Full-heavy tetraquarks in constituent quark models

TL;DR

This paper investigates full-heavy tetraquarks using two quark models, finding no bound states for $bbar{b}ar{b}$ but predicting possible resonance states for $ccar{c}ar{c}$, aligning with recent experimental hints.

Contribution

It provides a systematic analysis of full-heavy tetraquarks in two models, predicting resonance states and clarifying their structures and quantum numbers.

Findings

No bound states for $bbar{b}ar{b}$ in the chiral quark model.

Possible resonance states for $bbar{b}ar{b}$ in the quark delocalization model.

Resonance states for $ccar{c}ar{c}$ consistent with LHCb results.

Abstract

The full-heavy tetraquarks $bb\bar{b}\bar{b}$ and $cc\bar{c}\bar{c}$ are systematically investigated within the chiral quark model and the quark delocalization color screening model. Two structures, meson-meson and diquark-antidiquark, are considered. For the full-beauty $bb\bar{b}\bar{b}$ systems, there is no any bound state or resonance state in two structures in the chiral quark model, while the wide resonances with masses around 19.25 GeV and the quantum numbers $J^{P}=0^{+}$, $1^{+}$, and $2^{+}$ are possible in the quark delocalization color screening model. For the full-charm $cc\bar{c}\bar{c}$ systems, the results are qualitative consistent in two quark models. No bound state can be found in the meson-meson configuration, while in the diquark-antidiquark configuration there may exist the resonance states, with masses range between $6.3$ GeV to $7.4$ GeV, and the quantum numbers $J^{P}=0^{+}$, $1^{+}$, and $2^{+}$. And the separation between the diquark and the antidiquark indicates that these states may be the compact resonance states. All these full-charm resonance states are consistent with the latest results at LHCb collaboration and are worth searching in the experiments further.