Search for heavy $ZZ$ resonances in the $\ell^+\ell^-\ell^+\ell^-$ and $\ell^+\ell^-\nu\bar\nu$ final states using proton proton collisions at $\sqrt{s}= 13$ TeV with the ATLAS detector

TL;DR

This paper reports a search for heavy $ZZ$ resonances decaying into four-lepton or two-lepton plus neutrino final states using 13 TeV proton-proton collision data from the ATLAS detector, setting limits on various theoretical models.

Contribution

First search to analyze heavy $ZZ$ resonances in these specific final states at 13 TeV with ATLAS, providing new constraints on multiple beyond Standard Model theories.

Findings

No significant excess observed, leading to upper limits on production cross sections.

Constraints placed on two-Higgs-doublet models and Randall-Sundrum graviton models.

Mass ranges between 200 GeV and 2000 GeV explored.

Abstract

A search for heavy resonances decaying into a pair of $Z$ bosons leading to $\ell^+\ell^-\ell^+\ell^-$ and $\ell^+\ell^-\nu\bar\nu$ final states, where $\ell$ stands for either an electron or a muon, is presented. The search uses proton proton collision data at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$ collected with the ATLAS detector during 2015 and 2016 at the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model. The different ranges span between 200 GeV and 2000 GeV. The results are interpreted as upper limits on the production cross section of a spin 0 or spin 2 resonance. The upper limits for the spin 0 resonance are translated to exclusion contours in the context of Type I and Type II two-Higgs-doublet models, while those for the spin 2 resonance are used to constrain the Randall Sundrum model with an extra dimension giving rise to spin 2 graviton excitations.