Backward charmonium production in pi N collisions
Résumé
Hard exclusive backward production of a J/\psi meson in pion-nucleon collisions is studied in the framework of QCD collinear factorization. In this approach, a hard subprocess amplitude responsible for the production of the heavy quark-antiquark pair factorizes from soft hadronic matrix elements, such as the nucleon distribution amplitude and the pion-to-nucleon transition distribution amplitude. We argue that this reaction mechanism dominates the backward kinematical region for the medium energy pion beam at J-Parc.