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.

将进行两项实验来测试自然的基本对称性。 第一个实验将寻找宇宙中的首选方向。 这是通过精确测量水银核的能量来实现的，水银核的能量是其自旋相对于恒星的排列的函数。 这种首选空间方向的存在违反了局部洛伦兹不变性（LLI）原理，这是大多数当前物理理论的基本对称性之一。 第二个实验使用一种称为钆铁石榴石的陶瓷材料来寻找电子的永久电偶极矩（edm）。 这是应对物理学中最大的实验挑战之一的新颖方法。 基本粒子非零edm的存在将违反时间反转不变性原理。 观察到对上述任何一种自然对称性的违反都会从根本上改变我们对物理世界的理解。 弦理论和超对称仍然是粒子物理学中最有吸引力的两个理论，尽管两者都被证明很难测试。 有人提出，弦理论可能允许在接近 LLI 实验中探测的水平上违反局部洛伦兹不变性。 类似地，超对称性预测电子电偶极矩非常接近将在 edm 搜索中探测的水平。 LLI 实验可能会进一步改进精密光泵磁力计。 电火花实验将扩展我们对铁石榴石表面电磁相互作用的理解。 这种更好的理解对于未来的磁信息存储设备可能很重要。 这两个实验都将为本科生提供宝贵的培训。