Ultracold Neutron Electric Dipole Moment Experiment

超冷中子电偶极矩实验

• 批准号: SAPPJ-2019-00031
• 负责人: Martin, Jeffery
• 金额: $ 40.07万
• 依托单位: University of Winnipeg
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762533
• 关键词: Ultracold; Neutron; Electric; Dipole; Moment

Our experiment aims to measure the neutron electric dipole moment (nEDM) more precisely than ever before. A new measurement of the nEDM will place even tighter constraints on theories involving new sources of Charge-Parity (CP) violation beyond the standard model. It is believed these are required in order to explain the predominance of matter over antimatter (baryon asymmetry) in the universe today. Quite generically, the experiment will constrain broad classes of new physics scenarios which do not conserve CP. A new measurement also could impact a long-standing mystery in the standard model, involving the appararent lack of CP violation arising from the strong force. A discovery of a non-zero nEDM would be a major discovery, because it would shed light on a broad range of theories. A key tool in this search is a new source of ultracold neutrons (UCN). UCN are slow moving neutrons that can be stored in material, magnetic, and gravitational bottles. Once they've been confined using such methods, their properties can be studied very carefully to search for deviations from expectations based on the standard model of particle physics. Our scientific collaboration is named the TUCAN (TRIUMF Ultracold Advanced Neutron) collaboration. In the past three years, we have completed a new source of UCN in Canada (at TRIUMF, Vancouver, BC) with the help of collaborators from Japan. New funds for upgrades to the UCN source and for the construction of a new neutron EDM experiment have been secured from the Canada Foundation for Innovation and partner contributions including a substantial contribution from Japan. Once the upgrades are complete, the source is projected to provide the highest density of UCN in the world. The source will be used to advance fundamental physics experiments to unprecedented levels of precision. Our activities over the next three years will involve the completion of the UCN source upgrade and the nEDM experiment construction. We will also use the existing UCN source at TRIUMF for experiments aimed at answering critical questions for the overall success of the experiment.

我们的实验旨在比以往更精确地测量中子电偶极矩（nEDM）。 nEDM 的新测量将对涉及标准模型之外的电荷宇称 (CP) 违反的新来源的理论施加更严格的约束。人们相信这些是解释当今宇宙中物质相对反物质的优势（重子不对称性）所必需的。一般来说，该实验将限制大量不守恒 CP 的新物理场景。新的测量还可能会影响标准模型中长期存在的一个谜团，即明显缺乏由强力引起的 CP 破坏。非零 nEDM 的发现将是一项重大发现，因为它将阐明广泛的理论。这项研究的一个关键工具是新的超冷中子源（UCN）。 UCN 是缓慢移动的中子，可以存储在材料瓶、磁瓶和引力瓶中。一旦使用此类方法限制了它们，就可以非常仔细地研究它们的特性，以寻找与基于粒子物理学标准模型的预期的偏差。我们的科学合作被命名为 TUCAN（TRIUMF 超冷高级中子）合作。在过去的三年里，我们在日本合作者的帮助下在加拿大完成了一个新的 UCN 来源（位于不列颠哥伦比亚省温哥华的 TRIUMF）。用于升级 UCN 源和建设新中子 EDM 实验的新资金已从加拿大创新基金会和合作伙伴捐款（包括日本的大量捐款）获得。一旦升级完成，该源预计将提供世界上最高密度的 UCN。该源将用于将基础物理实验推进到前所未有的精度水平。我们未来三年的活动将包括完成 UCN 源升级和 nEDM 实验建设。我们还将使用 TRIUMF 现有的 UCN 源进行实验，旨在回答实验总体成功的关键问题。