In pursuit of lepton flavour violation. A search for the τ→μγγ decay with ATLAS at √s = 8 TeV

This thesis presents a search for the LFV τ-> μγγ channel at the center-of-mass energy of 8 TeV with the ATLAS detector, which is one of the detectors designed to study the high energy proton-proton collisions at the LHC. This channel has been analyzed here for the first time. No excess was observed with respect to the Standard Model and exclusion limits on the τ->μγγ branching fraction have been set on the order of 10^-4. The quest for charged lepton flavour violation will continue in the coming years.