We propose a novel model for lepton flavor and dark matter based on the
SU(2)Dβ gauge symmetry and vector-like leptons in its fundamental
representations. We introduce a dark SU(2)Dβ Higgs doublet and a Higgs
bi-doublet for the mass mixing between the vector-like lepton and the lepton.
As a result, the seesaw lepton masses are generated and there are sizable
one-loop contributions to the muon gβ2 via the SU(2)Dβ gauge bosons and the
relatively heavy vector-like lepton, as indicated in Fermilab E989. The
tree-level mass mixing between the Z boson and the isospin neutral gauge
boson of SU(2)Dβ in our model accounts for the shift in the W boson mass,
being consistent with Tevatron CDFII. Finally, we show that the isospin charged
gauge boson of SU(2)Dβ becomes a plausible candidate for dark matter with a
small mass splitting tied up to the modified W boson mass, and there is a
viable parameter space where the favored corrections to the muon gβ2 and the
W boson mass and the dark matter constraints are simultaneously fulfilled.Comment: 33 pages, 4 figures, v2: references added, v3: version to appear in
Phys. Rev.