Evidence for tWZ production in proton-proton collisions at <math altimg="si1.svg"><msqrt><mrow><mi>s</mi></mrow></msqrt><mo linebreak="goodbreak" linebreakstyle="after">=</mo><mn>13</mn></math> TeV in multilepton final states

The first evidence for the standard model production of a top quark in association with a W boson and a Z boson is reported. The measurement is performed in multilepton final states, where the Z boson is reconstructed via its decays to electron or muon pairs. At least one W boson, associated or from top quark decay, decays leptonically, too. The analysed data were marc:recorded by the CMS experiment at the CERN LHC in 2016–2018 in proton-proton collisions at $\sqrt{s}=13$ TeV, and correspond to an integrated luminosity of 138 fb⁻¹. The measured cross section is $354\pm 54(\text{stat})\pm 95(\text{syst})$ fb, and corresponds to a statistical significance of 3.4 standard deviations.