The Dependence of Nuclear Forces on Velocity

Abstract

It is shown that the Majorana force may be considered as a special case of a neutron-proton interaction dependent on velocity and angular momentum. Any interaction of this more general form, which is non-Wignerian, and represents attraction, accounts for the saturation properties of nuclear binding in the same way as do the Heisenberg and Majorana potentials. An analysis of the binding in heavy nuclei in terms of angular momentum is given on the basis of the Fermi-Thomas statistical model. An illustration is given showing that the assumption of velocity dependent forces is also consistent with the properties of light nuclei: a particular form of interaction, containing two parameters, is found to give results much the same as those of the ordinary Majorana theory. Finally, the most general dependence of two-particle forces on spin, separation, and velocity, consistent with the conservation laws, is determined, and it is pointed out that experiments on the scattering of fast neutrons in hydrogen are capable of deciding between Majorana forces and a more general form of velocity dependence.