CANDLES Search for neutrino-less double beta decay of (48)~Ca

摘要

CANDLES is the project to search for neutrino-less double beta decay (0vββ) of (48)~Ca. The observation of 0vββ will prove existence of a massive Majorana neutrino. For the 0vββ measurement, we need a low background condition because of a low decay rate of 0vββ. Now we installed the CANDLES III system at the Kamioka underground laboratory. The CANDLES III system realizes the low background condition by a characteristic structure and data analyses for background rejection. Here we report performances of the CANDLES III system.