Meson formfactor scheme for the chiral Lagrangian approach to J/psi breakup cross sections motivated by a relativistic quark model

Abstract

We suggest a new scheme for the introduction of formfactors for the SU(4) chiral meson Lagrangian approach to the J/psi breakup cross sections by pion and rho meson impact. This mesonic formfactor scheme respects the fact that on the quark level of description the contact and the meson exchange diagrams are constructed by so-called box and triangle diagrams which contain a different number of vertex functions for the quark-meson coupling. We present a model calculation for Gaussian vertex functions within the meson formfactor scheme and compare the results with those of the usual global formfactor model. We calibrate the new meson formfactor model with results for the pion impact processes from a relativistic quark model calculation by Ivanov et al. and present predictions for the rho-meson induced processes. We provide a fit formula for the resulting energy-dependent cross sections.