Double beta decay experiments and v-mass sensitivities

This is a brief report on Majorana neutrino(v) mass to be studied by neutrino-less double beta decays (0vββ). The v-mass depends on the nuclear structure of the ββ isotope, the effective detector volume and the background rate. Subjects discussed include 1 0vββ and v-mass, 2 0vββ nuclear matrix elements, and 3 0vββ experiments and v-mass sensitivities.