Fully heavy pentaquark states

Developing the calculation techniques to fivefold heavy hadrons, we perform study of novel fully $QQQQ\overline{Q}$ pentaquark states by QCD sum rule approach that is firmly based on basic theory. Numerically, masses are calculated be ${7.41}_{\ensuremath{-}0.31}^{+0.27}\text{ }\text{ }\mathrm{GeV}$ for $cccc\overline{c}$ and ${21.60}_{\ensuremath{-}0.22}^{+0.73}\text{ $bbbb\overline{b}$, respectively. In experiment, these predicted all-heavy could searched in ${\mathrm{\ensuremath{\Omega}}}_{QQQ}{\ensuremath{\eta}}_{Q}$ invariant mass spectrum.