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

par Lorenzo Santi (CERN)

lundi 21 sept. 2026, 11:00 → 12:00 Europe/Paris

200/0-Auditorium - Auditorium P. Lehmann (IJCLab)

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.