CAREER: Maximizing the Science Output of EXO-200

事业：最大化 EXO-200 的科学产出

• 批准号: 1654495
• 负责人: Liang Yang
• 金额: $ 75万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-15 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1654495&HistoricalAwards=false
• 关键词: CAREER; Maximizing; Science; Output; EXO

Neutrinos are among the most mysterious sub-atomic particles in the Universe. Recent breakthroughs in neutrino oscillation experiments have revealed that they have tiny masses and have raised several intriguing questions. Why are neutrinos so much lighter than the other particles? What is the absolute scale of the neutrino masses? And are the neutrinos their own antiparticles? The keys to addressing these questions may lie in the search for a very rare decay process called neutrinoless double beta decay. During such a decay, two neutrons inside a nucleus simultaneously decay into two protons, emitting two electrons and no neutrino. The goal of the project is to perform one of the most sensitive searches of this rare decay using data from the EXO-200 experiment. A discovery of this elusive decay would signify that neutrinos are their own antiparticles; thus neutrinos obtain their masses differently from other particles. The results may also shed light on the mystery of why there is more matter than anti-matter in the Universe. In addition to his research on neutrinos, the principal investigator will also develop an educational program to strengthen science education at the middle-school level. Specifically, the PI will organize workshops on middle-school physical science teaching in collaboration with the College of Education at the University of Illinois at Urbana-Champaign and build closer connections between middle-school students and science majors at Illinois through a series of innovative outreach activities.The project will integrate research, outreach, and education around the development of novel analysis techniques to enhance the performance of large liquid xenon detectors such as EXO-200. In its Phase-I operation, EXO-200 has demonstrated the unique capability of large liquid xenon detectors in the search for neutrinoless double beta decay in Xe-136. With detector upgrades in 2016 and three years of additional Phase-II running, EXO-200 can improve by threefold its sensitivity to the Xe-136 neutrinoless double beta decay half-life. The work focuses on the development of new analysis techniques to enhance the detector energy resolution and improve its background rejection capabilities, which are essential for maximizing the physics reach of EXO-200. Understanding and demonstrating the ultimate performance of EXO-200 can provide essential inputs to the design of future tonne-scale detectors. The analysis techniques to be developed can also be applied to large noble liquid detectors for particle physics experiments and medical imaging. In parallel, educational and outreach activities are planned to enhance middle school science education. The PI together with colleagues at Illinois will organize workshops for area middle school teachers on physical science teaching in accordance with the New Generation Science Standards and the development of hands-on classroom activities to implement the new standards. The PI will also direct undergraduate volunteers in outreach to middle school students through demonstrations, an online forum, and assisting in school-initiated science programs.

中微子是宇宙中最神秘的亚原子粒子之一。最近中微子振荡实验的突破揭示了它们具有微小的质量，并提出了几个有趣的问题。为什么中微子比其他粒子轻得多？中微子质量的绝对规模是多少？中微子是它们自己的反粒子吗？解决这些问题的关键可能在于寻找一种非常罕见的衰变过程，称为无中微子双β衰变。在这样的衰变过程中，原子核内的两个中子同时衰变成两个质子，发出两个电子，但没有中微子。该项目的目标是使用EXO-200实验的数据对这种罕见的衰变进行最敏感的搜索之一。这种难以捉摸的衰变的发现将意味着中微子是它们自己的反粒子；因此，中微子获得质量的方式与其他粒子不同。这一结果也可能揭开宇宙中为什么物质多于反物质的谜团。除了对中微子的研究外，首席研究员还将制定一个教育计划，以加强中学层面的科学教育。具体地说，国际和平研究所将与伊利诺伊大学香槟分校教育学院合作举办中学物理教学研讨会，并通过一系列创新的外联活动在伊利诺伊州中学生和理科专业学生之间建立更紧密的联系。该项目将围绕开发新的分析技术整合研究、外联和教育，以提高EXO-200等大型液体氙气探测器的性能。在第一阶段的运行中，EXO-200展示了大型液体氙气探测器在寻找Xe-136中的无中微子双β衰变方面的独特能力。随着探测器在2016年的升级和三年的额外第二阶段运行，EXO-200可以将其对Xe-136无中微子双β衰变半衰期的灵敏度提高三倍。这项工作的重点是开发新的分析技术，以提高探测器的能量分辨率和改善其背景抑制能力，这对于最大限度地扩大EXO-200的物理覆盖范围至关重要。了解和展示EXO-200的最终性能可以为未来吨级探测器的设计提供必要的投入。即将开发的分析技术也可以应用于大型稀有液体探测器，用于粒子物理实验和医学成像。同时，还计划开展教育和宣传活动，以加强中学科学教育。国际物理协会将与伊利诺伊州的同事一起，根据新一代科学标准，为地区中学教师组织物理教学讲习班，并开展实践课堂活动，以实施新标准。PI还将指导本科生志愿者通过演示、在线论坛和协助学校发起的科学项目来接触中学生。

项目成果

Search for nucleon decays with EXO-200

使用 EXO-200 搜索核子衰变

• DOI: 10.1103/physrevd.97.072007
• 发表时间: 2018
• 期刊: Physical Review D
• 影响因子: 5
• 作者: Albert, J. B.;Anton, G.;Badhrees, I.;Barbeau, P. S.;Bayerlein, R.;Beck, D.;Belov, V.;Breidenbach, M.;Brunner, T.;Cao, G. F.
• 通讯作者: Cao, G. F.

Search for Neutrinoless Double-Beta Decay with the Upgraded EXO-200 Detector

• DOI: 10.1103/physrevlett.120.072701
• 发表时间: 2018-02-15
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Albert, J. B.;Anton, G.;Ziegler, T.
• 通讯作者: Ziegler, T.