Searches for heavy $ZZ$ and $ZW$ resonances in the $\ell\ell qq$ and $\nu\nu qq$ final states in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

TL;DR

This study searches for heavy $ZZ$ and $ZW$ resonances in specific final states using 13 TeV proton-proton collision data from ATLAS, setting limits on possible new heavy particles within various theoretical models.

Contribution

It provides the first comprehensive search for heavy $ZZ$ and $ZW$ resonances in these final states at 13 TeV, with new upper bounds on production cross sections across a wide mass range.

Findings

No evidence of heavy resonance production was observed.

Upper bounds on cross sections were set for masses between 300 and 5000 GeV.

Constraints were placed on models with extra Higgs bosons, heavy vector triplets, and warped extra dimensions.

Abstract

This paper reports searches for heavy resonances decaying into $ZZ$ or $ZW$ using data from proton--proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV. The data, corresponding to an integrated luminosity of 36.1 fb$^{-1}$, were recorded with the ATLAS detector in 2015 and 2016 at the Large Hadron Collider. The searches are performed in final states in which one $Z$ boson decays into either a pair of light charged leptons (electrons and muons) or a pair of neutrinos, and the associated $W$ boson or the other $Z$ boson decays hadronically. No evidence of the production of heavy resonances is observed. Upper bounds on the production cross sections of heavy resonances times their decay branching ratios to $ZZ$ or $ZW$ are derived in the mass range 300--5000 GeV within the context of Standard Model extensions with additional Higgs bosons, a heavy vector triplet or warped extra dimensions. Production through gluon--gluon fusion, Drell--Yan or vector-boson fusion are considered, depending on the assumed model.