Complete the two-loop calculation of the Higgs-portal contribution to the W-boson mass

Derive the complete two-loop contribution of scalar and fermionic Higgs portals to the W-boson mass, and assess how the resulting prediction affects discrimination among Higgs-portal scenarios beyond the one-loop matching and running approximation.

Background

The paper includes the W-boson mass as an indirect probe of Higgs portals, but estimates its shift using one-loop matching followed by one-loop renormalisation-group running. The authors explicitly state that this does not constitute the full two-loop calculation of the portal contribution.

A complete calculation could alter the predicted correlations, especially in regions where the effective-field-theory approximation and the assumed hierarchy of scales are questionable. The unresolved calculation is therefore relevant to determining the reliability of W-boson-mass discrimination.

References

As we are limiting ourselves to Higgs-based observables in this paper and have not computed the full 2-loop contribution, we leave a more detailed exploration of this avenue for future work.

— A phenomenological profile of Higgs portals at future colliders  (2609.19258 - Detering et al., 16 Sep 2026) in Section 3.2, subsection ‘Model-dependent correlations among observables’