Nuclear structure and pairing correlations for the heavy elements

Number-conserving treatment of the BCS-Tamm-Dancoff approximation for deformed rare-earth nuclei

“…In this paper we do not show the properties of the BCS wave functions in the rare-earth region. They are found almost equal to the results [7] for the transuranic region. Now we shall consider the K~= 0-octupole states.…”

“…However, exact projection of the eigenfunctions of the particle number operator from the BCS wave functions was first proposed by Dietrich, Mang and Pradal (DMP) [6]. It was applied to deformed heavy nuclei by Mang, Poggenburg and Rasmussen [7]. According to them the method which only projects fixed-particle terms from the BCS wave functions was called as PBCS, while the FBCS method performs further the variation on the fixedparticle expression.…”

On the Restoration of Symmetry in Paired Fermion Systems

“…The corresponding equations have been numerically solved when the variational spaces are not too large and for schematic Hamiltonians [32,33]. However, in many realistic cases the task of finding the optimal intrinsic wave-function is too difficult to handle.…”

From odd-even staggering to the pairing gap in neutron matter

“…( 47) for odd-particle-number systems) they would, in principle, find different distributions than the ones that come from the BCS treatment described in Section II. This latter approach of minimizing the energy of the projected state is called the Variation After Projection Method (VAP) and it has been used to restore the particle-number symmetry for nn and pp pairing in nuclei [48] as well as the particle-number, spin and isospin symmetries in np pairing [22]. It can be shown that for strong pairing the VAP and BCS descriptions are equivalent [46].…”