Extrapolation of the differential cross section for triplet pp scattering to low energies

It has been shown that the differential cross section for low-energy triplet pp scattering that is caused by the sum of the nuclear and magnetic interactions in the Coulomb field of the protons is a rapidly oscillating function and has second-order poles in the forward and backward directions. In order to extrapolate such a cross section to the energy region below 10 MeV, a simple low-energy approximation has been proposed. New phenomena—proton-proton analogues of the Mott and Schwinger effects—are discussed.