d∗(2380) in a chiral constituent quark model

Abstract

After a brief review of the experimental findings of $d^{\ast }\left(2380\right)$ and several theoretical efforts to interpret its structure, the study of $d^{\ast }\left(2380\right)$ on the quark–gluon degrees of freedom is presented in detail. On the basis of the $SU\left(3\right)$ chiral constituent quark model and Resonating Group Method, the mass, width, wave function, and partial widths of almost all possible strong decays of the $d^{\ast }\left(2380\right)$ state with the $\Delta \Delta +C_8{C}_8$ structure are evaluated. The obtained results agree with the data quite well, which implies that $d^{\ast }\left(2380\right)$ could be assigned as a compact hexaquark system with the hidden-color component being dominant. The electromagnetic characteristics of $d^{\ast }$, such as the charge distribution, charge radius, multipole moment, and etc. are further calculated. Because of the sensitivity of these physical quantities to different interpretations of $d^{\ast }$, they can be used as additional physical quantities to distinguish the structures of $d^{\ast }$. Moreover, the production of $d^{\ast }$ from the $\gamma d$ reaction, from the ${\rm Y}\left(nS\right)$ decays in the $e^{+}{e}^{-}$ annihilations, and from the $p\bar{p}$ annihilation at forthcoming $\bar{P}$anda are also predicted and calculated. According to these predictions, experiments on Belle II, $\bar{P}$anda, BEPC, and other large scientific facilities may be used to look for the $d^{\ast }\left(2380\right)$ resonance and reveal its nature.