  We present predictions for the production cross section of t-quark pair
production in association with a Z boson at the next-to-leading order (NLO)
accuracy using matrix elements obtained from the HELAC-Oneloop package. We use
the subtraction method for computing the radiative corrections as implemented
in the POWHEG-Box, which was also used in several other computations of similar
complexity.

High Energy Physics - Phenomenology