Date of Award

Summer 2012

Document Type


Degree Name

Doctor of Philosophy (PhD)


Engineering Physics

First Advisor

Lee Sawyer


The transverse momentum (pT) dependence of azimuthal decorrelations in dijet events is studied with data collected, at an integrated luminosity of [special characters omitted] dt = (36 ± 4) pb−1, from collisions between protons at a center of mass energy of [special characters omitted] = 7 TeV using the ATLAS detector at the Large Hadron Collider. The results of the analysis of jets in a central rapidity of |y| < 0.8 and pT in the range 60 GeV < pT < 1200 GeV are presented. A new observable RΔ&phis;, defined as the fraction of the total dijet cross section corresponding to a particular range of opening angles between the two jets with the highest pT, is measured as a differential quantity in the pT of the jet with highest pT. The results of the analysis are compared with good agreement to next-to-leading order perturbative QCD calculations as well as the predictions from different Monte Carlo generators including PYTHIA and ALPGEN.