Search for a new Z' gauge boson via the pp W^ (*) Z' ^ ^^^ process in pp collisions at s=13 TeV with the ATLAS detector

A search for a new Z' gauge boson predicted by L_-L_ models, based on charged-current Drell-Yan production, pp W^ (*) Z' ^ ^^^, is presented. The data sample used corresponds to an integrated luminosity of 140 fb^-1 of proton-proton collisions at s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The search examines a final state of 3 plus large missing transverse momentum. Upper limits are set on the Z' production cross-section times branching ratio in the mass range of 5-81 GeV. After combining with the previous Z' search using the neutral-current Drell-Yan production with a 4 final state, the most stringent exclusion limits to date are achieved in the parameter space of the Z' coupling strength and mass.