Search for Neutrinoless Double Beta Decay with NEMO-3 and SuperNEMO Experiments

中微子振荡不仅证明了中微子有质量，而且还暗示了标准模型之外新对称性的存在。自然现象表明，对中微子的更深入了解可能会让我们对普朗克尺度能级的现象有一个了解，可以拓宽我们对基本力的认识，可以揭示轻子和重子的最初创造，并有助于提高我们对宇宙早期演化的理解。这些观测激发了对中微子性质的进一步研究，包括调查它们是Majorana型还是Dirac-type。马约拉纳型中微子导致无中微子双β衰变--一种二级弱核过程，其中原子量和原子数为（A，Z）的初始状态核转变为（A，Z + 2）的核，仅发射两个电子。末态的两个电子携带的总能量等于核跃迁的能量。这一看似简单的原理为探测无中微子双β衰变提供了主要的可观测性，并为寻找这种跃迁提出了实验挑战。该奖项将为该小组继续参与NEMO-3数据分析和第一个SuperNEMO模块（“演示器”）的建设提供资金。NEMO-3的数据于2003年至2011年在法国-意大利阿尔卑斯山下的莫达内地下实验室收集，将在未来几年内进行全面分析。对于SuperNEMO来说，未来三年将是完成和调试演示器的关键时期。该小组有两个新的重要任务：为所有演示器光电倍增管提供高压系统，并协调82-硒的放射性纯化和同位素箔的生产。更广泛的影响：证明或反驳中微子是马约拉纳型的可能揭示宇宙演化的早期阶段。这项实验将增进对自然界中一些最罕见现象的了解。在技术方面，该小组正在开发一种独特的低本底计数技术，该技术可以应用于物理学之外，并对社会普遍有益。他们计划在UT校园内建立一个展览馆，展示自然放射性，宇宙射线和相关亚原子现象的发现，基础物理学和应用。它将“讲述一个故事”，将教育，娱乐，着迷于寻求进一步的信息，也许引导学生或普通观众对科学。

Neutrino oscillations not only demonstrate that neutrinos have mass but also imply the existence of new symmetries beyond the Standard Model. Natural conjectures suggest that deeper understanding of neutrinos may provide a glimpse onto phenomena at a Planck-scale energy level, could broaden our knowledge of the fundamental forces, could shed light onto the initial creation of leptons and baryons, and can help to improve our understanding of the early evolution of the Universe. These observations motivate further studies of the properties of neutrinos including investigating if they are Majorana- or Dirac-type. Majorana-type neutrinos lead to a neutrinoless double beta decay -- the second-order weak nuclear process for which an initial state nucleus with atomic weight and number (A, Z) is transformed into a nucleus with (A, Z + 2) with the emission of only two electrons. The two electrons in the final state carry a total energy equal to the energy of the nuclear transition. This seemingly simple principle provides the main observable for detecting neutrinoless double beta decay and poses an experimental challenge in searches for such transitions.This award will provide funding to continue this group's participation in the NEMO-3 data analysis and in the construction of the first SuperNEMO module (the 'Demonstrator'). The NEMO-3 data, collected at the Modane Underground Laboratory under the French-Italian Alps between 2003 and 2011, will be fully analyzed over the next couple of years. For SuperNEMO, the next three years will be a critical period for completing and commissioning the Demonstrator. This group has two new important commitments: to provide the high voltage system for all Demonstrator photomultipliers, and to coordinate the radio-purification of 82-Selenium and production of isotopic foils.Broader Impact: Proving or disproving that neutrinos are Majorana-type may shed light onto the early stages of the evolution of the Universe. This experiment will advance knowledge about some of the rarest phenomena in Nature. On the technical side, the group is developing a unique low background counting technique which may be applied outside of physics and be of general benefit to society. They plan to build on the UT campus an exhibit gallery illustrating the discovery, the underlying physics, and applications of natural radioactivity, cosmic rays, and related subatomic phenomena. It would 'tell a story' that would educate, entertain, fascinate to seek further information, and perhaps steer students or general audience towards the sciences.