Interference effects for Higgs-mediated Z-pair plus jet production

TL;DR

This paper investigates the interference effects in Higgs-mediated Z-pair plus jet production at the LHC, focusing on the off-resonant region where the invariant mass exceeds 300 GeV, revealing similarities to inclusive ZZ production.

Contribution

It provides a detailed analysis of interference effects between Higgs signal and background diagrams in ZZ + jet production, highlighting their significance above the 300 GeV invariant mass threshold.

Findings

Interference effects are similar to those in inclusive ZZ production.

Rates are sufficient for study with jet-binned LHC data.

Interference is mainly an off-resonant effect for the Higgs boson.

Abstract

We study interference effects in the production channel ZZ + jet, in particular focusing on the role of the Higgs boson. This production channel receives contributions both from Higgs boson-mediated diagrams via the decay $H \to ZZ$ (signal diagrams), as well as from diagrams where the Z-bosons couple directly to a quark loop (background diagrams). We consider the partonic processes $gggZZ$ and $gq \bar{q} ZZ$ in which interference between signal and background diagrams first occurs. Since interference is primarily an off-resonant effect for the Higgs boson, we treat the Z-bosons as on-shell. Thus our analysis is limited to the region above threshold, where the invariant mass of the Z-pair, $m_{ZZ}$, satisfies the condition $m_{ZZ}>2m_Z$. In the region $m_{ZZ} > 300$ GeV we find that the interference in the ZZ + jet channel is qualitatively similar to interference in the inclusive ZZ channel. Moreover, the rates are sufficient to study these effects at the LHC once jet-binned data become available.