Fiducial cross-section measurements of top-quark pair production in association with a photon at $\sqrt{s}$ = 13 TeV with the ATLAS detector

TL;DR

This paper measures the production rate of top-quark pairs with an associated photon at 13 TeV using ATLAS data, employing neural networks to improve sensitivity in different decay channels.

Contribution

It presents the first fiducial cross-section measurements of top-quark pairs with a photon at 13 TeV, utilizing neural networks for enhanced analysis sensitivity.

Findings

Fiducial cross-sections measured in single-lepton and dilepton channels.

Neural networks improved event selection and sensitivity.

Results consistent with Standard Model predictions.

Abstract

Top-quark pairs in association with final state particles are produced in large quantities at the LHC due to the high centre-of-mass energy available in proton-proton collisions. One such topology is that of a prompt photon radiated from the top quark in addition to the final state particles from the top quark decay. Using 36.1 fb$^{-1}$ of data collected at $\sqrt{s}$ = 13 TeV with the ATLAS detector, fiducial cross-section results are shown in the single-lepton and dilepton channels. Object-level and event-level neural networks are used to increase sensitivity.