Investigate the pentaquark resonance in the $NK$ system

Abstract

A dynamical calculation of pentaquark systems with quark contents $uudd\bar{s}$ is performed in the framework of quark delocalization color screening model with the help of resonating group method. The effective potentials between baryon and meson clusters are given, and the possible bound states or resonances are investigated. The single calculations show that the $N{K}^{\ast }$ with $I=0,J^P={\frac{1}{2}}^{-}$, $\Delta K^{\ast }$ with $I=1,J^P={\frac{1}{2}}^{-}$, and $\Delta K^{\ast }$ with $I=2,J^P={\frac{3}{2}}^{-}$ are all bound, but they all turns into scattering states by coupling with the corresponding open channels. A possible resonance state $\Delta K^{\ast }$ with $I=1,J^P={\frac{5}{2}}^{-}$ is proposed. The mass is around $2110.5$ MeV, and the decay modes are $NK$ in $D$-wave or $NK\pi \pi$ in $P$-waves.

Comments: 7 pages, 4 figures