Precision W and Z cross-sections and the first measurement of the W boson mass with ATLAS

The Large Hadron Collider has produced more W and Z bosons than any other collider before. The large samples of leptonic bosons decays provide a unique opportunity for precision studies of the strong interaction and the electroweak interaction. These studies are facilitated by the high experimental precision achieved after a careful detector calibration.
New cross-section measurements allow novel insights into the proton structure. Specifically, strong constraints of the poorly known strange-quark distribution are demonstrated in a NNLO QCD analysis.
The mass of the W boson is a key parameter in the global electroweak fit to test the overall consistency of the Standard Model. The first complete W-boson mass measurement at the LHC is presented, which requires an extraordinary control over both experimental and theoretical effects.