Electroweak and QCD corrections to off-shell single-top production in association with a Z boson at the LHC

The associated production of a single top quark with a Z boson (tZj) represents an important probe of the electroweak (EW) sector of the Standard Model. Since differential measurements of tZj are expected to enhance the sensitivity to new-physics effects, and the experimental interest in this direction is growing in the light of upcoming LHC runs, it is crucial to improve the off-shell modelling of this process for realistic fiducial regions. We present the first Standard-Model calculation of the off-shell tZj production in the multi-lepton decay channel including NLO EW and QCD corrections to the LO EW signal. All off-shell effects and spin correlations are accounted for, both at LO and at NLO. Relying on a realistic fiducial volume, we highlight the most relevant effects coming from radiative corrections and from irreducible-background contamination on total and differential cross sections.