Abstract

We study the p(e,e(')pi(+))n reaction in the framework of an effective Lagrangian approach including nucleon, pi and rho meson degrees of freedom and show the importance of the rho-meson t-pole contribution to sigma(T), the transverse part of cross section. We test two different field representations of the rho meson, vector and tensor, and find that the tensor representation of the rho meson is more reliable in the description of the existing data. In particular, we show that the rho-meson t-pole contribution, including the interference with an effective nonlocal contact term, sufficiently improves the description of the recent JLab data at invariant mass W less than or similar to 2.2 GeV and Q(2)less than or similar to 2.5 GeV2/c(2). A "soft" variant of the strong pi NN and rho NN form factors is also found to be compatible with these data. On the basis of the successful description of both the sigma(L) and sigma(T) parts of the cross section we discuss the importance of taking into account the sigma(T) data when extracting the charge pion form factor F-pi from sigma(L).