On the mechanisms of superfluidity in atomic nuclei

Abstract

A system of equations is obtained for the Cooper gap in nuclei. The system takes two mechanisms of superfluidity into account in an approximation quadratic in the phonon- production amplitude : a Bardeen- Cooper- Schrieffer (BCS) type mechanism and a quasiparticle- phonon mechanism. These equations are solved for 120 Sn in a realistic approximation. If the simple procedures proposed are used to determine the new particle- particle interaction and to estimate the average effect, then the contribution of the quasiparticle- phonon mechanism to the observed width of the pairing gap is 26% and the BCS-type contribution is 74%. This means that at least in semimagic nuclei pairing is of a mixed nature - it is due to the two indicated mechanisms, the first being mainly a surface mechanism and the second mainly a volume mechanism.

6 pages

Cited by in corpus (14)

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• Continuum particle-vibration coupling method in coordinate-space representation for finite nuclei
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• Interaction of the single-particle and collective degrees of freedom in non-magic nuclei: the role of phonon tadpole terms
• Microscopic evaluation of the pairing gap
• Many-body correlations in nuclear superfluidity
• The two-proton shell gap in Sn isotopes
• Nuclear superfluidity at finite temperature
• Solution of the microscopic gap equation for a slab of nuclear matter with the Paris NN-potential
• Many-body theory for quasiparticle states in superfluid fermionic systems
• Spatial correlation properties of the anomalous density matrix in a slab of nuclear matter with realistic NN-forces
• Off-shell pairing correlations from meson-exchange theory of nuclear forces
• The microscopic pairing gap in a slab of nuclear matter for the Argonne v18 NN-potential
• On limits of ab initio calculations of pairing gap in nuclei