  At NLO in QCD, the $tWZ$ production process interferes with resonant LO
processes, $t\bar{t}Z$ and $t\bar{t}$, and a method to meaningfully disentangle
these overlapping processes needs to be employed. I discuss the diagram-removal
procedure needed to obtain an operative definition of $tWZ$ at NLO accuracy. I
also show the predictions we obtain in the context of the Standard Model and in
the Standard Model Effective Field Theory including the relevant dimension-six
SMEFT operators.
