Tests of fundamental physics using precision measurements of simple atomic systems

使用简单原子系统的精密测量进行基础物理测试

• 批准号: RGPIN-2018-05864
• 负责人: Hessels, Eric
• 金额: $ 4.44万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712130
• 关键词: Tests; fundamental; physics; using; precision

The proposed research involves several separate areas, each with very different methodologies and objectives. All areas are high-profile, and Dr. Hessels is considered by the international atomic physics community to be a leader in these areas: 1. Lamb shift and the proton charge radius The atomic hydrogen n=2 Lamb shift is being measured using microwaves and the new Frequency-Offset Separated-Oscillatory-Fields (FOSOF) technique developed in Dr. Hessels' group. When the measurement is completed, it will determine the charge radius of the proton at a higher precision than can be achieved from all other existing hydrogen measurements combined. This result will help to resolve (or enhance) the current several-standard-deviation discrepancy between different determinations of the charge radius. This discrepancy is referred to by the community as the proton radius puzzle, and has been the topic of hundreds of papers in the past 7 years. 2. Helium fine structure and the fine-structure constant New ultraprecise microwave FOSOF measurements of the n=2 triplet P fine structure of helium are being completed, and will be the most precise measurements of any helium fine structure. They will form a new precise test of quantum electrodynamics and will also move the precision measurements community closer to a high-precision determination of the fine-structure constant (the fundamental constant of nature that determines the strength of all electromagnetic interactions). A comparison between this determination of the fine-structure constant and a determination from the electron g-factor forms a strong test of the theories of physics (including possible effects of dark matter or other physics beyond the Standard Model). 3. Trapping, laser-cooling and precise spectroscopy of antimatter atoms Dr. Hessels and the ATRAP collaboration are preparing for an experiment in which trapped antihydrogen atoms will interact with laser light. The laser light will be used to slow the motion of the antimatter atoms, and this slowing is the next major step towards precision spectroscopy of these anti-atoms. A comparison between hydrogen and antihydrogen spectroscopy will test CPT and the symmetry between matter and antimatter. Successful laser cooling and spectroscopy of laser-cooled antimatter will greatly advance the field of antimatter research. 4. Other work Additionally, Dr. Hessels is working with the ATRAP collaboration on a more precise measurement of the antiproton magnetic moment, is collaborating with Dr. Horbatsch (York) on calculations of the effect of quantum interference on precision measurements, is collaborating with Dr. Storry (York) on precision spectroscopy of positronium and on the production of a new positronic atom (composed of a negative hydrogen ion and a positron), and is collaborating with Dr. Vutha (U. Toronto) on a new idea for measuring the electric dipole moment of the electron.

拟议的研究涉及几个不同的领域，每个领域都有非常不同的方法和目标。所有的领域都备受瞩目，而Hessel博士被国际原子物理学界认为是这些领域的领导者： 1.兰姆位移与质子电荷半径 氢原子n=2的兰姆位移正在使用微波和新的频率偏移分离振荡场（FOSOF）技术进行测量。当测量完成时，它将以比所有其他现有氢测量组合更高的精度确定质子的电荷半径。这一结果将有助于解决（或加强）目前的几个标准偏差之间的不同测定的电荷半径的差异。这种差异被社区称为质子半径之谜，在过去的7年里，它一直是数百篇论文的主题。 2.氦原子的精细结构和精细结构常数 氦的n=2三重态P精细结构的新的超精密微波FOSOF测量正在完成，并且将是任何氦精细结构的最精确测量。它们将形成量子电动力学的一种新的精确测试，也将使精密测量界更接近于精细结构常数（决定所有电磁相互作用强度的自然界基本常数）的高精度测定。精细结构常数的测定与电子g因子的测定之间的比较形成了对物理学理论（包括暗物质或标准模型之外的其他物理学的可能影响）的强有力的测试。 3.反物质原子的俘获、激光冷却和精确光谱学 博士哈登和ATRAP合作正在准备一个实验，在这个实验中，被困的反氢原子将与激光相互作用。激光将被用来减缓反物质原子的运动，这种减缓是实现这些反原子精确光谱学的下一个主要步骤。氢和反氢光谱之间的比较将测试CPT和物质与反物质之间的对称性。成功的激光冷却和激光冷却反物质的光谱学将极大地推进反物质研究领域。 4.其他工作 此外，Hessels博士正在与ATRAP合作研究反质子磁矩的更精确测量，正在与Horbatsch博士（约克）合作计算量子干涉对精确测量的影响，正在与Storry博士（约克）合作研究正电子素的精确光谱学和新正电子原子的产生（由负氢离子和正电子组成），并与Vutha博士（U。多伦多）的一个新的想法，测量电偶极矩的电子。