The beauty and the charm of the Higgs boson

by Dr Elisabeth Schopf (Uni Siegen)

Thursday 18 Dec 2025, 16:15 → 17:30 Europe/Berlin

ENC-D114 (ENC)

The Standard Model of particle physics is a tremendously successful theory describing the interactions of fundamental particles. However, certain observations, like dark matter or the matter-antimatter asymmetry in the universe, remain unexplained. The discovery of the Higgs boson opened a new window to search for physics beyond the Standard Model on the premise that every particle that has mass couples to the Higgs boson. Probing this assumption in experiments is an extremely powerful test of the Standard Model and is particularly important for the fundamental fermions, quarks and leptons, for which couplings to the Higgs field were added ad hoc to the Standard Model with the coupling strength chosen to be proportional to their mass. The experimental confirmation of this proportionality would also mark the first discovery of sub-atomic couplings that are non-universal but instead exhibit a strong correlation with mass. In this presentation, I will focus on the experimental study of Higgs-boson couplings to bottom and charm quarks with the ATLAS experiment using LHC proton-proton collisions from Run 2 (2015-2018). I will discuss the related experimental challenges and how honing experimental tools enabled searches for Higgs-boson couplings to charm quarks, which were initially deemed infeasible at a hadron collider, and transformed measurements of Higgs-boson decays to bottom quarks into a central pillar in the precise probe of the Higgs sector. I will review the status of these Higgs-boson studies in the landscape of ATLAS Higgs-boson research and give a brief outlook beyond LHC Run 2.