Doubly charmed pentaquark states in QCD sum rules

We have studied the mass spectra of doubly charmed pentaquark states in the Lambda () c D () and Sigma () c D () channels with J P 1 / 4 1 = 2 , 3 = 2 , and 5 = 2 within the framework of quantum chromodynamics sum rules. We use the parity projected sum rules to separate the contributions of negative and positive parities from the two -point correlations induced by the pentaquark interpolating currents. Our results show that the bound states of P cc pentaquarks may exist in the Lambda c D ( 1 - ) , Sigma c D ( 1 - ) , Sigma c D ( 3 - ) , Lambda c D ( 3 - ) , Lambda c D ( 5 - ) channels with 2 2 2 2 2 negative -parity and Sigma c D ( 1 + ) , Sigma c D ( 3 + ) , Sigma c D ( 3 + ) channels with positive -parity, since their masses are 2 2 2 predicted to be lower than the corresponding meson -baryon thresholds. However, they are still allowed to decay into the Xi () cc pi final states via strong interaction. The triply charged P +++ cc ( ccuud ) and neutral P 0 cc ( ccddu ) in the isospin quartet would definitely be pentaquark states due to their exotic charges. We suggest searching for these characteristic doubly charmed pentaquark signals in the P +++ cc -> Xi ()++ cc pi + = rho + , Sigma ()++ c D ()+ and P 0 cc -> Xi ()+ cc pi - = rho - , Sigma () 0 c D () 0 decays in the near future.