Photoproduction of K Σ in an effective Lagrangian approach

All the available data on differential cross sections, total cross sections, spin density matrix elements, and parity spin asymmetry for the γ p → K * + Σ 0 and γ p → K * 0 Σ + reactions are analyzed within an effective Lagrangian approach. The reaction amplitudes are constructed by considering the s -channel exchanges of N , Δ, and their excited states, the t -channel exchanges of K , K *, and κ, the u -channel exchanges of Λ, Σ, and Σ* , and the interaction current. Two fits with different reaction mechanisms are obtained that describe the data equally well. The s -channel Δ(1905)5=2 + resonance exchange is found to provide dominant contributions in both fits. The t -channel κ exchange only contributes significantly to γp → K * 0 Σ + in model II, which challenges the claim made in literature that the available parity spin asymmetry data supports the dominant contribution of κ exchange in γp → K * 0 Σ + .