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

TL;DR

This paper systematically studies the $D_{s0}^{*}(2317)$ meson using quark models, including two-quark, four-quark, and mixed structures, and finds that a mixed state best explains experimental data.

Contribution

It introduces a comprehensive analysis of $D_{s0}^{*}(2317)$ with mixed quark configurations using the Gaussian expansion method, highlighting the importance of unquenched effects.

Findings

The chiral quark model describes $D_{s0}^{*}(2317)$ and $D_{s1}(2460)$ well with appropriate parameters.

Four-quark calculations show no bound $DK$ state but indicate attractive interactions.

Mixed two-four-quark calculations align energies with experimental values, suggesting these particles are mixed states.

Abstract

Recently, the BES\uppercase\expandafter{\romannumeral3} Collaboration updated the data for the exotic state, $D^{*}_{s0}(2317)$, with a mass of $2318.3\pm1.2\pm1.2$ 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 $D_s$, $D_s^{*}$, $D_{s0}^{*}(2317)$, 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 $D_{s0}^{*}(2317)$ 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 $D_{s0}^{*}(2317)$ 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.