$QQ\bar{s}\bar{s}$ tetraquarks in the chiral quark model

TL;DR

This study systematically investigates $QQ\bar{s}\bar{s}$ tetraquark states using the chiral quark model, revealing potential narrow and wide resonance states across different configurations and quantum numbers, suggesting possible hadronic molecules.

Contribution

It introduces a comprehensive analysis of $QQ\bar{s}\bar{s}$ tetraquarks considering all configurations and color channels within the complex scaling chiral quark model framework, identifying multiple resonance states.

Findings

Several narrow and wide resonances for $cc\bar{s}\bar{s}$ and $bb\bar{s}\bar{s}$ tetraquarks.

Narrow resonances for $cb\bar{s}\bar{s}$ tetraquarks across multiple quantum numbers.

Masses of potential hadronic molecules are about 0.6 GeV above thresholds.

Abstract

The low-lying $S$-wave $QQ\bar{s}\bar{s}$ ($Q=c, b$) tetraquark states with $IJ^P=00^+$, $01^+$ and $02^+$ are systematically investigated in the framework of complex scaling range of chiral quark model. Every structure including meson-meson, diquark-antidiquark and K-type configurations, and all possible color channels in four-body sector are considered by means of a commonly extended variational approach, Gaussian expansion method. Several narrow and wide resonance states are obtained for $cc\bar{s}\bar{s}$ and $bb\bar{s}\bar{s}$ tetraquarks with $IJ^P=00^+$ and $02^+$. Meanwhile, narrow resonances for $cb\bar{s}\bar{s}$ tetraquarks are also found in $IJ^P=00^+$, $01^+$ and $02^+$ states. These results confirm the possibility of finding hadronic molecules with masses $\sim\,0.6\,\text{GeV}$ above the noninteracting hadron-hadron thresholds.