Study of the $Ω_{ccc}Ω_{ccc}$ and $Ω_{bbb}Ω_{bbb}$ dibaryons in QCD Sum Rules

Abstract

The recent observation of a family of fully-charm tetraquark states by the LHCb, ATLAS and CMS Collaborations suggests the possible existence of fully-heavy dibaryons. In this work, we investigate the $Ω_{ccc}Ω_{ccc}$ and $Ω_{bbb}Ω_{bbb}$ dibaryons in both the $^1S_0$ and $^5S_2$ channels using the method of QCD sum rules. We employ the iterative dispersion relation (IDR) method to efficiently compute the massive five-loop banana diagrams that appear in these systems, and properly address the tricky small-circle divergence problem in the nonperturbative terms. Our analyses reveal that for both charm and bottom systems, the scalar dibaryon lies lower than its tensor counterpart. The mass of the scalar $Ω_{ccc}Ω_{ccc}$ dibaryon is found to be slightly above the $2Ω_{ccc}$ mass threshold, while the $Ω_{bbb}Ω_{bbb}$ systems may form bound states.

Figures (7)

• Figure 1: Feynman diagrams involved in the OPE series.
• Figure 2: OPE convergence for the $\Omega_{ccc}\Omega_{ccc}$ dibaryon with $J^{P}=0^{+}$.
• Figure 3: The pole contribution for the scalar $\Omega_{ccc} \Omega_{ccc}$ dibaryon.
• Figure 4: Variation of hadron mass $m_X$ with $\tilde{s}_0$ for the $\Omega_{ccc}\Omega_{ccc}$ dibaryon with $J^{P}=0^{+}$.
• Figure 5: The $\chi^2(\tilde{s}_0)$ for the $\Omega_{ccc}\Omega_{ccc}$ dibaryon with $J^{P}=0^{+}$.