Systematic study of $D_{s0}^{\ast }$(2317) in quark models

Abstract

Recently, the BES\uppercase\expandafter{\romannumeral3} Collaboration updated the data for the exotic state, $D_{s0}^{\ast }(2317)$, with a mass of $2318.3\pm 1.2\pm 1.2$ MeV from the positronium annihilation process. Inspired by the experiment, we systematically investigated the $c\bar{q}$ meson family spectrum from the perspectives of two-quark, four-quark, and mixed two-four-quark structures, including $D_s$, $D_s^{\ast }$, $D_{s0}^{\ast }(2317)$, and $D_{s1}(2460)$, with the help of the Gaussian expansion method, which is a very accurate calculation method for few-body systems. We found that with appropriate spin-orbit coupling parameter $a_s$, the chiral quark model can effectively describe both $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$. The four-quark calculation shows that the $DK$ state does not form a bound state, but the effective potential calculation shows an attractive interaction between them. Finally, we performed mixed two-four-quark calculations, and the results, with the help of the unquenched effect, show that the energies of $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ are in better agreement with experimental values. Therefore, we conclude that these two particles are good candidates for mixed two-four-quark states.

10 pages, 5 figures