Covariant Isobar Model for K ⁺Λ Electroproduction

Kaon electroproduction process e + p → e′ + K ⁺ Λ has been investigated by using a covariant isobar model constructed from the appropriate Feynman diagrams. The corresponding propagators and vertex factors are obtained from our previous analysis. For the electromagnetic form factor we adopt the standard dipole one with the cuttoff considered as a free parameter. We include nucleon resonances with spins up to 9/2. All nucleon resonances listed in the particle listings of the Particle Data Group are considered in this investigation. The unknown parameters, including the electromagnetic and hadronic coupling constants,are extracted by fitting the predicted observables to the currently available experimental data.