Anomalous Neutral Gauge Boson Interactions and Simplified Models

Trilinear Z boson interactions are sensitive probes both of new sources of CP violation in physics beyond the standard model and of new particle thresholds. Measurements of trilinear Z interactions are typically interpreted in the frameworks of anomalous couplings and effective field theory, both of which require care in interpretation. To obtain a quantitative picture of the power of these measurements when interpreted in a TeV-scale context, we investigate the anatomy of ZZZ interactions and consider two minimal and perturbative simplified models which induce such interactions through new scalar and fermion loops at the weak scale, focusing on ZZ and vector boson fusion-induced Zjj production at the LHC and ZZ production at a future e(+)e(-) collider. We show that both threshold and non-threshold effects often arc small compared to the sensitivity of the LHC, while the increased sensitivity of a future lepton collider should allow us to constrain such scenarios through associated electroweak precision effects complementary to direct searches at hadron colliders.