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

宇宙中物质比反物质多得令人困惑，这是我们这个时代最大的谜团之一。提出的解决方案要求基本的时间反转对称性被破坏的程度比粒子物理标准模型中的可能程度要大得多，这表明尚未发现的新物理可能要对我们宇宙的这种基本属性负责。发现新物理学线索的一种强有力的方法是以超高精度搜索电子等基本粒子的永久电偶极矩。我们正在建立一个电子电偶极矩(EEDM)搜索实验，它可以比目前最好的测量提高4个数量级以上。*在精度上如此巨大的飞跃需要一种激进的新技术。特别是，与所有其他以前的努力相比，需要精确测量的电子数量要大得多。我们已经开发了一种新的方法来执行eEDM搜索，使用捕获在稀有气体晶体中的大量极性分子。由于分子结构的原因，极性分子中的电子经历了极大的电场。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提高了实验的测量时间(因此也提高了精度)，但也冻结了分子的运动，消除了对外部电场的需要，从而消除了许多潜在的系统误差。稀有气体固体中定向分子的集合也自然配备了出色的共磁仪，以抑制磁场波动带来的误差，从而实现高精度的电火花加工实验。所有这些特点导致电火花加工实验具有新的物理灵敏度，最高可达极高的能量尺度。这项实验将由EDMCued合作(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。*精确的eEDM测量是发现新物理的对撞机实验的一个独立于模型且至关重要的补充。这是加拿大的第一次此类努力，我们的目标是达到对新物理的灵敏度水平，比目前或拟议中的任何其他实验都高出许多个数量级。这项实验将使加拿大亚原子物理界处于高能物理精密前沿的世界领先地位，并培养新一代亚原子物理学家。

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.