The Impact of New Polarization Data from Bonn, Mainz and Jefferson Laboratory on $\gamma p \to \pi N$ Multipoles

Understand

New data on pion-photoproduction off the proton have been included in the partial wave analyses Bonn-Gatchina and SAID and in the dynamical coupled-channel approach J\"ulich-Bonn.

• All reproduce the recent new data well: the double polarization data for E, G, H, P and T in $\gamma p \to \pi^0 p$ from ELSA, the beam asymmetry $\Sigma$ for $\gamma p \to \pi^0 p$ and $\pi^+ n$ from Jefferson Laboratory, and the precise new differential cross section and beam asymmetry data $\Sigma$ for $\gamma p \to \pi^0 p$ from MAMI.
• The new fit results for the multipoles are compared with predictions not taking into account the new data.
• The mutual agreement is improved considerably but still far from being perfect.