Recently observed Pc as molecular states and possible mixture of Pc (4457)

A recently observed spectrum of P-c states exhibits a strong link to Sigma(c)(D) over bar(*) thresholds. In spite of successful molecular interpretations, we still push forward to wonder whether there exist finer structures. Utilizing the effecitve Lagrangians respecting heavy quark symmetry and chiral symmetry, as well as instantaneous Bethe-Salpeter equations, we investigate the Sigma(c)(D) over bar(*) interactions and three P-c, states. We confirm that P-c (4312) and P-c (4440) are good candidates of Sigma(c)(D) over bar and Sigma(c)(D) over bar(*) molecules with spin-1/2, respectively. Unlike other molecular calculations, our results indicate the P-c (4457) signal might be a mixture of spin-3/2 and spin-1/2 Sigma(c)(D) over bar(*) molecules, where the latter one appears to be an excitation of P-c (4440). Therefore we conclude that, confronting three LHCb P-c signals, there may exist not three, but four molecular states.