In “Electroweak Scalar Effects Beyond Dimension-6 in SMEFT” we explore the impact of heavy scalar fields on the Standard Model Effective Field Theory (SMEFT) by computing effective dimension-eight operators. Focusing on the Two Higgs Doublet Model and the Complex Triplet Scalar Model, we ‘integrate out’ heavy scalar fields at one-loop order in the so-called Green’s basis. We also examine the influence of these fields on the fermion sector, deriving fermionic effective operators up to dimension eight and mapping contributions onto non-redundant operator bases. The study assesses the significance of higher-order contributions in the SMEFT expansion, particularly for electroweak precision observables at future precision lepton machines like GigaZ. (Read more)