Charge dependent effects of the photon-pion exchange process in the n-n interaction

Considerable effort has been made to explain the observed charge dependence of the low-energy parameters of the 1S nucleon-nucleon scattering, as due to various electromagnetic corrections. Noyes has pointed out that the difference between the p-p effective ranges, rpp–rpn ≈ 0.4 fm, indicated by the experiment of Engelke et al., would imply that the p-p potential is more than 30% more attractive than the p-n potential in the region between 2 …