PION VS PHOTON-ABSORPTION ON THE DEUTERON

Using an NN -->, Delta N transition potential fixed by the reaction pp <----> d pi(+) a good agreement can be obtained also for the reaction gamma d --> pn in the Delta region. Further it is seen that the pi N Delta and pN Delta parameters of the widely used Bonn potential, fitti ng the NN sector, yield a transition potential too weak to reproduce t he pion production or absorption cross section.