Anomalous neutral gauge boson interactions and simplified models

TL;DR

This paper investigates how anomalous neutral gauge boson interactions, specifically Z boson interactions, can reveal new physics beyond the Standard Model by analyzing simplified models and their detectability at current and future colliders.

Contribution

It introduces minimal simplified models with scalar and fermion loops to study Z boson interactions and assesses their experimental sensitivity at the LHC and future colliders.

Findings

LHC sensitivity often exceeds threshold effects in these models.

Future lepton colliders can better constrain scenarios through electroweak precision measurements.

Threshold effects are generally small compared to collider sensitivities.

Abstract

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 are 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.