Towards a model-independent partial wave analysis for pseudoscalar meson photoproduction

TL;DR

This paper discusses the potential and limitations of model-independent partial wave analysis in pseudoscalar meson photoproduction, highlighting the minimal observables needed and the challenges in extracting resonance parameters.

Contribution

It demonstrates that complete experiments cannot fully determine resonance parameters and proposes a truncated partial wave analysis requiring fewer observables with minimal model assumptions.

Findings

Helicity amplitudes from complete experiments cannot determine resonance parameters.

A truncated partial wave analysis can be performed with only 5 observables.

Minimal model input suffices for partial wave analysis.

Abstract

Amplitude and partial wave analyses for pion, eta or kaon photoproduction are discussed in the context of `complete experiments'. It is shown that the model-independent helicity amplitudes obtained from at least 8 polarization observables including beam, target and recoil polarization can not be used to determine underlying resonance parameters. However, a truncated partial wave analysis, which theoretically requires only 5 observables will be possible with minimal model input.