%0 Journal Article %T Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector %A ATLAS Collaboration (Aad, G. et al %A Amos, K. R. %A Aparisi Pozo, J. A. %A Bailey, A. J. %A Bouchhar, N. %A Cabrera Urban, S. %A Cantero, J. %A Cardillo, F. %A Castillo Gimenez, V. %A Chitishvili, M. %A Costa, M. J. %A Didenko %A Escobar, C. %A Fiorini, L. %A Fullana Torregrosa, E. %A Fuster, J. %A Garcia, C. %A Garcia Navarro, J. E. %A Gomez Delegido, A. J. %A Gonzalez de la Hoz, S. %A Gonzalvo Rodriguez, G. R. %A Guerrero Rojas, J. G. R. %A Lacasta, C. %A Marti-Garcia, S. %A Martinez Agullo, P. %A Miralles Lopez, M. %A Mitsou, V. A. %A Monsonis Romero, L. %A Moreno Llacer, M. %A Munoz Perez, D. %A Navarro-Gonzalez, J. %A Poveda, J. %A Prades Ibañez, A. %A Rubio Jimenez, A. %A Ruiz-Martinez, A. %A Sabatini, P. %A Salt, J. %A Sanchez Sebastian, V. %A Sayago Galvan, I. %A Senthilkumar, V. %A Soldevila, U. %A Sanchez, J. %A Torro Pastor, E. %A Valero, A. %A Valiente Moreno, E. %A Valls Ferrer, J. A. %A Varriale, L. %A Villaplana Perez, M. %A Vos, M. %J Physical Review Letters %D 2023 %V 131 %N 15 %I Amer Physical Soc %@ 0031-9007 %G English %F ATLASCollaborationAad_etal2023 %O WOS:001102901700001 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5949), last updated on Sun, 25 Feb 2024 14:07:37 +0000 %X A search is made for potential ccc over bar c over bar tetraquarks decaying into a pair of charmonium states in the four ffiffi muon final state using proton-proton collision data at p s = 13 TeV, corresponding to an integrated luminosity of 140 fb-1 recorded by the ATLAS experiment at LHC. Two decay channels, J lig +J lig -4 μand J lig + ig(2S) -4 mu, are studied. Backgrounds are estimated based on a hybrid approach involving Monte Carlo simulations and data-driven methods. Statistically significant excesses with respect to backgrounds dominated by the single parton scattering are seen in the di-J lig channel consistent with a narrow resonance at 6.9 GeV and a broader structure at lower mass. A statistically significant excess is also seen in the J lig + ig(2S) channel. The fitted masses and decay widths of the structures are reported. %R 10.1103/PhysRevLett.131.151902 %U https://arxiv.org/abs/2304.08962 %U https://doi.org/10.1103/PhysRevLett.131.151902 %P 151902-22pp