Photoproduction reactionγn→K^*0Λ in an effective Lagrangian approach

Abstract：

In our previous work [Phys. Rev. C 101, 014003 (2020)], the photoproduction reaction $\gamma p \to K^{\ast +} \Lambda$ was investigated within an effective Lagrangian approach. The reaction amplitudes were constructed by including the t-channel K, $K^\ast$ , and κexchanges, u-channel Λ, Σ, and $\Sigma^\ast$ exchanges, s-channel N, $N(2000)5/2^+$ , and $N(2060)5/2^-$ exchanges, and interaction current. The data on the differential cross sections and spin density matrix elements were described simultaneously. In this study, we investigate the photoproduction reaction $\gamma n \to K^{\ast 0} \Lambda$ based on the same reaction mechanism as that of $\gamma p \to K^{\ast +} \Lambda$ to obtain a unified description of the data for $\gamma p \to K^{\ast +} \Lambda$ and $\gamma n \to K^{\ast 0} \Lambda$ within the same model. All hadronic coupling constants, form factor cutoffs, and the resonance masses and widths in the present calculations remain the same as in our previous work for $\gamma p \to K^{\ast +} \Lambda$ . The available differential cross-section data for $\gamma n \to K^{\ast 0} \Lambda$ are well reproduced. Further analysis shows that the cross sections of $\gamma n \to K^{\ast 0} \Lambda$ are dominated by the contributions of the t-channel Kexchange, while the s-channel $N(2000)5/2^+$ and $N(2060)5/2^-$ exchanges also provide considerable contributions.