You are here

Properties of neutrino and weak interactions, search for effects beyond the Standard Model, investigation of rare nuclear decays


Work number - P 1

F.A. Danevich, Yu.G. Zdesenko, V.V. Kobychev, G.P. Kovtun, L.L. Nagornaya, V.I. Tretyak, I.A. Tupitsyna, A.P.Shcherban

Presented by the Institute for Nuclear Research of NASU, Kyiv, Ukraine

The purpose of the research carried out during 1985-2014 years was study of neutrino and weak interaction, test of the fundamental laws (the Pauli principle, conservation laws of the electric charge, lepton and baryon numbers), search for dark matter (axions, sterile neutrinos, weakly interacting massive particles), measurements of neutrino fluxes from the Sun, Earth's mantle and other sources, study of rare alpha, beta, double beta and cluster decays. Ultra-low background scintillation spectrometry, techniques of deep purification of materials were developed, a few novel crystal scintillators were grown and investigated, several existing scintillation materials were studied, new methods of data analysis were developed. Cadmium tungstate scintillator from enriched isotopes of cadmium and molybdenum were developed for the first time to realize the experiments.

The two neutrino double beta decay was observed in 82-Se, 96-Zr, 100-Mo and 116-Cd, strict limits on the Majorana neutrino mass (< 0.3 - 1.7 eV), right-handed admixtures in the weak interaction, the effective Majoron-neutrino coupling constant were set. Double beta processes in more than 20 isotopes of calcium, zinc, strontium, ruthenium, molybdenum, cadmium, cerium, dysprosium, gadolinium, tungsten, osmium, platinum and mercury were investigated on a new level of sensitivity. New restrictions on axions mass, which can be emitted in the Sun were established. Strong limits on the photon electric charge, processes violating the electric charge conservation (electron and nucleon decay, charge non-conserving beta decay), disappearance of matter into additional dimensions were established. The Pauli principle was tested in atoms and atomic nuclei. The flux of the 7-Be solar neutrinos was precisely measured for the first time, which allowed to obtain new information about the neutrino oscillation, mass and mixing angles. The most stringent limit on antineutrino flux from the Sun was set, the flux of neutrino from Earth's mantle (geo-neutrino) was registered with highest accuracy, new limits on the neutrino magnetic moment and heavy sterile neutrino mixing were established. Alpha activity of natural tungsten and europium, alpha decay of 190-Pt and beta decay of 115-In to the excited levels of daughter nuclei were discovered, the beta spectrum and the half-life of 113-Cd were measured with the highest up to date accuracy.

 

Number of publications: 369 papers, 16 patents. The publications were cited 2477 times in Scopus, h-index = 25 (both numbers without self citations