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Oxana Smirnova

Oxana Smirnova

Senior Lecturer, Deputy Head of division

Oxana Smirnova

Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector

Author

  • G. Aad
  • T.P.A. Åkesson
  • C. Doglioni
  • P.A. Ekman
  • V. Hedberg
  • H. Herde
  • B. Konya
  • E. Lytken
  • R. Poettgen
  • N.D. Simpson
  • E. Skorda
  • O. Smirnova
  • L. Zwalinski

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