Strong pairing approximation in comparison with the exact solutions to the pairing Hamiltonian

Results of the Strong Pairing Approximation (SPA) as a method with the exact particle number conservation are compared with those of the quasiparticle method (QM). It is shown that SPA comes to the same equations as QM for the gap parameter, chemical potential and one- and two-quasiparticle states. Calculations are performed for Gd-148(64)84 as an example, and compared with the exact solutions to the pairing Hamiltonian.