Published: 2013
Total Pages: 141
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Dijet production is measured in proton--proton collisions with a center-of-mass energy of 7 TeV at the LHC. Double-differential dijet cross sections are presented as functions of the dijet mass and rapidity separation of the two highest-transverse-momentum jets in an event. The data sample collected in 2011 by the ATLAS detector is considered, corresponding to an integrated luminosity of 4.5 fb -1. Jets are defined using the anti-kt algorithm, with two choices of the jet radius parameter, R = 0.4 and R = 0.6. The results are compared with next-to-leading-order (NLO) perturbative calculations, as well as NLO Monte Carlo generator predictions. In both cases, electroweak effects are accounted for. A method for the quantitative comparison of theory predictions with data is presented, employing a frequentist technique. This allows for strong statements on which sets of parton distribution functions best describe the data. A theory of quark compositeness modeled by contact interactions is confronted by the unfolded data using the CLs technique, an example of the versatility of the measurement.