$ND$ and $NB$ systems in quark delocalization color screening model

Abstract

The $ND$ and $NB$ systems with $I=0$ and $1$, $J^P={\frac{1}{2}}^{\pm }$, ${\frac{3}{2}}^{\pm }$, and ${\frac{5}{2}}^{\pm }$ are investigated within the framework of quark delocalization color screening model. The results show that all the positive parity states are unbound. By coupling to the $N{D}^{\ast }$ channel, the state $ND$ with $I=0,J^P={\frac{1}{2}}^{-}$ can form a bound state, which can be invoked to explain the observed $\Sigma (2800)$ state. The mass of the $N{D}^{\ast }$ with $I=0,J^P={\frac{3}{2}}^{-}$ is close to that of the reported ${\Lambda }_c(2940{)}^{+}$, which indicates that ${\Lambda }_c(2940{)}^{+}$ can be explained as a $N{D}^{\ast }$ molecular state in QDCSM. Besides, the $\Delta D^{\ast }$ with $I=1,J^P={\frac{5}{2}}^{-}$ is also a possible resonance state. The results of the bottom case of $NB$ system are similar to those of the $ND$ system. Searching for these states will be a challenging subject of experiments.

Comments: 7 pages, 3 figures. arXiv admin note: text overlap with arXiv:1510.04648, arXiv:1311.4732