Non-Standard Neutrinoless Double Beta Decay and its Implications
The talk will focus on the effective approach to lepton number violation
and the implications of potential future observation of lepton number
violating (LNV) processes, primarily of neutrinoless double beta decay. The
interplay between lepton number violation at high and low energies is of
particular interest, as constraints on theories of baryogenesis can be
obtained. For a model independent description the LNV effective operators
on top of the SM Lagrangian are considered. Each such operator contributes
to neutrinoless double beta decay in a number of ways and the understanding
of the mutual relations among all the operators is crucial when determining
the dominant contribution. Moreover, the nuclear side of the problem plays
an important role, as a thorough calculation of corresponding nuclear
matrix elements is needed for the estimation of the effective couplings and
it can also help to pinpoint the dominant mechanism triggering neutrinoless
double beta decay. Apart from the effective field approach, I will also
outline the possible extension of our arguments to a general UV-completed
model.