Speaker
Description
The top-quark pair production in association with a $W$ boson is an important background to processes like $t\bar{t}H$ or 4-tops production. Due to higher order electroweak corrections, the process is difficult to model. In consequence, a mismodelling of $t\bar{t}W$ surpassing 2$\sigma$ has been observed in previous analyses. Thus, it is of high importance to increase our understanding of it.
This talk will give an overview of the measurement of the $t\bar{t}W$ cross-section in the multi-lepton channel, i.e. $2\ell$SS and $3\ell$, using the full Run 2 dataset. In addition to a measurement in the inclusive phase space, the extraction of the cross-section in a fiducial phase space, as well as the measurement of the ratio $\sigma(t\bar{t}W^+ )/\sigma(t\bar{t}W^-)$ will be discussed. The fit to extract the cross-section is performed simultaneously to a template fit estimating the main background contributions.
