Understanding the nature of the heavy pentaquarks and searching for them in pion-induced reactions

Understand

We investigate the reaction $\pi^- p \to \pi^- J/\psi p$ via the open-charm hadron rescattering diagrams.

• Due to the presence of the triangle singularity (TS) in the rescattering amplitudes, the TS peaks can simulate the pentaquark-like resonances arising in the $J/\psi p$ invariant mass distributions, which may bring ambiguities on our understanding of the nature of the exotic states.
• Searching for the heavy pentaquark in different processes may help us to clarify the ambiguities, because of the highly process-dependent characteristic of the TS mechanism.