Measurement of the double polarisation observable E in single pseudoscalar meson production

TL;DR

This paper reports measurements of the double polarisation observable E in single pseudoscalar meson production, using a highly capable detector setup to analyze photoproduction reactions with polarized beams and targets.

Contribution

It provides new experimental data on the observable E for pion and eta photoproduction, enhancing understanding of polarization effects in meson production.

Findings

Measured the double polarisation observable E for pion and eta photoproduction.

Utilized the Crystal Barrel/TAPS setup for comprehensive angular coverage.

Achieved high precision in polarization measurements.

Abstract

Polarisation observables are measured with the Crystal Barrel/TAPS experiment at ELSA for photoproduction reactions with various final states, using a circularly or linearly polarised photon beam and a longitudinally or transversely polarised frozen spin butanol target. The Crystal Barrel/TAPS setup provides a nearly 4$\pi$ angular coverage, a good energy resolution and a high detection efficiency for photons, and is therefore ideally suited to study final states comprising neutral mesons. Results for the measurement of the double polarisation observable E for pion and eta photoproduction off the proton are presented.