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

通过在巨大的超低放射性环境KamLAND中部署大量的^氘，已经快速和经济有效地实现了世界上最高的无中微子双β衰变搜索灵敏度<136>。先前关于^ Ge的肯定断言<76>已经被一个使用相同原子核的实验的综合分析所否定。同时得到了有效Majorana质量的上限为120~ 250 meV。与此同时，更精确的地球中微子观测与反应堆关闭数据开始检查地球模型。

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.