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 7 sigma level. We investigate two simple extensions of the standard model with an extra U(1) dark sector. One is the U(1)x extension, where the U(1)(x )gauge field mixes with the standard model through gauge kinetic terms. The other is a general U(1)(AY+Bq) extension 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 by 10 MeV at most. The U(1)(AY+Bq)extension 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.

Automated summary

The CDF collaboration has recently reported a deviation of the W boson mass from the standard model prediction at a 7 sigma level. We have investigated two simple extensions of the standard model involving an additional U(1) dark sector, namely the U(1)x extension and the general U(1)(AY+Bq) extension. By fitting experimental constraints, we find that the U(1)x extension with only kinetic mixing can enhance the W boson mass by up to 10 MeV, while the U(1)(AY+Bq) extension can easily generate a 77 MeV enhancement of the W boson mass.