Jet and Photon measurements from ATLAS

Differential measurements of inclusive jet and di-jet production provide stringent tests of higher order QCD predictions and provide inputs for determination of parton density functions. Inclusive jet multiplicity ratios are sensitive to the strong coupling constant $alpha_{S}$ and have reduced sensitivity to the uncertainties due to parton distribution functions. Measurements of the inclusive prompt isolated photon and diphoton cross sections provide a direct probe of short-distance physics, complementary to that from measurements of jets or vector-bosons, and are sensitive to the gluon density of the proton. The measurements are compared to next-to-leading-order or higher-order QCD calculations.