Exact and Nearly Exact Pairing Treatment for Large Scale Calculations

Abstract

International audienceIn this article we present an analysis of the practical applicability of the earlier introduced PSY-MB method in solving the nuclear pairing Hamiltonian. In particular, we illustrate the convergence properties of the ground-state correlation energy, as well as the first excitation energy, in the case of the so-called picket-fence model where 32 particles are distributed over 64 equispaced, doubly-degenerated levels. In order to illustrate the ability of the method, we compare the correlation energies of the ground-state to the exact solutions obtained with the Richardson formalism, as well as the BCS approach, in function of the increasing monopole pairing strength parameter