Doubly charmed pentaquark states in QCD sum rules

Abstract: We have studied the mass spectra of doubly charmed pentaquark states in the $\Lambda {c}^{()}D^{()}$ and $\Sigma _{c}^{()}D^{()}$ channels with $J^P=1/2^\pm$, $3/2^\pm$ and $5/2^\pm$ within the framework of QCD 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 $\Lambda cD\, (\frac{1}{2}^-)$, $\Sigma _cD\, (\frac{1}{2}^-)$, $\Sigma _cD^*\, (\frac{3}{2}^-)$, $\Lambda _c^*D\, (\frac{3}{2}^-)$, $\Lambda _c^D^\, (\frac{5}{2}^-)$ channels with negative-parity and $\Sigma _cD\, (\frac{1}{2}^+)$, $\Sigma _cD^\ast\, (\frac{3}{2}^+)$, $\Sigma _c^\ast D\, (\frac{3}{2}^+)$ channels with positive-parity, since their masses are predicted to be lower than the corresponding meson-baryon thresholds. However, they are still allowed to decay into the $\Xi{cc}^{(\ast)}\pi$ final states via strong interaction. The triply charged $P_{cc}^{+++}(ccuu\bar d)$ and neutral $P_{cc}^{0}(ccdd\bar u)$ 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 $P_{cc}^{+++}\to\Xi_{cc}^{(\ast) ++}\pi^+/\rho^+$, $\Sigma_c^{(\ast)++}D^{(\ast)+}$ and $P_{cc}^{0}\to\Xi_{cc}^{(\ast) +}\pi^-/\rho^-$, $\Sigma_c^{(\ast)0}D^{(\ast)0}$ decays in the near future.