: A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[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.
Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector / Add, G., Aloisio, A., Alviggi, M., Auricchio, S., Canale, V., Cirotto, F., Della Pietra, M., Merola, L., Massarotti, P., Rossi, E., Conventi, F., Izzo, V., Sekhniaidze, G.G., Camerlingo, M.T., Iengo, P., Di Donato, C., De Asmundis, R., Carlino, G., Doria, A., Al, E.t., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 131:15(2023), p. 151902. [10.1103/PhysRevLett.131.151902]
Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector
A. Aloisio;M. Alviggi;S. Auricchio;V. Canale;F. Cirotto;M. Della Pietra;L. Merola;P. Massarotti;E. Rossi;LOFFREDO, Salvatore
2023
Abstract
: A search is made for potential ccc[over ¯]c[over ¯] tetraquarks decaying into a pair of charmonium states in the four muon final state using proton-proton collision data at sqrt[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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
