We investigate the neutral hidden charm pentaquark states $P_c^0(4380)$ and $P_c^0(4450)$ in the ${\pi }^{-}p\to J/\psi n$ reaction within an effective Lagrangian approach. The background contributions for the process mainly come from $t$-channel $\pi$ and $\rho$ meson exchanges. The contributions of the $P_c^0(4380)$ and $P_c^0(4450)$ states give clear peak structures in the magnitude of $1\mu \mathrm{b}$ at center-of-mass energies 4.38 GeV and 4.45 GeV in the total cross sections. Hence, this reaction may provide a new platform to search for neutral $P_c$ states. It is expected that our estimated total cross sections, together with the angular distributions, can be tested by future experiments at J-PARC.

• Received 2 November 2015

DOI:https://doi.org/10.1103/PhysRevD.93.034009