@Article{ATLASCollaborationAad_etal2023, author="ATLAS Collaboration (Aad, G. et al 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 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="Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector", journal="Physical Review Letters", year="2023", publisher="Amer Physical Soc", volume="131", number="15", pages="151902--22pp", abstract="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 $\mu$and 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.", optnote="WOS:001102901700001", optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=5949), last updated on Sun, 25 Feb 2024 14:07:37 +0000", issn="0031-9007", doi="10.1103/PhysRevLett.131.151902", opturl="https://arxiv.org/abs/2304.08962", opturl="https://doi.org/10.1103/PhysRevLett.131.151902", language="English" }