Microscopic calculations for the 4He continuum

Abstract

A detailed theoretical model for the 4He system is constructed within the framework of the dynamical R-matrix formalism of Lane and Robson. The internal states are expanded on a basis of properly symmetrized translationally invariant harmonic oscillator eigenstates including all states up to [Formula: see text] of oscillator excitation. Scattering results for the 3H(p,p), 3He(n,n), 3H(p,n), 2H(d,d), 2H(d,p), and 2H(d,n) reactions are presented. Phase shift calculations for the p + 3H and n + 3He channels suggest a (1+, 0) assignment for the 25.5 MeV level. Detailed scattering calculations are in qualitative agreement with measured results. The results are also compared with resonating group and field theoretic models. Although each model has its advantages, none is able to provide a complete description of the 4He system.