The $1D$-wave bottom-strange baryons and possible interpretation of ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6333{)}^0$

Abstract

Inspired by the LHCb's newest observation of two new excited ${\Xi }_b^0$ states, we systematically study the strong decays of the low-lying $\lambda$- and $\rho$-modes $1D$-wave ${\Xi }_b$ and ${\Xi }_b^{{}^{\prime }}$ baryons using the chiral quark model within the $j$-$j$ coupling scheme. Based on the measured masses and strong decay properties of ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6333{)}^0$, we explain the two states as the $\lambda$-mode $1D$ ${\Xi }_b$ states with $J^P=3/2^{+}$ and $J^P=5/2^{+}$, respectively. Moreover, under this assignment, another dominant decay channel of ${\Xi }_b(6327{)}^0$ is ${\Xi }_b^{\prime }\pi$ and that of ${\Xi }_b(6333{)}^0$ is ${\Xi }_b^{\ast }\pi$. Hence, the decay modes ${\Xi }_b^{\prime }\pi$ and ${\Xi }_b^{\ast }\pi$ may be another ideal channels as well to decode the inner structure of ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6333{)}^0$, respectively. For other unseen $1D$ ${\Xi }_b$ and ${\Xi }_b^{\prime }$ states, our results indicate: (i) ${\Xi }_b|J^P={\frac{3}{2}}^{+},2{⟩}_{\rho }$ and ${\Xi }_b|J^P={\frac{5}{2}}^{+},2{⟩}_{\rho }$ are most likely to be narrow states with a width of $\Gamma \simeq (12-30)$ MeV, and dominantly decay into ${\Sigma }_{b}K$ and ${\Sigma }_b^{\ast }K$, respectively; (ii) The $1D$ ${\Xi }_b^{\prime }$ baryons are not broad states, and the widths vary in the range of $\Gamma \simeq (14-46)$ MeV. These states have a good potential to be observed in their dominant decay processes.

10 page, 5 figures