Dijet Angular Distributions at the ATLAS Experiment

TL;DR

This paper reports measurements of dijet angular distributions from early 7 TeV proton-proton collisions at the LHC, comparing them with QCD predictions and setting limits on quark compositeness.

Contribution

First measurement of dijet angular distributions at 7 TeV with ATLAS, testing QCD and constraining new physics models.

Findings

Good agreement between data and QCD predictions

Set limits on quark compositeness

Demonstrated feasibility of early LHC measurements

Abstract

Dijet angular distributions from the first proton-proton collisions at 7 TeV have been measured with the ATLAS detector at the LHC. The dataset used corresponds to a total integrated luminosity of 61 $\pm$ 7 nb$^{-1}$. Comparing the distributions with Monte Carlo based QCD predictions shows good agreement between data and QCD. The distributions are used to set limits on the existence of quark compositeness.