Measurement of the electroweak production cross section of Z bosons associated with dijets with the ATLAS detector

An observation of electroweak Zjj production and a measurement of the fiducial cross section has been presented. The cross section is in excellent agreement with the SM NLO prediction from Powheg+Pythia. This process includes the VBF diagram which is very similar to the VBF production of a Higgs and to the vector boson scattering process, making it an excellent standard candle for studying such processes. In addition fiducial cross sections of inclusive Zjj production have been measured in five fiducial phase spaces with varying sensitivity to the electroweak component. All measurements are in excellent agreement with the NLO SM prediction from Powheg+Pythia. Differential distributions have also been measured of variables sensitive to VBF kinematics. These distributions are compared to NLO Powheg+Pythia predictions and LO Sherpa predictions. The former provides an excellent description of the dijet kinematics, whereas the latter provides an excellent description of the in-gap activity. No one MC prediction describes all distributions accurately.