Mixing of one-particle-one-hole projected states with the variation after projection wave functions

Abstract

In this paper, we study the mixing of one-particle-one-hole projected states with the variation after projection (VAP) wave functions in an attempt to improve the approximation of this method. It turns out that, when minimizing only the lowest (yrast) energy with given spin and parity, the one-particle-one-hole projected states cannot be mixed into the converged VAP wave function, which is very similar to the situation of the Hartree-Fock method. However, if one minimizes the sum of several lowest energies with the same spin and parity, the one-particle-one-hole mixing can make some improvements to the VAP wave functions. We expect such one-particle-one-hole mixing may be useful in the calculations of the low-lying excited states in heavy nuclei with a large model space.