18 0 10 20 30 d U  /dt [ b/GeV 2 ] -4 -2 0 2 4 d TT  /dt [ b/GeV 2 ] p( )n n( )p 0 0.1 0.2 0.3 -t [GeV$^{2}$] -6 -4 -2 0 2 d LT  /dt [ b/GeV 2 ] 0 0.1 0.2 0.3 -t [GeV$^{2}$] Q$^{2 }$= 0.70 GeV 2 Q$^{2 }$= 0.70 GeV 2 W = 2.19 GeV W = 2.19 GeV DESY DESY = 0.86 = 0.86 0 5 10 15 20 d U  /dt [ b/GeV 2 ] -1 0 1 d TT  /dt [ b/GeV 2 ] p( )n n( )p 0.1 0.2 0.3 0.4 0.5 -t [GeV$^{2}$] -3 -2 -1 0 1 d LT  /dt [ b/GeV 2 ] 0.1 0.2 0.3 0.4 0.5 -t [GeV $^{2}$] Q$^{2 }$= 1.35 GeV 2 Q 2  1.35 GeV 2 W = 2.19 GeV = 2.19 GeV DESY DESY = 0.84 0.84 FIG. 12: (Color online) The differential cross sections dσ$_{U}$ /dt = dσ$_{T}$/dt + εdσ$_{T}$/dt (top), dσ$_{TT}$/dt (middle) a nd dσ$_{LT}$/dt (bottom) in exclusive reactions p ( γ $^{∗}$, π $^{+}$) n (left panels) and n ( γ $^{∗}$, π$^{−}$) p (right panels) in the kinematics of DESY e xperiments for the average values of Q 2 = 0 . 7 GeV $^{2}$, W = 2 . 19 GeV, ε = 0 . 86 and Q 2 = 1 . 35 GeV $^{2}$, W = 2 . 19 GeV, ε = 0 . 84. The notations for the curves are the same as in Figure 6. The exper imental data are from Ref. [13, 14]. jectory. However, in electroproduction the π − /π + asym- metry is driven by the resonance contributions through the different ( Q $^{2}$, s ( u )) dependence of the transition form factors, Eqs. (43) and (44), in the π + and π − channels. For instance, the dash-dotted curves in Figure 11 do not account for the contributions of resonances; the π − /π + ratio is bigger than unity. In the right panel we show the results for the values of Q 2 = 1 . 35 GeV 2 and ε = 0 . 84. shown to be in remarkable agreement with t he π − /π + electroproduction ratio. This is surprising since the model of [53] is not compatible with the JLAB l/t data in the same ( Q $^{2}$, W ) region [4]. Before drawing definite conclusions concerning these discrepancies, we compare in Figure 12 our model results with the measured differential cross sections dσ$_{U}$/dt = dσ$_{T}$/dt + εdσ$_{T}$/dt (top), dσ$_{TT}$/dt (middle) and dσ$_{LT}$/dt (bottom) in exclusive reactions p ( γ ∗ , π $^{+}$) n (left panels) and n ( γ ∗ , π − ) p (right panels). The experimental data are from Refs. [13, 14]. The average values of ( Q $^{2}$, W, ε ) are the same as in Figure 11 for the π − /π + ratio. The Our dash-dotted curves which describe the Regge model without the r/p -effects are at variance with the results reported in Ref. [53] where the gauge invariant Regge model with the nucleon-pole contribution has been