 发表时间: 2021-09-18
• 期刊: Physical Review D
• 影响因子: 5
• 作者: E. Shaw;M. Ross;C. Hagedorn;E. Adelberger;J. Gundlach
• 通讯作者: J. Gundlach