Towards Common $t\bar{t}$ Monte-Carlo Settings for ATLAS and CMS

Both ATLAS and CMS use POWHEG+PYTHIA8 Monte-Carlo simulations to model the $t\bar{t}$ process. A commonly agreed upon set of POWHEG and PYTHIA8 parameters is presented and compared to the nominal ATLAS and CMS settings. Samples generated with the different settings are compared using a publicly available Rivet routine. Comparisons are presented to demonstrate that samples produced with the Common Settings by both collaborations are in agreement with each other. Samples generated with the Common Settings can be used to compare ATLAS and CMS analyses.