Argonne effect - evidence for the shell structure of proton

Shell structure of the proton is discussed. Elactic scattering of polarized protons on a polarized proton target in the case of parallel spin orientation is considered. Scattering of protons with parallel spins is mainly dictated by the difference of scattering amplitudes at the flight of a polarized proton from the left and from the right of a polarized target proton. The problem of nucleon shell properties is considered briefly