ИСТИНА

The use of the ab initio (from first principles) no core shell model (NCSM) has proven to be highly successful, especially in systematically solving low-energy bound state problems. While there are many advantages in using the NCSM, there are also major technical difficulties in applying it to describe non-relativistic scattering states and reactions in the continuum despite recent progress. The modified Hulth ́en–Kohn method extending the NCSM to the continuum spectrum was suggested by Efros to address those shortcomings by allowing one to accurately compute the continuum wave function in a computationally feasible manner. We combine the ideas of the Efros method with some achievements of the HORSE formalism to further refine the Efros method. We provide an illustration of the technique by calculating the two-body scattering problem. We demonstrate other two-body applications of the method, including calculation of the p(n,γ)d reaction and the use of the S-matrix pole technique to compute resonance energies (Er), widths (Γ), and bound states. We show that given low-lying eigenfunctions of a Hamiltonian H with a truncated nucleon-nucleon (NN) interaction, we get accurate results. This suggests great promise for applicability to few-body problems, of which we provide results for n + α → 5He scattering in the resonance region.