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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691080
• 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，每个领域都有不同的方法和目标。所有领域都备受瞩目，Hessels 博士被国际原子物理学界认为是这些领域的领导者：***1。兰姆位移和质子电荷半径***原子氢 n=2 兰姆位移是使用微波和 Hessels 博士小组开发的新频偏分离振荡场 (FOSOF) 技术来测量的。测量完成后，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（或增强）当前不同的电荷半径测定之间的几个标准偏差的差异。这种差异被社区称为质子半径之谜，并且是过去 7 年中数百篇论文的主题。***2。氦精细结构和精细结构常数 ***对氦的 n=2 三重态 P 精细结构的新型超精密微波 FOSOF 测量正在完成，这将是对任何氦精细结构最精确的测量。它们将形成一种新的量子电动力学精确测试，也将使精密测量界更接近精细结构常数（决定所有电磁相互作用强度的自然基本常数）的高精度确定。精细结构常数的确定与电子 g 因子的确定之间的比较形成了对物理理论（包括暗物质或标准模型之外的其他物理的可能影响）的强有力的检验。 ***3.反物质原子的捕获、激光冷却和精确光谱***博士。 Hessels 和 ATRAP 合作团队正在准备一项实验，其中捕获的反氢原子将与激光相互作用。激光将用于减慢反物质原子的运动，这种减慢是实现这些反原子精密光谱的下一个重要步骤。氢和反氢光谱之间的比较将测试 CPT 以及物质和反物质之间的对称性。成功的激光冷却和激光冷却反物质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 合作更精确地测量反质子磁矩，正在与 Horbatsch 博士（约克）合作计算量子干涉对精确测量的影响，正在合作与 Storry 博士（约克）合作研究正电子素的精密光谱和新正电子原子（由负氢离子和正电子组成）的生产，并正在与Vutha 博士（多伦多大学）提出了测量电子电偶极矩的新想法。**