Neutron-Proton Scattering with Spin-Orbit Coupling. I. General Expressions

Abstract

Neutron-proton scattering in the triplet spin state is discussed under the following assumptions about the nuclear forces: (1) the forces are conservative, (2) they allow time-reversal, i.e., the reciprocity law is valid, (3) the spin vectors of the neutron and proton enter in a symmetrical way, so that the total spin of of the system is preserved during the collision, and (4) the forces have a finite range. We do not assume that the forces can be derived from a potential function (i.e., that they are velocity-independent).