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

通过 NEMO-3 和 Super-NEMO 实验寻找无中微子双贝塔衰变

• 批准号: 0702695
• 负责人: Karol Lang
• 金额: --
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0702695&HistoricalAwards=false
• 关键词: Search; Neutrinoless; Double; Beta; Decay

The observation of neutrino oscillations has shown that neutrinos have mass. This is the first direct evidence of physics beyond the Standard Model. This discovery has renewed and strengthened interest in neutrinoless double beta decay experiments which provide the only practical way to determine whether neutrinos are Majorana or Dirac particles. Such experiments have also the potential to determine the absolute scale of the neutrino mass and help resolve the neutrino mass hierarchy question. The answers to these fundamental issues may be important to a better understanding of the fundamental forces of Nature and the evolution of the Universe. The authors of this proposal wish to participate in the ongoing experiment NEMO-3, currently the most sensitive search for neutrinoless double beta decays, and in the next generation experiment Super-NEMO. The NEMO team currently operates the NEMO-3 apparatus, located in the Modane Underground Laboratory in the Frejus Tunnel under the French-Italian Alps. In Super-NEMO, just as in NEMO-3, and unlike in most other neutrinoless double beta decay experiments, the final state is reconstructed through several observables relating topology and electron energy. This is a technique common to particle and nuclear physics experiments and provides a powerful tool for measuring and rejecting background. This group has been invited to join the NEMO collaboration to work on both NEMO-3 and Super-NEMO and to bring their expertise with scintillator calorimeters. They are developing a simulation package based on GEANT-4 which is becoming the core optics package for Super-NEMO and an important R&D tool in several labs investigating various calorimeter options for Super-NEMO. They have both validated the results of simulations and constructed prototypes which could provide a valuable input to the final design of Super-NEMO. The broader impact of this proposal stems from the fact that Super-NEMO is essentially an assembly of many small sub-detectors which can be prototyped and operated on a bench. This is ideally suited for training and educating undergraduate students.

中微子振荡的观测表明中微子有质量。这是物理学超越标准模型的第一个直接证据。这一发现重新激发并加强了人们对无中微子双β衰变实验的兴趣，该实验提供了确定中微子是马约拉纳粒子还是狄拉克粒子的唯一实用方法。这样的实验也有可能确定中微子质量的绝对尺度，并帮助解决中微子质量等级问题。这些基本问题的答案可能对更好地理解自然的基本力量和宇宙的演化很重要。该提案的作者希望参与正在进行的NEMO-3实验，目前对无中微子双β衰变的最敏感的搜索，以及下一代实验Super-NEMO。NEMO团队目前正在操作NEMO-3仪器，该仪器位于法国-意大利阿尔卑斯山下的Frejus隧道中的Modane地下实验室。在超级NEMO中，就像在NEMO-3中一样，并且与大多数其他无中微子双β衰变实验不同，最终状态是通过几个与拓扑结构和电子能量相关的观测值重建的。这是粒子和核物理实验中常见的技术，为测量和拒绝背景提供了强大的工具。该小组已被邀请加入NEMO合作，致力于NEMO-3和Super-NEMO的研究，并将他们的专业知识与闪烁体量热计结合起来。 他们正在开发一个基于GEANT-4的模拟包，该包正在成为Super-NEMO的核心光学包，也是几个实验室研究Super-NEMO各种热量计选项的重要研发工具。他们验证了模拟结果，并构建了原型，可以为Super-NEMO的最终设计提供有价值的投入。这一提议的更广泛影响源于这样一个事实，即超级NEMO基本上是许多小型子探测器的组装，这些子探测器可以在工作台上原型化和操作。这非常适合培训和教育本科生。