Effects of $N(2000){5/2}^+$ on $γp \to K^+ Λ(1405)$

Abstract: The photoproduction reaction of $\gamma p \to K^+\Lambda(1405)$ is investigated based on an effective Lagrangian approach at the tree-level approximation with the purpose of understanding the reaction mechanism and extracting the resonance contents and the associated resonance parameters in this reaction. Apart from the $t$-channel $K$ and $K^\ast$ exchanges, $s$-channel nucleon ($N$) exchange, $u$-channel $\Sigma$, $\Lambda$, and $\Lambda(1405)$ exchanges, and generalized contact term, the exchanges of a minimum number of $N$ resonances in the $s$ channel are taken into account in constructing the reaction amplitudes to describe the experimental data. It is found that by introducing the $N(2000){5/2}^+$ resonance exchange in the $s$ channel, one can reproduce the most recent differential cross-section data from the CLAS Collaboration quite well. Further analysis shows that the cross sections of $\gamma p \to K^+\Lambda(1405)$ at high energies are dominated by the $t$-channel $K$ exchange, while the contributions from the $s$-channel $N$ and $N(2000){5/2}^+$ exchanges are rather significant to the cross sections in the near-threshold energy region. Predictions for the beam and target asymmetries for $\gamma p \to K^+\Lambda(1405)$ are given.