Kaon electroproduction on the proton

A model of kaon photoproduction in the p(e, e′K+)Λ, p(e, e′K+)Σ0, and p(e, e′K0)Σ+ processes with the square of the momentum transfer Q2 up to 2.5 GeV2 is proposed. The photoproduction amplitude includes the s-, t-, and u-channel Born and s- and u-channel resonance contributions calculated in the tree approximation. The unitarity of the photoproduction amplitude is partially recovered by introducing the momentum dependence of the hadron decay widths of resonances and an additional effective width taking into account the effect of coupling between open channels without strangeness. The specificities of the calculations are allowance for the longitudinal electromagnetic coupling of photons to hadrons and the introduction of strongly Q2-dependent suppression factors for the Born and resonance components of the photoproduction amplitude. This approach provides an accurate description of the existing data on the angular and Q2 distributions for the p(e, e′K+)Λ and p(e, e′K+)Σ0 reactions. This model also correctly reproduces the dependence of the ratio σ(Σ0)/σ(Λ) separately for longitudinally and transversely polarized components of the kaon photoproduction cross section in the p(e, e′K+)Λ and p(e, e′K+)Σ0 processes.