Search

In 2019, two new structures Λ b (6146) and Λ b (6152) were observed by the LHCb Collaboration at the invariant mass spectrum of Λ b 0 π + π - , which aroused a hot discussion about their inner structures. The Λ b (6146) and Λ b (6152) might still be molecular states because their masses are close to threshold of a B ¯ meson and a nucleon. In this work, we perform a systematical investigation of possible heavy baryonic molecular states from the B ¯ N interaction. Since the B ¯ N channel strongly couples to the B ¯ ∗ N channel, the possible B ¯ N - B ¯ ∗ N bound states are also studied. The interaction of the system considered is described by the t-channel σ , π , η , ω , and ρ mesons exchanges. By solving the non-relativistic Schrödinger equation with the obtained one-boson-exchange potentials, the B ¯ (∗) N bound states with different quantum numbers are searched. The calculation suggests that recently observed Λ b (6146) can be assigned as a P-wave B ¯ N molecular state with spin parity J P = 3 / 2 + or a B ¯ N - B ¯ ∗ N bound state. However, assignment of Λ b (6152) as an F-wave B ¯ N molecular is disfavored. The Λ b (6152) can be explained as meson–baryon molecular state with a small B ¯ N component. The calculation also predict the existence of two B ¯ N - B ¯ ∗ N bound states with J P = 1 / 2 - and J P = 3 / 2 - . [ABSTRACT FROM AUTHOR]