Eur. Phys. J. C (2023) 83: 645
https://doi.org/10.1140/epjc/s10052-023-11814-2

Regular Article - Theoretical Physics

Is $d^{\ast }(2380)$ a compact hexaquark state?

¹ Department of Physics, Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems, Nanjing Normal University, 210023, Nanjing, People’s Republic of China
² Department of Physics, Yangzhou University, 225009, Yangzhou, People’s Republic of China

^c jlping@njnu.edu.cn

Received: 18 May 2023
Accepted: 9 July 2023
Published online: 21 July 2023

Abstract

The most fascinating dibaryon in the non-strange quark sector is $d^{\ast }(2380)$, which was reported by WASA-at-COSY Collaboration and confirmed by A2@MAMI Collaboration. The reported mass and decay width are $M\approx 2.37$ GeV, $\mathrm{\Gamma }\approx 70$ MeV and the quantum numbers are $I{J}^P={03}^{+}$. The structure of $d^{\ast }(2380)$ 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 $d^{\ast }(2380)$ in the framework of constituent quark models without assuming the presupposed structure. The results show that the radius of $d^{\ast }(2380)$ 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 $\mathrm{\Delta }$s dominate the state is possible.