Uncovering a chirally suppressed mechanism of $0\nu\beta\beta$ decay with LHC searches

Understand

$\Delta L =2$ lepton number violation (LNV) at the TeV scale could provide an alternative interpretation of positive signal(s) in future neutrinoless double beta $(0\nu\beta\beta)$ decay experiments.

• An interesting class of models from this point of view are those that at low energies give rise to dimension-9 vector operators and a dimension-7 operator, both of whose $0\nu\beta\beta$-decay rates are "chirally suppressed".
• We study and compare the sensitivities of $0\nu\beta\beta$-decay experiments and LHC searches to a simplified model in this class of TeV-scale LNV that is also $SU(2)_L \times U(1)_Y$ gauge invariant.
• The searches for $0\nu\beta\beta$ decay, which are here diluted by a chiral suppression of the vector operators, are found to be less constraining than LHC searches whose reach is increased by the assumed kinematic accessibility of the mediator particles.