Electroexcitation of the P33(1232), P11(1440), D13(1520), S11(1535) at Q^2=0.4 and 0.65(GeV/c)^2

Abstract

Using two approaches: dispersion relations and isobar model, we have analyzed recent high precision CLAS data on cross sections of π^0, π^+, and ηelectroproduction on protons, and the longitudinally polarized electron beam asymmetry for p(\vec{e},e'p)π^0 and p(\vec{e},e'n)π^+. The contributions of the resonances P33(1232), P11(1440), D13(1520), S11(1535) to πelectroproduction and S11(1535) to ηelectroproduction are found. The results obtained in the two approaches are in good agreement with each other. There is also good agreement between amplitudes of the γ^* N \to S11(1535) transition found in πand ηelectroproduction. For the first time accurate results are obtained for the longitudinal amplitudes of the P11(1440), D13(1520) and S11(1535) electroexcitation on protons.

9 pages, 9 figures