Measurement of jet shapes in top pair events at sqrt(s) = 7 TeV using the ATLAS detector

TL;DR

This paper measures the internal structure of jets produced in top-quark pair events at 7 TeV, revealing differences between jets from bottom quarks and light quarks using ATLAS data.

Contribution

It provides the first detailed comparison of jet shapes from bottom-quark and light-quark jets in top-pair events at the LHC.

Findings

Light-quark jets have narrower momentum flow distributions than b-quark jets.

Jet shape measurements help distinguish between different quark origins.

Results improve understanding of jet substructure in top-quark decays.

Abstract

A measurement of jet shapes in top-quark pair events using 1.8 fb(-1) of sqrt(s) = 7 TeV pp collision data recorded by the ATLAS detector at the LHC is presented. Samples of top-quark pair events are selected in both the single-lepton and dilepton final states. The differential and integrated shapes of the jets initiated by bottom-quarks from the top-quark decays are compared with those of the jets originated by light-quarks from the hadronic W-boson decays in the single-lepton channel. The light-quark jets are found to have a narrower distribution of the momentum flow inside the jet area than b-quark jets.