Proton Compton Scattering and Neutral-Pion Photoproduction at Large Angles

The differential cross sections for $\gamma p\to \gamma p$ and $\gamma p\to {\pi }^{0}p$ have been measured from $\mathrm{}\left|t\right|=0.7\mathrm{} \mathrm{to} 4.3$ Ge${\mathrm{V}}^2$ and for incident energies in the range 2 to 6 GeV. The energy dependence of Compton scattering is well described by parton model ideas. However, the energy dependences of ${\pi }^0$ photoproduction and the ratio of Compton scattering to ${\pi }^0$ photoproduction are not consistent with dimensional counting arguments.