Henryk Witala
A novel approach to include pp Coulomb force into the 3N Faddeev calculations
The long-range nature of the Coulomb force prevents the application of
the standard techniques developed for short-range interactions in the analysis
of nuclear reactions involving two protons.
A novel approach to include the pp Coulomb force into the momentum space
3N Faddeev calculations will be presented. It is based on a standard
formulation for short range forces and relies on the screening of the
long-range Coulomb interaction. In order to avoid all uncertainties
connected with the application of the partial wave expansion, inadequate when
working with long-range forces, the 3-dimensional pp screened Coulomb t-matrix
is used directly. The feasibility of that approach will be demonstrated in case
of elastic pd scattering and breakup reaction using a simple dynamical model
for the nuclear part of the interaction. The physical pd elastic scattering
amplitude can be obtained from the off-shell solutions of the Faddeev equation
and has a well defined screening limit. Thus for pd elastic scattering there
is no need of renormalization not only for observables but for the elastic pd
amplitude itself. In contrast to elastic scattering, in case of the pd breakup
the on-shell solutions of the Faddeev equation are required. They demand
renormalization in the screening limit which can be achieved through
renormalization of the pp t-matrices.