Study of the reaction $\gamma p\to p\pi^0\eta$

TL;DR

This study investigates the $\gamma p o p\pi^0\eta$ reaction, identifying intermediate states and resonances through partial wave analysis, providing detailed resonance parameters and decay information.

Contribution

It presents a detailed partial wave analysis of the $\gamma p o p\pi^0\eta$ reaction, identifying six $\Delta$ resonances and two nucleon resonances with their pole positions and decay branching ratios.

Findings

Identification of intermediate states: $\Delta^+(1232)\eta$, $N(1535)^+\pi^0$, $pa_0(980)$.

Observation of six $\Delta$ resonances with specific quantum numbers.

Determination of pole positions and decay branching ratios for the resonances.

Abstract

The reaction $\gamma p\to p\pi^0\eta$ has been studied with the CBELSA detector at the tagged photon beam of the Bonn electron stretcher facility. The reaction shows contributions from $\Delta^+(1232)\eta$, $N(1535)^+\pi^0$ and $pa_0(980)$ as intermediate states. A partial wave analysis suggests that the reaction proceeds via formation of six $\Delta$ resonances, $\Delta(1600)P_{33}$, $\Delta(1920)P_{33}$, $\Delta(1700)D_{33}$, $\Delta(1940)D_{33}$, $\Delta(1905)F_{35}$, $\Delta(2360)D_{33}$, and two nucleon resonances $N(1880)P_{11}$ and $N(2200)P_{13}$, for which pole positions and decay branching ratios are given.