Six-lepton Z' resonance at the Large Hadron Collider

Area of Science:

• Particle Physics
• High Energy Physics
• Beyond Standard Model Physics

Background:

• New physics models propose the existence of a Z' weak boson linked to an additional U(1) gauge symmetry.
• A heavy Higgs boson could decay into two Z bosons.

Purpose of the Study:

• To investigate the distinctive Large Hadron Collider (LHC) signal from Z' boson production and decay via Z' --> ZH --> ZZZ.
• To explore the Z' boson's decay into three pairs of leptons as a unique signature.
• To motivate an independent 6-lepton resonance search, irrespective of dilepton search outcomes.

Main Methods:

• Analysis of Z' boson production and decay channels at the LHC.
• Reconstruction of Higgs (H) and Z' boson masses and widths from the Z' --> ZH --> ZZZ decay signature.
• Investigation of Z' decay modes, including Z' --> 3 pairs of leptons.

Main Results:

• The Z' --> ZH --> ZZZ decay presents a nearly background-free and distinctive LHC signal.
• This decay channel allows for the reconstruction of both H and Z' boson masses and widths.
• The Z' decay to 3 pairs of leptons offers a particularly unique signature.
• The ZH decay mode is viable even if the Z' boson is decoupled from leptons.

Conclusions:

• The Z' --> ZH --> ZZZ decay provides a powerful tool for discovering new physics at the LHC.
• The distinct 6-lepton signature from Z' decays warrants dedicated searches.
• This research highlights the potential for uncovering new physics through specific decay channels, even when other channels are constrained.