W boson mass in NP models with an extra U(1) gauge group*

Abstract The precise measurement of the W boson mass is closely related to the contributions of new physics (NP), which can significantly constrain the parameter space of NP models, particularly those with an additional local gauge group. The inclusion of a new Z ' gauge boson and gauge couplings in these models can contribute to the oblique parameters S , T , and U and the W boson mass at tree level. Considering the effects of kinetic mixing, in this study, we calculate and analyze the oblique parameters S , T , and U and the W boson mass in such NP models. We find that the kinetic mixing effects can make significant contributions to the W boson mass, and these contributions can be eliminated by redefining the gauge boson fields by removing neutral currents with charged leptons if the leptonic Yukawa couplings are invariant under the extra local gauge group, even with nonzero kinetic mixing effects.