Recent QCD results from ATLAS

ATLAS has has performed several measurements of phenomena connected to QCD at soft scales or at the transition to the hard regime. These include the measurements at different centre-of-mass energies in Run-1 and Run-2 of the elastic, inelastic and total cross sections in pp collisions, the properties of minimum bias and the underlying event interactions, particle production and their correlations, as well as of diffractive and exclusive events. These results are sensitive to non-perturbative models of soft QCD. Jet and photon production cross sections have been measured differentially for inclusive and multi-object final states at 7, 8 and 13 TeV pp collisions with the ATLAS detector and are compared to expectations based on next-to-leading order QCD calculations as well as Monte Carlo simulations. Further studies of jet production properties include the measurements of jet properties, and the determination of the strong coupling constant alpha_s. These measurements provide direct probes of short-distance physics and are sensitive to the parton densities of the proton, as well as fragmentation models.