Spin Polarisation of tbar{t}γγ production at NLO+PS with GoSam interfaced to MadGraph5_aMC@NLO

We present an interface between the multipurpose NLO Monte Carlo tool MadGraph5_aMC@NLO and the automated one-loop amplitude generator GoSam. As a first application of this novel framework, we compute the NLO corrections to $pp \to t\bar{t}H$ and $pp \to t\bar{t}\gamma\gamma$ matched to a parton shower. In the phenomenological analyses of these processes, we focus our attention on observables which are sensitive to the polarisation of the top quarks.