A SEARCH FOR NEUTRINOLESS DOUBLE BETA DECAY OF <8Ca

A search for neutrinoless double beta decay of "Ca is being carried out in a coal mine near Beijing. Large scintillation crystals of natural CaF2 are used as both the detector and the beta source. Results obtained after the first 1700 houts data taking give 3. 6 X 1021 years as the lower limit of the half-life of the neutrinoless double beta decay of "Ca. The upper limit of effevtive neutrino mass calculated according to the theoretical half-life by Qing Chengrui et al is less than 13. 7 eV. The experiment is still in progressing.