Photoproduction and Electroproduction of Pions in the Region of theN*(1238)

Abstract

The photoproduction and electroproduction of pions is treated relativistically. A new solution for the 3-3 amplitudes is obtained which includes recoil and is insensitive to a cutoff. Corrections to the $E_{0+}$ and $M_{1-}$ amplitudes are evaluated by using fixed-$t$ dispersion relations. Good results are obtained in the region around the 3-3 resonance up to $\pi -N$ center-of-mass energies about 1300 MeV and electron momentum transfer up to 3.8 Be${\mathrm{V}}^2$.