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/psi production induced by pion beams off the nucleon, particularly the heavy pentaquarks P-c(4380) and P-c(4450) in intermediate states, based on a hybridized Regge model. The process involving rho and pi meson exchange in the tchannel is considered as background, and the heavy pentaquark exchange is included in the schannel. The coupling constants such as the.NNand pNNvertices are taken from the NN potentials, whereas those for the J/psi p pi and J/psi pi pi vertices are determined by using experimental data based on the branching ratios. In order to estimate the P-c(4380) and P-c(4450) coupling constants, we use the experimental upper limit on the total cross section as a guide for the pi N -> J/psi N 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 1nb. (C) 2016 The Author(s). Published by Elsevier B.V.