IFIC Seminar: The beauty and the beast of the Higgs boson. Higgs and Di-Higgs measures from a Flavour Tagging perspective

por Dr. Lorenzo Santi (CERN)

martes 15 sept. 2026 12:00 → 13:30 Europe/Madrid

1001-Primera-1-1-1 - Paterna. Seminario (Universe)

The Higgs boson couples most strongly to the heaviest fermions, making the identification of beauty and charm jets -- flavour tagging -- the cornerstone of a large fraction of the ATLAS Higgs programme. This seminar reviews the recent transition to transformer-based taggers, from GN2 to GN3, which has brought substantial gains in $b$- and $c$-jet identification over previous-generation algorithms, together with the calibration strategies required to turn these gains into reliable physics results. I will then discuss how these improvements propagate to Higgs measurements: the single-Higgs decays $H \to b\bar{b}$ and the still-elusive $H \to c\bar{c}$, and the di-Higgs frontier, where $HH \to b\bar{b}\gamma\gamma$ provides the sharpest handle on the Higgs self-coupling and $t\bar{t}HH$ searches probe the top-Higgs sector.