@article{d61e52e5a0014158afdb5e45602708bf,
title = "Observation of an Excess of Dicharmonium Events in the Four-Muon Final State with the ATLAS Detector",
abstract = "A search is made for potential cc{\=c} {\=c} tetraquarks decaying into a pair of charmonium states in the four ffiffi muon final state using proton-proton collision data at ps ¼ 13 TeV, corresponding to an integrated luminosity of 140 fb−1 recorded by the ATLAS experiment at LHC. Two decay channels, J=ψ {\th} J=ψ → 4μ and J=ψ {\th} ψ {\dh}2S{\TH} → 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 {\th} ψ {\dh}2S{\TH} channel. The fitted masses and decay widths of the structures are reported.",
author = "{ATLAS Collaboration} and G. Aad and B. Abbott and Abbott, {D. C.} and {Abed Abud}, A. and K. Abeling and Abhayasinghe, {D. K.} and Abidi, {S. H.} and AbouZeid, {O. S.} and Abraham, {N. L.} and H. Abramowicz and H. Abreu and R. Abreu and Y. Abulaiti and Acharya, {B. S.} and B. Achkar and L. Adam and {Adam Bourdarios}, C. and L. Adamczyk and L. Adamek and J. Adelman and M. Adersberger and A. Adiguzel and S. Adorni and T. Adye and Affolder, {A. A.} and Y. Afik and C. Agapopoulou and Agaras, {M. N.} and A. Aggarwal and C. Agheorghiesei and Aguilar-Saavedra, {J. A.} and A. Ahmad and F. Ahmadov and Ahmed, {W. S.} and X. Ai and G. Aielli and S. Akatsuka and M. Akbiyik and {\AA}kesson, {T. P.A.} and E. Akilli and Akimov, {A. V.} and {Al Khoury}, K. and Alberghi, {G. L.} and J. Albert and {Alconada Verzini}, {M. J.} and S. Alderweireldt and M. Aleksa and Aleksandrov, {I. N.} and B. Parida and M. Pitt",
note = "Publisher Copyright: {\textcopyright} 2023 CERN, for the ATLAS Collaboration.",
year = "2023",
month = oct,
day = "13",
doi = "10.1103/PhysRevLett.131.151902",
language = "English",
volume = "131",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "15",
}