Explaining the W boson mass anomaly and dark matter with a U(1) dark sector

The W boson mass recently reported by the CDF collaboration shows a deviation from the standard model prediction with an excess at the 7σ level.We investigate two simple extensions of the standard model with an extra U(1) dark sector.One is the U(1)xextension,where the U(1)xgauge field mixes with the standard model through gauge kinetic terms.The other is a general U(1)AY+Bqextension of the standard model.Fitting various experimental constraints,we find that the U(1)xextension with only kinetic mixing can enhance the W boson mass by10 MeV at most.The U(1)AY+Bqextension can easily generate a 77 MeV enhancement of the Wboson mass and also offer a viable dark matter candidate with a mass ranging from several hundred GeV to TeV,which may be detected by future dark matter direct detection experiments with improved sensitivities.