Molecular nature of Pcs (4459) and its heavy quark spin partners

Inspired by the observation of the P-cs(4459) state by LHCb recently, we reexamine the results of the interaction of the J/y/A channel with its coupled channels, exploiting the coupled channel unitary approach combined with heavy quark spin and local hidden gauge symmetries. By tuning the only free parameter, we find a pole of (4459.07 + i6.89) MeV below the (D) over bar*Xi(c) threshold, which was consistent with the mass and width of the P-cs(4459) state. Thus, we assume the P-cs(4459) state to be a (D) over bar*Xi(c) bound state with the possible degeneracy of J(P) =1/2- and J(P) =3/2- According to this degeneracy, it would have a two-pole structure, like P-cs (4450) before. There is another pole in the J(P) = 1/2- sector, (4310.53 + i8.23) MeV, corresponding to a deep bound state of (D) over bar*Xi(c) . Furthermore, the previously predicted loosely bound states (D) over bar Xi'(c) (D) over bar*Xi'(c), (D) over bar*Xi(c)* with J = 1/2, I = 0 and (D) over bar Xi'(c,) (D) over bar*Xi(c), (D) over bar*Xi(c)* with J = 3/2, I = 0 may exist as either bound states or unbound virtual states. We hope that future experiments can search for the (D) over bar(*)Xi(c) molecular states not only in their dominant decay channels (D) over bar (s)(*)Lambda(c), but also in the channels J/psi/Lambda and eta(c)Lambda in order to reveal their different natures.

Automated summary

The study reexamines the characteristics of the P-cs(4459) state using a coupled channel unitary approach, finding it to possibly be a (D) over bar*Xi(c) bound state with a two-pole structure. Additionally, a deep bound state is identified at (4310.53 + i8.23) MeV, along with the potential existence of other bound states or unbound virtual states as previously predicted.