Scotoseesaw model implied by dark right-handed neutrinos

We find a dark gauge symmetry $U(1)_D$ that transforms nontrivially only for three right-handed neutrinos, $\nu_{1,2,3R}$. The anomaly cancellation demands that they have a dark charge $D=0,-1,+1$ assigned to $\nu_{1,2,3R}$, respectively. The dark charge is broken by two units down to a dark parity, i.e. $U(1)_D\to P_D=(-1)^D$, which stabilizes a dark matter candidate. Interestingly, the model manifestly supplies neutrino masses via joint seesaw and scotogenic mechanisms, called scotoseesaw.