Abstract and subjects
CANDLES(CAlcium fluoride for the study of Neutrinos and Dark matters by Low Energy Spectrometer) is the experiment to search for the neutrino-less double beta decay(O nu beta beta) of Ca-48 with CaF2 scintillator. Ca-48 has the highest Q(beta beta)-value (4.3 MeV) among all isotope candidates for O nu beta beta. It enables us to measure signals with very low background condition. After rejection analysis with 131 days x 86 kg data for background events from radioactive contaminations in the CaF2 scintillators, no events are observed in the Q(beta beta)-value region. As a result, the Ovflfl half-life of Ca-48 is greater than 6.2 x 10(22) yr (90% confidence level). For further high sensitive measurement of Ca-48 O nu beta beta search, we have been developing the Ca-48 enrichment and CaF2 scintillating bolometer techniques. In this paper, the latest result for CANDLES and the status of scintillating bolometer development are described.