Anatomy of the newly observed hidden-charm pentaquark states: PC(4312), PC(4440) and PC(4457)

We study the newly reported hidden-charm pentaquark candidates P-C(4312), P-C(4440) and P-C(4457) from the LHCb Collaboration, in the framework of the effective-range expansion and resonance compositeness relations. The scattering lengths and effective ranges from the S-wave Sigma(C) (D) over bar and Sigma(C) (D) over bar* scattering are calculated by using the experimental results of the masses and widths of the P-C(4312), P-C(4440) and P-C(4457). Then we calculate the couplings between the J/psi p, Sigma(C) (D) over bar channels and the pentaquark candidate P-C(4312), with which we further estimate the probabilities of finding the J/psi p and E-C(D) over bar components inside P-C(4312). The partial decay widths and compositeness coefficients are calculated for the P-C(4440) and P-C(4457) states by including the J/psi p and Sigma(C) (D) over bar* channels. Similar studies are also carried out for the three P-C states by including the Lambda(C)(D) over bar* and Sigma(C) (D) over bar ((*)) channels. (C) 2019 The Authors. Published by Elsevier B.V.