Recently, scientists have made great progresses in experiments in searching for the excited states of $\Xi_{ b}$ and $\Lambda_{ b}$ baryons such as the $\Lambda_{ b}(6072)$, $\Lambda_{ b}(6146)$, $\Lambda_{ b}(6152)$, $\Xi_{ b}(6227)$, $\Xi_{ b}(6100)$, $\Xi_{ b}(6327)$ and $\Xi_{ b}(6333)$. Stimulated by these progresses, we give a systematical analysis about the $1D$ and $2D$ states of $\Xi_{ b}$ and $\Lambda_{ b}$ baryons with the method of QCD sum rules. By constructing three types of interpolating currents, we calculate the masses and pole residues of these heavy baryons with different excitation modes $(L_{ \rho},L_{ \lambda})=(0,2)$, $(2,0)$ and $(1,1)$. As a result, we decode the inner structures of $\Lambda_{ b}(6146)$, $\Lambda_{ b}(6152)$, $\Xi_{ b}(6327)$ and $\Xi_{ b}(6333)$, and favor assigning these states as the $1D$ baryons with the quantum numbers $(L_{ \rho},L_{ \lambda})=(0,2)$ and $\frac{ 3}{ 2}^{ +}$, $\frac{ 5}{ 2}^{ +}$, $\frac{ 3}{ 2}^{ +}$ and $\frac{ 5}{ 2}^{ +}$, respectively. In addition, the predictions about the masses and pole residues of the other $1D$ and $2D$ states of $\Xi_{ b}$ and $\Lambda_{ b}$ baryons in this paper are helpful in studying the D-wave bottom baryons in experiments in the future.
Categories: hep-ph