@misc{10481/85939,
year = {2023},
month = {10},
url = {https://hdl.handle.net/10481/85939},
abstract = {A search is made for potential cc¯c¯c tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at √s=13  TeV, corresponding to an integrated luminosity of 140  fb−1 recorded by the ATLAS experiment at LHC. Two decay channels, J/ψ+J/ψ→4μ and J/ψ+ψ(2S)→4μ, 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/ψ 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/ψ+ψ(2S) channel. The fitted masses and decay widths of the structures are reported.},
organization = {CERN},
organization = {MICINN, Spain},
organization = {COST},
organization = {ERC},
organization = {ERDF},
organization = {Horizon 2020},
organization = {Marie Skłodowska-Curie Actions},
organization = {European Union},
organization = {La Caixa Banking Foundation},
organization = {CERCA Programme Generalitat de Catalunya},
organization = {PROMETEO},
organization = {GenT Programmes Generalitat Valenciana, Spain},
organization = {PIC (Spain)},
publisher = {American Physical Society},
title = {Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector},
doi = {10.1103/PhysRevLett.131.151902},
author = {Aad, G. and Rodríguez Chala, Mikael and Atlas Collaboration},
}