Measurement of the W boson mass with the ATLAS detector

This thesis describes a measurement of the W boson mass with the ATLAS detector based on the data-set recorded by ATLAS in 2011 at a centre-of-mass energy of 7 TeV, and corresponding to 4.6 inverse femtobarn of integrated luminosity. Measurements are performed through template fits to the transverse momentum distributions of charged leptons and to transverse mass distributions of the W boson, in electron and muon decay modes in various kinematic categories. The individual measurements are found to be consistent and their combination leads to a value of \begin{eqnarray} \nonumber m_W &=& 80371.1 \pm 18.6~\text{MeV}, \end{eqnarray} The measured value of the W boson mass is compatible with the current world average of $m_W = 80385 \pm 15~$MeV. The uncertainty is competitive with the current most precise measurements performed by the CDF and D0 collaborations.