Aspects of Zcs(3985) and Zcs(4000)

Abstract

In the present work, we investigate the ${\ensuremath{\eta}}_{c}K$, $J/\ensuremath{\psi}K$, ${\ensuremath{\eta}}_{c}{K}^{*}$, and $J/\ensuremath{\psi}{K}^{*}$ hidden-charm decay modes for the $c\overline{c}s\overline{u}$ four-quark system in the molecular and compact tetraquark scenarios using the quark-exchange model. Our theoretical results indicate that if the newly observed states ${Z}_{cs}(3985)$ and ${Z}_{cs}(4000)$ are two different states, ${Z}_{cs}(4000)$ may be interpreted as the mixture $\frac{1}{\sqrt{2}}({D}^{0}{D}_{s}^{*\ensuremath{-}}+{D}^{*0}{D}_{s}^{\ensuremath{-}})$, of which the $J/\ensuremath{\psi}K$ partial decay width is about $\mathrm{\ensuremath{\Gamma}}\ensuremath{\sim}2.89\text{ }\text{ }\mathrm{MeV}$, while ${Z}_{cs}(3985)$ may be explained as the mixture $\frac{1}{\sqrt{2}}(\ensuremath{-}{D}^{0}{D}_{s}^{*\ensuremath{-}}+{D}^{*0}{D}_{s}^{\ensuremath{-}})$, of which the $J/\ensuremath{\psi}K$ partial decay width is small to zero. Moreover, if the state ${Z}_{cs}(4000)$ can be explained as the mixed state $\frac{1}{\sqrt{2}}({D}^{0}{D}_{s}^{*\ensuremath{-}}+{D}^{*0}{D}_{s}^{\ensuremath{-}})$, indeed, the partial decay width ratio between $J/\ensuremath{\psi}K$ and ${\ensuremath{\eta}}_{c}{K}^{*}$ is close to unit, which indicates the decay channel ${\ensuremath{\eta}}_{c}{K}^{*}$ may be a ideal channel as well to decode the inner structure of ${Z}_{cs}(4000)$. In addition, the partial decay width for the tensor molecular state $|{D}^{*0}{D}_{s}^{*\ensuremath{-}}{⟩}_{{2}^{+}}$ decaying into $J/\ensuremath{\psi}{K}^{*}$ can reach up to a few MeV, which shows this tensor molecular state has a good potential to be observed in this decay channel.