The newly observed ${\Lambda }_b(6072{)}^0$ structure and its $\rho -$mode nonstrange partners

Abstract

Inspired by the newly observed ${\Lambda }_b(6072)$ structure, we investigate its strong decay behaviors under various assignments within the ${}^3{P}_0$ model. Compared with the mass and total decay width, our results suggest that the ${\Lambda }_b(6072)$ can be regarded as the lowest $\rho -$mode excitation in ${\Lambda }_b$ family. Then, the strong decays of $\rho -$mode nonstrange partners for the ${\Lambda }_b(6072)$ are calculated. It is found that the $J^P=5/2^{-}$ ${\Lambda }_b$ and ${\Lambda }_c$ states are relatively narrow, and mainly decay into the ${\Sigma }_b^{(\ast )}\pi$ and ${\Sigma }_c^{(\ast )}\pi$ final states, respectively. These two states have good potentials to be observed in future experiments, which may help us to distinguish the three-quark model and diquark model.

Comments: 8 pages, 4 figures, comments and suggestions are welcome