Hadronic Antenna Patterns to Distinguish Production Mechanisms for Large-E_T Jets

TL;DR

The paper tackles distinguishing production mechanisms behind large ET jets by exploiting hadronic antenna patterns that encode color flow in soft-gluon radiation. It derives parton-level antenna expressions for QCD, a Z' contribution, and composite-interaction scenarios, then folds them with PDFs to produce observable hadron-level distributions. Key results show distinct radiation patterns for QCD vs Z' and for contact interactions, including resonance-associated peaks and color-structure dependent antenna sums. The method offers a new diagnostic tool for current and future hadron-collider experiments and has broader relevance to processes like Higgs production and rapidity-gap physics in DIS.

Abstract

Hadronic antenna patterns provide a tool able to diagnose different patterns of colour flow in large-E_T jet events. They reflect the underlying short-distance dynamics, and are sensitive to colour coherence and interference between the initial- and final-state partons. We discuss how hadronic antenna patterns may be used on large-E_T events from the Fermilab Tevatron or the CERN LHC to distinguish between conventional QCD and new physics production mechanisms such as a possible Z' boson or compositeness.

Figures (7)

• Figure 1: Jet configuration for the numerical studies described in the text.
• Figure 2: Ratio of the $2\to 3$ and $2 \to 2$ matrix elements as a function of the soft gluon azimuthal angle about the large-$E_T$ jet, for various QCD and $Z'$ subprocesses.
• Figure 3: Ratio of the $2\to 3$ and $2 \to 2$ matrix elements as a function of the soft gluon azimuthal angle about the large-$E_T$ jet for the $u \bar{u} \to d \bar{d} (g)$ subprocess, including QCD and $Z'$ contributions.
• Figure 4: Decomposition of the $u \bar{u} \to d \bar{d} (g)$ radiation pattern of Fig. \ref{['fig:qcdzp']}, for $E_T = 400$ GeV. The curves represent the various contributions to the $2\to 3$ matrix element squared, normalized in each case to the total QCD$+Z'$$2\to 2$ matrix element squared.
• Figure 5: Ratio of approximate and exact matrix elements, as described in the text.