Identifying Exotic Hidden-Charm Pentaquarks

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 ${\mathrm{\Sigma }}_c(2455)D^{*}$ and ${\mathrm{\Sigma }}_c^{*}(2520)D^{*}$ 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.

Figure 1

The variations of the obtained OPE effective potentials for the ${\mathrm{\Sigma }}_c^{(*)}{\overline{D}}^{*}$ systems to $r$, and obtained bound state solutions. Here, the masses of $P_c(4380)$ and $P_c(4450)$ can be reproduced well under the ${\mathrm{\Sigma }}_c{\overline{D}}^{*}$ with $(I=1/2,J=3/2)$ and ${\mathrm{\Sigma }}_c^{*}{\overline{D}}^{*}$ with $(I=1/2,J=5/2)$ molecular assignments, respectively. $\mathrm{\Lambda }=2.35\mathrm{GeV}$ and $\mathrm{\Lambda }=1.77\mathrm{GeV}$ are taken for the ${\mathrm{\Sigma }}_c{\overline{D}}^{*}$ and ${\mathrm{\Sigma }}_c^{*}{\overline{D}}^{*}$ systems, respectively. The blue curves are the effective potentials, and the red line stands for the corresponding energy levers. Additionally, the obtained spatial wave functions are given here.