Regge approach to charged-pion photoproduction at invariant energies above 2 GeV

TL;DR

This paper employs a Regge model with absorptive corrections to analyze high-energy pion photoproduction data, predicting observables below 3 GeV and identifying potential resonance signals around 2 GeV.

Contribution

It introduces a Regge-based approach with absorptive corrections to reliably model non-resonant amplitudes and detect resonance signatures in pion photoproduction data.

Findings

Resonance signatures around 2 GeV in polarized photon asymmetry data.

Indications of resonance structures in differential cross sections at JLab energies.

Model successfully predicts observables below 3 GeV based on high-energy data.

Abstract

A Regge model with absorptive corrections is employed in a global analysis of the world data on positive and negative pion photoproduction for photon energies from 3 to 8 GeV. In this region resonance contributions are expected to be negligible so that the available experimental information on differential cross sections and single polarization observables at -t \leq 2 GeV^2 allows us to determine the non-resonant part of the reaction amplitude reliably. The model amplitude is then used to predict observables for photon energies below 3 GeV. Differences between our predictions and data in this energy region are systematically examined as possible signals for the presence of excited baryons. We find that the data available for the polarized photon asymmetry show promising resonance signatures at invariant energies around 2 GeV. With regard to differential cross sections the analysis of negative pion photoproduction data, obtained recently at JLab, indicates likewise the presence of resonance structures around 2 GeV