Coulomb effects in proton-deuteron scattering near threshold

Abstract

Elastic proton-deuteron scattering at energies near threshold is studied using a method which allows the effective, energy-dependent proton-deuteron potential to be given in closed form if the nuclear part of the two-nucleon potential is assumed to be separable. Using the standard Yamaguchi form for the separable term, the various contributions to the effective p-d potential at sub-break-up energies are discussed, the point-charge Coulomb term is isolated and shorter-ranged corrections are developed to lowest order in the small parameter e2m1/2/h(cross)( mod Ed mod )1/2 approximately=0.15, where mod Ed mod is the deuteron binding energy. An analytic evaluation is given of the difference between the n-d and p-d scattering lengths in the spin-quartet channel. The result (apd-and)s=3/2 approximately=4.3 fm is in fair agreement with the experimental value of about 5.7 fm.