Hard QCD at ATLAS

The production of photons, W/Z bosons and jets in proton-proton collisions at the LHC allows perturbative QCD to be probed in extreme regions of phase space. In this talk, we present recent precision measurements of diphoton production and Z-boson production in association with jets, using data collected by the ATLAS experiment at 13 TeV. For jet fragmentation, we present a measurement of the fragmentation properties of b-quark initiated jets, studied using charged B mesons. All of the measurements are corrected for detector effects and are compared to the predictions of state-of-the-art Monte Carlo event generators. We also present fits to determine parton distribution functions (PDFs) using hard QCD measurements from ATLAS at various sqrt(s) values together with HERA data.