Combination of searches for heavy resonances using 139 fb$^{-1}$ of proton–proton collision data at $\sqrt{s}$ = 13 TeV with the ATLAS detector

Searches for new heavy resonances decaying into different pairings of $W$, $Z$, or Higgs bosons, as well as directly into leptons, are presented using a data sample corresponding to 139 fb$^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 13 TeV collected from 2015-2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting bosonic decay modes in the $VV$: $qqqq$, $\nu\nu qq$, $\ell\nu qq$, $\ell\ell qq$, $\ell\nu\ell\ell$, and $VH$: $qqbb$, $\nu\nu bb$, $\ell\nu bb$, and $\ell\ell bb$ final states are combined, searching for a narrow-width resonance. Likewise, analyses selecting the leptonic $\ell\nu$ and $\ell\ell$ final states are combined. These sets of analyses are then further combined with each other. No significant deviation from the Standard Model prediction is observed. A simplified model predicting a spin-1 heavy vector-boson triplet is investigated. Cross-section limits are set at the 95% confidence level using an asymptotic approximation and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario and 4.5 TeV in a strongly coupled scenario.