A Missing Piece in the Neutrinoless Beta-Decay Puzzle

The observation of a nuclear process called neutrinoless double-beta decay might help researchers figure out what gives neutrinos their mass and why there’s far more matter than antimatter in the Universe. While this hypothetical decay has never been observed, experiments have placed constraints on the maximum rate at which it could occur. Now Vincenzo Cirigliano of Los Alamos National Laboratory, New Mexico, and colleagues show that previous calculations of neutrinoless double-beta decay might have neglected a contribution that is critical for interpreting experimental data.