Treatment of top-quark backgrounds in extreme phase spaces: the ''top $p_{T}$ reweighting'' and novel data-driven estimations in ATLAS and CMS

The top quark plays an important role in searches for physics beyond the SM, both as a dominant background and as a key signature for the signal. The most notable feature found in the top physics analyses: the disagreement between simulation and data of the top quark $p_{T}$ spectrum - is highlighted. A reweighting procedure which significantly improves the agreement between simulation and data, also known as the ''top $p_{T}$ reweighting'', is summarised. Commonly raised points concerning the reweighting to fixed-order predictions are discussed, and several refined approaches are proposed. An overview of recent searches by the ATLAS and CMS Collaborations applying novel data-driven techniques for the estimation of this background are presented, with a focus on high $p_{T}$ and/or large multiplicity regimes.