A measurement of the Drell-Yan differential cross section using data from proton-proton collisions at 7 TeV with the ATLAS detector

LHC proton-proton collisions at a centre of mass energy of √s = 7 TeV were observed in 2011. From a 1.68 fb−1 sample of the data collected using the ATLAS detector, electron-positron pairs originating from the Drell-Yan process were selected using a cut based analysis. After the selection process, an estimate of the background was determined followed by the selection efficiency, detector resolution, reconstruction efficiency, and kinematic acceptance. Using these, the Drell-Yan differential cross section was calculated as a function of invariant mass between 26 and 66 GeV/c2. This measurement has a precision between 12.4% and 8.01% from the lower invariant mass bins to the higher ones. The Drell-Yan cross section in proton-proton collisions depends on empirical quantities known as parton distribution functions which parametrize the structure of the proton. The measurement outlined in this thesis observes a region in parton distribution function phase space previously untouched by experiments.