Ultracold EEDM - Measuring The Electron's Electric Dipole Moment Using Ultracold Molecules

超冷 EEDM - 使用超冷分子测量电子的电偶极矩

• 批准号: EP/X030180/1
• 负责人: Michael Tarbutt
• 金额: $ 239.12万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX030180%2F1
• 关键词: Ultracold; EEDM; Measuring; Electron; Electric

Our understanding of the fundamental particles, forces and symmetries of nature is far from complete. Our best theory of particle physics - the Standard Model - explains the particles and forces observed in experiments, yet fails to explain many cosmological observations about the Universe. We have little understanding of dark matter or dark energy, and no explanation for the observed asymmetry between matter and antimatter. Many theories have been constructed to address these shortcomings, but none are yet supported by experimental evidence. We aim to shed light on these important problems in particle physics and cosmology by measuring the roundness of electrons with exquisite precision.The roundness of a particle is quantified by its electric dipole moment (EDM). A non-zero EDM violates time-reversal symmetry, implying that nature has an arrow of time at a fundamental level. In almost all theories, this symmetry needs to be violated to explain the preponderance of matter over anti-matter in the Universe. In the Standard Model, the predicted value of the electron EDM is extremely tiny, whereas most new theories, including most forms of supersymmetry, predict values many orders of magnitude larger. Furthermore, some theories of dark matter predict EDMs that oscillate with a magnitude and timescale that can be measured. Thus, EDM measurements offer extraordinary potential for new discoveries - they tell us about the fundamental symmetries essential to understanding the origins and nature of our Universe, they distinguish decisively between the Standard Model and its extensions, and they offer clues about the nature of dark matter.We have built an instrument that measures the electron EDM using electrons in heavy molecules. The molecules are spin-polarized and the spin precession rate in an electric field is measured to determine the EDM. We cool the molecules to a few microkelvin so that we can watch the spin precess for a long time. This makes the measurement far more precise and is the key advance over previous measurements. The goals of the project are to bring the instrument to full sensitivity, study and control systematic effects that could give false results, then determine the electron roundness at least ten times better than ever before. We will also build the upgrades needed for a further factor of ten improvement. Our result will be sensitive to new particles with masses beyond the reach of the greatest colliders, and to interactions that orchestrated the matter-antimatter asymmetry in the Universe.

我们对自然的基本颗粒，力和对称性的理解远非完整。我们的最佳粒子物理理论 - 标准模型 - 解释了实验中观察到的颗粒和力，但无法解释有关宇宙的许多宇宙学观察。我们对暗物质或暗能量几乎没有理解，也没有解释物质和反物质之间的不对称性。已经建立了许多理论来解决这些缺点，但没有实验证据支持。我们的目的是通过以精确的精度来测量电子的圆度来阐明这些重要的问题。非零的EDM违反了时间反转对称性，这意味着大自然在基本层面上具有一定的时间。在几乎所有理论中，需要违反这种对称性，以解释物质比宇宙中反物质的优势。在标准模型中，电子EDM的预测值非常小，而大多数新理论（包括大多数形式的超对称性）预测了许多数量级的值。此外，一些暗物质的理论预测了可以测量的幅度和时间尺度振荡的EDM。因此，EDM的测量为新发现提供了非凡的潜力 - 他们告诉我们有关了解我们宇宙的起源和性质至关重要的基本对称性，它们在标准模型及其扩展方面进行了果断区分，并且它们提供了有关暗物质的性质的线索。我们建立了一种用电子EDM在重分子中进行电子的仪器。分子是自旋偏振的，并测量电场中的自旋进动速率以确定EDM。我们将分子冷却至几种微核素，以便可以长时间观察旋转进攻。这使得测量更加精确，并且是先前测量值的关键进步。该项目的目标是使该工具达到完全敏感性，研究和控制可能会产生错误结果的系统效应，然后确定电子圆度至少比以往任何时候都好十倍。我们还将建立进一步提高10倍的升级。我们的结果将对具有最大山脉最大的质量的新颗粒敏感，并对在宇宙中精心策划的物质抗反感的相互作用。