We have been studying double beta decay of
Neutrino‐less double beta decay (0νββ) is currently known to be only experiment to verify whether lepton number is not conserved. The non‐conservation is the key to create matter dominated universe by the so‐called Leptogenesys. Our first stage experiment using the ELEGANT VI detector system gave the best lower limit of the half life of 0νββ of
We have been developing CANDLES detector system to sense much longer life‐time region. We have developed techniques to reduce backgrounds further. The CADLES detector system was installed at Kamioka underground laboratory. Here I describe a schematic view of the system.