Possible Triple-Scattering Experiments

Triple-scattering experiments may be used to get additional information about the spin-dependence of the scattering matrix of the second scatterer. In general two new parameters describing the scattering may be determined by means of two distinct experiments, one in which the successive scattering planes are parallel and one in which the successive scattering planes are at right angles to each other. The relation between these parameters and the scattering matrix is given for the cases of protons scattered from a spin-zero target and of proton-proton scattering. For the former case the magnitude of the left-right asymmetry in the third scattering is calculated on the basis of a phenomenological model due to Fermi in the Born approximation. Further experimental possibilities for $p\ensuremath{-}p$ scattering are discussed.