Search for $Z'$ via $ZH$ associated production at LHC

TL;DR

This paper investigates the potential to detect and analyze extra neutral gauge bosons ($Z'$) at the LHC through associated production with a Higgs and Z boson, focusing on couplings and signal suppression.

Contribution

It introduces a method to study $Z'$ properties via $ZH$ associated production and proposes kinematic cuts to suppress background, enhancing detection prospects.

Findings

Couplings of $Z'$ to quarks can be probed through specific decay channels.

Angular distributions of leptons reveal chiral coupling ratios.

Background processes can be effectively reduced with kinematic cuts.

Abstract

Many new physics models predict the existence of extra neutral gauge bosons ($Z'$). Inspired by the recent development on Higgs search, we study the properties of $Z'$ via the Higgs and $Z$ boson associated production. The couplings of $Z'$ to quarks can be investigated through $pp \to Z'\to ZH\to l^+l^-b \bar b$ process, which also provides extraordinary signal for understanding the properties of $Z'ZH$ interaction. The standard model background processes can be significantly suppressed by adopting appropriate kinematic cuts. The charged lepton angular distributions are related to the ratio of chiral couplings of $Z'$ to quarks via $Z'ZH$ interaction.