K*{\Lambda}(1116) photoproduction and nucleon resonances

초록

In this presentation, we report our recent studies on the $K^{\ast }\Lambda (1116)$ photoproduction off the proton target, using the tree-level Born approximation, via the effective Lagrangian approach. In addition, we include the nine (three- or four-star confirmed) nucleon resonances below the threshold ${\sqrt{s}}_{\mathrm{th}}\approx 2008$ MeV, to interpret the discrepancy between the experiment and previous theoretical studies, in the vicinity of the threshold region. From the numerical studies, we observe that the $S_{11}(1535)$ and $S_{11}(1650)$ play an important role for the cross-section enhancement near the ${\sqrt{s}}_{\mathrm{th}}$. It also turns out that, in order to reproduce the data, we have the vector coupling constants $g_{K^{\ast }{S}_{11}(1535)\Lambda }=(7.0\sim 9.0)$ and $g_{K^{\ast }{S}_{11}(1650)\Lambda }=(5.0\sim 6.0)$.