Photoproduction of $\Lambda^*$ and $\Sigma^*$ resonances with $J^P=1/2^-$ off the proton

TL;DR

This paper investigates the photoproduction mechanisms of hyperon resonances $ ext{Lambda}^*(1405)$ and $ ext{Sigma}^*(1400)$, incorporating a dynamically generated nucleon resonance $N^*(1895)$ and employing a Regge model to match experimental data.

Contribution

It introduces a combined effective Lagrangian and Regge approach to model hyperon photoproduction, highlighting the role of $N^*(1895)$ in generating these resonances.

Findings

Good agreement with CLAS data for $ ext{Lambda}^*(1405)$ production.

Predictions for $ ext{Sigma}^*(1400)$ production observables.

Provides polarization observables for future experiments.

Abstract

We study the photoproduction of the $\Lambda(1405)$ and $\Sigma(1400)$ hyperon resonances, the latter of which is not a well established state. We evaluate the $s$-, $t$- and $u$-channel diagrams in the Born approximation by employing the effective Lagrangians. A new ingredient is the inclusion of a nucleon resonance $N^*(1895)$ that is dynamically generated with predictions for its coupling to the $K\Lambda(1405)$ and $K\Sigma(1400)$ channels. To extend the applicability of the model to energies beyond the threshold region, we consider a Regge model for the $t$-channel $K$- and $K^*$-exchanges. Our results are in good agreement with the CLAS data available on $\Lambda(1405)$, while for $\Sigma(1400)$ we predict observables for its production. We also provide polarization observables for both hyperon productions, which can be useful in future experimental investigations. The present study provides new information on the nucleon resonance $N^*(1895)$ which can be an alternative source for generating the hyperon resonances $\Lambda(1405)$ and $\Sigma(1400)$.