Possible interpretation of the newly observed ${\Omega }_b$ states

Abstract

Inspired by the newly observed ${\Omega }_b$ states by the LHCb Collaboration, we investigate the two-body strong decays of the low-lying $\lambda$-mode ${\Omega }_b$ baryons up to $N=2$ shell using the chiral quark model within the $j$-$j$ coupling scheme. Our results indicate that: (i) the newly observed states ${\Omega }_b(6316{)}^{-}$ and ${\Omega }_b(6330{)}^{-}$ are good candidates of the light spin $j=1$ states, while the spin-parity $J^P=1/2^{-}$ and $J^P=3/2^{-}$ cannot be distinguished. The other two states, ${\Omega }_b(6340)$ and ${\Omega }_b(6350)$ mostly correspond to the light spin $j=2$ states, while the spin-parity $J^P=3/2^{-}$ and $J^P=5/2^{-}$ cannot be distinguished as well.(ii) The $2S$ states with spin-parity $J^P=1/2^{+}$ and $J^P=3/2^{+}$, respectively, might be narrow states with a width of $\Gamma <2$ MeV. (iii) The $1D$ states are not broad and the total decay widths vary from several to dozens of MeV, which have a good potential to be observed in future experiments.

8 pages,3 figures