Measurement of the W-boson mass at the ATLAS experiment

We present the W boson mass measurement with the ATLAS detector based on the 2011 data-set recorded by ATLAS at a centre-of-mass energy of $\sqrt{s} = 7$ TeV, and corresponding to 4.6 fb$^{−1}$ of integrated luminosity. Measurement is performed through template fits to transverse momentum distributions of charged leptons as well as to transverse mass distributions of the W boson in electron and muon decay modes in various kinematic categories. The measured value is compatible to the current world average. The uncertainty is competitive to the current most precise measurements performed by the CDF and D0 collaborations.