The oblique parameters in the 2HDM with vector-like quarks: confronting M W CDF-II anomaly

Abstract

The CDF collaboration has released a new measurement of the W boson mass using their complete data set with 8.8 fb⁻¹ in pp¯ collisions. This result deviates from the Standard Model prediction by around 7σ. We explain how the two Higgs doublet model (2HDM) with vector-like quarks (VLQs) is affected by the recently discovered W boson mass. In our study, we include both theoretical constraints such as perturbative unitarity and vacuum stability as well as a number of experimental constraints. We also look into how the effective mixing angle, measured by the SLD collaboration in addition to the CDF W-boson mass, is used to determine the S and T parameters. In the alignment limit, we investigate the case where the lighter CP-even neutral Higgs boson of the 2HDM is the one found at the LHC and demonstrate how the parameter space of the 2HDM type II in the presence of VLQs is constrained. It is found that in most cases, there is a cancellation between the 2HDM and VLQs contributions, which enlarges the parameter space of both models.