Canonical seesaw implication for two-component dark matter

We show that the canonical seesaw mechanism implemented by the U(1)(B-L) gauge symmetry provides two-component dark matter naturally. The seesaw scale that breaks B - L defines a residual gauge symmetry to be Z(6) = Z(2) circle times Z(3), where Z(2) leads to the usual matter parity, while Z(3) is newly recognized, transforming quark fields nontrivially. The dark matter components-that transform nontrivially under the matter parity and Z(3), respectively-can gain arbitrary masses, despite the fact that the Z(3) dark matter may be heavier than the light quarks u, d. This dark matter setup can address the XENON1T anomaly recently observed and other observables, given that the dark matter masses are nearly degenerate, heavier than the electron and the B - L gauge boson Z', as well as the fast- moving Z(3) dark matter has a large B - L charge, while the Z' is viably below the beam dump experiment sensitive regime.

Automated summary

The canonical seesaw mechanism via U(1)(B-L) gauge symmetry can naturally provide two-component dark matter. The dark matter components transform nontrivially under matter parity and Z(3) symmetry, allowing for arbitrary masses.