Current-enhanced excited states in lattice QCD three-point functions

Excited-state contamination remains one of the leading sources of systematic uncertainty in the precise determination of hadron structure observables from lattice QCD. In this letter, we present a general argument, inspired by meson dominance ideas and implemented through the variational method, to identify which excited states are enhanced by the choice of the inserted current and kinematics. The argument is supported by numerical evidence across multiple hadronic channels and provides both a conceptual understanding and practical guidance to account for excited-state effects in hadron three-point function analyses.