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允许中微子是它们自己的反粒子（即马约拉纳粒子）的可能性，在这种情况下，可能会发生一种被称为无中微子双β衰变（NLDBD）的超罕见形式的核衰变。 如果中微子被证明是马约拉纳粒子，它将为中微子的质量非常小提供一个解释;指向新的物理学，其能量超出了我们最强大的对撞机的范围;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。 PI将培训研究生的新技术，使他们能够在高科技为基础的职业竞争。 此外，PI有一个创新的方案，在推广到公众。 LEGEND实验将使用MAJORANA协作组织开发的超纯材料和GERDA协作组织开发的液态冷冻剂主动屏蔽，建造一个分阶段部署的吨级实验，具有发现半衰期超过10 e28年的NLDBD的潜力。 该项目将通过建立对MAJORANA DEMONSTRATOR背景的充分理解，并减少与液态制冷剂康普顿否决中宇宙成因氩同位素相关的背景，来扩展LEGEND对NLDBD和暗物质的敏感性。 具体而言，PI及其团队的目标是：使用Monte Carlo模拟和实验数据构建MAJORANA DEMONSTRATOR NLDBD实验的综合背景模型;研究锗探测器阵列在液体氖环境中部署的可行性，以扩展LEGEND的物理范围;并为LEGEND-200（200公斤）和LEGEND-1000（1000公斤）开发初步设计和背景模型该奖项反映了NSF的法定使命，并通过使用基金会的智力价值进行评估，更广泛的影响审查标准。

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.