Doubly-Charm and Doubly-Bottom Pentaquark molecular States via the QCD sum rules

In the present work, the doubly-charm and doubly-bottom pentaquark molecular states D^ (*) c^ (*) and B^ (*) b^ (*) are studied via the QCD sum rules. Sixteen color singlet-singlet type currents with the definite isospin-spin-parity IJP are constructed to interpolate the corresponding hadronic states with the same quantum numbers. The masses and pole residues of those doubly-heavy pentaquark molecular states are calculated, the results show that their masses are all below the corresponding meson-baryon thresholds, which means that they are possible bound states, not resonant states, moreover, the possible decay channels for the doubly-charm molecular states are given.