U.S.-Japan Cooperative Science: Development of a Method to Identify a Daughter ion of Double Beta Decay in Xe-136

9815625Fairbank该奖项支持斯坦福大学William Fairbank教授和日本福井大学Mitsuhiro Miyajima教授为期两年的合作研究项目。 研究人员将致力于开发一种检测单个 Ba -136 离子的方法，这些离子是由液态氙中 Xe-136 原子的罕见双 β 衰变产生的。 衰变和单离子检测技术的独特组合有望使 Xe-136 中双 β 衰变的无背景搜索成为可能。 从长远来看，预计灵敏度将提高两个数量级。 预计将首次观测到XE-136的双中微子双β衰变，并且随着零中微子衰变灵敏度的提高，可能会达到0.01 eV左右的电子中微子质量极限。 该项目汇集了两个具有互补专业知识和研究能力的实验室的努力。美国研究人员的专业知识是小光信号领域，日本研究人员拥有该领域的核专业知识。 无中微子双贝塔衰变的积极结果将意味着超越标准模型的新物理学，并可能有助于解释天体物理学之谜，例如太阳中微子和宇宙射线中微子缺陷以及宇宙中暗物质的组成。 这项研究通过研究生的参与来促进国际人力资源的发展。 通过思想和技术的交流，该项目将拓宽我们的基础知识基础，促进国际理解与合作。 ***

9815625FairbankThis award supports a two year collaborative research project between Professor William Fairbank of Stanford University and Professor Mitsuhiro Miyajima of Fukui University in Japan. The researchers will be undertaking a study of the development of a method of detecting single Ba+-136 ions which are created by rare double beta decay of Xe-136 atoms in liquid xenon. The unique combination of decay and single ion detection technologies is expected to make possible a background-free search for double beta decay in Xe-136. In the long term, a two-orders of magnitude improvement in sensitivity is projected. Then it is expected that two-neutrino double beta decay of XE-136 will be observed for the first time and that, with the improved sensitivity for zero-neutrino decay, an electron neutrino mass limit around 0.01 eV may be reached. This project brings together the efforts of two laboratories that have complementary expertise and research capabilities. The U.S. researchers' expertise is in the area of small optical signals and the Japanese have the nuclear expertise in this area. A positive result for neutrinoless double beta decay would imply new physics beyond the Standard Model and may help explain astrophysical mysteries such as the solar neutrino and cosmic ray neutrino deficits and the composition of dark matter in the universe. This research advances international human resources through the participation of graduate students. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. ***