Study of neutrinoless double-beta decay using the neutrino detector, KamLAND

通过在巨大和超低放射性环境中部署大量的^&lt；136和gt；Xe，世界上寻找无中微子双β衰变的最高灵敏度已经迅速和经济有效地实现。通过结合使用相同原子核的分析和实验，先前关于76&gt；GE的正面说法已被驳斥。给出了有效马约拉纳质量的上限为120~250 meV。与此同时，使用反应堆关闭数据进行的更精确的地球中微子观测开始检验地球模型。

The world highest sensitivity of the search for neutrino-less double beta decay has been quickly and cost-effectively achieved by deploying large amount of ^<136>Xe in the huge and ultra-low radioactivity environment, KamLAND. The previous positive claim with ^<76>Ge has been refuted by a combined analysis with an experiment using the same nuclei. Also an upper limit on the effective Majorana mass of 120～250meV has been obtained. Simultaneously, more precise geo-neutrino observation with the reactor-off data started to examine Earth models.