An random phase approximation ground state in agreement with the conservation laws

M. Tohyama, Peter Schuck

Tatiana N. Antsygina, V. A. Slyusarev, А. В. Свидзинский

M. Tohyama

Abstract The number conservation law in the odd-particle number random-phase approximation (oRPA) and its extension (EoRPA) is studied by applying them to a pairing model and 16O. It is found in the application to 16O that the number conservation law is not fulfilled in oRPA or EoRPA and that it is drastically improved in EoRPA due to the inclusion of ground-state correlation effects. PACS numbers: 21.60.Jz

Nguyen Dinh Dang

The self-consistent random-phase approximation (SCRPA) is reexamined within a multilevel-pairing model with double degeneracy. It is shown that the expressions for occupation numbers used in the original version of the SCRPA violate the particle number for nonsymmetric particle-hole (ph) spectra. A renormalization is introduced to restore the particle number, which leads to the expressions of occupation numbers similar to those derived by Hara et al. for the ph case. The results of calculations within the ph symmetric case show that this number-conserving SCRPA yields the energies of the ground state and the first excited state of the system with $\ensuremath{\Omega}+2$ particles relative to the ground state of the system with $\ensuremath{\Omega}$ particles in close agreement with those obtained within the original SCRPA. However, it gives a slightly larger correlation energy.

João da Providência

Alexander L. Fetter, Charles B. Hanna

The self-consistent Hartree approximation, which satisfies the basic conservation laws and ensures gauge invariance, is applied to free anyons in two dimensions, both at zero temperature and at low temperature. The resulting zero-temperature description is essentially equivalent to the previous random-phase approximation.