Investigation of 2$\beta$ Decay of $^{116}$Cd with the Help of Enriched $^{116}$CdWO$_4$ Crystal Scintillators

Double beta decay of Cd-116 has been investigated with the help of radiopure enriched (CdWO4)-Cd-116 crystal scintillators in the experiment Aurora. The half-life of Cd-116 relatively to the 2 nu 2 beta decay of Cd-116 to the ground level of Sn-116 is measured with the highest up-to-date accuracy as T-1/2 = [2.69 +/- 0.02 (stat.) +/- 0.14 (syst.)] x 10(19) yr. A new improved limit on the 0 nu 2 beta decay of 116Cd to the ground state of 116Sn is set as T-1/2 >= 2.4 x 10(23) yr at 90% C.L., that corresponds to the effective Majorana neutrino mass limit in the range < m(nu)> <= (1.1 - 1.6) eV, depending on the nuclear matrix elements used in the estimations. New improved limits on other 2 processes in 116Cd (decays with majoron emission, transitions to excited levels of Sn-116) were set at the level of T-1/2 >= 10(21) - 10(22) yr.