Speaker
Description
In the Standard Model (SM), flavour-specific effects originate from the Higgs couplings to fermions encoded in the Yukawa matrices. UV-complete extensions of the SM typically introduce additional flavour-dependent couplings, which can significantly affect precision collider and flavour observables. In this talk, we explore the flavour structure of higher-dimensional operators in the SM effective field theory (SMEFT) framework and investigate how the known hierarchies in the SM Yukawa sector can guide power-counting schemes for flavour-dependent Wilson coefficients. We extended the AutoEFT software package by implementing flavour spurions scaling in powers of the Wolfenstein parameter $\lambda$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. This approach enables us to systematically investigate flavour scenarios between Minimal Flavour Violation (MFV) and Froggatt-Nielsen (FN) models in the quark-flavour sector. Using an explicit example, we illustrate our method by deriving flavour power-counting hierarchies for dimension-six Wilson coefficients.