Enriched Xenon Observatory for double beta decay

丰富的氙气天文台(EXO)合作致力于寻找136Xe的无中微子双β衰变(0？)。对这种衰变的观察将证明中微子是它们自己的反粒子(Majorana)，提供关于中微子质量的规模和顺序的信息，并为轻子数非守恒提供第一个证据。 Exo目前正在运行一个浓缩的氙液--相时间投影室 (EXO200)新墨西哥州卡尔斯巴德附近。利用这次实验收集的数据，EXO首次对136Xe的规则双β衰变进行了测量，并在寻找无中微子衰变方面取得了世界领先的测量结果。加拿大集团为这些努力做出了重大贡献，为该项目提供了硬件和分析方面的专业知识。例如，加拿大人在探测器设计和工程、校准系统和分析协调方面承担了主要责任。Jacques Farine教授(Laurentian)目前是EXO科学委员会主席，David Sclair教授(Carleton)是EXO执行委员会成员。EXO200将在至少两年的时间里继续收集数据，并预计将继续站在寻找0？ 为了显著提高搜索超出EXO200的0？的敏感度，它将 这是EXO扩大其探测器技术和降低背景水平所必需的。基于EXO200的成功，合作伙伴正在致力于开发下一代液相检测器(Nexo)。随着TRIUMF集团加入EXO，加拿大人处于有利地位，将在EXO的下一阶段开发中领导重要组成部分。这项工作将包括校准系统的设计，紫外线敏感型光电探测器的评估，蒙特卡罗 卡罗模拟、探测器工程和持续的钡标签开发。SNOLAB的“冷冻舱”可以为下一阶段的EXO提供一个很好的家，合作伙伴正在考虑这一点来为Nexo寻找概念。 虽然液态探测器可能被证明是下一代EXO的最佳选择， 气相检测仪有很多明显的优点。因此，加拿大集团将继续进行探测器的研发，特别是气相可能性的钡标记。

The Enriched Xenon Observatory (EXO) collaboration is engaged in a search for the neutrinoless double beta decay (0?ßß) of 136Xe. Observation of this decay would prove that neutrinos are their own anti-­-pariticle (Majorana), provide information on the scale and ordering of neutrino masses, and give the first evidence for lepton number non-­-conservation. EXO is currently operating an enriched xenon liquid-­-phase time projection chamber (EXO200) near Carlsbad, New Mexico. With data collected from this experiment, EXO made the first measurement of the regular double beta decay of 136Xe and has produced world-­-leading measurements in the search for the neutrinoless decay. Canadian groups have contributed significantly to these efforts providing both hardware and analysis expertise to the project. For example, Canadians have taken lead responsibility for elements of detector design and engineering, calibration systems, and analysis coordination. Prof. Jacques Farine (Laurentian) is currently chair of the EXO Scientific Board and Prof. David Sinclair (Carleton) is serving on the EXO Executive Committee. EXO200 will continue collecting data for at least 2 more years and expects to remain at the forefront of the search for the 0?ßß decay. To substantially improve sensitivity in the search for 0?ßß beyond EXO200, it will be necessary for EXO to scale up its detector technology and decrease the background levels. Based on the success of EXO200, the collaboration is pursuing development of a next-­-generation liquid-­-phase detector (nEXO). With the addition of the TRIUMF group to EXO, the Canadians are well-­-positioned to lead significant components in the development of the next phase of EXO. This work will include design of calibration systems, evaluation of UV sensitive photo-­-detectors, Monte Carlo simulation, detector engineering, and continued Barium tagging development. The SNOLAB ‘cryopit’ could provide an excellent home for this next phase of EXO, and the collaboration is pursuing concepts for nEXO with this in mind. While a liquid-­-phase detector might prove the best option for the next scale of EXO, there are distinct advantages that might be gained from a gas-­-phase detector. Hence the Canadian groups will continue to pursue detector R&D and, in particular, barium tagging for the gas-­-phase possibility.