Progress and Challenges in Neutrinoless Double Beta Decay
Neutrinoless double-beta decay is the most sensitive laboratory probe of lepton number violation, and its detection is being pursued by ambitious experimental programs. The observation of this decay will have far reaching consequences: demonstrate that neutrinos are Majorana fermions, shed light on the neutrino absolute masses and mass-generation mechanism, and give insight into leptogenesis scenarios key to understand the matterantimatter asymmetry in the universe. The interpretation of a positive or null measurement, however, relies on the identification of the lepton-number-violating mechanism driving the decay, and on having reliable nuclear matrix elements. This workshop will focus on recent advances in lattice QCD, chiral effective field theory, and many-body nuclear theory towards the determination of the relevant lepton-number-violating decay channel, with associated transition operators, and the controlled calculation of the corresponding nuclear matrix elements; in addition, we will discuss the challenges that remain to be faced.