In the neutrinoless double beta decay (0νβ-β-) two neutrons are transformed into two protons and only two electrons are emitted in the final state. This is a very encouraging case due to its implications in fundamental physics since it can only occur if neutrinos are massive and Majorana particles (neutrinos and antineutrinos are identical particles). Additionally, the inverse of the half-life of this process is proportional to the neutrino effective mass. Therefore, an eventual detection of this decay mode would determine the absolute scale of the mass of these elementary particles.

The main goal of this research line is the study of nuclear matrix elements of lepton number violating decays using advanced quantum many-body techniques to solve the nuclear many-body problem. In particular, the research is focused on the development and application of nuclear energy density functional methods (EDF) to these processes. These methods have been recently applied to 0νβ-β- NMEs calculations for all possible candidates, showing a large flexibility to include systematically collective degrees of freedom (deformation, pairing, etc.).