Strong decays of low-lying $D$-wave ${\Xi }_b/{\Xi }_b^{\prime }$ baryons with QPC model

Abstract

For further decoding the inner structure of the two excited ${\Xi }_b$ states observed by LHCb, we perform a systematical study of the strong decays of the low-lying $1D$-wave ${\Xi }_b$ and ${\Xi }_b^{\prime }$ excitations using the quark pair creation model within the $j-j$ coupling scheme. Combining with the measured masses and decay properties of ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6327{)}^0$, the two excited states can be explained as $1D$ $\lambda$-mode ${\Xi }_b$ states ${\Xi }_b|J^P={\frac{3}{2}}^{+},2{⟩}_{\lambda \lambda }$ and ${\Xi }_b|J^P={\frac{5}{2}}^{+},2{⟩}_{\lambda \lambda }$, respectively. If such a view were correct, ${\Xi }_b^{\prime }\pi$ and ${\Xi }_b^{\prime \ast }\pi$ could be another interesting channels for experimental exploring of the ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6327{)}^0$, respectively. Those calculations are good consistent with the results within the chiral quark model. In addition, for the other missing $1D$-wave ${\Xi }_b$ and ${\Xi }_b^{\prime }$ excitations, our predictions indicate that:(i) the two $\rho$-mode $1D$ ${\Xi }_b$ states are likely to be moderate states with a width of $\Gamma \sim 50$ MeV. The $J^P=3/2^{+}$ state dominantly decays into ${\Sigma }_{b}K$ and ${\Xi }_b^{\prime }\pi$, while the $J^P=5/2^{+}$ state decays primarily through ${\Sigma }_b^{\ast }K$ and ${\Xi }_b^{\prime \ast }\pi$. (ii) The $\lambda$-mode $1D$ ${\Xi }_b^{\prime }$ states may be moderate states with a widths of about several to dozens of MeV. Most of the $\lambda$-mode $1D$ ${\Xi }_b^{\prime }$ states mainly decay into the $1P$-wave bottomed baryon via the pionic decay processes. Meanwhile, several $\lambda$-mode $1D$ ${\Xi }_b^{\prime }$ states have significant decay rates into $\Lambda B$. (iii) While, the $\rho$-mode $1D$ ${\Xi }_b^{\prime }$ states are predicted to be very broad states with a width of about several hundreds MeV. It will be a great challenge to explore the $\rho$-mode $1D$ ${\Xi }_b^{\prime }$ states in experiments for their broad widths.

Comments: 11 pages, 5 figures