@Article{ATLASCollaborationAad_etal2024, author="ATLAS Collaboration (Aad, G. et al and Aikot, A. and Amos, K. R. and Aparisi Pozo, J. A. and Bailey, A. J. and Bouchhar, N. and Cabrera Urban, S. and Cantero, J. and Cardillo, F. and Castillo Gimenez, V. and Chitishvili, M. and Costa, M. J. and Didenko, M. and Escobar, C. and Fiorini, L. and Fullana Torregrosa, E. and Fuster, J. and Garcia, C. and Garcia Navarro, J. E. and Gomez Delegido, A. J. and Gonzalez de la Hoz, S. and Gonzalvo Rodriguez, G. R. and Guerrero Rojas, J. G. R. and Lacasta, C. and Marti-Garcia, S. and Martinez Agullo, P. and Miralles Lopez, M. and Mitsou, V. A. and Monsonis Romero, L. and Moreno Llacer, M. and Munoz Perez, D. and Navarro-Gonzalez, J. and Poveda, J. and Prades Iba{\~{n}}ez, A. and Rubio Jimenez, A. and Ruiz-Martinez, A. and Sabatini, P. and Salt, J. and Sanchez Sebastian, V. and Sayago Galvan, I. and Senthilkumar, V. and Soldevila, U. and Sanchez, J. and Torro Pastor, E. and Valero, A. and Valiente Moreno, E. and Valls Ferrer, J. A. and Varriale, L. and Villaplana Perez, M. and Vos, M.", title="Search for the decay of the Higgs boson to a Z boson and a light pseudoscalar particle decaying to two photons", journal="Physics Letters B", year="2024", publisher="Elsevier", volume="850", pages="138536--24pp", abstract="A search for the decay of the Higgs boson to a Z boson and a light, pseudoscalar particle, a, decaying respectively to two leptons and to two photons is reported. The search uses the full LHC Run 2 proton-proton collision data at root s = 13 TeV, corresponding to 139 fb-1 collected by the ATLAS detector. This is one of the first searches for this specific decay mode of the Higgs boson, and it probes unexplored parameter space in models with axion-like particles (ALPs) and extended scalar sectors. The mass of the a particle is assumed to be in the range 0.1-33 GeV. The data are analysed in two categories: a merged category where the photons from the a decay are reconstructed in the ATLAS calorimeter as a single cluster, and a resolved category in which two separate photons are detected. The main background processes are from Standard Model Z boson production in association with photons or jets. The data are in agreement with the background predictions, and upper limits on the branching ratio of the Higgs boson decay to Za times the branching ratio a -> yy are derived at the 95{\%} confidence level and they range from 0.08{\%} to 2{\%} depending on the mass of the a particle. The results are also interpreted in the context of ALP models.", optnote="WOS:001202034400001", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=6104), last updated on Mon, 29 Apr 2024 06:31:08 +0000", issn="0370-2693", doi="10.1016/j.physletb.2024.138536", opturl="https://arxiv.org/abs/2312.01942", opturl="https://doi.org/10.1016/j.physletb.2024.138536", language="English" }