Correlated scattering corrections to eikonal few-body models

A basic assumption which underpins recent applications of eikonal few-body models to nuclear scattering and nuclear reactions is that of the addition of the constituent scattering phases. We investigate the accuracy of this assumption in the case of the elastic scattering of ⁸He, treated as a five-constituent (α+4n) system, from a light target nucleus at energies of 10’s of MeV/nucleon. To do so we calculate Feshbach’s correlated scattering or overlapping potential contributions to the eikonal model phase shifts in this many-body case. We find that even for ⁸He, with ten contributing pair-wise potential overlaps, these terms introduce corrections that are small in comparison with available experimental precision and also compared to those phase additive noneikonal corrections which arise from the use of an improved description of the phase shifts for each of the constituent-target subsystems within the few-body model.