How to extract the P33(1232) resonance contributions from the amplitudes M1+3/2, E1+3/2, S1+3/2 of pion electroproduction on nucleons

Within the dispersion relation approach, solutions of integral equations for the multipoles M-1+(3/2),E-1+(3/2),S-1+(3/2) are found at 0 less than or equal to Q(2) less than or equal to 3 GeV2. These solutions should be used as input for the resonance and nonresonance contributions in the analyses of pion electroproduction data in the P-33(1232) resonance region. It is shown that resonance contribution is not right; there is a contribution in these amplitudes which has and is produced by rescattering effects in the diagrams corresponding to the nucleon and pion-poles. This contribution is reproduced by the dispersion relations: Taking into account nonresonance contributions in the amplitudes M-1+(3/2),E-1+(3/2), the helicity amplitudes A(p)(1/2),A(p)(3/2) and the ratio E2/M1 for the gamma N-->P-33(1232) transition are extracted from experiment at Q(2)=0. They are in good agreement with quark model predictions.