Minimal anomalous $\mathrm{U}(1)$ theories and collider phenomenology

TL;DR

This paper explores the collider signatures of anomalous U(1) gauge bosons in minimal extensions of the Standard Model, focusing on unique decay modes and constraints from current collider data, with implications for future experiments.

Contribution

It introduces a framework for anomaly cancellation via the Green-Schwarz mechanism in minimal U(1) models and analyzes their collider phenomenology including rare decay modes.

Findings

Derived constraints from LHC dilepton and dijet searches.

Calculated decay rates for Z' to ZZ and Z-photon modes.

Discussed potential observation of signatures at LHC and ILC.

Abstract

We study the collider phenomenology of a neutral gauge boson $Z'$ arising in minimal but anomalous $\mathrm{U}(1)$ extensions of the Standard Model (SM). To retain gauge invariance of physical observables, we consider cancellation of gauge anomalies through the Green-Schwarz mechanism. We categorize a wide class of $\mathrm{U}(1)$ extensions in terms of the new $\mathrm{U}(1)$ charges of the left-handed quarks and leptons and the Higgs doublet. We derive constraints on some benchmark models using electroweak precision constraints and the latest 13 TeV LHC dilepton and dijet resonance search data. We calculate the decay rates of the exotic and rare one-loop $Z'$ decays to $ZZ$ and $Z$-photon modes, which are the unique signatures of our framework. If observed, these decays could hint at anomaly cancellation through the Green-Schwarz mechanism. We also discuss the possible observation of such signatures at the LHC and at future ILC colliders.