Speaker
Description
The mass origin of neutrinos still remains unknown. One of the possible scenarios is that neutrinos have Majorana masses, which leads to neutrino less double-beta decay (0$\nu\beta\beta$).
CANDLES is a project to search for the 0$\nu\beta\beta$ events of ${}^{48}$Ca, which has the highest Q$_{\beta\beta}$-value of 4.27\,MeV among the double beta decay isotopes. We developed a CANDLES-III detector system with 96 CaF$_2$ scintillation crystals with natural Ca isotope, which corresponds to 350\,g of ${}^{48}$Ca, and took data with almost 3 years of observation, at the Kamioka underground laboratory. We are analyzing data with the various methods to reduce background events to increase a sensitivity to the signal.
In this talk, the analysis of background reduction and the latest status of the search for the $0\nu\beta\beta$ will be reported. We have been developing the key technologies for the next generation detector system, such as isotope enrichment of ${}^{48}$Ca and high energy resolution detector. The current status of these development will be also presented.
