Measurements of top-quark pair differential and double-differential cross-sections in the $\ell$+jets channel with $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector

TL;DR

This paper reports detailed measurements of top-quark pair production cross-sections in proton-proton collisions at 13 TeV using the ATLAS detector, comparing results with theoretical models to test the Standard Model.

Contribution

First comprehensive differential and double-differential cross-section measurements for top-quark pairs in the lepton+jets channel at 13 TeV with resolved and boosted topologies.

Findings

Good agreement between data and theoretical predictions

Measurements enable precision tests of Monte Carlo generators

Results cover various kinematic variables and jet multiplicities

Abstract

Single- and double-differential cross-section measurements are presented for the production of top-quark pairs, in the lepton + jets channel at particle and parton level. Two topologies, resolved and boosted, are considered and the results are presented as a function of several kinematic variables characterising the top and $t\bar{t}$ system and jet multiplicities. The study was performed using data from $pp$ collisions at centre-of-mass energy of 13 TeV collected in 2015 and 2016 by the ATLAS detector at the CERN Large Hadron Collider (LHC), corresponding to an integrated luminosity of $36~\mathrm{fb}^{-1}$. Due to the large $t\bar{t}$ cross-section at the LHC, such measurements allow a detailed study of the properties of top-quark production and decay, enabling precision tests of several Monte Carlo generators and fixed-order Standard Model predictions. Overall, there is good agreement between the theoretical predictions and the data.