Six-Lepton Z' Resonance at the Large Hadron Collider

TL;DR

This paper explores a novel six-lepton resonance signature at the LHC from a Z' boson decaying via a Higgs into three Z bosons, providing a background-free detection channel for new physics models.

Contribution

It introduces a new six-lepton resonance search strategy for Z' bosons that decay through a Higgs into three Z bosons, independent of dilepton constraints.

Findings

Six-lepton final state offers a nearly background-free signal.

The Z' decay mode can be detected even if it is leptophobic.

Reconstruction of Z' and Higgs masses is feasible with this channel.

Abstract

New physics models admit the interesting possibility of a Z' weak boson associated with an extra U(1) gauge symmetry and a Higgs boson that is heavy enough to decay into a pair of Z bosons. Then Z' production and decay via Z' -> ZH -> ZZZ has a distinctive LHC signal that is nearly background free and reconstructs the H and Z' masses and widths. The Z' decay to 3 pairs of leptons is especially distinctive. The ZH decay mode exists even if the Z' is decoupled from leptons, which motivates an independent 6-lepton resonance search regardless of the dilepton search results.