In this work, a new functional is introduced to treat pairing correlations in
finite many-body systems. Guided by the projected BCS framework, the energy is
written as a functional of occupation numbers. It is shown to generalize the
BCS approach and to provide an alternative to Variation After Projection
framework. Illustrations of the new approach are given for the pairing
Hamiltonian for various particle numbers and coupling strengths. In all case, a
very good agreement with the exact solution is found.Comment: Proceeding of the International Symposium: Forefronts of Researches
in Exotic Nuclear Structures- Niigata201
