XVIII International Conference on Hadron Spectroscopy and Structure (HADRON2019)

The updated analysis of LHCb in the $\Lambda_b^0\to J/\psi p K^-$ process with nine times data sample in Run II presents three narrow pentaquark structures instead of two in the previous analysis. However, although the large data sample is available, the quantum numbers of the three pentaquarks and the corresponding anglular momentum distribution are still missing. As these three pentaquarks are close to the $\left(\bar{D},\bar{D}^*\right)+\left(\Sigma_c(2455),\Sigma_c(2520)\right)$ thresholds, they could be accepted as hadronic molecular states. We do an overall fit for the lineshape of these three states by solving Lippmann-Schwinger equation with dynaimc pion as well as the inelastic channel to study, to which extent, these three structures could exist as hadronic molecular states. Their quantum numbers and the corresponding angular distributions are also presented for the comparison with further experimental analysis.