Pc(4312)+ and Pc(4337)+ as interfering ΣcD¯ and ΛcD¯* threshold cusps

S.X. Nakamura, 2, ∗ A. Hosaka, 4 and Y. Yamaguchi University of Science and Technology of China, Hefei 230026, People’s Republic of China State Key Laboratory of Particle Detection and Electronics (IHEP-USTC), Hefei 230036, People’s Republic of China Research Center for Nuclear Physics, Osaka University, Ibaraki 567-0047, Japan Advanced Science Research Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, Japan The recent LHCb data on B s → J/ψpp̄ revealed a new pentaquark-like Pc(4337) + structure, while finding no evidence for Pc(4312) + discovered earlier in Λb → J/ψpK . Though puzzling, the data actually offer an important hint to understand the nature of the pentaquark candidates. We develop a model to analyze the B s → J/ψpp̄ data. We find that a ΣcD̄ one-loop mechanism causes a threshold cusp that fits well the Pc(4337) + peak. Also, the ΣcD̄ and ΛcD̄ ∗ threshold cusps interfere with each other to reproduce an oscillating behavior in the proton helicity angle distribution. These results combined with our earlier analysis on Λb → J/ψpK − indicate that Pc(4312) + and Pc(4337) + are created by different interference patterns between the ΣcD̄ and ΛcD̄ ∗ (anomalous) threshold cusps. The proposed scenario consistently explains why the Pc(4312) + and Pc(4337) + peaks appear in Λb → J/ψpK − and B s → J/ψpp̄, respectively, but not vice versa or both.