# Photoproduction of meson pairs: First measurement of the polarization observable I^s

## TL;DR

This paper reports the first measurement of the polarization observable I^s in meson pair photoproduction, revealing high sensitivity to reaction dynamics and providing new insights into partial wave contributions.

## Contribution

First experimental measurement of the polarization observable I^s in multi-meson photoproduction, enhancing understanding of reaction mechanisms and partial wave analysis.

## Key findings

- Large asymmetries indicate high sensitivity to reaction dynamics
- Polarization observables provide significant information on partial waves
- Results improve constraints on theoretical models

## Abstract

The polarization observable I^s, a feature exclusive to the acoplanar kinematics of multi-meson final states produced via linearly polarized photons, has been measured for the first time. Results for the reaction g p -> p pi0 eta are presented for incoming photon energies between 970 MeV and 1650 MeV along with the beam asymmetry I^c. The comparably large asymmetries demonstrate a high sensitivity of I^s to the dynamics of the reaction. Fits using Bonn-Gatchina partial wave analysis demonstrate that the new polarization observables carry significant information on the contributing partial waves.