Further Properties of High-Mass Multijet Events at the Fermilab Proton-Antiproton Collider

TL;DR

This study compares high-mass multijet event properties at Fermilab with QCD predictions and phase-space models, finding that QCD calculations accurately describe the data for three to five jets, supporting the dominance of 2->2 scattering plus gluon radiation.

Contribution

It demonstrates that leading order QCD calculations and parton shower models effectively describe multijet events with up to five jets at Fermilab.

Findings

QCD predictions match multijet distributions for 3-5 jets

2->2 scattering plus gluon radiation approximates full LO QCD

Phase-space model does not describe the data well

Abstract

The properties of high-mass multijet events produced at the Fermilab proton-antiproton collider are compared with leading order QCD matrix element predictions, QCD parton shower Monte Carlo predictions, and the predictions from a model in which events are distributed uniformly over the available multibody phase-space. Multijet distributions corresponding to (4N-4) variables that span the N-body parameter space are found to be well described by the QCD calculations for inclusive three-jet, four-jet, and five-jet events. The agreement between data, QCD Matrix Element calculations, and QCD parton shower Monte Carlo predictions suggests that 2 -> 2 scattering plus gluon radiation provides a good first approximation to the full LO QCD matrix element for events with three, four, or even five jets in the final state.