A search for a WZ resonance, in the fully leptonic final state (electrons or muons), is performed using 139 fb-1 of data collected at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider.
The results are interpreted in terms of a singly charged
Higgs boson of the Georgi-Machacek model, produced by
WZ fusion, and of a Heavy Vector Triplet, with the resonance produced by WZ fusion or the Drell-Yan process.
No significant excess over the Standard Model prediction is observed and limits are set on the production cross-section times branching ratio as a function of the resonance mass for these processes.