Perturbative Hartree-Fock-Bogoliubov model for many-body pairing correlations

Journal Article · Fri Apr 01 04:00:00 EST 2005 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PhysRevC.71.044302· OSTI ID:20696048

Hagino, K ^[1]; Sagawa, H ^[2]

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1. Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
2. Center for Mathematical Sciences, University of Aizu, Ikki-machi, Aizu-Wakamatsu, Fukushima 965-8580 (Japan)

We develop a perturbative model to treat the off-diagonal components in the Hartree-Fock-Bogoliubov (HFB) transformation matrix, which are neglected in the Bardeen-Cooper-Schrieffer (BCS) approximation. Applying the perturbative model to a weakly bound nucleus {sup 84}Ni, it is shown that the perturbative approach reproduces well the solutions of the HFB method both for the quasiparticle energies and the radial dependence of quasiparticle wave functions. We find that the nonresonant part of the continuum single-particle state can acquire an appreciable occupation probability when there exists a weakly bound state close to the Fermi surface. This result originates from the strong coupling between the continuum particle state and the weakly bound state, and it is absent in the BCS approximation. The limitations of the BCS approximation are pointed out in comparison with the HFB and the present perturbative model.

• OSTI ID: 20696048
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 4 Vol. 71; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BCS THEORY
BOUND STATE
COMPARATIVE EVALUATIONS
CORRELATIONS
FERMI LEVEL
HARTREE-FOCK METHOD
HARTREE-FOCK-BOGOLYUBOV THEORY
MANY-BODY PROBLEM
NICKEL ISOTOPES
NUCLEAR MODELS
PERTURBATION THEORY
PROBABILITY
STRONG-COUPLING MODEL
WAVE FUNCTIONS