Has the origin of the third-family fermion masses been determined?

Precision measurements of the Higgs couplings are, for the first time, directly probing the mechanism of fermion mass generation. The purpose of this work is to determine to what extent these measurements can distinguish between the tree-level mechanism of the Standard Model and the theoretically motivated alternative of radiative mass generation. Focusing on the third-family, we classify the minimal one-loop models and find that they fall into two general classes. By exploring several benchmark models in detail, we demonstrate that a radiative origin for the tau-lepton and bottom-quark masses is consistent with current observations. While future colliders will not be able to rule out a radiative origin, they can probe interesting regions of parameter space.

Automated summary

Precision measurements of the Higgs couplings are now probing the mechanism of fermion mass generation, particularly focusing on the third-family, and revealing that radiative mass generation models can be consistent with current observations. Future colliders may not rule out a radiative origin for fermion masses, but can explore interesting regions of parameter space.