# Differential cross-section measurements of boosted top quarks at $\sqrt{s} = 13$ TeV with the ATLAS detector

## TL;DR

This paper presents measurements of the differential cross-sections of highly boosted top quarks at 13 TeV, comparing experimental data with Monte Carlo simulations to evaluate the accuracy of theoretical models.

## Contribution

It provides the first detailed differential measurements of boosted top quarks at 13 TeV using ATLAS data, including unfolding techniques and comparison with various MC generators.

## Key findings

- MC generators predict a harder pT spectrum than observed in data
- Rapidity distribution shows good agreement between MC and data
- Results help refine top quark modeling in high-energy collisions

## Abstract

Differential cross-section measurements of highly boosted top quarks are presented. The dataset used has an integrated luminosity of $3.2$ fb$^{-1}$, recorded at a centre-of-mass energy of $\sqrt{s}=13$ TeV with the ATLAS detector at the CERN Large Hadron Collider in 2015. Events are selected in the lepton + jets channel, containing one isolated lepton and a large radius jet that is identified as originating from a top quark using substructure tagging techniques. The measured transverse momentum and absolute rapidity distributions are unfolded to remove detector effects and compared to a range of Monte Carlo simulations. The transverse momentum distribution shows that all Monte Carlo generators used predict a harder spectrum than observed in data, while the rapidity distribution agrees well between MC and data.