Interference effects for Higgs boson mediatedZ-pair plus jet production

Abstract

We study interference effects in the production channel $ZZ+\text{jet}$, in particular focusing on the role of the Higgs boson. This production channel receives contributions both from Higgs boson mediated diagrams via the decay $H\ensuremath{\rightarrow}ZZ$ (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 $gq\overline{q}ZZ$ 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 ${m}_{ZZ}>2{m}_{Z}$. In the region ${m}_{ZZ}>300\text{ }\text{ }\mathrm{GeV}$ we find that the interference in the $ZZ+\text{jet}$ 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.