W mass measurement with the ATLAS detector

par Dr maarten boonekamp (cea)

lundi 22 mai 2017, 14:00 → 15:00 Europe/Paris

ATLAS is a multipurpose high-energy physics experiment designed to test the Standard Model in all possible ways : measurements of cross sections, branching ratios and particle properties are compared to the predictions of the theory, the existence of the Higgs boson was verified, and searches for new particles are actively pursued. Among the most precise predictions of the SM is the relation between the masses of the Higgs boson, of the top quark and of the electroweak gauge bosons, the Z and the W. With the known values of the first three, the mass of the W is predicted with a relative precision of 10^-4, 2 to 3 times better than the best experimental determinations. I will present the first measurement of this parameter by ATLAS, summarize the analysis methods, the main results and insist on the experimental and phenomenological developments that are needed to bring the measurement precision below that of the SM prediction.