Modelling of the $t\bar{t}H$ and $t\bar{t}V$ $(V=W,Z)$ processes for $\sqrt{s}=13$ TeV ATLAS analyses

Production of top quark pairs in association with heavy Standard Model bosons is important both as a signal and a background in several ATLAS analyses. Strong constraints on such processes cannot at present be obtained from data, and therefore their modelling by Monte Carlo simulation as well as the associated uncertainties are important. This note documents the Monte Carlo samples currently being used in ATLAS for the $t\bar{t}H$ and $t\bar{t}V$ ($V=W,Z$ vector bosons) processes for $\sqrt{s}=13$ TeV proton-proton collisions.