Strange hidden-charm tetraquarks in constituent quark models

TL;DR

This study investigates the nature of the $Z_{cs}(3985)^{-}$ tetraquark, finding no molecular bound states but suggesting it could be a compact resonance within certain diquark-antidiquark configurations, using two quark models.

Contribution

It provides a systematic analysis of strange hidden-charm tetraquarks with two models, excluding molecular explanations and proposing resonance states as possible explanations for the observed particle.

Findings

No bound molecular states found in both models.

Possible resonance states with specific mass ranges identified.

$Z_{cs}(3985)^{-}$ may be a compact resonance, not a molecular state.

Abstract

Inspired by the newly reported $Z_{cs}(3985)^{-}$ by the BESIII Collaboration, we systematically investigate the strange hidden-charm tetraquark systems $cs\bar{c}\bar{u}$ with two structures: meson-meson and diquark-antidiquark. Two quark models: the chiral quark model (ChQM) and the quark delocalization color screening model (QDCSM) are used here. Similar results are obtained in both two quark models. There is no any bound state in either ChQM or QDCSM, which excludes the molecular state explanation ($D_{s}D^{*}/D_{s}^{*}D/D_{s}^{*}D^{*}$) of the reported $Z_{cs}(3985)^{-}$. However, the effective potentials for the diquark-antidiquark $cs\bar{c}\bar{u}$ systems shows the possibility of some resonance states with mass range of $3916.5\sim 3964.6$ MeV for $IJ^{P}=\frac{1}{2} 0^{+}$, $4008.8\sim 4091.2$ MeV for $IJ^{P}=\frac{1}{2} 1^{+}$, $4246.8\sim 4418.1$ MeV for $IJ^{P}=\frac{1}{2} 2^{+}$. So the observed $Z_{cs}(3985)^{-}$ state is possible to be explained as a compact resonance state composed of $cs\bar{c}\bar{u}$ with $IJ^{P}=\frac{1}{2} 0^{+}$ or $IJ^{P}=\frac{1}{2} 1^{+}$. The study of the scattering process of corresponding open channels is under way to check this conclusion.