Study of the $\gamma p\to \pi^0\eta p$ reaction with the A2 setup at MAMI

TL;DR

This paper presents a detailed analysis of the $\gamma p o \pi^0\eta p$ reaction using high-precision data from the A2 setup at MAMI, enabling improved partial-wave analyses and model comparisons in the energy range up to 1.45 GeV.

Contribution

It introduces a new event-by-event analysis method for three-body final states, providing the most precise data to date for this reaction and refining theoretical models.

Findings

High-statistics data improves understanding of reaction dynamics.

Refined partial-wave analyses yield more reliable results.

Comparison with models shows the need for adjustments in existing theories.

Abstract

The data available from the A2 Collaboration at MAMI were analyzed to select the $\gamma p\to \pi^0\eta p$ reaction on an event-by-event basis, which allows for partial-wave analyses of three-body final states to obtain more reliable results, compared to fits to measured distributions. These data provide the world's best statistical accuracy in the energy range from threshold to $E_{\gamma}=1.45$ GeV, allowing a finer energy binning in the measurement of all observables needed for understanding the reaction dynamics. The results obtained for the measured observables are compared to existing models, and the impact from the new data is checked by the fit with the revised Mainz model.