Interpretation of the newly observed Λ b ( 6146 ) and Λ b ( 6152 ) states in a chiral quark model

The strong decays of the low-lying λ-mode Λb(1D,2S) and Σb(2S) states are studied in a chiral quark model. We find that (i) the newly observed Λb(6146/6152) resonances in the Λbπ+π− spectrum by the LHCb Collaboration might be explained with the λ-mode Λb(1D) states in the quark model. It should be emphasized that whether the structure in the Λbπ+π− spectrum corresponds to two states or one state should be further clarified with more observations in future experiments. (ii) The Λb(2S) |JP=12+,0⟩ state mainly decays into Σb*π channel, which may be an ideal channel for searching for this Λb(2S) state in future experiments. (iii) The Σb(2S) |JP=12+,1⟩ and |JP=32+,1⟩ dominantly decay into Λbπ with Γ≃3.82 MeV and Γ≃4.72 MeV, respectively.