Probing PeV-scale new physics using the electron electric dipole moment

利用电子电偶极矩探索 PeV 尺度的新物理

• 批准号: SAPPJ-2019-00057
• 负责人: Vutha, Amar
• 金额: $ 11.44万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762721
• 关键词: Probing; PeV; scale; new; physics

The bewildering excess of matter over antimatter in the universe is one of the biggest puzzles of our time. The proposed solutions to this puzzle require that fundamental time-reversal symmetry is violated to a much larger extent than is possible within the Standard Model of particle physics, suggesting that undiscovered new physics could be responsible for such a basic property of our universe. A powerful way to discover hints of new physics is to search with ultra-high precision for a permanent electric dipole moment of fundamental particles such as electrons. We are building an electron electric dipole moment (eEDM) search experiment that can improve upon the current best measurements by more than 4 orders of magnitude. Such a large leap in precision requires a radical new technique. In particular, compared to all other previous efforts, a much larger number of electrons need to be precisely measured. We have developed a new method to perform an eEDM search using a large ensemble of polar molecules trapped in a rare-gas crystal. Electrons in polar molecules experience extremely large electric fields due to the molecular structure. The lattice of the rare-gas crystal fixes the orientation and position of the molecules: trapping molecules in this way improves the measurement time (and therefore the precision) of the experiment, but also freezes molecular motion and removes the need for an externally applied electric field, thereby eliminating many classes of potential systematic errors. An ensemble of oriented molecules in a rare-gas solid is also naturally equipped with excellent co-magnetometers to suppress errors from magnetic field fluctuations, enabling a high-precision eEDM experiment. All of these features result in an eEDM experiment with new physics sensitivity up to extremely high energy scales. This experiment will be performed by the EDMCubed Collaboration (University of Toronto, York University, Michigan State University) using an apparatus located at York University. Precision eEDM measurements are a model-independent and vitally important complement to collider experiments for discovering new physics. This is the first Canadian effort of its kind, and we aim to achieve a level of sensitivity to new physics that is many orders of magnitude beyond any other current or proposed experiment. This experiment will place the Canadian subatomic physics community in a world leading position at the precision frontier of high energy physics, and train a new generation of subatomic physicists.

宇宙中物质多于反物质，令人眼花缭乱，这是我们这个时代最大的谜题之一。针对这个难题提出的解决方案要求基本的时间反转对称性被违反的程度比粒子物理学标准模型中可能的程度大得多，这表明尚未发现的新物理学可能是我们宇宙的这种基本属性的原因。发现新物理学线索的一个有效方法是以超高精度搜索电子等基本粒子的永久电偶极矩。我们正在构建电子电偶极矩 (eEDM) 搜索实验，该实验可以将当前最佳测量结果提高 4 个数量级以上。 如此大的精度飞跃需要一种全新的技术。特别是，与之前的所有其他努力相比，需要精确测量更多数量的电子。我们开发了一种新方法，使用稀有气体晶体中捕获的大量极性分子来执行 eEDM 搜索。由于分子结构，极性分子中的电子会经历极大的电场。稀有气体晶体的晶格固定了分子的方向和位置：以这种方式捕获分子可以提高实验的测量时间（从而提高精度），而且还可以冻结分子运动并无需外部施加电场，从而消除许多类别的潜在系统错误。稀有气体固体中的定向分子集合自然也配备了出色的共磁力计，以抑制磁场波动引起的误差，从而实现高精度 eEDM 实验。所有这些功能使得 eEDM 实验具有高达极高能量尺度的新物理灵敏度。该实验将由 EDMCubed 合作组织（多伦多大学、约克大学、密歇根州立大学）使用位于约克大学的设备进行。精密 eEDM 测量是对撞机实验的独立模型和至关重要的补充，以发现新的物理现象。这是加拿大的首次此类尝试，我们的目标是达到比任何其他当前或拟议的实验高出许多数量级的新物理学敏感度。该实验将使加拿大亚原子物理学界在高能物理精密前沿处于世界领先地位，并培养新一代亚原子物理学家。