Orateur
Description
The study of single W and Z boson production at the LHC provides stringent tests of the electroweak theory and perturbative QCD. The ATLAS experiment has measured the W boson production cross section in the LHC data from 2022 at 13.6 TeV. By forming ratios with Z and ttbar production cross sections, this measurement becomes a sensitive probe of the quark and gluon content of the proton. Moreover, ATLAS has used these signatures for a range of precision measurements that are highlighted in this talk. Extraordinarily precise double-differential measurements of the Z boson in the full phase space of the decay leptons at a centre-of-mass energy of 8 TeV are discussed. The recoil of the Z-boson is sensitive to quark and gluon emissions and is used to determine the strong coupling constant in a novel approach. Measurements of the transverse momentum of the W and Z boson at 5 and 13 TeV from dedicated LHC runs with reduced instantaneous luminosity are also presented. In addition, the production rate of Z+jet events with large missing transverse momentum is used to measure the decay width of the Z boson decaying to neutrinos. Differential measurements of this topology with minimal assumptions on theoretical calculations are discussed and allow comparisons to the Standard Model as well as the interpretation in beyond-the-Standard-Model scenarios. A search for exclusive hadronic decays of the W boson to single pions, Kaons or rho-mesons in association with a photon are highlighted, and provide a test bench for the quantum chromodynamics factorization formalism. Finally, the LHC pp collision data collected by the ATLAS experiment at sqrt(s)=7 TeV is revisited to measure the W boson mass and it???s width.
