Lambda(1520) photoproduciton off the proton target with Regge contributions

TL;DR

This study models Lambda(1520) photoproduction off protons using Regge contributions and tree-level terms, successfully explaining high-energy data and polarization observables with a gauge-invariant approach.

Contribution

It introduces a gauge-invariant Reggeized model for Lambda(1520) photoproduction that extends beyond the resonance region and incorporates polarization effects.

Findings

Regge contributions are essential for high-energy angular distributions.

Polarization observables are insensitive to Regge effects due to contact-term dominance.

The model reproduces experimental data qualitatively across energies and angles.

Abstract

We investigate the Lambda(1520,3/2^-)=Lambda* photoproduction off the proton target with the Regge contributions to go beyond the resonance region, in addition to the tree-level Born terms consisting of the s, t, and u channels, and contact term. For this purpose, the Reggeized propagators for the K and K* exchanges in the t channel are employed in a gauge-invariant manner. We also take into account the contribution from a nucleon resonance D_{13}(2030). We compute the angular and energy dependences of the production process, including polarization observables, such as the photon-beam asymmetry and the polarization-transfer coefficients, resulting in good qualitative agreement with current experimental data. It turns out that the Regge contributions are necessary to explain the high-energy data beyond E_{gamma}~4 GeV especially for the angular dependences in the forward-scattering region. On the contrary, the polarization observables are insensitive to the Regge contributions due to the contact-term dominance and gauge invariance. We also compute the K^{-}-angle distribution function in the Gottfried-Jackson frame, using the polarization-transfer coefficients in the z direction. It shows nontrivial theta and E_{gamma} dependences in the forward-scattering region.