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 ffiffi s p ¼ 13 TeV, corresponding to an integrated luminosity of 140 fb−1 recorded by the ATLAS experiment at LHC. Two decay channels, J=ψ þ J=ψ → 4μ and J=ψ þ ψð2SÞ → 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 þ ψð2SÞ channel. The fitted masses and decay widths of the structures are reported.

Title

PHYSICAL REVIEW LETTERS

Publisher

APS

Publisher Country

United States of America

Publication Type

Prtinted only

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Year

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