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Information × Registration Number 0219U000643, 0118U005411 , R & D reports Title Study of the nature of neutrino and weak interaction in double beta decay of atomic nuclei popup.stage_title Head Danevich Fedor, Registration Date 13-02-2019 Organization Scientific Center "Institute for Nuclear Research" of National Academy of Sciences of Ukraine popup.description2 In the experiment with scintillation detectors of cadmium tungstate enriched with cadmium-116, the half-life of the 116Cd nucleus with respect to the two-neutrino double beta decay was measured with the best accuracy: T1/2=2.63(+0.11/-0.12) x10^19 years, and new restrictions were established for the neutrinoless mode of decay of this nucleus T1/2>=2.2x10^23 years, where the limit on the mass of the light Majorana neutrino follows from: <(1.0-1.7) eV. In this experiment, the limitations on the parameters of the non-conservation of the lepton number were obtained, and the most stringent restriction on the two-neutrino double beta decay with violation of the Lorentz invariance was established. Precision measurements of the half-life of the 82Se nucleus were carried out in relation to the two-neutrino double beta decay T1/2=[9.39+/-0.17(stat)+/-0.58(sys)] x10^19 years, and new restrictions on the neutrinoless mode of decay of this nucleus T1/2>=2.5x10^23 years, where the limit on the mass of the light Majorana neutrino <(1.2-3.0) eV follows from. The half-life of the 150Nd nucleus with respect to the two-neutrino double beta decay to the excited level of the child nucleus was measured: T1/2=[4.7+4.1/-1.9(stat)+/-0.5(sys)] x10^20 years. The experiment continues to reduce the statistical error. For the first time, a search for double beta decay of 162Er and 170Er nuclei was performed at the sensitivity level of T1/2>=(10^15-10^18) years. One of the most accurate measurements of the half-life of the 212Po nucleus was performed with the use of a liquid thorium-loaded scintillator. The preliminary half-life of the 212Po nucleus is T1/2=(294.8+/-1.9) ns. The experiment continues in order to register more events to reduce statistical and systematic errors. For the first time, the crystal of Li2Mg2(MoO4)3 has been studied as a scintillation bolometer to search for double beta decay of 100Mo nuclei. New methods of estimating the mass of neutrinos from experiments with several nuclides are proposed. The possibility of reducing the background by recording Cerenkov radiation from tellurium oxide crystals in an experiment aimed to search for double beta decay of 130Te was proven for the first time. Product Description popup.authors Бойко Роман Сергійович Даневич Федор Анатолiйович Зарицький Микола Миколайович Зуєва Олена Володимирівна Касперович Дмитро Васильович Кобичев Владислав Валерійович Кобичев Роман Владиславович Кобичева Лариса Миколаївна Кропив'янський Борис Миколайович Пода Денис Валентинович Поліщук Оксана Григорівна Сокур Назар Володимирович Тимошенко Андрiй Iванович Третяк Володимир Iллч Шкурупій Олег Юрійович popup.nrat_date 2020-04-02 Close