Vincent Hedberg
Senior lecturer
Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector
Author
Summary, in English
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.
Department/s
- Particle and nuclear physics
- eSSENCE: The e-Science Collaboration
Publishing year
2023
Language
English
Publication/Series
Physical Review Letters
Volume
131
Issue
15
Document type
Journal article
Publisher
American Physical Society
Topic
- Subatomic Physics
Keywords
- article
- luminance
- Monte Carlo method
Status
Published
ISBN/ISSN/Other
- ISSN: 1079-7114