Anomalous triple gauge boson couplings in $ZZ$ production at the LHC and the role of $Z$ boson polarizations

TL;DR

This paper investigates anomalous neutral gauge boson couplings in ZZ production at the LHC using polarization asymmetries and cross sections to set limits, highlighting the sensitivity of polarization asymmetries to CP-odd couplings.

Contribution

It introduces a method combining polarization asymmetries and cross sections with MCMC to constrain anomalous couplings in ZZ production at the LHC.

Findings

Polarization asymmetries improve sensitivity to anomalous couplings.

The asymmetry $A_{x^2-y^2}$ probes CP-odd couplings effectively.

Significant constraints on anomalous couplings are achievable with high luminosity.

Abstract

We study anomalous couplings among neutral gauge bosons in $ZZ$ production at the LHC for $\sqrt{s}=13$ TeV in $4$-lepton final state. We use the cross section and polarization asymmetries of the $Z$ boson to estimate simultaneous limits on anomalous coupling using Markov-Chain--Monte-Carlo (MCMC) method for luminosities $35.9$ fb$^{-1}$, $150$ fb$^{-1}$, $300$ fb$^{-1}$ and $1000$ fb$^{-1}$. The $CP$-even polarization asymmetry $A_{x^2-y^2}$ is sensitive mainly to the $CP$-odd couplings $f_4^{Z/\gamma}$ (quadratically) providing a probe to identify $CP$-odd nature of interaction at the LHC. We find that the polarization asymmetries significantly improve the estimation of anomalous couplings should a deviation from the Standard Model (SM) be observed.