The decays of the Higgs boson into rare decay channels like H→Zγ→ℓℓγ and H→μμ are very challenging due to their small branching ratios and large backgrounds. The first decay, H→Zγ→ℓℓγ, is sensitive to potential BSM effects since SM contributions are loop-suppressed. The second provides the best opportunity to test the Yukawa sector for the 2nd fermion generation. This seminar will present improved analyses for both decay channels using the large Run 3 data set (data collected between 2022 and 2024) and the combinations with the respective Run 2 results. Thanks to the increase in the sample size and to better analysis techniques, these measurements significantly enhance the sensitivity to these rare Higgs boson decays over previous ATLAS publications.

Refreshments will be served at 10h30