Full-heavy tetraquarks in constituent quark models

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.