File:PhysRevC.100.015205.pdf

English: We study the photoproduction and electroproductions of the vector kaon off the proton, i.e., γ(*)p→K*+π0Σ0, and investigate the line shape of the π0Σ0 invariant mass in an effective Lagrangian approach with the inclusion of a K∗NΛ∗ interaction. Relevant electromagnetic form factors for the neutral hyperons and charged strange mesons are constructed by considering experimental and theoretical information. We find that the Λ∗ peak is clearly observed for the photoproduction and electroproductions with the finite K∗NΛ∗ interaction, whereas the clear peak signals survive only for the electroproduction, when we ignore the interaction. These different behaviors can be understood by different Q2 dependencies in the K∗ electromagnetic and K∗→γK transition form factors. We suggest a photon-polarization asymmetry Σ to extract information of the K∗NΛ∗ interaction. It turns out that Σ near the Λ∗ peak region becomes negative with a finite K∗NΛ∗ interaction while positive without it for Q2=0, because of the different naturalities of K and K∗ exchanges. For Q2≠0, we observe more obvious signals in the peak region owing to the additional contribution of the longitudinal virtual photon for Λ∗.