[Paper Review] Gluon Radiation and Top Quark Physics

L. H. Orr, T. Stelzer+1 more|ArXiv.org|Sep 13, 1996

Particle physics theoretical and experimental studies3 citations

TL;DR

This paper investigates gluon radiation in top quark production and decay, analyzing its impact on jet multiplicity and mass reconstruction. Using perturbative QCD calculations, it demonstrates that initial- and final-state radiation significantly alter event topology, complicating top quark mass measurements and necessitating refined QCD corrections for precision physics at hadron colliders.

ABSTRACT

Radiation of gluons gives rise to extra jets in top quark events that can lead to complications in event reconstruction and mass measurement. I review recent results for gluon radiation in top quark production and decay, and discuss their implications for top quark physics.

Motivation & Objective

• To understand the role of gluon radiation in top quark events at hadron colliders.
• To quantify how gluon emission affects jet multiplicity and event topology in top quark production and decay.
• To assess the impact of QCD radiation on top quark mass reconstruction accuracy.
• To provide theoretical foundations for correcting radiation effects in experimental analyses.
• To support precision top quark physics by identifying key radiation contributions in QCD processes.

Proposed method

• Applies perturbative QCD to calculate initial- and final-state radiation in top quark pair production via gluon fusion and quark annihilation.
• Uses leading-order matrix elements with real gluon emission to model additional jets in top quark events.
• Performs parton-level simulations to study radiation patterns in both production and decay chains.
• Analyzes the kinematic effects of radiation on reconstructed top quark masses and event topology.
• Incorporates radiation corrections into event generation frameworks to model realistic detector-level signatures.
• Compares radiation patterns in different production modes (gg → tt̄, qq̄ → tt̄) and decay channels.

Experimental results

Research questions

• RQ1 How does gluon radiation affect the number and kinematics of jets in top quark events?
• RQ2 What is the relative contribution of initial-state versus final-state radiation to jet multiplicity?
• RQ3 How does gluon emission distort top quark mass measurements in experimental analyses?
• RQ4 What are the dominant QCD corrections from radiation in top quark pair production and decay?
• RQ5 To what extent do radiation effects complicate event reconstruction and mass reconstruction in top quark physics?

Key findings

• Gluon radiation leads to significant additional jet activity, particularly in the final state of top quark decays.
• Initial-state radiation contributes substantially to jet multiplicity, especially in gluon fusion processes.
• Radiation effects distort reconstructed top quark masses, introducing systematic shifts in event-by-event measurements.
• Final-state radiation in top quark decay produces collimated jets that can mimic additional physics signals.
• The inclusion of real gluon emission in matrix elements is essential for accurate modeling of top quark events.
• Radiation patterns differ significantly between gg → tt̄ and qq̄ → tt̄ production, affecting analysis strategies.