Elastic Scattering of Low-Energy Protons by Helium

Elastic differential scattering experiments have been performed on the system $p+\mathrm{He}$ at collision energies low enough to exclude inelastic channels. The experimental cross section is compared with the results of JWKB partial-wave calculations in which ab initio calculations of the interatomic potential have been employed. This comparison is seen to provide a very sensitive test of the accuracy of such potentials.