Search for heavy resonances decaying into a pair of Z bosons in the $\ell^+\ell^−\ell′^+\ell′^−$ and $\ell^+\ell^−\nu\bar{\nu}$ final states using 139 fb$^{−1}$ of proton–proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector

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 collected from 2015 to 2018 that corresponds to an integrated luminosity of 139 fb$^{−1}$ which is the full data statistics collected by the ATLAS detector during the Run 2 of the Large Hadron Collider. Different mass ranges for the hypothetical resonances are considered, depending on the final state and model and spanning from 200 GeV to 2000 GeV. In the absence of a significant observed excess, 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.