  We propose and study a novel extension of the Standard Model based on the B-L
gauge symmetry that can account for dark matter and neutrino masses. In this
model, right-handed neutrinos are absent and the gauge anomalies are canceled
instead by four chiral fermions with fractional B-L charges. After the breaking
of $U(1)_{B-L}$, these fermions arrange themselves into two Dirac particles,
the lightest of which is automatically stable and plays the role of the dark
matter. We determine the regions of the parameter space consistent with the
observed dark matter density and show that they can be partially probed via
direct and indirect dark matter detection or collider searches at the LHC.
Neutrino masses, on the other hand, can be explained by a variant of the
type-II seesaw mechanism involving one of the two scalar fields responsible for
the dark matter mass.
