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

阿尔法是欧洲核子研究中心的一个反物质实验。ALPHA合作涉及来自7个国家14个机构的科学家。这些科学家中有三分之一以上来自加拿大的研究实验室和大学。加拿大团队（ALPHA-Canada）的成员来自TRIUMF，UBC，SFU，UCalgary和YorkU。自2005年成立以来，它一直获得NSERC的重大项目资助，并获得了2013年NSERC波兰尼奖，并为众多ALPHA成就做出了重大贡献。阿尔法项目的目标是测量和比较“反氢”（反H）的性质-中性反物质的最简单原子形式-与普通氢的性质。在这样做的过程中，我们直接测试和挑战关于物质和反物质之间的相似性和差异（“对称性”）的基本理论，这个问题可以说是物理学中最大的未解决问题之一。自2011年以来，Alpha已经宣布了许多重要和备受瞩目的里程碑式成就，包括：中性反物质的长期捕获（2011年），原理微波研究的证明（2012年），对捕获的反H的引力测量（2013年），原位陷阱诊断（2013-14）和高精度测量抗H的电荷中性[1/10^8（2014），1/10^9（2016）]。阿尔法最近完成了一项重大升级，阿尔法加拿大在NSERC的支持下作出了重大贡献。新的ALPHA-2设备允许光学访问捕获的反H精确激光光谱，实验目前正在欧洲核子研究中心进行。我们对ALPHA-2的贡献包括：设计和制造新的反原子阱低温恒温器;升级探测器读出数据采集，陷阱电子，激光和微波系统。迄今为止，使用ALPHA-2的工作包括：抗H收集率提高至少10倍，用腔存储激光初步探测抗H，以及脉冲莱曼-α激光系统的调试。Alpha-Canada团队在ALPHA-2的调试和运行中发挥着重要作用，包括在探测器分析和脉冲激光系统操作方面提供领导。在与CFI和三个省的合作中，Alpha-Canada和Alpha通过设计、建造和制造与Alpha-2并行运行的第二台设备，进行了另一次基础设施升级。 ALPHA-g是一个系统，旨在测量中性反H上的引力，并回答“如果一个反物质苹果掉下来，它会怎么掉下来？”这个问题。该提案要求资助一个令人兴奋和高度可见的三年研究计划。它将导致有史以来第一次激光光谱学和原子反H的冷却，改进其超精细分裂的测量精度，探测基础物理，首次测量其莱曼-α光谱，以及首次观察到反H的引力自由落体。

ALPHA is an antimatter experiment based at CERN. The ALPHA Collaboration involves scientists from 14 institutions in 7 countries. Over one-third of these scientists come from Canadian research laboratories and universities. The Canadian team (ALPHA-Canada) has members at TRIUMF, UBC, SFU, UCalgary, and YorkU. It has held major project funding from NSERC since its inception in 2005, received the 2013 NSERC Polanyi Award, and has made significant contributions to numerous ALPHA achievements.***The goal of the ALPHA project is to measure and compare the properties of 'antihydrogen' (anti-H) - the simplest atomic form of neutral antimatter - with those of ordinary hydrogen. In doing so, we directly test and challenge fundamental theories about similarities and differences (‘symmetries') between matter and antimatter, an issue that is arguably one of the greatest unsolved problems in physics. Since 2011, ALPHA has announced many significant and high profile milestone achievements, including: long term trapping of neutral antimatter (2011), proof of principle microwave studies (2012), gravitational force measurements on trapped anti-H(2013), in situ trap diagnostics (2013-14) and high precision measurements of the charge neutrality of anti-H [1 part in 10^8 (2014), 1 part in 10^9 (2016)].***ALPHA recently completed a major upgrade, to which ALPHA-Canada made major contributions with NSERC support. The new ALPHA-2 apparatus allows optical access to trapped anti-H for precision laser spectroscopy, experiments that are currently underway at CERN. Our contributions to ALPHA-2 included: design and fabrication of the new anti-atom trap cryostat; upgrades to the detector readout data acquisition, trap electronics, laser, and microwave systems. Work to date with ALPHA-2 includes at least 10-fold improvement in anti-H collection rates, initial probing of anti-H with cavity-stored laser light, and commissioning of a pulsed Lyman-α laser system. The ALPHA-Canada team plays a prominent role in ALPHA-2 commissioning and operation, including providing leadership on detector analysis and pulsed laser system operation.***In partnership with CFI and three provinces, ALPHA-Canada and ALPHA have undertaken another infrastructure upgrade through design, construction, and fabrication of a second apparatus to run in parallel with ALPHA-2. ALPHA-g is a system designed to measure the gravitational forces on neutral anti-H and answer the question “If an antimatter apple was dropped, how would it fall?”***This proposal requests funding to support an exciting and highly-visible three-year program of research. It will result in the first-ever laser spectroscopy and cooling of atomic anti-H, improved measurements of the its hyperfine splitting at a precision that probes fundamental physics, first measurements of its Lyman-α spectra, and the first-ever observation of gravitational free-fall of anti-H.