Neutrinoless Double-Beta Decay with Germanium Detectors: Majorana Demonstrator and LEGEND

使用锗探测器的无中微子双贝塔衰变：马约拉纳演示器和传奇

• 批准号: 1812409
• 负责人: Matthew Green
• 金额: $ 41.86万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1812409&HistoricalAwards=false
• 关键词: Neutrinoless; Double; Beta; Decay; Germanium

The non-zero masses and neutral electric charge of neutrinos allows for the possibility that neutrinos are their own antiparticles (i.e. Majorana particles), in which case an ultra-rare form of nuclear decay known as neutrinoless double-beta decay (NLDBD) may occur. If neutrinos are shown to be Majorana particles, it would provide an explanation for the very small masses of neutrinos; point to new physics at energies beyond the reach of our most powerful colliders; and motivate an explanation for the prevalence of matter over anti-matter in the Universe. This award supports software and instrumentation research on an experiment to test the Majorana characteristics of neutrinos and the next phase experiment, called LEGEND. Both experiments use ultra-pure germanium detectors and are at the cutting edge of science. The PI will train graduate students in novel techniques that will allow them to compete in high-technology based careers. Additionally, the PI has an innovative program in outreach to the public. The LEGEND Experiment will use the ultra-pure materials developed by the MAJORANA Collaboration and the liquid cryogen active shielding developed by the GERDA Collaboration in the construction of a phased-deployment ton-scale experiment with discovery potential for NLDBD at half-lives beyond 10e28 years. This project will extend LEGEND's sensitivity to NLDBD and dark matter by building on a full understanding of the backgrounds in the MAJORANA DEMONSTRATOR and reducing backgrounds associated with cosmogenic Argon isotopes in a liquid cryogen compton veto. Specifically, the PI and his group aim to: construct a comprehensive background model of the MAJORANA DEMONSTRATOR NLDBD experiment using Monte Carlo simulations and experimental data; investigate the feasibility of germanium detector array deployment in a liquid neon environment to extend the physics reach of LEGEND; and develop preliminary designs and background models for the LEGEND-200 (200-kg) and LEGEND-1000 (1000-kg) phases of the LEGEND experiment.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.

中微子的非零质量和中性电荷使得中微子可能是它们自己的反粒子（即马约拉纳粒子），在这种情况下，可能会发生一种超罕见的核衰变形式，即无中微子双β衰变（NLDBD）。如果中微子被证明是马约拉纳粒子，它将为中微子的微小质量提供一个解释；指出我们最强大的对撞机无法达到的能量下的新物理学；并激发对宇宙中物质比反物质普遍存在的解释。该奖项支持软件和仪器研究的实验，以测试中微子的马约拉纳特性和下一阶段的实验，称为LEGEND。这两个实验都使用了超纯锗探测器，处于科学的前沿。该项目将培养研究生掌握新技术，使他们能够在以高科技为基础的职业中竞争。此外，PI还有一个面向公众的创新项目。LEGEND实验将使用MAJORANA合作开发的超纯材料和GERDA合作开发的液冷源主动屏蔽，在建设一个分阶段部署的吨级实验中发现半衰期超过10e28年的NLDBD。该项目将在充分了解马约拉纳演示器背景的基础上，扩展LEGEND对NLDBD和暗物质的灵敏度，并减少液冷compton veto中与宇宙起源氩同位素相关的背景。具体而言，PI及其团队的目标是：利用蒙特卡罗模拟和实验数据构建MAJORANA DEMONSTRATOR NLDBD实验的综合背景模型；研究在液态氖环境中部署锗探测器阵列的可行性，以扩展LEGEND的物理覆盖范围；为LEGEND实验的LEGEND-200 （200-kg）和LEGEND-1000 （1000-kg）阶段制定初步设计和背景模型。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。

项目成果

Investigation of ASIC-based signal readout electronics for LEGEND-1000

• DOI: 10.1088/1748-0221/15/09/p09022
• 发表时间: 2020-05
• 期刊: Journal of Instrumentation
• 影响因子: 1.3
• 作者: F. Edzards;S. Mertens;L. Bombelli;G. Zuzel;D. Fink;S. Schönert;D. Radford;M. Green;M. Laubenstein;A. Alborini;G. Othman;M. Willers

ADC Nonlinearity Correction for the Majorana Demonstrator

• DOI: 10.1109/tns.2020.3043671
• 发表时间: 2021-03-01
• 期刊: IEEE TRANSACTIONS ON NUCLEAR SCIENCE
• 影响因子: 1.8
• 作者: Abgrall, N.;Allmond, J. M.;Shanks, B.
• 通讯作者: Shanks, B.

Signatures of muonic activation in the Majorana Demonstrator

马约拉纳演示器中μ子激活的特征

• DOI: 10.1103/physrevc.105.014617
• 发表时间: 2022
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Arnquist, I. J.;Avignone, F. T.;Barabash, A. S.;Barton, C. J.;Bertrand, F. E.;Blalock, E.;Bos, B.;Busch, M.;Buuck, M.;Caldwell, T. S.
• 通讯作者: Caldwell, T. S.

Search for trinucleon decay in the MAJORANA DEMONSTRATOR

• DOI: 10.1103/physrevd.99.072004
• 发表时间: 2019-04-12
• 期刊: PHYSICAL REVIEW D
• 影响因子: 5
• 作者: Alvis, S. I.;Arnquist, I. J.;Zhu, B. X.
• 通讯作者: Zhu, B. X.

Multisite event discrimination for the MAJORANA DEMONSTRATOR

• DOI: 10.1103/physrevc.99.065501
• 发表时间: 2019-06-07
• 期刊: PHYSICAL REVIEW C
• 影响因子: 3.1
• 作者: Alvis, S., I;Arnquist, I. J.;Zhu, B. X.
• 通讯作者: Zhu, B. X.