Dynamical coupled-channels analysis of H-1(e,e(')pi)N reactions

作者：Julia Diaz B^*; Kamano H; Lee T S H; Matsuyama A; Sato T; Suzuki N

来源：Physical Review C, 2009, 80(2): 025207.

DOI：10.1103/PhysRevC.80.025207

We have performed a dynamical coupled-channels analysis of available p(e,e(')pi)N data in the region of W <= 1.6 GeV and Q(2)<= 1.45 (GeV/c)(2). The channels included are gamma N-*, pi N, eta N, and pi pi N that has pi Delta, rho N, and sigma N components. With the hadronic parameters of the model determined in our previous investigations of pi N ->pi N, pi pi N reactions, we have found that the available data in the considered W <= 1.6 GeV region can be fitted well by only adjusting the bare gamma N-*-> N-* helicity amplitudes for the lowest N-* states in P-33, P-11, S-11, and D-13 partial waves. The sensitivity of the resulting parameters to the amount of data included in the analysis is investigated. The importance of coupled-channels effect on the p(e,e(')pi)N cross sections is demonstrated. The meson cloud effect, as required by the unitarity conditions, on the gamma N-*-> N-* form factors are also examined. Necessary future developments, both experimentally and theoretically, are discussed.

• 出版日期2009-8