Double beta decay: An interface between nuclear, particle and atomic physics

Abstract

General properties of the nuclear matrix elements (NMEs) related to the various modes of neutrinoless double β decays are examined and analyzed. The decays include the electron-emitting double beta-minus decays β-β- and the various positron-emitting/electron capture decays. Special interest is devoted to the neutrinoless double electron capture decay with a resonance condition.