Observation of an excess of dicharmonium events in the four-muon final state with the ATLAS detector

0579073 - FZÚ 2024 RIV US eng J - Článek v odborném periodiku
Aad, G. - Abbott, B. - Abeling, K. - Chudoba, Jiří - Federičová, Pavla - Hejbal, Jiří - Jačka, Petr - Kepka, Oldřich - Kroll, Jiří - Kupčo, Alexander - Latoňová, Věra - Lokajíček, Miloš - Lysák, Roman - Marčišovský, Michal - Mikeštíková, Marcela - Němeček, Stanislav - Šícho, Petr - Staroba, Pavel - Svatoš, Michal - Taševský, Marek … celkem 2928 autorů
Observation of an excess of dicharmonium events in the four-muon final state with the ATLAS detector.
Physical Review Letters. Roč. 131, č. 15 (2023), č. článku 151902. ISSN 0031-9007. E-ISSN 1079-7114
Výzkumná infrastruktura: CERN-CZ III - 90240
Institucionální podpora: RVO:68378271
Klíčová slova: muon: pair production * numerical calculations: Monte Carlo * ATLAS
Obor OECD: Particles and field physics
Impakt faktor: 8.6, rok: 2022
Způsob publikování: Open access

A search is made for potential ccc¯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.
Trvalý link: https://hdl.handle.net/11104/0347972