Heavy pentaquark states Pc(4380) and Pc(4450) in the J/ψ production induced by pion beams off the nucleon

In this study, we investigate the J/ψ production induced by pion beams off the nucleon, particularly the heavy pentaquarks Pc(4380) and Pc(4450) in intermediate states, based on a hybridized Regge model. The process involving ρ and π meson exchange in the t channel is considered as background, and the heavy pentaquark exchange is included in the s channel. The coupling constants such as the ρNN and πNN vertices are taken from the NN potentials, whereas those for the J/ψρπ and J/ψππ vertices are determined by using experimental data based on the branching ratios. In order to estimate the Pc(4380) and Pc(4450) coupling constants, we use the experimental upper limit on the total cross section as a guide for the πN→J/ψN reaction. The background total cross section is the order of 10−4-10−3 nb. In the vicinity of the heavy pentaquark masses, the total cross section reaches about 1 nb.