2 N’ reaction plane scattering plane z e e’ FIG. 1: Exclusive reaction N ( e, e $^{′}$π ) N ′ in the laboratory. φ stands for the azimuthal angle between the electron scattering ( e, e $^{′}$) plane and reaction N ( γ $^{∗}$, π ) N ′ plane. tions to a generalized parton distribution (GPD) based handbag diagram. This approach has been followed in Ref. [28] where p ( γ ∗ , π $^{+}$) n is considered using the hand- bag approach with a π -pole contribution. Indeed, the data from JLAB demonstrate [3, 4] that the magnitude and sign of the interference cross sections are not com- patible with the simple exchange of a pion trajectory in the t -channel. Because, the contributions from exchange of heavy mesons are small [25] this would suggest the presence of a large transverse resonance or partonic in- terfering background to the meson-pole contributions. In this work we attempt a phenomenological approach to model the hard scattering or, using a duality argu- ment, the presence of nucleon resonances beyond the t -channel meson-pole amplitudes. The meson-exchange processes dominate in high-energy photoproduction and low Q 2 electroproduction above the resonance region. One way to describe this region is to assume that the co- herent sum of baryon resonance contributions would be expected by duality arguments to be equivalent to a sum over t -channel Regge trajectories. However, in electro- production, with plausible assumptions concerning the coupling constants and transition form factors, the ex- change of heavy mesons alone does not explain the trans- verse cross section and turns out to be marginal [25]. It is also a generic rule that single t -channel meson-exchange processes vanish in the forward π + direction. On the other hand, pion exchange does play an important role at near forward directions and must be included, as must be the nucleon-pole charge term to satisfy gauge invariance. The nucleon magnetic transitions vanish in the forward production and can be neglected [29]. For instance, in photoproduction this suggests an extreme phenomeno- logical scenario, known as an electric model, where the only relevant contributions to π ± production at forward angles are the ones from π -exchange and the nucleon Born term where the inclusion of the latter is manda- tory to conserve gauge invariance. also affects the longitudinal cross section making the π - pole dominance in the longitudinal response rather ques- tionable. Based on a quantitative description of electro- production data achieved in this work in a large range of ( Q $^{2}$, W ) from JLAB to DIS region at HERMES the present results may assist in the experimental analysis and extraction of the pion charge form factor to mini- mize systematic uncertainties. Recall that it is essential to use theoretical model input for the extraction of the pion form factor [5]. The outline of the present paper is as follows. In the Section II we briefly recall the kinematics and definition of the cross sections in exclusive ( e, e ′ π ± ) electroproduc- tion reaction. In Section III we discuss our treatment of gauge invariant π -exchange in the Regge pole model. In Section IV we consider the effect of nucleon resonances and derive the transition form factors using an exclusive- inclusive connection. In Section V we consider the con- tribution of vector ρ (770) and axial-vector a$_{1}$ (1260) and b$_{1}$ (1235) Regge trajectories. In Section VI we briefly dis- cuss the π ± photoproduction at forward angles. Then the model is extended to electroproduction. In Sections VII-IX the results are compared to the experimental data from JLAB, DESY and Cornell. In Section X we compare our results with the HERMES data. The Q 2 behavior of the cross sections is studied in Section XI. The polarized beam-spin asymmetry and the role played by the axial- vector mesons in ( ⃗ e, e ′ π ± ) are discussed in Section XII. In Section XIII the model predictions for JLAB at 12 GeV are presented. The conclusions are summarized in Sec- tion XIV. Some details of the calculations are relegated to the Appendix. By reggeization of the π -exchange one takes into ac- count higher mass and higher spin excitations. At for- ward angles considered here the momentum transfer − t is small and the exchanged π -trajectory is close to its first materialization. However, the nucleons in the s ( u )- channel pole amplitudes are highly off-mass-shell and with increasing values of ( Q $^{2}$, W ) the effect of nucleon resonances should become more and more important. This is because of the well known hardening of the higher mass resonance transition form factors which must re- spect the scaling properties of deep inelastic structure functions in inclusive scattering [30, 31]. We shall follow this suggestion and model the contribution of nucleon res- onances using a local Bloom-Gilman connection between the exclusive and inclusive processes. Another question which we address here is a possible contribution of the resonance (or partonic) background to the longitudinal cross section σ$_{L}$ which is presently used to get the information about the pion form fac- tor. Indeed, the same resonance/partonic background We recall briefly the kinematics in exclusive π electro- production II. KINEMATICS AND DEFINITIONS e ( l ) + N ( p ) → e ′ ( l ′ ) + π ( k ′ ) + N ′ ( p ′ ) , (2)