Elastic Photon-Proton Scattering in the 50-130-GeV Range

In the tagged-photon beam at Fermilab, differential cross sections were measured for the elastic scattering of photons on a liquid-hydrogen target. The diffractive forward peak was measured for photon energies between 50 and 130 GeV and $\left|t\right|$ values between 0.07 and 1.20 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^2$. The shape of the diffraction peak is similar to that seen in $\pi -p$ scattering. The magnitude is that predicted by the optical theorem.