Basic research for search for neutrino-less double beta decay of 136Xe in KamLAND

我们进行了研究和开发，以实现KamLAND中具有世界最高灵敏度的双β衰变搜索。在本研究的前半部分，我们开发了KamLAND中使用的微型气球，微型气球的安装方法，载氙液体闪烁体的填充方法。在技术建立后，我们制作了微球，安装了微球，并填充了氙装载的液体闪烁体。然后，我们开始了KamLAND-Zen实验，KamLAND-Zen合作报告了78天的观测数据。双中微子双β衰变的半衰期<136>是2。38±0。02（统计）±0。14（系统）10^21年无中微子双β衰变半衰期的下限<136>是&gt; 5。7× 10^24年。

We performed research and developments to realize double beta decay search in KamLAND with world highest sensitivity. First half of this research, we developed mini-balloon which is used in KamLAND, method of installation of mini-balloon, method of filling of xenon loaded liquid scintillator. After the establishment of techniques, we made mini-balloon, installed mini-balloon, and filled xenon loaded liquid scintillator. Then, we started KamLAND-Zen experiment.KamLAND-Zen collaboration reported first results with 78 days of observation data. The two-neutrino double beta decay half-life of <136>^Xe is 2. 38±0. 02(stat.)±0. 14(syst.)× 10^21 year. The lower limit of neutrino-less double beta decay half-life of <136>^Xe is > 5. 7× 10^24 year.