Top-quark pair production in association with a $Z$ boson in the 4$\ell$ channel with the ATLAS experiment

Abstract

The cross section of the $t\bar{t}Z$~and $t\bar{t}W$~processes are measured in a simultaneous fit using 36.1 ${\text{fb}}^{-1}$ of of proton--proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV recorded by the ATLAS experiment at the LHC. In addition, a fit is performed in the 4$\ell$ channel only, resulting in a cross section of ${\sigma }_{t\bar{t}Z}=1.07\pm 0.26\text{pb}$. This result is consistent with the combined fit and agrees with the prediction by the Standard Model.

Proceedings for the 11th International Workshop on Top Quark Physics (TOP2018). 4 pages, 2 figures

References in corpus (2)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Measurement of the $t\bar{t}Z$ and $t\bar{t}W$ production cross sections in multilepton final states using 3.2 fb${}^{-1}$ of $pp$ collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector