Measurement of dijet production with a veto on additional central jet activity in pp collisions at sqrt(s)=7 TeV using the ATLAS detector

TL;DR

This paper measures jet activity between dijets in proton-proton collisions at 7 TeV, comparing results to various theoretical models and simulations to understand QCD emissions and jet veto effects.

Contribution

It provides the first detailed measurement of jet veto survival probability and jet multiplicity in the rapidity interval between dijets at 7 TeV, testing multiple QCD models.

Findings

Jet veto survival probability decreases with increasing rapidity separation.

Data favor certain QCD models over others in describing jet activity.

Results constrain theoretical predictions of QCD radiation patterns.

Abstract

A measurement of jet activity in the rapidity interval bounded by a dijet system is presented. Events are vetoed if a jet with transverse momentum greater than 20 GeV is found between the two boundary jets. The fraction of dijet events that survive the jet veto is presented for boundary jets that are separated by up to six units of rapidity and with mean transverse momentum 50 < pT(avg) < 500 GeV. The mean multiplicity of jets above the veto scale in the rapidity interval bounded by the dijet system is also presented as an alternative method for quantifying perturbative QCD emission. The data are compared to a next-to-leading order plus parton shower prediction from the POWHEG-BOX, an all-order resummation using the HEJ calculation and the PYTHIA, HERWIG++ and ALPGEN event generators. The measurement was performed using pp collisions at sqrt(s)=7 TeV using data recorded by the ATLAS detector in 2010.