The structureless $\exp \mathrm{}(1.8t)\mathrm{}$ behavior of recent $\mathrm{pp}$ data for $\mathrm{}\left|t\right|\mathrm{}\gtrsim 2$ Ge${\mathrm{V}}^2$, $\sqrt{s}=53\mathrm{}$ GeV, is shown to be in sharp disagreement with dip-structure predictions from popular models of diffraction. Flip amplitudes, real parts, and large-angle effects are quantitatively insufficient to resolve the discrepancy. Modifications of some familiar ideas on diffraction (like eikonalization) seem necessary.

• Received 12 November 1976

DOI:https://doi.org/10.1103/PhysRevLett.38.124