Electro-excitation amplitudes of the Delta-isobar in the Skyrme model

Abstract

Electro magnetic transition form factors for the excitation of the Delta33-resonance are evaluated in the Skyrme model. They crucially rely on rotationally induced deformations of the hedgehog soliton which are suppressed by two N_C-orders as compared to the leading parts of the isovector current. Partial photon coupling through vector mesons is included in a schematic way. Recoil corrections are approximated by a boost to the equal-velocity frame. The results for the photodecay amplitudes agree with experimental numbers and the shapes of M1, E2, C2 - transition form factors show essential features as observed in electro-excitation experiments.

Comments: 15 pages, LaTeX, 4 PS figures. Revised version, more references and 1 figure added