Leptonic anomalous magnetic moments in $ u$SMEFT

We investigate contributions to the anomalous magnetic moments of charged leptons in the neutrino-extended Standard Model Effective Field Theory ($ u$SMEFT). We discuss how $ u$SMEFT operators can contribute to a leptons magnetic moment at one- and two-loop order. We show that only one operator can account for existing electronic and muonic discrepancies, assuming new physics appears above $1$ TeV. In particular, we find that a right-handed charged current in combination with minimal sterile-active mixing can explain the discrepancy for sterile neutrino masses of $mathcal O(100)$ GeV while avoiding direct and indirect constraints. We discuss how searches for sterile neutrino production at the (HL-)LHC, measurements of $hrightarrow mu^+ mu^-$ and searches for $hrightarrow e^+ e^-$, neutrinoless double beta decay experiments, and improved unitarity tests of the CKM matrix can further probe the relevant parameter space.