Identifying exotic hidden-charm pentaquarks

Abstract

The LHCb Collaboration at the Large Hadron Collider at CERN discovered two pentaquark states $P_c(4380)$ and $P_c(4450)$. These two hidden-charm states are interpreted as the loosely bound ${\Sigma }_c(2455)D^{\ast }$ and ${\Sigma }_c^{\ast }(2520)D^{\ast }$ molecular states in the boson exchange interaction model, which provides an explanation for why the experimental width of $P_c(4450)$ is much narrower than that of $P_c(4380)$. The discovery of the new resonances $P_c(4380)$ and $P_c(4450)$, indeed, opens a new page for hadron physics. The partners of $P_c(4380)$ and $P_c(4450)$ should be pursued in future experiments.

Comments: 5 pages, 2 tables and 1 figure. More discussions and references added. Accepted by Phys. Rev. Lett