A Measurement of the Azimuthal Decorrelation in Di-Jet Events in Proton-Proton Collisions at $\sqrt{s}$ = 7 TeV at the Large Hadron Collider

A measurement of the azimuthal decorrelation in di-jet events in proton-proton col- lisions at √s = 7 TeV is presented. Using 19.6 nb−1 of data collected in the ATLAS detector this measurement uses the angle (Δφ) in the transverse plane between the two leading pT jets to measure the normalized differential cross section σ1 tot dσ (Δφ) . An unfolding correction is a applied to give a jet-level result. The unfolded spectrum is compared to the predictions of two Monte Carlo event generators: Pythia and Herwig++.