Off-shell effects in the dynamical model of pion photoproduction

Abstract

In terms of the dynamical model the rescattering effects for the Eo+, MI+ and El+ multipoles are analyzed. Strong correlation between the sensitivity to the off-shell behaviour of the T~u-matrix and the representation of the pion propagator in the photoproduction operator is shown to exist. For the time-ordered choice of a pion propagator the effect of a final state interaction is determined by the charge-exchange channel. In this case the off-shell effects are not important. It is also shown that the value of the coupling constant of the E2-transition in the 7NA-vertex depends on a version of the separable model for the ~N-interaction in the P33-channel. PACS: 25.20.Lj