Aad, G.Aakvaag, E.Abbott, B.Abeling, K.Abicht, N.J.Abidi, S.H.Aboelela, M.Aboulhorma, A.Abramowicz, H.Abreu, H.Abulaiti, Y.Acharya, B.S.Ackermann, A.Adam Bourdarios, C.Adamczyk, L.Addepalli, S.V.Addison, M.J.Adelman, J.Adiguzel, A.Adye, T.et al.2025-03-142025-03-142024Physics Letters B, 2024; 855:138762-1-138762-250370-26931873-2445https://hdl.handle.net/2440/143875Searches for exclusive decays of the Higgs boson into 𝐷∗𝛾 and of the 𝑍 boson into 𝐷0𝛾 and 𝐾0 𝑠 𝛾 can probe flavour-violating Higgs boson and 𝑍 boson couplings to light quarks. Searches for these decays are performed with a 𝑝𝑝 collision data sample corresponding to an integrated luminosity of 136.3 fb−1 collected at √𝑠=13TeV between 2016–2018 with the ATLAS detector at the CERN Large Hadron Collider. In the 𝐷∗𝛾 and 𝐷0𝛾 channels, the observed (expected) 95% confidence-level upper limits on the respective branching fractions are ß(𝐻 → 𝐷∗𝛾) <1.0(1.2) ×10−3, ß(𝑍 → 𝐷0𝛾) < 4.0(3.4) ×10−6, while the corresponding results in the 𝐾0 𝑠 𝛾 channel are ß(𝑍 →𝐾0 𝑠 𝛾) <3.1(3.0) ×10−6.en© 2024 The Author(s). Published by Elsevier B.V. Funded by SCOAP³. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Higgs boson decaysJournal article10.1016/j.physletb.2024.138762697764