Fully charmed tetraquark states in color structure via QCD sum rules

Chun-Meng Tang; Chun-Gui Duan; Liang Tang

doi:10.1140/epjc/s10052-024-13102-z

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2024) 84: 743
https://doi.org/10.1140/epjc/s10052-024-13102-z

Regular Article - Theoretical Physics

Fully charmed tetraquark states in $8_{[c \bar{c}]} \otimes 8_{[c \bar{c}]}$ $8_{[c\bar{c}]}\otimes 8_{[c\bar{c}]}$ color structure via QCD sum rules

Chun-Meng Tang¹, Chun-Gui Duan¹^,2 and Liang Tang¹^c

¹ College of Physics and Hebei Key Laboratory of Photophysics Research and Application, Hebei Normal University, 050024, Shijiazhuang, China
² Hebei Key Laboratory of Physics and Energy Technology, North China Electric Power University, 071000, Baoding, China

^c tangl@hebtu.edu.cn

Received: 13 May 2024
Accepted: 6 July 2024
Published online: 26 July 2024

Abstract

Stimulated by the recent experimental results on the fully-charm tetraquark states, we systematically calculate the mass spectra of the fully-charm tetraquark states in $8_{[c \bar{c}]} \otimes 8_{[c \bar{c}]}$ $8_{[c\bar{c}]}\otimes 8_{[c\bar{c}]}$ color configuration via QCD sum rules. By constructing nine $8_{[c \bar{c}]} \otimes 8_{[c \bar{c}]}$ $8_{[c\bar{c}]}\otimes 8_{[c\bar{c}]}$ type currents with quantum numbers $J^{PC} = 0^{- +}, 0^{- -}, 1^{- +}, 1^{+ -}, 1^{- -}$ $J^{PC}=0^{-+},0^{--},1^{-+},1^{+-},1^{--}$ and $2^{+ +}$ $2^{++}$ , we perform analytic calculation up to dimension six in the operator product expansion (OPE). We find the fully-charm tetraquark states with $J^{PC} = 1^{+ -}, 2^{+ +}$ $J^{PC}=1^{+-},2^{++}$ lie around 6.48 $\sim$ $\sim$ 6.62 GeV while the fully-charm tetraquark states with $J^{PC} = 0^{- +}, 0^{- -}, 1^{- -}, 1^{- +}$ $J^{PC}=0^{-+},0^{--},1^{--},1^{-+}$ are about 6.85 $\sim$ $\sim$ 7.02 GeV. Notably, the mass predictions for the $c \bar{c} c \bar{c}$ $c\bar{c}c\bar{c}$ tetraquarks, specifically those with $J^{PC} = 2^{+ +}$ $J^{PC}=2^{++}$ , align with the broad structure identified by LHCb. Moreover, the masses of fully-charm tetraquarks with $J^{PC} = 0^{- +}$ $J^{PC}=0^{-+}$ and $1^{- +}$ $1^{-+}$ are anticipated to match closely with the mass of X(6900), considering the margin of error. Such findings hint at the presence of some $8_{[c \bar{c}]} \otimes 8_{[c \bar{c}]}$ $8_{[c\bar{c}]}\otimes 8_{[c\bar{c}]}$ components within the di- $J / ψ$ $J/\psi$ structures observed by LHCb. The predictions for tetraquark states with $J^{PC} = 0^{- -}, 1^{+ -}, 1^{- -}$ $J^{PC}=0^{--},1^{+-},1^{--}$ may be accessible in the future BelleII, Super-B, PANDA, and LHCb experiments.

© The Author(s) 2024

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