# Differential measurements of $t \overline{t}$ production in ATLAS

## TL;DR

This paper reports on differential measurements of top-antitop production at the LHC by ATLAS, showing good overall modeling but highlighting discrepancies in top quark transverse momentum spectra, and contributing to improved gluon PDF constraints.

## Contribution

It provides new differential cross section measurements of $t \overline{t}$ production and incorporates these into PDF fits to reduce gluon PDF uncertainties at high momentum fractions.

## Key findings

- Monte Carlo models generally agree with measurements
- Discrepancies observed in top quark transverse momentum spectra
- Measurements improve gluon PDF constraints at large x

## Abstract

Differential cross sections of $t \overline{t}$ production have been measured by the ATLAS experiment at the LHC. Monte Carlo calculations provide an overall good modeling of all measured distributions, except for the transverse momentum of the top quark, for which all the generators at the next-to-leading order produce harder spectra. These measurements have been also included in the PDF fits, contributing to a sensible reduction of the gluon PDF uncertainty at large $x$.