Rare Event Searches at MIT

尽管粒子物理学的标准模型取得了成功，但它并不是故事的终点。该模型没有解释的特征太多了，包括暗物质的起源，为什么中微子质量如此之轻，物质-反物质不对称是如何产生的，以及为什么只有在弱力作用下才会出现电荷对奇偶性的破坏。这些问题激励着麻省理工学院（MIT）的罕见事件搜索小组。该奖项为两个超越标准模型的搜索提供支持：轴子搜索ABRACADABRA和中微子双衰变（NLDBD）搜索KamLAND-Zen和相关的研发项目NuDot。ABRACADABRA将进行轴子的搜索，轴子是被认为形成暗物质的粒子之一。中微子双β衰变的演示将解决为什么中微子质量如此轻以及宇宙中物质-反物质不对称的原因等问题。该计划将通过将本科生纳入该计划，为社会带来几个有益的方面。这些项目的多学科方面吸引了各个专业的学生，让学生们有机会接触粒子和核物理，否则他们可能会错过机会。NuDOT和ABRACADABRA探测器正在与当地公司的科学家密切合作开发。这使小组中的本科生有机会选择不同的职业道路，并促进学术界和工业界之间的紧密联系。kamland - zen将是第一个吨级NLDBD实验。NuDot是一个潜在的升级路径，可以打开更大规模的大门。另一方面，ABRACADABRA在新一波“桌面”超标准模型实验中处于领先地位。这在很大程度上是一个未知的实验，因为它即将产生第一个结果。ABRACADABRA将发现级粒子物理学带回了大学。提议的研究的高智力价值体现在物理问题与粒子物理计划优先级小组（P5）确定的“科学驱动因素”的优秀一致性上。该提案涉及：1)与中微子质量相关的物理学的追求；2)暗物质新物理的发现；3)探索未知的新粒子、相互作用和物理原理。这项工作同样与核科学咨询委员会（NSAC）的长期计划保持一致，该委员会呼吁迅速开展NLDBD实验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Despite its successes, the Standard Model of particle physics cannot be the end of the story. There are too many features that the model does not explain, including the origin of dark matter, why neutrino masses are so light, how the matter-antimatter asymmetry arose, and why Charge-Parity-violation only appears when weak forces are concerned. These are the questions that motivate the Rare Event Search Group at the Massachusetts Institute of Technology (MIT). This award provides support for two beyond-Standard-Model searches: the axion search ABRACADABRA, and the neutrinoless double-beta decay (NLDBD) search KamLAND-Zen and related R&D project NuDot. ABRACADABRA will undertake a search for axions, which are one of the particles postulated to form dark matter. A demonstration of neutrinoless double-beta decay would address the questions of why neutrino masses are so light and what produces the matter-anti-matter asymmetry in the universe.The program will deliver several beneficial aspects to society through its integration of undergraduates into the program. The multidisciplinary aspects of the projects are appealing to students across a range of majors, exposing students to particle and nuclear physics when they might otherwise have missed the opportunity. The NuDOT and ABRACADABRA detectors are being developed in close association with scientists at local companies. This exposes the undergraduates in the group to alternative career paths as well as promoting strong ties between academia and industryKamLAND-Zen will be the first ton-scale NLDBD experiment. NuDot, which is a potential upgrade path, can open the door to even large scales. On the other hand, ABRACADABRA is leading the way in a new wave of "table top" beyond-Standard-Model experiments. This is a largely unknown experiment, because it is about to bring out first results. ABRACADABRA brings discovery-level particle physics back to the university. The high intellectual merit of the proposed studies is demonstrated by the excellent alignment of the physics questions with the "science drivers" identified by the Particle Physics Program Prioritization Panel (P5). This proposal addresses: 1) the pursuit of the physics associated with neutrino mass; 2) the identification of the new physics of dark matter; and 3) the exploration of the unknown for new particles, interactions and physical principles. This work is similarly well-aligned with the Long Range Plan of the Nuclear Science Advisory Committee (NSAC), which made the call to move quickly on NLDBD experiments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.