Massive Neutrinos and Nuclear Structure
- 2:30 – 3:30 p.m. Part I
- 3:30 – 3:40 p.m. Break
- 3:40 – 4:40 p.m. Part II
In this presentation the current status and perspective of the field of the single beta and double beta-decays is reviewed in the context of massive neutrinos. The problem of direct measurement of neutrino mass with help of the beta-decay of tritium (KATRIN), 187Re (MARE) and the electron capture of 163Ho (ECHo) is addressed. A connection of the neutrinoless double beta decay (0-decay) to neutrino oscillations is analyzed.
In view of recent measurements of the mixing angle m13, the possibility to determine the difference of two CP Majorana phases of the neutrino mixing matrix from the study of 0-decay is investigated. The claim of 0-decay in 76Ge with recent negative results in 136Xe and in other nuclei is compared, and with the lifetime ranges allowed or excluded at 90 C.L. are inferred. A novel mechanism of the 0-decay is presented.
It is induced by lepton number violating 4-fermion neutral current interactions of neutrino with quarks from decaying nucleus. The net effect of these interactions results in generation of an effective in-medium Majorana neutrino mass. The present-day results of the calculation of the 0-decay nuclear matrix elements are briefly discussed, in particular those achieved recently within QRPA with partial restoration of the isospin symmetry.
The possibility to discriminate between different pairs of CP non-conserving mechanisms inducing the 0-decay by using data on 0-decay half-lives of different nuclei is addressed. Further, the resonant neutrinoless double-electron capture in 152Gd, 164Er, and 180W atoms, associated with the ground-state to ground-state nuclear transitions is subject of interest.