Nucleon Resonances in $\varvec{\gamma p \rightarrow K^{*+} \Lambda }$

Abstract

We use an effective Lagrangian approach in the tree-level approximation to analyze the high-precision cross-section data for $\gamma p \rightarrow K^{*+}\Lambda$ reported by the CLAS Collaboration. Apart from the t-channel K, $\kappa$, $K^*$ exchanges, the s-channel nucleon (N) exchange, the u-channel $\Lambda$, $\Sigma$, $\Sigma ^*(1385)$ exchanges, and the generalized contact current, we found that at least two nucleon resonances ($N^*$’s) should be considered to well describe the high-precision cross-section data. One is the $N(2060){5/2}^-$ that is responsible for the shape of the angular distribution near the $K^*\Lambda$ threshold via its interference with the t-channel K exchange, and the other could be one of the $N(2000){5/2}^+$, $N(2040){3/2}^+$, $N(2100){1/2}^+$, $N(2120){3/2}^-$ and $N(2190){7/2}^-$. The results for $\Sigma$, T and P are predicated and it is pointed out that more data on these observables are needed to further pin down the resonance contents and their associated parameters in this reaction.