: 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, Et. - 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.