Measurement of V+jet production and MPI with ATLAS

The production of jets in association with a $W$ or $Z$ boson in proton-proton collisions at 7 TeV allows the study of multileg QCD diagrams. Differential cross sections have been measured with the ATLAS detector as a function of several kinematic variables up to high jet multiplicities and compared to new higher-order QCD calculations. The ratio of ($W$ + a single jet)/($Z$ + a single jet) can provide a very precise test of QCD and has also been measured. Topologies with a vector boson and jets in the final state are also sensitive to double parton scattering which has been measured using $W$+2 jet events. More exclusive processes of $W+b$ production and $W+D$ production have also been measured.