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

TL;DR

This paper analyzes the newly observed $ ext{Xi}_b$ baryons using a chiral quark model, proposing their quantum states, decay channels, and predicting properties of other unseen $1D$ $ ext{Xi}_b$ states to guide future experiments.

Contribution

It provides a systematic interpretation of the $ ext{Xi}_b(6327)^0$ and $ ext{Xi}_b(6333)^0$ as $1D$-wave states with specific quantum numbers, and predicts decay modes and widths for other $1D$ $ ext{Xi}_b$ baryons.

Findings

$ ext{Xi}_b(6327)^0$ is a $ ext{1D}$ $ ext{lambda}$-mode state with $J^P=3/2^+$.

$ ext{Xi}_b(6333)^0$ is a $ ext{1D}$ $ ext{lambda}$-mode state with $J^P=5/2^+$.

Predicted widths for other $1D$ $ ext{Xi}_b$ states are between 12-46 MeV, decaying mainly into $ ext{Sigma}_b K$ and $ ext{Sigma}^*_b K$.

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 $\Xi^{'}_{b}$ 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 $\Xi'_b\pi$ and that of $\Xi_{b}(6333)^{0}$ is $\Xi_b^*\pi$. Hence, the decay modes $\Xi'_b\pi$ and $\Xi_b^*\pi$ 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 $\Xi'_b$ states, our results indicate: (i) $\Xi_b|J^P=\frac{3}{2}^+,2\rangle_{\rho}$ and $\Xi_b|J^P=\frac{5}{2}^+,2\rangle_{\rho}$ are most likely to be narrow states with a width of $\Gamma\simeq(12-30)$ MeV, and dominantly decay into $\Sigma_bK$ and $\Sigma^*_bK$, respectively; (ii) The $1D$ $\Xi'_b$ 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.