Neutron-Proton Scattering in the Region 0-5 Mev

Abstract

The theoretical cross section for scattering of neutrons by protons has been calculated on the basis of a pure central Yukawa potential with the same range in $^{1}S$ and $^{3}S$ states, corresponding to meson mass 200 and 300, respectively. The results indicate that the best over-all fit with most recent scattering experiments would be obtained with a meson mass of roughly 350 ${m}_{e}$. Allowing different ranges in singlet and triplet states and making use of the deuteron binding energy, we found a "triplet mass" of 290 and a "singlet mass" of about 380.A further result of this work is that, at least in the case of Yukawa potential, the "effective range" approximation is prone to give the total cross section much more accurately than the singlet and triplet cross sections separately. Accordingly, this approximation ought to be handled with some care in other problems than $n\ensuremath{-}p$ scattering.