Is $$d^*(2380)$$ d ∗ ( 2380 ) a compact hexaquark state?

Abstract

Abstract The most fascinating dibaryon in the non-strange quark sector is $$d^*(2380)$$ d ∗ ( 2380 ) , which was reported by WASA-at-COSY Collaboration and confirmed by A2@MAMI Collaboration. The reported mass and decay width are $$M\approx 2.37$$ M ≈ 2.37 GeV, $$\Gamma \approx 70$$ Γ ≈ 70 MeV and the quantum numbers are $$IJ^P=03^+$$ I J P = 03 + . The structure of $$d^*(2380)$$ d ∗ ( 2380 ) is still in controversy. In the present calculation, the powerful method in few-body system, Gaussian expansion method (GEM) is employed to explore the structure of $$d^*(2380)$$ d ∗ ( 2380 ) in the framework of constituent quark models without assuming the presupposed structure. The results show that the radius of $$d^*(2380)$$ d ∗ ( 2380 ) is around 0.8 fm, it is a very compact object. Because of the compact structure, the color singlet-singlet component has a large overlap with the color octet-octet one, two colorless, large overlapped $$\Delta $$ Δ s dominate the state is possible.