Relatore
Descrizione
The discovery of the Higgs boson with a mass of 125 GeV completed the particle
content predicted by the Standard Model (SM). Even though this model is well
established and consistent with many measurements, it is not capable to solely
explain some observations. Many extensions of the SM addressing such shortcomings
have additional (neutral or charged) Higgs bosons. In some models, the Higgs boson
can also serve as a portal to a dark sector, through e.g. invisible decays. Finally,
new physics could also appear through modifications of the cross-section and
kinematics of the elusive Higgs boson pair (HH) production process. The current
status of searches for additional low- and high-mass Higgs bosons, for invisible
Higgs boson decays and for HH production, based on the full LHC Run 2 dataset of the
ATLAS experiment at 13 TeV, are presented.
