Evidence supporting the existence of Pc(4380)± from the recent measurements of Bs → J=ψp(p)over-bar

Very recently, the LHCb collaboration released the newest measurements of B-s -> J=psi pp over bar , where an enhancement structure near 4.34 GeV was observed in the invariant mass spectrum of J=psi p with the statistical significance of 3.1-3.7 sigma. In this work, by performing a combined analysis for the three invariant mass spectra of Bs -> J=psi pp over bar , we find that this J=psi p structure near 4.34 GeV can correspond to the contributions from the Pc(4380)+ state with the assumption of J(P) = 3/2(-) together with the reflections of B-s -> (f*(2) -> pp over bar )J=psi. Here, P-c(4380) was first observed in A(b) -> J=psi pKbut not confirmed in the updated LHCb data in 2019, and f*(2) means the exciting light isoscalar tensor meson around 2.0 GeV. Thus, this provides a possible evidence to support the existence of the pentaquark Pc(4380). Specifically, the assumed spin parity J(P) = 3/2(-) of P-c(4380) is consistent with a prediction of the theoretical explanation of an S-wave over bar DEc* molecular bound state.

Automated summary

Recent measurements by the LHCb collaboration reveal a potential contribution from the Pc(4380)+ state in the process of Bs -> J=psi pp over bar, providing possible evidence for the existence of the pentaquark Pc(4380).