Fully heavy pentaquarks in quark models

The fully heavy pentaquarks $cccc\bar{c}$ and $bbbb\bar{b}$ are systematically investigated within the chiral quark model and quark delocalization color screening model. The results are consistent in both two moelds, and the effect of the channel-coupling is crucial for forming a bound state of the fully heavy pentaquark system. Three possible fully heavy pentaquarks are obtained, which are the $cccc\bar{c}$ state with $J^P = 1/2^-$ and the mass of $7891.9 \sim 7892.7$ MeV, the $bbbb\bar{b}$ state with $J^P=1/2^-$ and the mass of $23810.1 \sim 23813.8$ MeV, and the $bbbb\bar{b}$ state with $J^P = 3/2^-$ and the mass of $23748.2 \sim 23752.3$ MeV. All these fully heavy pentaquark states are worth searching in future experiments.