Roberto COVARELLI (UniTo) – Séminaire – 09 fév. 2024 – 14h

Why we do need (HL)-LHC: final states with multibosons

The Standard Model (SM) of particle physics predicts triple and quartic gauge, Higgs, and gauge-Higgs couplings, generated by the non-Abelian SU(2)_L x U(1)_Y symmetry of the electroweak interaction and the shape of the Higgs potential. Experimental access to such couplings is only achievable by investigating rare multi-boson final states and is challenging for many reasons: very small cross-sections of the relevant processes, interference with other SM couplings, and large backgrounds. 
The long 13-TeV run of the LHC has enabled detailed studies of final states with two gauge bosons, the first observations of elusive processes such as vector-boson scattering and tri-boson production, and the search for Higgs-boson pair production. A dramatic improvement in the precision of such measurement is expected thanks to the large-statistics runs at 13.6 TeV and in the high-luminosity LHC phase.
The seminar will review the history of multi-boson final states, the recent results from the CMS and ATLAS Collaborations, and the perspective for the future runs, showing how the increased amount of data will be a game-changer for studying the related couplings and finding possible hints of beyond-the-SM physics in them.