Spin correlations in top pair with di-gamma production at NLO+PS

In this talk an interface is presented between the multi-purpose next-to-leading-order Monte Carlo tool MADGRAPH5-AMC@NLO and the automated one-loop amplitude generator GOSAM. As a phenomenological application of this work, the interface is used to make predictions for the ttH and ttgg processes at the 13 TeV LHC. The differences between these two processes is studied, focussing in particular on observables that are sensitive to the polarisation of the top quarks. This talk is based on Ref. [1].