Probing Fundamental Physics with Gravitational Experiments

用引力实验探索基础物理

• 批准号: 2309195
• 负责人: Jens Gundlach
• 金额: $ 105万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309195&HistoricalAwards=false
• 关键词: Probing; Fundamental; Physics; Gravitational; Experiments

In modern physics nature is described by two theories. One is the “Standard Model,” which describes all material properties with quantum particles; the other is “General Relativity”, Einstein’s theory that describes gravitation. Most physicists think that there must be a connection between these two theories, but to date there is no experimental signature for such a connection. Furthermore, the discoveries of dark matter and dark energy suggest that gravitational phenomena exist that lie outside of General Relativity. The group at the University of Washington specializes in measuring ultra-feeble forces to search for unprecedentedly small deviations from gravity as described by General Relativity. While observing any deviations from General Relativity would be a revolutionary scientific discovery, it may also have consequences for future technical applications of GPS or next-generation precision clocks. Furthermore, using instruments developed for gravity measurement, the group will look for signatures of dark matter. Technology and technical expertise developed by this group has applications ranging from industrial metrology to earthquake prediction to preparing the country’s STEM workforce.Modern ideas for unifying gravity and particle physics, as well as the observation of dark energy and dark matter, suggest that some aspects of gravity remain undiscovered. The table-top experiments of the University of Washington gravity laboratory (Eöt-Wash Group) provide a unique opportunity to search for new physics at the intersection of General Relativity, cosmology, and particle physics. The group is a leader in the field of ultra-weak force detection through technical expertise and innovation and by responding to the most relevant timely and timeless physics questions. Specifically, the group will: 1) Test the equivalence principle (EP): It is almost certain that any connection between General Relativity and the Standard Model violates the EP. The group’s torsion balances provided the most precise laboratory EP-tests. With highly increased sensitivity through fused silica torsion fibers, a novel gravity gradient measurement, an improved pendulum and better instrument control, new EP measurements will be carried out that will be up to 15 times more sensitive than the group’s previous measurements in constraining B-L couplings. Furthermore, the EP-test’s generality and relevance to cosmology will be enhanced by probing the EP involving hydrogen-rich test masses. 2) Test Newton's Inverse-Square Law (ISL) at short distances: The group will use its expertise in measuring gravity at short distances to build a new instrument and carry out measurements to test gravity at distances as short as 20 µm. 3) Search for ultra-light dark matter using torsion balances. 4) Advance the frontier of low-frequency ultra-small-force technology: Innovative and challenging technology development has enabled the group’s success. The group will further improve angle measurement and develop interferometric and capacitive distance gauges.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.

在现代物理学中，自然是由两种理论来描述的。一个是“标准模型”，它用量子粒子描述了所有的物质属性;另一个是“广义相对论”，爱因斯坦的理论描述了引力。 大多数物理学家认为这两个理论之间一定有联系，但到目前为止，还没有实验迹象表明这种联系。 此外，暗物质和暗能量的发现表明引力现象存在于广义相对论之外。华盛顿大学的这个小组专门测量超微弱的力，以寻找广义相对论所描述的前所未有的微小重力偏差。虽然观察到任何偏离广义相对论的现象都将是一个革命性的科学发现，但它也可能对GPS或下一代精密时钟的未来技术应用产生影响。此外，利用为重力测量而开发的仪器，该小组将寻找暗物质的特征。这个小组开发的技术和技术专长的应用范围从工业计量到地震预测，再到培养该国的STEM劳动力。统一引力和粒子物理学的现代思想，以及对暗能量和暗物质的观测，表明引力的某些方面仍然没有被发现。华盛顿大学重力实验室（Eöt-Wash Group）的桌面实验为在广义相对论、宇宙学和粒子物理学的交叉点上寻找新物理学提供了一个独特的机会。该集团是超弱力检测领域的领导者，通过技术专长和创新，并通过回应最相关的及时和永恒的物理问题。具体而言，该小组将：1）测试等效原理（EP）：几乎可以肯定的是，广义相对论和标准模型之间的任何联系都违反了EP。该集团的扭力天平提供了最精确的实验室EP测试。通过熔凝石英扭转光纤、新型重力梯度测量、改进的摆锤和更好的仪器控制，将进行新的EP测量，其灵敏度将比该小组以前在约束B-L耦合方面的测量高出15倍。此外，EP测试的通用性和宇宙学的相关性将通过探测EP涉及富氢的测试质量来增强。2)在短距离测试牛顿平方反比定律（ISL）：该小组将利用其在短距离测量重力方面的专业知识，建造一种新的仪器，并在短至20 µm的距离上进行测量以测试重力。3)用扭秤寻找超轻暗物质。4)推进低频超小力技术的前沿：创新和具有挑战性的技术开发使集团取得了成功。这个奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。