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

TL;DR

This study investigates the photoproduction of K*Λ(1116) off protons near threshold energies, incorporating nucleon resonances to better match experimental data using an effective Lagrangian approach.

Contribution

It introduces a detailed analysis of nucleon resonances' roles in K*Λ(1116) photoproduction, improving theoretical-experimental agreement near threshold.

Findings

S11(1535) and S11(1650) resonances significantly enhance cross-section near threshold.

Vector coupling constants are estimated as g_{K^*S_{11}(1535)Λ}=(7.0–9.0) and g_{K^*S_{11}(1650)Λ}=(5.0–6.0).

Including nucleon resonances explains discrepancies between previous theories and experimental results.

Abstract

In this presentation, we report our recent studies on the $K^*\Lambda(1116)$ 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 $\sqrt{s}_\mathrm{th}\approx2008$ 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 $g_{K^*S_{11}(1535)\Lambda}=(7.0\sim9.0)$ and $g_{K^*S_{11}(1650)\Lambda}=(5.0\sim6.0)$.