π±ρ-+ production in photon-photon collisions

We calculate the process γγ* → π± ρ-+ using the Brodsky-Lepage mechanism for QCD exclusive processes, with two different types of expressions for the meson (π, ρ) wave function. The predictions obtained for the various helicity terms, the angular distribution and the integrated cross section are compared with those computed for γγ* → π+π- under similar assumptions. We notice that in the real photon limit (γγ → π±ρ-+) the reaction cross section vanishes; this appears to be a particular feature of the model used, at least at lowest order. (orig.)