Student seminar - Giulia Gonella and Théo Megy

Théo Megy: Search for SM H->tautau with ATLAS.

Abstract: The decay of a Higgs boson into a pair of tau leptons is the most sensitive channel in order to access Higgs boson couplings to fermions. This talk will introduce the analysis developed to search for this process using the data measured by the ATLAS detector in 2015 and 2016, and will present the results obtained. In particular, the estimation and the validation of the Z->tautau background will be discussed in details.

Giulia Gonella: Observation and measurement of the electroweak W ± W ± jj process with the ATLAS detector

Measurements of the electroweak sector of the Standard Model are a way to probe the mechanism of electroweak symmetry breaking at LHC, and to detect small deviations from the theoretical predictions, through which the effect of new physics could manifest itself. In this context the scattering of vector bosons (VBS) is a key process. In particular the production of W bosons pairs is a vital test of the mechanism. The talk will give an overview of the reasons for this investigation and will present the main techniques for the measurement of the electroweak production of two W bosons with the same electric charge in the signature of two leptons, missing transverse energy and two jets with the ATLAS experiment at the LHC.