Speaker
Description
In this talk, we will present the results of a coupled-channel analysis of the $J/\Psi p$ invariant mass distribution, in which the $P_c$ states are treated as $\Sigma_c^{(*)}\bar D^{(*)}$ molecules, [Phys. Rev. Lett., 124, 072001 (2020)] and its recent update [arXiv:2102.07159 [hep-ph]]. The effective $\bar D^{(*)}\Sigma_c^{(*)}$ meson-baryon scattering potential involves the long-range one-pion exchange interactions and short-range operators constrained by heavy quark spin symmetry (HQSS) and renormalization group invariance. In addition to the $J/\Psi p$, the $\Lambda_c \bar D^{(*)}$ and $\eta_c p$ are included as explicit inelastic channels, as required by unitarity and HQSS. The approach yields a very good description of the data. Apart from the three established states, a new state, associated with the $J^P=3/2^-$ $\Sigma_c^{*} \bar D$ molecule and predicted from HQSS, has a clear manifestation in the data. The line shapes in the elastic and inelastic channels are predicted and will be important for revealing the decay properties of the $P_c$ states and their quantum numbers, once new data become available.
