Single photo and electroproduction of pions at EBAC and JLAB

Within the Excited Baryon Analysis Center we have performed a dynamical coupled-channels analysis of the available p(e,e' π)N data in the region of W ≤ 1.6 GeV and Q2 ≤ 1.45 (GeV/c)2. The channels included are γ * N, πN, ηN, and ππN which has πΔ, ρN, and σN components. With the hadronic parameters of the model determined in our previous investigations of πN → πN reaction, we have found that the available data in the considered W ≤1.6 GeV region can be fitted well by only adjusting the bare γ * N → N * helicity amplitudes for the lowest N * states in P33, P11, S11 and D13 partial waves. The meson cloud effect, as required by the unitarity conditions, on the γ * N → N * form factors are examined. (author)