ATLAS experiment
During Gianotti's time as Spokesperson of ATLAS, the experiment was one of two involved in the observation of the Higgs boson. On 4 July 2012 Gianotti announced the discovery of the particle. Until the observation, the Higgs boson was a purely theoretical part of the Standard Model of particle physics. Gianotti's deep understanding of the ATLAS experiment, and her leadership, were recognised as major factors in the discovery.