Coupled channel effects in meson photo and electroproduction at high energy

Jean-Marc Laget
JLab

In the energy range accessible at JLab6 and JLab12, the coupling to the vector 
meson production channels provides us with a natural explanation of two long 
standing problems: i) the magnitude of the cross section of charged pion 
photoproduction near 90 degrees and its scaling behavior (s^-7), ii) the strong 
cross section of the neutral pion electroproduction at large Q^2 recently 
measured at JLab. I will present this approach which relates the amplitudes 
of several reactions recently determined at JLab.