Measurement of Z-boson cross sections and strong-coupling constant with ATLAS

In this talk, a precise measurement of the production properties of the $Z$-boson in the full phase space of the decay leptons is presented. The measurement is based on LHC pp collision data collected by the ATLAS experiment in 2012 at $\sqrt{s}=8$~TeV. The double-differential cross-section distributions in $Z$-boson transverse momentum and rapidity are measured in the pole region with unprecedented precision. In a novel approach, the measured boson transverse momentum is used to determine the coupling constant of the strong force. The analysis is facilitated by state-of-the-art predictions at third order accuracy in perturbative QCD, supplemented by resummation of logarithmically-enhanced contributions in the small transverse-momentum region of the lepton pairs. The extracted strong coupling is the most precise determination of the strong coupling from a single measurement to date.