Speaker
Description
We have analyzed the $\gamma p \rightarrow p \pi^0 \eta$ process with a particular focus on the role of the triangle singularity which appears in the decay of the $\Delta(1700)$ into $\eta \Delta(1232)$,
where the $\Delta(1232)$ goes into $p$ emitting a $\pi^0$, while the $N(1535)$ is formed from the $\eta p$ interaction.
In addition to the triangle diagram, we take account of the tree level contribution stemming from the $\gamma p \rightarrow \Delta(1700) \rightarrow \eta \Delta(1232)$ process, followed by $\Delta(1232) \rightarrow\pi^0 p$.
We have obtained a characteristic energy dependence from the triangle diagram in the $\pi^0 N(1535)$ production,
and a good agreement with the experimental determination up to 1.3 GeV.
Furthermore, we found some differences between our results in the $\eta \Delta(1232)$ production and the analysis performed in the experiment,
which might indicate the importance of incorporating the contribution from the triangle diagram in the standard partial wave analysis.
