First Run 3 data/MC plots for the measurement of the top-quark pair production cross-section in pp collisions at centre-of-mass energy of 13.6 TeV with the ATLAS experiment at the LHC

TL;DR

This paper presents the first measurement of top-quark pair production cross-section at 13.6 TeV using ATLAS data from LHC Run 3, providing crucial tests of QCD and background estimates for new physics searches.

Contribution

It reports the initial data/Monte Carlo comparison for top-quark pair production at 13.6 TeV, marking the first such measurement in this energy regime with ATLAS.

Findings

Data collected at 13.6 TeV with 790 pb$^{-1}$ luminosity.

Comparison of observed data with theoretical predictions.

Validation of top-quark pair reconstruction in electron-muon final state.

Abstract

The top quark is the heaviest known elementary particle. Its large mass, close to the scale of electroweak symmetry breaking, hints at a unique role in the Standard Model of particle physics. The study of top quark-antiquark ($t\bar{t}$) production is an important part of the physics programme of the ATLAS experiment at the CERN Large Hadron Collider (LHC). It allows quantum chromodynamics to be probed at some of the highest reachable energy scales. The $t\bar{t}$ production also forms a crucial background in many searches for physics beyond the Standard Model. Therefore, precise measurements the $t\bar{t}$ process are essential to fully exploit the discovery potential of the LHC. A comparison of data and prediction in the electron-muon final state is presented, aiming to reconstruct $t\bar{t}$ events. Data are collected in the period F1 of the LHC Run 3 at the centre-of-mass of 13.6 TeV, during the first week of August 2022, corresponding to an integrated luminosity of about 790 pb$^{-1}$.