Lepton number

Particle physics

Physics

Electron

Lepton

Physics beyond the Standard Model

Nuclear physics

Neutrino

Cosmology

Beta decay

Quantum mechanics

Double beta decay

Annual Review of Nuclear and Particle Science

Neutrinoless double-beta decay is a forbidden, lepton-number-violating nuclear transition whose observation would have fundamental implications for neutrino physics, theories beyond the Standard Model and cosmology. In this review, we summarize the theoretical progress to understand this process, the expectations and implications under various particle physics models, as well as the nuclear physics challenges that affect the precise predictions of the decay half-life. We will also provide a synopsis of the current and future large-scale experiments that aim at discovering this process in physically well-motivated half-life ranges.

Neutrinoless Double-Beta Decay: Status and Prospects