[SU(2)]3 dark matter

An extra SU(2)D gauge factor is added to the well-known left-right extension of the standard model (SM) of quarks and leptons. Under SU(2)L×SU(2)R×SU(2)D, two fermion bidoublets (2,1,2) and (1,2,2) are assumed. The resulting model has an automatic dark U(1) symmetry, in the same way that the SM has automatic baryon and lepton U(1) symmetries. Phenomenological implications are discussed, as well as the possible theoretical origins of this proposal.