Aad, G.Abbott, B.Abeling, K.Abidi, S. H.Aboulhorma, A.Abramowicz, H.Çetin, Serkant Ali2024-05-192024-05-1920230370-26931873-2445https://doi.org10.1016/j.physletb.2023.138292https://hdl.handle.net/20.500.12713/5732Searches for the exclusive decays of the Higgs boson to an omega meson and a photon or a K* meson and a photon can probe flavour-conserving and flavour-violating Higgs boson couplings to light quarks, respectively. Searches for these decays, along with the analogous Z boson decay to an omega meson and a photon, are performed with a pp collision data sample corresponding to integrated luminosities of up to 134 fb(-1) collected at root s = 13 TeV with the ATLAS detector at the CERN Large Hadron Collider. The obtained 95% confidence-level upper limits on the respective branching fractions are B(H -> omega gamma) < 5.5 x 10(-4), B(H -> K*gamma) < 2.2 x 10(-4) and B(Z -> omega gamma) < 3.9 x 10(-6). The limits for H -> omega gamma and Z -> omega gamma) are 370 times and 140 times the Standard Model expected values, respectively. The result for Z -> omega gamma corresponds to a two-orders-of-magnitude improvement over the limit obtained by the DELPHI experiment at LEP.eninfo:eu-repo/semantics/openAccessHierarchyArticle847WOS:0011279536000012-s2.0-85180605865N/A10.1016/j.physletb.2023.138292Q1