Flavoured Neutrinoless Double Beta Decay

Understand

We discuss a mechanism of neutrinoless double beta decay, where neutrinos of different flavours come into play.

• This is realized by effective flavour-violating scalar interactions.
• As one consequence, we find that within the normal mass ordering the neutrino effective mass may no longer vanish due to contributions from other flavours.
• We evaluate the necessary nuclear matrix elements, consider the interference between the standard diagram and the new scalar one, and analyze a UV-complete model that realizes the scalar interaction.