Neutrino Physics at the University of Chicago

20世纪最重要的智力成就之一是粒子物理学标准模型（SM）的发展。这个模型成功地将当时已知的所有基本粒子划分为具有相似量子特性的等级。迄今为止，该模型的有效性已被欧洲核子研究中心大型强子对撞机发现的希格斯玻色子所证实。然而，目前存在的标准模型留下了许多关于宇宙的问题，包括为什么希格斯质量具有它所具有的价值以及为什么宇宙中没有反物质等基本问题。寻找这些和其他关于宇宙的开放性问题的答案的主要领域之一，它是如何形成的，为什么它是这样的，就是把重点放在中微子的特性研究上，并利用我们所知道的和可以学到的中微子作为超越标准模型（BSM）的科学探测器。标准模型预测有三种不同的中微子，它们都是无质量的，可以通过它们与物质相互作用时所经历的不同相互作用来区分。但是最近的测量完全改变了我们对中微子的认识。我们现在知道中微子确实有质量，正因为如此，它们实际上可以从一种类型转变为另一种类型。此外，实验测量表明可能存在另一种类型的惰性中微子。对这些不寻常粒子相互作用的详细测量是探索超越标准模型的新物理的最有希望的方法之一。芝加哥大学是费米实验室的短基线中微子（SBN）实验的联合发言人小组，该实验将解决在几个中微子实验中观察到的各种异常是否可能是新物理学的迹象，特别是低质量“无菌”中微子粒子的存在。深地下中微子实验（DUNE）将对中微子和反中微子振荡进行全面测量，以研究中微子CP违逆，确定中微子质量特征态的顺序，并对中微子标准模型进行精度测试。DUNE将利用费米实验室的加速器中微子束和对地外中微子（包括超新星爆炸产生的中微子）的敏感。这两个实验都采用了一种革命性的中微子物理探测器技术——液态氩时间投影室，DUNE的目标是在前所未有的规模上实现这一技术，SBN探测器在数据的构建、操作和分析方面提供了宝贵的经验。芝加哥小组在近距离探测器SBND的设计和建造以及近距离探测器和多探测器物理分析的准备中发挥了主导作用。在DUNE上，该小组在实验的大型线平面（称为阳极平面组件）的最终设计和生产计划的开发中发挥了主导作用，这是DUNE液氩时间投影室的主要检测元件。芝加哥小组支持并共同领导恩里科·费米暑期实习生项目，这是一个长期的教育项目，面向芝加哥南部公立学校的中学生。认识到在教育过程中早期接触学生的重要性，该计划使学生参与粒子物理学的概念，并让他们亲身接触基于现代电子学的创意项目。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。

One of the major intellectual achievements of the 20th century was the development of the Standard Model (SM) of particle physics. This model succeeded in classifying all of the elementary particles known at the time into a hierarchy of groups having similar quantum properties. The validity of this model to date was confirmed by the discovery of the Higgs boson at the Large Hadron Collider at CERN. However, the Standard Model as it currently exists leaves open many questions about the universe, including such fundamental questions as to why the Higgs mass has the value it has and why there is no antimatter in the universe. One of the primary areas to search for answers to these and other open questions about the universe, how it came to be, and why it is the way it is, is to focus on a study of the properties of neutrinos and to use what we know and can learn about neutrinos as probes of science Beyond the Standard Model (BSM). The Standard Model predicted that there were three different kinds of neutrinos, all massless, that were distinguishable through the different interactions that they undergo whenever they interact with matter. But recent measurements have totally changed our picture of neutrinos. We now know that neutrinos do have a mass and because they do, they can actually change from one type to another. Additionally, experimental measurements have indicated the possibility of yet an additional type of sterile neutrino. Detailed measurements of the interactions of these unusual particles are one of the most promising ways to probe for new physics beyond the Standard Model.The Short-baseline Neutrino (SBN) Experiment at Fermilab, for which Chicago is a co-spokesperson group, will address whether the various anomalies observed in several neutrino experiments could be indications of new physics and in particular the existence of low-mass "sterile" neutrino particles. The Deep Underground Neutrino Experiment (DUNE) will make comprehensive measurements of neutrino and anti-neutrino oscillations to investigate neutrino CP violation, determine the ordering of the neutrino mass eigenstates, and perform precision tests of the neutrino Standard Model. DUNE will take advantage of both an accelerator-based neutrino beam from Fermilab and be sensitive to extra-terrestrial neutrinos, including those from supernova explosions.Both experiments employ a transformative detector technology for neutrino physics, the liquid argon time projection chamber, which DUNE aims to realize at unprecedented scales, and for which the SBN detectors are providing invaluable experience in the construction, operation, and analysis of data. The Chicago group plays a leading role in the design and construction of the near detector, SBND, and in preparation of both near detector and multi-detector physics analyses. On DUNE, the group has taken a leading role in development of the final design and production plan for the experiment's large wire planes, called Anode Plane Assemblies, the primary detection element of the DUNE Liquid Argon Time Projection Chambers. The Chicago group supports and co-leads the Enrico Fermi Summer Interns program, a long-running educational program for middle school students from south-side Chicago public schools. Recognizing the importance of reaching students at an early age in the education process, the program engages the students in concepts of particle physics and gives them hands-on exposure to creative projects based on modern electronics.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.