Particle-, nuclear- and atomic-physics aspects of rare weak decays of nuclei

Abstract

Neutrinoless double-beta (0νββ) decay of nuclei is a process that requires the neutrino to be a massive Majorana particle and thus cannot proceed in the standard model of electro-weak interactions. The 0νββ decay takes place in atomic nuclei where it can be observed, at least in principle, by underground neutrino experiments. This work touches a special topic of the 0νββ decay, namely the emerging field of experimental and theoretical studies of the resonant neutrinoless double electron-capture decay of an atomic nucleus.