Large-Angle Proton-Proton Scattering and the Pomeranchuk Trajectory

Proton-proton scattering at large momentum transfers is analyzed in detail, with spin and the Pauli principle taken into account. It is pointed out that various empirical formulas that fit the gross feature of the data in the neighborhood of 90° c.m. scattering angle are essentially consequences of the Pauli principle. From the data we directly determine the effective Regge trajectory. Two different trajectories seem to dominate different ranges of momentum transfer, and the switchover from one to the other happens almost discontinuously. The trajectories are consistent with $1+0.5t$ and $1+0.25t$, respectively. This supports an earlier model proposed by Huang, Jones, and Teplitz, who suggested that the two trajectories correspond to the Pomeranchuk trajectory and a Regge cut generated by it. Assuming this interpretation, we deduce some properties of the Pomeranchuk trajectory. The differential cross section for $\mathrm{pp}$ scattering at large momentum transfers is fitted in detail, using this model. Consequences for polarization in $\mathrm{pp}$ scattering and the cross sections for $p\overline{p}$ scattering are also discussed.