Fundamental Symmetry Tests with Trapped Antihydrogen: ALPHA at CERN/AD

捕获反氢的基本对称性测试：CERN/AD 的 ALPHA

• 批准号: SAPPJ-2020-00022
• 负责人: Fujiwara, Makoto
• 金额: $ 64.84万
• 依托单位: TRIUMF
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 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=718764
• 关键词: Fundamental; Symmetry; Tests; Trapped; Antihydrogen

This grant will support Canadian contributions to the scientific program of the CERN-based ALPHA Collaboration. The goal of ALPHA is to measure properties of the antihydrogen atom to the highest precision possible, and to compare them to those of the ordinary hydrogen atom. These comparisons serve as tests of fundamental symmetries between matter and antimatter, and are expected to shed light on issues that rank amongst some of the greatest unsolved problems in physics. The ALPHA Collaboration comprises approximately 50 scientists from 15 institutions in 7 countries. More than a third of those individuals come from Canadian research laboratories and universities (collectively called ALPHA-Canada), and will be supported by this grant. ALPHA-Canada has been funded by NSERC continuously since the ALPHA Collaboration was formed in 2005, and has played leading roles in many of ALPHA's most significant accomplishments. Examples of earlier high-profile milestones driven by NSERC funding include: stable (Nature 2010) and long term (Nature Physics 2011) trapping of neutral antimatter, proof of principle microwave spectroscopy (Nature 2012), and tests of charge neutrality (Nature Communications 2014 and Nature 2016). During the tenure of our most recent three-year funding cycle, we dramatically advanced the field of antihydrogen physics. In particular, construction and commissioning of a new apparatus (ALPHA-2) enabled us to transition from what one might call “proof-of-principle” demonstrations to a robust program of precision physics. Examples of scientific milestones attained since our last SAP Project Grant application was submitted to NSERC (October 2016) include: observation of laser-induced two-photon 1S-2S transitions in antihydrogen (Nature 2017), and a subsequent 2 part-per-trillion measurement of the frequency of that transition (Nature 2018); observation of the ground hyperfine spectrum of antihydrogen (Nature 2017), and a subsequent 9 part-per-million measurement of the frequency of that transition (Nature, under review); observation of the 1S-2P Lyman-alpha transition in antihydrogen (Nature 2018), and a subsequent measurement of the fine structure and Lamb shift (Nature, under review); and laser-cooling of antihydrogen and subsequent 1S-2S spectroscopy of laser-cooled antihydrogen (manuscripts under preparation). Further to this, we have developed and constructed yet another antihydrogen apparatus: ALPHA-g. The purpose of ALPHA-g is to enable experiments that will probe the gravitational interaction between antihydrogen and the Earth, yielding a first direct test of Einstein's Equivalence Principle in the antimatter sector. ALPHA-Canada has, is, and will play leading roles most aspects of the ALPHA-g program. In this application, we request funding to support and exciting and highly visible three-year program of activities that will significantly advance the frontiers of precision fundamental symmetry tests with antihydrogen atoms.

这笔赠款将支持加拿大对基于 CERN 的 ALPHA 合作项目的科学计划的贡献。 ALPHA 的目标是以尽可能高的精度测量反氢原子的性质，并将其与普通氢原子的性质进行比较。这些比较可以作为物质和反物质之间基本对称性的测试，并有望揭示物理学中一些最大的未解决问题之一。 ALPHA 合作组织由来自 7 个国家 15 个机构的约 50 名科学家组成。其中超过三分之一来自加拿大研究实验室和大学（统称为 ALPHA-Canada），并将获得这笔赠款的支持。自 2005 年 ALPHA 协作组织成立以来，ALPHA-Canada 一直受到 NSERC 的资助，并在 ALPHA 的许多最重要成就中发挥了主导作用。由 NSERC 资助推动的早期备受瞩目的里程碑的例子包括：中性反物质的稳定捕获（《自然》，2010 年）和长期（《自然·物理学》，2011 年）、微波光谱学原理证明（《自然》，2012 年）以及电荷中性测试（《自然·通讯》，2014 年和《自然》，2016 年）。 在我们最近的三年资助周期期间，我们极大地推进了反氢物理学领域的发展。特别是，新设备（ALPHA-2）的建造和调试使我们能够从所谓的“原理验证”演示过渡到强大的精密物理程序。自我们上次向 NSERC 提交 SAP 项目拨款申请（2016 年 10 月）以来取得的科学里程碑的例子包括：观察反氢中激光诱导的双光子 1S-2S 跃迁（《自然》杂志，2017 年），以及随后对该跃迁频率进行万亿分之二的测量（《自然》杂志，2018 年）；观察反氢的地面超精细光谱（《自然》，2017 年），以及随后百万分之九的跃迁频率测量（《自然》，正在审查中）；观察反氢中的 1S-2P 莱曼-α 跃迁（《自然》，2018 年），以及随后测量精细结构和兰姆位移（《自然》，正在审查中）；反氢的激光冷却和随后的激光冷却反氢的 1S-2S 光谱（手稿正在准备中）。 除此之外，我们还开发并建造了另一种反氢装置：ALPHA-g。 ALPHA-g 的目的是使实验能够探测反氢与地球之间的引力相互作用，从而对反物质领域的爱因斯坦等效原理进行首次直接测试。 ALPHA-Canada 已经、现在并将在 ALPHA-g 计划的大部分方面发挥主导作用。 在此申请中，我们请求资金来支持令人兴奋且高度引人注目的三年活动计划，该计划将显着推进反氢原子精确基本对称测试的前沿。