RUI: Searching for Preferred Directions in Space and Time

RUI：在空间和时间中寻找首选方向

• 批准号: 0855465
• 负责人: Larry Hunter
• 金额: $ 35.97万
• 依托单位: Amherst College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855465&HistoricalAwards=false
• 关键词: RUI; Searching; Preferred; Directions; Space

Two experiments will be pursued that test the fundamental underlying symmetries of nature. The first of these experiments will look for a preferred direction in the universe. This is accomplished by precisely measuring the energy of a mercury nucleus as a function of the alignment of its spin with respect to the fixed stars. The existence of such a preferred spatial direction violates the principle of Local Lorentz Invariance (LLI), one of the underlying symmetries of most current physical theories. The second experiment searches for a permanent electric dipole moment (edm) of the electron using a ceramic material called gadolinium iron garnet. This is a novel approach to one of the greatest experimental challenges in physics. The existence of a non-zero edm of a fundamental particle would violate the principle of time-reversal invariance. Observation of a violation of either of the above symmetries of nature would radically alter our understanding of the physical world. String theory and supersymmetry remain two of the most attractive theories in particle physics, though both have proven to be very difficult to test. It has been suggested that string theory might allow for a violation of local Lorentz invariance at a level close to that which will be probed in the LLI experiment. Similarly, supersymmetry predicts an electron electric dipole moment very close to the level that will be probed in the edm search. The LLI experiment may result in further improvements in precise optically pumped magnetometers. The edm experiment will stretch our understanding of electromagnetic interactions at the surfaces of the iron garnets. This improved understanding might be important in future magnetic information storage devices. Both of these experiments will provide valuable training to undergraduates.

将进行两个测试自然基本对称性的基本对称性的实验。 这些实验中的第一个将寻找宇宙中的首选方向。 这是通过精确测量汞核的能量来实现的，这是其自旋相对于固定恒星对齐的函数。 如此优选的空间方向的存在违反了局部洛伦兹不变性（LLI）的原理，这是大多数当前物理理论的基础对称性之一。 第二个实验使用称为Gadolinium Iron Garnet的陶瓷材料来寻找电子的永久性电偶极矩（EDM）。 这是针对物理学中最大的实验挑战之一的新方法。 基本粒子的非零EDM的存在将违反时间转换不变性的原理。 观察违反上述自然对称性的侵犯将根本改变我们对物理世界的理解。 弦理论和超对称性仍然是粒子物理学中最有吸引力的两个理论，尽管事实证明这两种理论很难测试。 有人提出，弦理论可能允许在LLI实验中探测的水平上违反局部洛伦兹的不变性。 同样，超对称性预测电子偶极矩非常接近EDM搜索中将探测的水平。 LLI实验可能会导致精确的光泵仪的进一步改善。 EDM实验将扩展我们对铁石榴石表面上电磁相互作用的理解。 在将来的磁性信息存储设备中，这种改善的理解可能很重要。 这两个实验都将为大学生提供宝贵的培训。