Hidden charm pentaquark with strangeness $P_{cs}^{\ast }(4739)$ as a ${\Sigma }_c\bar{D}\bar{K}$ bound state

Abstract

Motivated by the recent discovery of the first hidden charm pentaquark state with strangeness $P_{cs}(4459)$ by the LHCb Collaboration, we study the likely existence of a three-body ${\Sigma }_c\bar{D}\bar{K}$ bound state, which shares the same minimal quark content as $P_{cs}(4459)$. The ${\Sigma }_c\bar{D}$ and $DK$ interactions are determined by reproducing $P_c(4312)$ and $D_{s0}^{\ast }(2317)$ as ${\Sigma }_c\bar{D}$ and $\bar{D}\bar{K}$ molecules, respectively, while the ${\Sigma }_c\bar{K}$ interaction is constrained by chiral effective theory. We indeed find a three-body bound state by solving the Schrödinger equation using the Gaussian Expansion Method, which can be viewed as an excited hidden charm pentaquark state with strangeness, $P_{cs}^{\ast }(4739)$, with $I(J^P)=1(1/2^{+})$ and a binding energy of $77.8_{-10.3}^{+25}$ MeV. We further study its strong decays via triangle diagrams and show that its partial decay widths into $D{\Xi }_c^{\prime }$ and $D_s^{\ast }{\Sigma }_c$ are of a few ten's MeV, with the former being dominant.

17 pages, 4 figures