Flavoured gauge extension of singlet-doublet fermionic dark matter: neutrino mass, high scale validity and collider signatures

We propose an Abelian gauged version of the singlet-doublet fermionic dark matter (DM) model where the DM, combination of a vector like fermion doublet and a fermion singlet, is naturally stabilised by the gauge symmetry without requiring any ad-hoc discrete symmetries. In order to have an enlarged parameter space for the DM, accsessible at collider experiments like the Large Hadron Collider (LHC), we consider the additional gauge symmetry to be based on the quantum B − 3Lτ. The restriction to third generation of leptons is chosen in order to have weaker bounds from the LHC on the corresponding gauge boson. The triangle anomalies arising in this model can be cancelled by the inclusion of a right handed neutrino which also takes part in generating light neutrino masses through type I seesaw mechanism. The model thus offers a potential thermal DM candidate, interesting collider signatures and correct neutrino mass along with a stable electroweak vacuum and perturbative couplings all the way up to the Planck scale. We constrain our model parameters from these requirements as well as existing relevant constraints related to DM and colliders.