$\eta'$ decays with GlueX data*

The different decays of the light meson $\eta'$ provide a laboratory to test low-energy Quantum Chromodynamics. For example, the dominant hadronic decay modes of the $\eta'$, $\eta'\to\eta\pi^+\pi^-$ and $\eta'\to\eta\pi^0\pi^0$, are interesting for many reasons. First, vector resonances do not contribute due to G-parity conservation, allowing for the study of the properties of the scalar resonance $f_0(500)$. Second, these decays allow us to perform tests of chiral perturbation theory and its possible extensions. Third, the presence of both $\eta$ and $\eta'$ allows for the study of the mixing properties of these mesons. Lastly, they offer an opportunity to constrain $\eta\pi$ scattering.

In this talk, we report on the status of the Dalitz plot analysis for photoproduced $\eta'$ in the reaction $\gamma p \to p \eta'$, for the decay channel $\eta'\to\eta\pi\pi$ using the Phase I data set recorded by the GlueX experiment in Hall D at Jefferson Laboratory.