Flavorful electroweak precision observables in the Standard Model effective field theory

Electroweak precision observables (EWPOs) measured at the W and Z poles provide stringent limits on possible beyond the Standard Model physics scenarios. In an effective field theory (EFT) framework, the next-to-leading-order QCD and electroweak results for EWPOs yield indirect limits on possible fourfermion operators that do not contribute to the observables at tree level. Here, we calculate the next-toleading corrections to EWPOs induced by flavor nonuniversal four-fermion interactions and find that the extracted limits on EFT coefficients have a strong dependence on the flavor structure of the four-fermion operators. The limits on several EFT coefficients obtained using next-to-leading-order corrections to EWPOs are comparable to those obtained from top quark pair production at the LHC.